Method and device for antenna calibration

• US 6,127,966 A
• Filed: 05/15/1998
• Issued: 10/03/2000
• Est. Priority Date: 05/16/1997
• Status: Expired due to Term

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Erhage, Lars Ingemar
• Primary Examiner(s): Gregory, Bernarr E.
• Application Number:
  US09/079,854
• Time in Patent Office: 872 Days
• Field of Search: 342/165, 342/168, 342/169, 342/170, 342/171, 342/172, 342/173, 342/174, 342/368, 342/369, 342/370, 342/371, 342/372, 342/373, 342/374, 342/375, 342/376, 342/377
• US Class Current: 342/174
• CPC Class Codes: G01S 2013/0245 Radar with phased array antenna
• CPC Class Codes: G01S 7/4026 Antenna boresight
• CPC Class Codes: G01S 7/4052 by simulation of echoes
• CPC Class Codes: G01S 7/406 using internally generated reference signals, e.g. via delay line, via RF or IF signal injection or via integrated reference reflector or transponder
• CPC Class Codes: H01Q 3/267 Phased-array testing or checking devices

Abstract

The present invention relates to the problem of calibrating an antenna system (23) comprising an electrically controlled antenna (25) using a test antenna (45) arranged near the electrically controlled antenna, with the possibility of calibrating during operation, when disturbing reflections or other unknown signal influences are present when signals are transmitted between the test antenna and the electrically controlled antenna or between the electrically controlled antenna and the test antenna. The electrically controlled antenna comprises a number of modules (27-(1-N)) having means (91-(1-N)) for controlling the complex amplification of the modules. Each module is arranged with a commandable reference mode at reception and/or transmission. The antenna system is calibrated for reception and transmission, respectively, by transmitting test signals between the test antenna and the electrically controlled antenna and/or by transmitting test signals between the electrically controlled antenna and the test antenna, the effect of the unknown signal influence being eliminated by utilization of the reference modes at reception and/or transmission.

Claims

1. A method for the calibration of an antenna system during reception arranged to utilize at least one carrier frequency, said antenna system including a test antenna, an electrically controlled antenna having at least two modules with control means for control of received amplitude and phase processing factors for the respective module and means for generating control signals to the control means, said control signals being associated with at least one value of amplitude and phase processing factors at reception for the respective module, and each of the modules being arranged with a commandable isolated mode, comprising the following steps:

a) arranging, for each module, a commandable reference mode at reception, for which the amplitude and phase processing factors at the reception for the module are known; and

b) calibrating, at reception, substantially all the modules for at least one of the carrier frequencies based on an investigation of the received signal by transmitting test signals through the test antenna and receiving them through the electrically controlled antenna, whereby the effect of an unknown signal influence on the test signals is eliminated by use of the reference modes at reception for the modules.

2. A method according to claim 1, wherein the step b) in turn comprises the following substeps:

c) selecting one of the carrier frequencies;

d) selecting one of the modules;

e) selecting a first test signal, comprising the selected carrier frequency;

f) transmitting the selected first test signal through the test antenna;

g) receiving the selected first test signal transmitted through the test antenna, through the electrically controlled antenna with the selected module commanded to its reference mode at reception and with the other modules commanded to their isolated modes, whereby a first received signal, corresponding to the reference mode at reception for the selected module (27-i) and the selected first test signal is obtained;

h) comparing the first received signal and the selected first test signal;

i) calibrating at reception of the selected module for the selected carrier frequency and said at least value of the one amplitude and phase processing factors at reception for the selected module, using the comparison, according to the substep h), between the first received signal and the selected first test signal, to eliminate the influence of the unknown signal influence; and

j) repeating the substeps d) through i) until substantially all the modules have been selected.

3. A method according to claim 2, wherein the step b) in turn comprises the following substeps:

k) repeating the substeps c) through j) until a predetermined number of the carrier frequencies has been selected.

4. A method according to claim 3, wherein the substep p) in turn comprises the following substep:

t) measuring a second amplitude and phase processing factor ratio at reception for the selected module, corresponding to the selected carrier frequency and the selected value of the commanded amplitude and phase processing factors at reception for the selected module.

5. A method according to claim 4, wherein the selection of the selected second test signal in the substep m) implies that a second narrowband oscillator signal is selected as the second test signal, the second narrowband oscillator signal having a centre frequency substantially corresponding to the selected carrier frequency.

6. A method according to claim 5, wherein the substep t) in turn comprises the following substeps:

u) detecting a phase difference between the second received signal and the selected second test signal; and

v) detecting an amplitude ratio between the second received signal and the selected second test signal, said second amplitude and phase processing factor ratio at reception for the selected module having an argument corresponding to the phase difference detected in the substep u) and an absolute value corresponding to the amplitude ratio detected in the substep v).

