System and method for dual-band antenna matching

• US 20040263411A1
• Filed: 07/26/2004
• Published: 12/30/2004
• Est. Priority Date: 02/12/2002
• Status: Active Grant

• Current Assignee: Kyocera Corporation
• Original Assignee: Kyocera Wireless Corporation (Kyocera Corporation)
• Inventors: Fabrega-Sanchez, Jorge, Poilasne, Gregory, Toncich, Stanley S., Tran, Allen
• Granted Patent: US 7,180,467 B2
• Time in Patent Office: Days
• US Class Current: 343/861
• CPC Class Codes: G01R 27/2694 Measuring dielectric loss, e.g. loss angle, loss factor or power factor
• CPC Class Codes: H01G 7/06 having a dielectric selected for the variation of its permittivity with applied voltage, i.e. ferroelectric capacitors electrets H01G7/02
• CPC Class Codes: H01L 27/0808 Varactor diodes
• CPC Class Codes: H01P 1/203 Strip line filters
• CPC Class Codes: H01P 1/20336 Comb or interdigital filters
• CPC Class Codes: H01P 1/20363 Linear resonators
• CPC Class Codes: H01P 1/20381 Special shape resonators
• CPC Class Codes: H01P 1/2039 Galvanic coupling between Input/Output
• CPC Class Codes: H01P 1/2056 Comb filters or interdigital filters with metallised resonator holes in a dielectric block
• CPC Class Codes: H01P 1/213 combining or separating two or more different frequencies H01P1/215 takes precedence
• CPC Class Codes: H01P 5/04 with variable factor of coupling
• CPC Class Codes: H01Q 1/00 Details of, or arrangements associated with, antennas arrangements for varying orientation of directional pattern H01Q3/00
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 13/02 Waveguide horns
• CPC Class Codes: H01Q 13/06 Waveguide mouths horns H01Q13/02
• CPC Class Codes: H01Q 13/203 Leaky coaxial lines
• CPC Class Codes: H01Q 13/22 Longitudinal slot in boundary wall of waveguide or transmission line H01Q13/203 takes precedence
• CPC Class Codes: H01Q 3/44 varying the electric or magnetic characteristics of reflecting, refracting, or diffracting devices associated with the radiating element
• CPC Class Codes: H01Q 9/0407 Substantially flat resonant element parallel to ground plane, e.g. patch antenna dipole H01Q9/285; monopole H01Q9/40
• CPC Class Codes: H01Q 9/0421 with a shorting wall or a shorting pin at one end of the element H01Q9/0414 takes precedence
• CPC Class Codes: H01Q 9/0442 : with particular tuning means
• CPC Class Codes: H01Q 9/16 : with feed intermediate between the extremities of the antenna, e.g. centre-fed dipole H01Q9/44 takes precedence
• CPC Class Codes: H01Q 9/28 : Conical, cylindrical, cage, strip, gauze, or like elements having an extended radiating surface; Elements comprising two conical surfaces having collinear axes and adjacent apices and fed by two-conductor transmission lines waveguide horns or mouths H01Q13/00; slot antennas H01Q13/00
• CPC Class Codes: H01Q 9/30 : with feed to end of elongated active element, e.g. unipole H01Q9/44 takes precedence
• CPC Class Codes: H01Q 9/42 : with folded element, the folded parts being spaced apart a small fraction of the operating wavelength
• CPC Class Codes: H03B 5/04 : Modifications of generator to compensate for variations in physical values, e.g. power supply, load, temperature
• CPC Class Codes: H03B 5/1841 : the frequency-determining element being a strip line resonator H03B5/1805, H03B5/1817, H03B5/1864 and H03B5/1882 take precedence
• CPC Class Codes: H03B 5/362 : the amplifier being a single transistor H03B5/364 - H03B5/368 take precedence
• CPC Class Codes: H03F 1/56 : Modifications of input or output impedances, not otherwise provided for
• CPC Class Codes: H03F 2200/294 : the amplifier being a low noise amplifier [LNA]
• CPC Class Codes: H03F 2200/372 : Noise reduction and elimination in amplifier
• CPC Class Codes: H03F 3/191 : Tuned amplifiers H03F3/193, H03F3/195 take precedence
• CPC Class Codes: H03H 7/38 : Impedance-matching networks
• CPC Class Codes: H03J 5/246 : using electronic means H03J5/244 takes precedence
• CPC Class Codes: H03L 1/022 : by indirect stabilisation, i.e. by generating an electrical correction signal which is a function of the temperature H03L1/021 takes precedence
• CPC Class Codes: H03L 7/18 : using a frequency divider or counter in the loop H03L7/20, H03L7/22 take precedence
• CPC Class Codes: H04B 1/0053 : with common antenna for more than one band
• CPC Class Codes: H04B 1/0458 : Arrangements for matching and coupling between power amplifier and antenna or between amplifying stages matching circuits in general H03H
• CPC Class Codes: H04B 1/30 : for homodyne or synchrodyne receivers demodulator circuits H03D1/22