7. A method according to claim 4, wherein the selection of the selected second test signal in the substep m) implies that a second broadband signal is selected as the selected second test signal, said second broadband signal comprising the selected carrier frequency.

8. A method according to claim 7, wherein the substep t) in turn comprises the following substeps:

x) generating a Fourier transform of the second received signal;

y) generating a Fourier transform of the selected second test signal; and

z) generating a second ratio value corresponding to a ratio between the value of the Fourier transform according to the substep x), at the selected carrier frequency and the value of the Fourier transform according to the substep y) at the selected carrier frequency, said second amplitude and phase processing factor ratio at reception for the selected module corresponding to the second ratio value.

9. A method according to claim 2, wherein the substep i) in turn comprises the following substeps:

l) selecting a value for the amplitude and phase processing factors at reception for the selected module;

m) selecting a second test signal comprising the selected carrier frequency;

n) transmitting the selected second test signal through the test antenna;

o) receiving the selected second test signal transmitted through the test antenna through the electrically controlled antenna, with the selected module commanded to reception with the selected value of the amplitude and phase processing factors at reception for the selected module and with the other modules commanded to their isolated modes, whereby a second received signal, corresponding to the selected value of the commanded amplitude and phase processing factors at reception for the selected module and the selected second test signal is obtained;

p) comparing the second received signal and the selected second test signal;

q) generating a value corresponding to a complex error amplification at reception for the selected module, this being done in dependence of the comparison, according to substep h), of the first received signal and the selected first test signal and the comparison, according to substep p) of the second received signal and the selected second test signal; and

r) switching the control signals associated with the selected value of the amplitude and phase processing factors at reception for the selected module to the control means for controlling the received amplitude and phase processing factors for the selected module in dependence of the value corresponding to the received amplitude and phase processing factor error for the selected module.

10. A method according to claim 9, wherein the substep i) in turn comprises the following substep:

s) repeating the substeps l) through r) until a predetermined number of values of the amplitude and phase processing factors at reception for the selected module have been selected.

11. A method according to claim 9, wherein the switching of the control signals to the control means in the substep r) implies that this is done in such a way that the phase shift of the selected module at reception is reduced corresponding to an argument to the complex error amplification at reception and in such a way that the amplification of the selected module at reception is changed by a factor corresponding to one divided by the value of the received amplitude and phase processing factor error.

12. A method according to claim 2, wherein the substep h) in turn comprises the following substep:

aa) measuring a first amplitude and phase processing factor ratio at reception for the selected module, corresponding to the reference mode at reception for the selected module and the selected carrier frequency.

13. A method according to claim 12, wherein the selection of the selected first test signal in the substep e) implies the selection of a first narrowband oscillator signal as the first selected test signal, said first narrowband oscillator signal having a centre frequency substantially corresponding to the selected carrier frequency.

14. A method according to claim 13, wherein the substep aa) in turn comprises the following substeps:

ab) detecting a phase difference between the first received signal and the selected first test signal; and

ac) detecting an amplitude ratio between the first received signal and the selected first test signal, the first amplitude and phase processing factor ratio at reception for the selected module having an argument corresponding to the phase difference detected in the substep ab) and an argument corresponding to the amplitude ratio detected in the substep ac).

15. A method according to claim 12, wherein the selection of the selected first test signal in the substep e) implies the selection of a first broadband signal as the selected first test signal, the first broadband signal comprising the selected carrier frequency.

16. A method according to claim 15, wherein the substep aa) in turn comprises the following substeps:

ad) generating a Fourier transform of the first received signal;

ae) generating a Fourier transform of the selected first test signal; and

af) generating a first ratio value corresponding to a ratio of the value of the Fourier transform according to the substep ad) at the selected carrier frequency and the value of the Fourier transform according to the substep ae) at the selected carrier frequency, the first amplitude and phase processing factor ratio at reception for the selected module corresponding to the first ratio value.

17. A method according to claim 1, wherein the step a) in turn comprises the following substeps:

ag) selecting for each module a setting of the control signal controlling the control means for controlling the received amplitude and phase processing factors for the respective module;

ah) making a survey of the received amplitude and phase processing factors for the modules corresponding to the selected settings for the control signals;

ai) storing data corresponding to the survey according to the substep ah) in the antenna system; and

aj) arranging at least one temperature measuring device in the antenna system.

18. A method for the calibration of an antenna system during transmission arranged to utilize at least one carrier frequency, said antenna system comprising a test antenna, an electrically controlled antenna having at least two modules with control means for the control of transmitted amplitude and phase processing factors for the respective module and means for generating control signals to the control means, said control signals being associated with at least one value of said transmitted amplitude and phase processing factors at transmission for the respective module, and each of the modules being arranged with a commandable isolated mode, comprising the following steps:

a) arranging, for each module, a commandable reference mode at reception, for which the amplitude and phase processing factors at the reception for the module is known; and

b) calibrating, at transmission, substantially all the modules for at least one of the carrier frequencies based on an investigation of the transmitted signal by transmitting test signals through the test antenna and receiving them through the electrically controlled antenna, and by transmitting test signals through the electrically controlled antenna and receiving them through the test antenna, whereby the effect of an unknown signal influence on the test signals is eliminated by use of the reference modes at reception for the modules.

19. A method according to claim 18, wherein the step b) in turn comprises the following substeps:

c) selecting one of the carrier frequencies;

d) selecting one of the modules as a reference module;

e) selecting a value for the commanded amplitude and phase processing factors at transmission for the reference module as a value for comparison at transmission;

f) calibrating the reference module during transmission for the selected carrier frequency in relationship to the transmitted amplitude and phase processing factors for the reference module, corresponding to the selected carrier frequency and the value for comparison at transmission; and

g) calibrating substantially all the modules in addition to the reference module, at transmission for the selected carrier frequency in relationship to the transmitted amplitude and phase processing factors for the reference module, corresponding to the selected carrier frequency and the value for comparison at transmission.

20. A method according to claim 19, wherein the step b) in turn comprises the following substeps:

h) repeating the substeps c) through g) until a predetermined number of the carrier frequencies has been selected.

21. A method according to claim 19, wherein the substep f) in turn comprises the following substeps:

i) selecting a first test signal, comprising the selected carrier frequency;

j) transmitting the selected first test signal through the electrically controlled antenna with the reference module commanded to its transmission mode with the value for comparison at transmission and with the other modules commanded to their isolated modes;

k) receiving the first test signal, transmitted from the electrically controlled antenna by the test antenna, whereby a first received signal, corresponding to the reference module the value for comparison at transmission and the first test signal are obtained;

l) comparing the first received signal and the selected first test signal;

m) calibrating, at transmission, the reference module in relationship to the transmitted amplitude and phase processing factors for the reference module, corresponding to the selected carrier frequency and the value for comparison at transmission, for the selected carrier frequency and at least one value of the amplitude and phase processing factors at transmission for the reference module, utilizing the comparison according to the substep

     1) of the first received signal and the selected first test signal.

22. A method according to claim 21, wherein the substep m) in turn comprises the following substeps:

n) selecting a value for the amplitude and phase processing factors at reception for the reference module;

o) selecting a second test signal comprising the selected carrier frequency;

p) transmitting the selected second test signal, through the electrically controlled antenna, with the reference module commanded to its transmission mode with the selected value of the amplitude and phase processing factors at transmission for the reference module and with the other modules commanded to their isolated modes;

q) receiving the selected second test signal transmitted from the electrically controlled antenna by the test antenna whereby a second received signal, corresponding to the selected value of the amplitude and phase processing factor at transmission for the reference module and the second test signal, is obtained;

r) comparing the second received signal to the selected second test signal;

s) generating a value corresponding to a amplitude and phase processing factor error ratio at transmission for the reference module, corresponding to the selected carrier frequency, the selected value of the amplitude and phase processing factors at transmission for the reference module and the value for comparison at transmission, said generation being carried out in dependence of the comparison, according to the substep l), of the first received signal and the selected first test signal and the comparison, according to the substep r) of the second received signal and the selected second test signal; and

t) switching the control signals associated with the selected value of amplitude and phase processing factors at transmission for the reference module to the control means for controlling the transmitted amplitude and phase processing factors for the reference module, this being done in dependence of the value corresponding to the amplitude and phase processing factor error ratio at transmission for the reference module.

23. A method according to claim 22, wherein the substep m) in turn comprises the following substep:

u) repeating the substeps n) through t) until a predetermined number of values of the amplitude and phase processing factors at transmission for the reference module have been selected.

24. A method according to claim 22, wherein the switching of the control signals to the control means in the substep

t) implies that this is done in such a way that the phase shift of the reference module is reduced corresponding to an argument to the amplitude and phase processing factor error ratio at transmission for the reference module and in such a way that the amplification of the reference module is changed by a factor corresponding to one divided by an absolute value of the complex error ratio at reception for the reference module.