Abstract

A dual-band antenna matching system and a method for dual-band impedance matching are provided. The method comprises: accepting a frequency-dependent impedance from an antenna; and, selectively supplying a conjugate impedance match for the antenna at either a first and a second communication band, or a third and a fourth communication band. More specifically, the method comprises: tuning a first tuning circuit to a first frequency; and, simultaneously tuning a second tuning circuit to a second frequency. In response, a conjugate match is supplied to the antenna in the first communication band in response to the first frequency. Simultaneously, the antenna is matched in the second communication band in response to the second frequency. When the first tuning circuit is tuned to a third frequency, and the second tuning circuit is tuned to a fourth frequency, then conjugate matches are supplied for the third and fourth communication bands, responsive to the third and fourth frequencies, respectively.

Claims

1. A dual-band antenna matching system, the system comprising:

an antenna having an interface port with a frequency-dependent impedance; and

,

a dual-band matching circuit including an output port connected to the antenna interface port, selectively supplying a conjugate impedance for;

a first and a second communication band; and

,

a third and a fourth communication band.

2. The system of claim 1 wherein the dual-band matching circuit supplies a conjugate impedance simultaneously for:

the first communication band in response to a first tuned frequency; and

,

the second communication band in response to a second tuned frequency.

3. The system of claim 2 wherein the dual-band matching circuit supplies a conjugate impedance simultaneously for:

the third communication band in response to a third tuned frequency; and

,

the fourth communication band in response to a fourth tuned frequency.

4. The system of claim 3 wherein the dual-band matching circuit further includes:

a first tuning circuit selectively tunable to the first and third frequencies;

a second tuning circuit selectively tunable to the second and fourth frequencies.

5. The system of claim 4 wherein the first and second tuning circuits each include:

a ferroelectric (FE) dielectric material having a variable dielectric constant responsive to a control voltage; and

,

an interface to receive the control voltage.

6. The system of claim 5 wherein first and second tuning circuits accept a control voltage in the range between zero and three volts dc.

7. The system of claim 5 wherein the first and second tuning circuits include a ferroelectric variable capacitor selected from the group including interdigital, gap, and overlay capacitors

8. The system of claim 4 wherein the first tuning circuit includes:

a first inductor with a fixed inductance value;

a first variable capacitor with a selectable capacitance value; and

,

wherein the second tuning circuit includes;

a second inductor with a fixed inductance value;

a second variable capacitor with a selectable capacitance value.

9. The system of claim 5 wherein the first inductor is connected in shunt between the dual-band circuit output port and a reference voltage;

wherein the first variable capacitor has a first terminal connected to the dual-band circuit output port;

wherein the second inductor is connected in series between a second terminal of the first variable capacitor and a dual-band matching circuit input port; and

,

wherein the second variable capacitor has a first terminal connected in shunt between the first variable capacitor second terminal and the reference voltage.

10. The system of claim 9 wherein the first inductor has an inductance of 8.2 nano-Henrys (nH);

wherein the first variable capacitor has a capacitance in the range between 1.5 and 4 picofarads (pF);

wherein the second inductor has an inductance of 4.7 nH;

wherein the second variable capacitor has a capacitance in the range between 0.7 and 2 pF.

11. The system of claim 10 wherein the first frequency is responsive to the first variable capacitor having a value of 1.5 pF, and the third frequency is responsive to the value of 4 pF;

and,

wherein the second frequency is responsive to the second variable capacitor having a value of 0.7 pF, and the fourth frequency is responsive to the value of 2 pF.

12. The system of claim 11 wherein the dual-band matching circuit supplies a conjugate impedance at:

the first and second communication band; and

,

the third and fourth communication band, where the first and third communication bands are the same.

13. The system of claim 12 wherein the dual-band matching circuit supplies conjugate impedances at a first (third) communication band in the range between 824 and 894 megahertz (MHz), at a second communication band in the range of 1850 and 1990 MHz, and at a fourth communication band in the range of 1565 to 1585 MHz.

14. The system of claim 1 wherein the dual-band matching circuit supplies conjugate impedances at a first communication band in the range between 824 and 894 megahertz (MHz), at a second communication band in the range of 1850 and 1990 MHz, at a third communication band in the range of 880 to 960 MHz, and at a fourth communication band in the range of 1710 to 1880 MHz.

15. The system of claim 1 wherein the dual-band matching circuit is a matching topology selected from the group including a tunable series element, a tunable shunt element, “

L”

, π

, “

T”

, and combinations of the above-mentioned topologies.

16. The system of claim 1 wherein a dual-band matching circuit:

simultaneously supplies a conjugate impedance for the first and second communication bands having a return loss of better than 2;

1; and

,

simultaneously supplies a conjugate impedance for the third and fourth communication bands having a return loss of better than 2;

1.

17. A wireless communications device with a dual-band antenna matching system, the device comprising:

a transceiver having a wireless communications port to communicate in a first, second, third, and fourth communication band;

an antenna having an interface port with a frequency-dependent impedance;

a dual-band matching circuit including an input port connected to the transceiver wireless communications port and an output port connected to the antenna interface port selectively supplying a conjugate impedance for;

the first and second communication band; and

,

the third and fourth communication band.

18. The device of claim 17 wherein the dual-band matching circuit supplies a conjugate impedance simultaneously for:

the first communication band in response to a first tuned frequency; and

,

the second communication band in response to a second tuned frequency.

19. The device of claim 18 wherein the dual-band matching circuit supplies a conjugate impedance simultaneously for:

the third communication band in response to a third tuned frequency; and

,

the fourth communication band in response to a fourth tuned frequency.

20. The device of claim 19 wherein the dual-band matching circuit further includes:

a first tuning circuit selectively tunable to the first and third frequencies; and

,

a second tuning circuit selectively tunable to the second and fourth frequencies.

21. The device of claim 20 wherein the first and second tuning circuits each include:

a ferroelectric (FE) dielectric material having a variable dielectric constant responsive to a control voltage; and

,

an interface to receive the control voltage.

22. The device of claim 21 wherein first and second tuning circuits accept a control voltage in the range between zero and three volts dc.

23. The device of claim 21 wherein the first and second tuning circuits include a ferroelectric variable capacitor selected from the group including interdigital, gap, and overlay capacitors

24. The device of claim 20 wherein the first tuning circuit includes:

a first inductor with a fixed inductance value;

a first variable capacitor with a selectable capacitance value; and

,

wherein the second tuning circuit includes;

a second inductor with a fixed inductance value;

a second variable capacitor with a selectable capacitance value.

25. The device of claim 24 wherein the first inductor is connected in shunt between the dual-band circuit output port and a reference voltage;

wherein the first variable capacitor has a first terminal connected to the dual-band circuit output port;

wherein the second inductor is connected in series between a second terminal of the first variable capacitor and a dual-band matching circuit input port; and

,

wherein the second variable capacitor has a first terminal connected in shunt between the first variable capacitor second terminal and the reference voltage.

26. The device of claim 25 wherein the first inductor has an inductance of 8.2 nano-Henrys (nH);

wherein the first variable capacitor has a capacitance in the range between 1.5 and 4 picofarads (pF);

wherein the second inductor has an inductance of 4.7 nH; and

,

wherein the second variable capacitor has a capacitance in the range between 0.7 and 2 pF.

27. The device of claim 26 wherein the first frequency is responsive to the first variable capacitor having a value of 1.5 pF, and the third frequency is responsive to the value of 4 pF;

and,

wherein the second frequency is response to the second variable capacitor having a value of 0.7 pF, and the fourth frequency is responsive to the value of 2 pF.

28. The device of claim 27 wherein the dual-band matching circuit supplies a conjugate impedance at:

the first and second communication band; and

,

the third and fourth communication band, where the first and third communication bands are the same.

29. The device of claim 28 wherein the dual-band matching circuit supplies conjugate impedances at a first (third) communication band in the range between 824 and 894 megahertz (MHz), at a second communication band in the range of 1850 and 1990 MHz, and at a fourth communication band in the range of 1565 to 1585 MHz.