25. A method according to claim 19, wherein the step g) in turn comprises the following substeps:

v) selecting a third test signal, comprising the selected carrier frequency;

w) transmitting the selected third test signal through the test antenna;

x) receiving the selected third test signal transmitted through the test antenna, through the electrically controlled antenna by the reference module commanded to its reference mode at reception and with the other modules commanded to their isolated modes, whereby a third received signal, corresponding to the reference mode at reception for the reference module and the selected third test signal is obtained;

y) comparing the third received signal and the selected third test signal;

z) selecting a fourth test signal comprising the selected carrier frequency;

aa) transmitting the selected fourth test signal through the electrically controlled antenna with the reference module commanded to its transmission mode with the value for comparison at transmission and with the other modules commanded to their isolated modes;

ab) receiving the fourth test signal, transmitted from the electrically controlled antenna by the test antenna, whereby a fourth received signal, corresponding to the reference module, the value for comparison at transmission and the first test signal is obtained;

ac) comparing the fourth received signal to the selected fourth test signal;

ad) selecting one of the modules in addition to the reference module;

ae) calibrating, at transmission, the selected module in relationship to the amplitude and phase processing factors of the reference module, corresponding to the selected carrier frequency and the value for comparison at transmission, for the selected carrier frequency and at least one value of amplitude and phase processing factors at transmission for the selected module, utilizing the comparison, according to the substep ac) of the fourth received signal and the fourth test signal, and the comparison, according to the substep y), between the third received signal and the third test signal to eliminate the effects of the unknown signal influence; and

af) repeating the substeps ab) and ac) until substantially all the modules have been selected.

26. A method according to claim 25, wherein the substep ac) in turn comprises the following substeps:

ag) selecting a fifth test signal;

ah) transmitting the selected fifth test signal through the test antenna;

ai) receiving the selected fifth test signal transmitted through the test antenna, through the electrically controlled antenna with the selected module commanded to its reference mode at reception and with the other modules commanded to their isolated modes, whereby a fifth received signal, corresponding to the reference mode at reception for the selected module and the selected fifth test signal is obtained;

aj) comparing the fifth received signal and the selected fifth test signal;

ak) selecting a value of amplitude and phase processing factors at transmission for the selected module;

al) selecting a sixth test signal comprising the selected carrier frequency;

am) transmitting the selected sixth test signal, through the electrically controlled antenna, with the selected module commanded to its transmission mode with the selected value of amplitude and phase processing factors at transmission for the selected module and with the other modules commanded to their isolated modes;

an) receiving the selected sixth test signal transmitted from the electrically controlled antenna by the test antenna whereby a sixth received signal, corresponding to the selected value of amplitude and phase processing factors at transmission for the selected module and the selected sixth test signal, is obtained;

ao) comparing the sixth received signal to the selected sixth test signal;

ap) generating a value corresponding to an amplitude and phase factor error ratio at transmission for the selected module, corresponding to the selected carrier frequency, the selected value of amplitude and phase processing factors at transmission for the selected module and the value for comparison at transmission, said generation being carried out in dependence of the comparison, according to the substep y), of the third received signal and the selected third test signal and the comparison, according to the substep ac) of the fourth received signal and the selected fourth test signal, the comparison according to the substep aj) of the fifth received signal and the fifth test signal, and the comparison according to the substep ao) of the sixth received signal and the selected sixth test signal; and

aq) switching the control signals associated with the selected value of amplitude and phase processing factors at transmission for the selected module to the control means for controlling the transmitted amplitude and phase processing factors for the selected module, this being done in dependence of the value corresponding to the amplitude and phase processing factor error ratio at transmission for the selected module.

27. A method according to claim 26, wherein the substep ac) in turn comprises the following substep:

ar) repeating the substeps ak) through aq) until a predetermined number of values of amplitude and phase processing factors at reception for the selected module have been selected.

28. A method according to claim 26, wherein the switching of the control signals to the control means in the substep

aq) implies that the control signals are switched in such a way that the phase shift of the selected module is reduced corresponding to an argument to the amplitude and phase processing factor error ratio for the selected module at reception and in such a way that signal modification by the selected module is changed by a factor corresponding to one divided by the value of the amplitude and phase processing factor error ratio at transmission for the selected module.

29. A method for the calibration of an antenna system during transmission, said antenna system being arranged to utilize at least one carrier frequency, and including a test antenna, an electrically controlled antenna having at least two modules with control means for the control of transmitted amplitude and phase processing factors for the respective module and means for generating control signals to the control means, said control signals being associated with at least one value of said amplitude and phase processing factors at transmission for the respective module, and each of the modules being arranged with a commandable isolated mode, comprising the following steps:

a) arranging, for each module, a commandable reference mode at transmission, at which the transmitted amplitude and phase processing factors for the module is known; and

b) calibrating, at transmission, substantially all the modules for at least one of the carrier frequencies based on an investigation of the transmitted signal by transmitting test signals through the electrically controlled antenna and receiving them through the test antenna, and by transmitting test signals through the electrically controlled antenna and receiving them through the test antenna whereby the effect of an unknown signal influence on the test signals is eliminated by use of the reference modes at transmission for the modules.

30. A method according to claim 29, wherein the step b) in turn comprises the following substeps:

c) selecting one of the carrier frequencies;

d) selecting one of the modules;

e) selecting a first test signal, comprising the selected carrier frequency;

f) transmitting the selected first test signal through the electrically controlled antenna, with the selected module commanded to its reference mode at transmission and with the other modules commanded to their isolated modes;

g) receiving the selected first test signal transmitted through the electrically controlled antenna, through the test antenna, whereby a first received signal, corresponding to the reference mode at transmission for the selected module and the selected first test signal is obtained;

h) comparing the first received signal to the selected first test signal;

i) calibrating, at transmission, the selected module for the selected carrier frequency and at least a value of the commanded amplitude and phase processing factors at transmission for the selected module, using the comparison, according to the substep h), between the first received signal and the selected first test signal, to eliminate the influence of the unknown signal influence; and

j) repeating the substeps d) through i) until substantially all the modules have been selected.

31. A method according to claim 30, wherein the step b) in turn comprises the following substep:

k) repeating the substeps c) through j) until a predetermined number of the carrier frequencies has been selected.

32. A method according to claim 30, wherein the substep i) in turn comprises the following substeps:

l) selecting a value for the transmitted amplitude and phase processing factors for the selected module;

m) selecting a second test signal comprising the selected carrier frequency;

n) transmitting the selected second test signal through the electrically controlled antenna with the selected module commanded to its transmission mode with the selected value of the amplitude and phase processing factors at transmission for the selected module and with the other modules commanded to their isolated modes;

o) receiving the selected second test signal transmitted through the electrically controlled antenna through the test antenna, whereby a second received signal, corresponding to the selected value of the amplitude and phase processing factors at transmission for the selected module and the selected second test signal is obtained;

p) comparing the second received signal and the selected second test signal;

q) generating a value corresponding to a amplitude and phase processing factors error at transmission for the selected module corresponding to the selected carrier frequency and the selected value of the amplitude and phase processing factors at transmission for the selected module, this being done in dependence of the comparison, according to the substep h), between the first received signal and the selected first test signal and the comparison, according to the substep p) between the second received signal and the selected second test signal; and

r) switching the control signals associated with the selected value of amplitude and phase processing factors at transmission for the selected module to the control means for controlling the transmitted amplitude and phase processing factors for the selected module in dependence of the value corresponding to the transmitted amplitude and phase processing factors for the selected module.

33. A method according to claim 32, wherein the substep i) in turn comprises the following substep:

s) repeating the substeps l) through r) until a predetermined number of values of the amplitude phase processing factors at transmission for the selected module have been selected.

34. A method according to claim 32, wherein the switching of the control signals to the control means in the substep r) implies that this is done in such a way that the phase shift of the selected module at transmission is reduced corresponding to an argument to the amplitude and phase processing factors error at transmission and in such a way that the amplification of the selected module at transmission is changed by a factor corresponding to one divided by the value of the transmitted amplitude and phase processing factors error.

35. A method for the calibration of an antenna system during reception, said antenna system being arranged to utilize at least one carrier frequency, and comprising a test antenna, an electrically controlled antenna having at least two modules with controllable control means for the control of received amplitude and phase processing factors for the module and means for generating control signals to the control means, said control signals being associated with at least one value of amplitude and phase processing factors at reception for the respective module, and each of the modules being arranged with a commandable isolated mode, comprising the following steps:

a) arranging, for each module, a commandable reference mode at transmission, at which the transmitted amplitude and phase processing factors for the module is known; and

b) calibrating substantially all the modules at reception for at least one of the carrier frequencies based on an investigation of the received signals by transmitting test signals through the test antenna and receiving them through the electrically controlled antenna, and transmitting test signals through the electrically controlled antenna and receiving them through the test antenna, whereby the effect of an unknown signal influence on the test signals is eliminated by use of the reference modes at reception for the modules.

36. A method according to claim 35, wherein the step b) in turn comprises the following substeps:

c) selecting one of the carrier frequencies;

d) selecting one of the modules as a reference module;

e) selecting a value for the transmitted amplitude and phase processing factors for the reference module as a value for comparison at reception;

f) calibrating of the reference module during reception for the selected carrier frequency in relationship to the received amplitude and phase processing factors for the reference module, corresponding to the selected carrier frequency and the value for comparison at reception; and

g) calibrating the reference module at reception for the selected carrier frequency in relationship to the received amplitude and phase processing factors for the reference module, corresponding to the selected carrier frequency and the value for comparison at reception.

37. A method according to claim 36, wherein the step b) in turn also comprises the following substeps:

h) repeating the steps c) through g) until a predetermined number of carrier frequencies have been selected.