30. The device of claim 17 wherein the dual-band matching circuit supplies conjugate impedances at a first communication band in the range between 824 and 894 megahertz (MHz), at a second communication band in the range of 1850 and 1990 MHz, at a third communication band in the range of 880 to 960 MHz, and at a fourth communication band in the range of 1710 to 1880 MHz.

31. The device of claim 17 wherein the dual-band matching circuit is a matching topology selected from the group including a tunable series element, a tunable shunt element, “

L”

, π

, “

T”

, and combinations of the above-mentioned topologies.

32. The device of claim 17 wherein a dual-band matching circuit:

simultaneously supplies a conjugate impedance for the first and second communication bands having a return loss of better than 2;

1; and

,

simultaneously supplies a conjugate impedance for the third and fourth communication bands having a return loss of better than 2;

1.

33. A method for dual-band impedance matching an antenna, the method comprising:

accepting a frequency-dependent impedance from an antenna; and

,

selectively supplying a conjugate impedance match for the antenna at;

a first and a second communication band; and

,

a third and a fourth communication band.

34. The method of claim 33 further comprising:

tuning a first tuning circuit to a first frequency;

simultaneously tuning a second tuning circuit to a second frequency; and

,

wherein selectively supplying the conjugate impedance for matching the antenna at the first and second communication bands includes;

matching the antenna at the first communication band in response to the first frequency; and

,

simultaneously matching the antenna at the second communication band in response to the second frequency.

35. The method of claim 34 wherein tuning the first tuning circuit includes tuning to a third frequency;

wherein simultaneously tuning the second tuning circuit includes tuning to a fourth frequency; and

,

wherein selectively supplying a conjugate impedance for matching the antenna at the third and fourth communication bands includes;

matching the antenna at the third communication band in response to the third frequency; and

,

simultaneously matching the antenna at the fourth communication band in response to the fourth frequency.

36. The method of claim 35 wherein tuning the first and second tuning circuits includes:

supplying first and second control voltages, respectively, to the first and second tuning circuits; and

,

adjusting the dielectric constant of a ferroelectric (FE) dielectric material in response to the control voltages.

37. The method of claim 35 wherein tuning the first tuning circuit includes tuning a first variable capacitor, with a selectable capacitance value, connected to a first inductor with a fixed inductance value;

and,

wherein tuning the second tuning circuit includes tuning a second variable capacitor, with a selectable capacitance value, connected to a second inductor with a fixed inductance value.

38. The method of claim 37 wherein tuning the first tuning circuit includes tuning a first variable capacitor with a selectable capacitance value in the range between 1.5 and 4 picofarads (pF), connected to a first inductor with a fixed inductance value of 8.2 nano-Henrys (nH);

and,

wherein tuning the second tuning circuit includes tuning a second variable capacitor with a selectable capacitance value in the range of 0.7 and 2 pF, connected to a second inductor with a fixed inductance value of 4.7 nH.

39. The method of claim 38 wherein tuning the first tuning circuit to the first frequency includes using a first variable capacitor value of 1.5 pF, and tuning to the third frequency includes using a first variable capacitor value of 4 pF;

and,

wherein tuning the second tuning circuit to the second frequency includes using a second variable capacitor value of 0.7 pF, and tuning to the fourth frequency using a second variable capacitor value of 2 pF.

40. The method of claim 39 wherein matching the antenna at the first communication band and second communication band includes matching the antenna to a first communication band in the range of 824 to 894 MHz and a second communication band in the range of 1850 to 1990 MHz;

wherein matching the antenna at the third communication band and the fourth communication band includes matching the antenna to a third communication band in the range of 824 to 894 MHz a fourth communication band in the range of 1565 to 1585 MHz.

41. The method of claim 33 wherein matching the antenna at the first communication band and second communication band includes matching the antenna to a first communication band in the range of 824 to 894 MHz and a second communication band in the range of 1850 to 1990 MHz;

wherein matching the antenna at the third communication band and the fourth communication band includes matching the antenna to a third communication band in the range of 880-960 MHz a fourth communication band in the range of 1710-1880 MHz.

42. The method of claim 33 wherein selectively supplying a conjugate impedance match for the antenna includes using a matching topology selected from the group including a series tunable element, a shunt tunable element, an “

L”

network, a π

network, a “

T”

network, and combinations of the above-mentioned topologies.