38. A method according to claim 36, wherein the step f) in turn comprises the following substeps:

i) selecting a first test signal, comprising the selected carrier frequency;

j) transmitting the selected first test signal through the test antenna;

k) receiving the selected first test signal transmitted through the test antenna, through the electrically controlled antenna with the reference module commanded to its reception mode with the value for comparison at reception and with the other modules commanded to their isolated modes, whereby a first received signal, corresponding to the reference module, the value for comparison at reception and the selected first test signal is obtained;

l) comparing the first received signal and the selected first test signal;

m) calibrating, at reception, the reference module in relationship to the received amplitude and phase processing factors for the reference module, corresponding to the selected carrier frequency and the value for comparison at reception, for the selected carrier frequency and at least one value of the amplitude and phase processing factors at reception for the reference module, utilizing the comparison according to the substep l) of the first received signal and the selected first test signal.

39. A method according to claim 38, wherein the substep m) in turn comprises the following substeps:

n) selecting a value for the received amplitude and phase processing factors for the reference module;

o) selecting a second test signal comprising the selected carrier frequency;

p) transmitting the selected second test signal through the test antenna;

q) receiving the selected second test signal transmitted through the test antenna through the electrically controlled antenna, with the reference module commanded to reception with the selected value of the amplitude and phase processing factors at reception for the reference module and with the other modules commanded to their isolated modes, whereby a second received signal, corresponding to the selected value of the amplitude and phase processing factors at reception for the module and the selected second test signal is obtained;

r) comparing the second received signal and the selected second test signal;

s) generating a value corresponding to a received amplitude and phase processing factors error ratio for the reference module, corresponding to the selected carrier frequency, the selected value of the amplitude and phase processing factors at reception for the reference module and the value for comparison at reception, this being done in dependence of the comparison, according to the substep l), between the first received signal and the selected first test signal and the comparison, according to the substep r) between the second received signal and the selected second test signal; and

t) switching the control signals associated with the selected value of the amplitude and phase processing factors at reception for the reference module to the control means for controlling the received amplitude and phase processing factors for the reference module, this being done in dependence of the value corresponding to the received amplitude and phase processing factors error ratio for the reference module.

40. A method according to claim 39, wherein the substep m) in turn comprises the following substep:

u) repeating the substeps n) through t) until a predetermined number of values of the amplitude and phase processing factors at reception for the reference module have been selected.

41. A method according to claim 39, wherein the switching of the control signals to the control means in the substep t) implies that this is done in such a way that the phase shift of the reference module at reception is reduced corresponding to an argument to the received amplitude and phase processing factors error ratio for the reference module and in such a way that the amplification of the reference module at reception is changed by a factor corresponding to one divided by an absolute value of the received amplitude and phase processing factors for the reference module.

42. A method according to claim 36, wherein the step g) in turn comprises the following substeps:

v) selecting a third test signal, comprising the selected carrier frequency;

w) transmitting the selected third test signal through the electrically controlled antenna, with the reference module commanded to the reference mode at transmission and with the other modules commanded to their isolated modes;

x) receiving the selected third test signal transmitted through the electrically controlled antenna, through the test antenna, whereby a third received signal, corresponding to the reference mode at transmission for the reference module and the selected third test signal is obtained;

y) comparing the third received signal and the third test signal;

z) selecting a fourth test signal comprising the selected carrier frequency;

aa) transmitting the selected fourth test signal through the test antenna;

ab) receiving the fourth test signal, transmitted from the test antenna by the electrically controlled antenna, with the reference module commanded to reception mode with the value for comparison at reception and with the other modules commanded to their isolated modes;

whereby a fourth received signal, corresponding to the reference module, the value for comparison at transmission and the first test signal are obtained;

ac) comparing the fourth received signal to the selected fourth test signal;

ad) selecting one of the modules in addition to the reference module;

ae) calibrating the selected module at reception in relationship to the amplitude and phase processing factors of the reference module, corresponding to the selected carrier frequency and the value for comparison at reception, for the selected carrier frequency and at least one value of the amplitude and phase processing factors at reception for the selected module, utilizing the comparison, according to the substep y), of the third received signal and the third test signal to eliminate the effects of the unknown signal influence; and

af) repeating the substeps ab) and ac) until substantially all the modules have been selected.

43. A method according to claim 42, wherein the substep ac) in turn comprises the following substeps:

ag) selecting a fifth test signal

ah) transmitting the selected fifth test signal through the electrically controlled antenna with the selected module commanded to its reference mode at transmission, and with the other modules commanded to their isolated modes;

ai) receiving the selected fifth test signal transmitted through the electrically controlled antenna through the test antenna, whereby a fifth received signal, corresponding to the reference mode at transmission for the selected module and the selected fifth test signal is obtained;

aj) comparing the fifth received signal and the selected fifth test signal;

ak) selecting a value of the amplitude and phase processing factors at reception for the selected module;

al) selecting a sixth test signal comprising the selected carrier frequency;

am) transmitting the selected sixth test signal through the test antenna;

an) receiving the selected sixth test signal transmitted through the test antenna, through the electrically controlled antenna with the selected module commanded to its reception mode with the selected value of the amplitude and phase processing factors at reception for the selected module and with the other modules commanded to their isolated modes, whereby a sixth received signal, corresponding to the reference mode at reception for the selected module and the selected sixth test signal is obtained;

ao) comparing the sixth received signal and the selected sixth test signal;

ap) generating a value corresponding to a received amplitude and phase processing factors'"'"' error ratio for the selected module corresponding to the selected carrier frequency and the selected value of the amplitude and phase processing factors at reception for the selected module, and the value for comparison at reception, this being done in dependence of the comparison, according to the substep y), between the third received signal and the selected third test signal, the comparison according to the substep ac) of the fourth received signal and the selected fourth test signal, the comparison according to the substep aj) of the fifth received signal and the selected fifth test signal and the comparison, according to the substep ao) between the sixth received signal and the selected sixth test signal; and

aq) switching the control signals associated with the selected value of the commanded amplitude and phase processing factors at reception for the selected module to the control means for controlling the received amplitude and phase processing factors for the selected module, this being done in dependence of the value corresponding to the transmitted amplitude and phase processing factors'"'"' error ratio for the selected module.

44. A method according to claim 43, wherein the substep ac) in turn comprises the following substep:

ar) repeating the substeps ak) through aq) until a predetermined number of values of the amplitude and phase processing factors at reception for the selected module.

45. A method according to claim 43, wherein the switching of the control signals to the control means in the substep ao) implies that the control signals are switched in such a way that the phase shift of the selected module at reception is reduced corresponding to an argument to the amplitude and phase processing factors'"'"' error ratio for the selected module at reception and in such a way that the amplification of the selected module at reception is changed by a factor corresponding to one divided by the value of the transmitted amplitude and phase processing factors'"'"' error ratio for the selected module.

46. A self calibrating antenna system arranged to utilize at least one carrier frequency, comprising

a test antenna;

an electrically controlled antenna having at least two modules with control means for the control of a received amplitude and phase processing factors for the respective module, each module being arranged with a commandable isolated mode, in which mode the module substantially does not let signals through;

means for generating control signals to the control means, said control signals to the control means being associated with at least one value of amplitude and phase processing factors at reception for the respective module;

means for generating test signals, said antenna system being arranged in such a way that the test signals are transmitted through the test antenna;

a receiver, arranged to receive the test signals as well as signals received through the electrically controlled antenna, wherein each module is arranged with a commandable reference mode at reception, at which the received amplitude and phase processing factors for the module is known; and

that the antenna system is arranged for calibrating at reception of substantially all the modules based on an investigation of the received signals for the modules by transmitting test signals through the test antenna and receiving them through the electrically controlled antenna by the receiver, said antenna system being arranged to eliminate the effect of an unknown signal influence on the test signals by use of the reference modes at reception for the modules.

47. A self calibrating antenna system according to claim 46, wherein the antenna system comprises memory means, said memory means comprising data describing the received amplitude and phase processing factors for each module as a function of frequency and temperature, corresponding to predetermined settings of the control signals to the control means for controlling the received amplitude and phase processing factors for the module, and

that the antenna system comprises at least one temperature measuring device.

48. A self calibrating antenna system according to claim 46, wherein each module comprises a reference device, for example a transmission conductor;

that each module comprises controllable switches arranged in such a way that electronic circuitry in the module may be bypassed through the reference device;

that the antenna system comprises memory means, said memory means comprising data describing the received amplitude and phase processing factors for each module, when the electronic circuitry in the module is bypassed through the reference device, as a function of the frequency and the temperature; and

that the antenna system comprises at least one temperature measuring device.

49. A self calibrating antenna system arranged to utilize at least one carrier frequency, comprising a test antenna;

an electrically controlled antenna comprising at least two modules having control means for controlling transmitted amplitude and phase processing factors for the respective module, each module being arranged with a commandable isolated mode, in which the module substantially does not let any signals through;

means for generating control signals to the control means, said control signals to the control means being associated with at least one value of a commanded amplitude and phase processing factors at transmission for the respective module;

means for generating test signals, said antenna system being arranged in such a way that the test signals can be transmitted on command either through the test antenna or through the electrically controlled antenna;

a receiver, arranged to receive the test signals and, on command, to receive signals either through the test antenna or the electrically controlled antenna, wherein each module is arranged with a commandable reference mode at reception, at which the amplitude and phase processing factors of the module is known; and

that the antenna system is arranged for calibration at reception of substantially all the modules for at least one of the carrier frequencies based on an investigation of the transmitted signals at transmission for the modules by transmitting test signals through the test antenna and receiving them through the electrically controlled antenna, and by transmitting test signals through the electrically controlled antenna and receiving them through the test antenna of the receiver, said antenna system being arranged to eliminate the effect of an unknown signal influence on the test signals by use of the reference modes at reception for the modules.

50. A self calibrating antenna system arranged to utilize at least one carrier frequency, comprising:

a test antenna;

an electrically controlled antenna having at least two modules with control means for the control of received amplitude and phase processing factors for the respective module, each module being arranged with a commandable isolated mode, at which the module substantially does not let signals through;

means for generating control signals to the control means, said control signals being associated with at least one value of amplitude and phase processing factors at reception for the respective module;

means for generating test signals, said antenna system being arranged in such a way that the test signals are transmitted through the electrically controlled antenna;

a receiver, arranged to receive the test signals as well as signals received through the electrically controlled antenna, wherein each module is arranged with a commandable reference mode at transmission, at which the transmitted amplitude and phase processing factors for the module is known; and

that the antenna system is arranged for calibrating, at transmission, substantially all the modules based on an investigation of the transmitted signals at transmission for the modules by transmitting test signals through the electrically controlled antenna and receiving them through the test antenna by the receiver, said antenna system being arranged to eliminate the effect of an unknown signal influence on the test signals is eliminated by use of the reference modes at transmission for the modules.

51. A self calibrating antenna system according to claim 50, wherein the antenna system comprises memory means, said memory means comprising data describing the transmitted amplitude and phase processing factors for each module as a function of frequency and temperature, corresponding to predetermined settings of the control signals to the control means for controlling the transmitted amplitude and phase processing factors for the module and that the antenna system comprises at least one temperature measuring device.

52. A self calibrating antenna system according to claim 50, wherein each module comprises a reference device, for example a transmission conductor;

that each module comprises controllable switches arranged in such a way that electronic circuitry in the module may be bypassed through the reference device;

that the antenna system comprises memory means, said memory means comprising data describing the transmitted amplitude and phase processing factors for each module, when the electronic circuitry in the module is bypassed through the reference device, as a function of the frequency and the temperature; and

that the antenna system comprises at least one temperature measuring device.

53. A self calibrating antenna system arranged to utilize at least one carrier frequency, comprising:

a test antenna;

an electrically controlled antenna comprising at least two modules having control means for controlling received amplitude and phase processing factors for the respective module, each module being arranged with a commandable isolated mode, in which the module substantially does not let any signals through;

means for generating control signals to the control means, said control signals to the control means being associated with at least one value of amplitude and phase processing factors at reception for the respective module;

means for generating test signals, said antenna system being arranged in such a way that the test signals on command can be transmitted either through the test antenna or through the electrically controlled antenna;

a receiver, arranged to receive the test signals and, on command, to receive signals either through the test antenna or the electrically controlled antenna, wherein each module is arranged with a commandable reference mode at transmission, in which the amplitude and phase processing factors of the module are known; and

that the antenna system is arranged for calibration of substantially all the modules at reception for at least one of the carrier frequencies based on an investigation of the transmitted signals at transmission for the modules by transmitting test signals through the test antenna and receiving them through the electrically controlled antenna by the receiver, and by transmitting test signals through the electrically controlled antenna and receiving them through the test antenna of the receiver said antenna system being arranged to eliminate the effect of an unknown signal influence on the test signals by use of the reference modes at reception for the modules.

54. A method for calibrating an antenna system comprising the steps of:

transmitting, from a test antenna, a test signal at a selected carrier frequency;

subjecting the transmitted test signal to distortion;

receiving, at said antenna system, said distorted test signal;

processing said received test signal at a selected processing module within said antenna system using a predetermined amplitude and phase factor associated with a reference mode of said selected processing module to generate a processed test signal;

comparing said test signal with said processed test signal; and

calibrating said antenna system to mitigate said distortion based on a result of said comparison.

55. The method of claim 54, further comprising the steps of:

providing said selected module with a variable attenuator and a variable phase shifter; and

processing said received test signal by setting said variable attenuator and said variable phase shifter using said predetermined amplitude and phase factor being retrieved from a memory device within said antenna system.

56. The method of calibrating an antenna system according to claim 55, further comprising the steps of:

arranging the modules with reference modes by making a survey of the amplitude and phase factors for the processing modules as a function of temperature and frequency; and

arranging at least one temperature measuring device in the antenna system.