Power control circuitry for achieving wide dynamic range in a transmitter

• US 5,307,512 A
• Filed: 06/03/1991
• Issued: 04/26/1994
• Est. Priority Date: 06/03/1991
• Status: Expired due to Term

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Mitzlaff, James E.
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): URBAN, EDWARD F
• Application Number:
  US07/709,459
• Time in Patent Office: 1,058 Days
• Field of Search: 455/126, 455/127, 455/67.1, 455/102, 455/115, 455/118, 455/52.1, 330/144, 330/279, 330/284
• US Class Current: 455/126
• CPC Class Codes: H03G 3/3042 in modulators, frequency-changers, transmitters or power amplifiers transmission power control in bidirectional transmission systems H04W52/04
• CPC Class Codes: H04B 2001/0416 having gain or transmission power control

Abstract

Power control circuitry (100) uses two attenuators in the transmit path to achieve wide dynamic range. An intermediate frequency (IF) attenuator (200) is placed before a mixer (212) in the IF section of the transmit path and a radio frequency (RF) attenuator (221) is placed after the mixer (212) in the RF section of the transmit path. Power control circuitry (236) controls setting of the two attenuators in response to a magnitude control signal (102) related to a RF output signal at a desired power level. To conserve battery power of the subscriber unit, only the RF attenuator (221) is adjusted when the desired power level is to be within a given range below the maximum transmission level. For ranges below the given range, the RF attenuator (221) is set for maximum attenuation and the IF attenuator (200) is adjusted.

Claims

1. Control circuitry for adjusting the level of an output signal comprising:

first means for adjusting a priori the level of a signal having a first frequency to produce an adjusted signal having a first frequency;

means, coupled to said first means for adjusting, for translating said adjusted signal having a first frequency to a translated signal having a second frequency;

second means, coupled to said means for translating, for adjusting a priori the level of said translated signal having a second frequency to produce the adjusted output signal having a second frequency;

means, coupled to said second means for adjusting, for amplifying said adjusted output signal having a second frequency to produce an amplified adjusted output signal having a second frequency;

means, coupled to said means for amplifying, for detecting a magnitude of said amplified adjusted output signal having a second frequency to produce a magnitude detection signal; and

means for controlling said first and second means for adjusting and said means for amplifying based on input from at least said magnitude detection signal and an adjustment control signal.

2. The control circuitry of claim 1 wherein said first means for adjusting further comprises means for attenuating the level of said signal having a first frequency.

3. The control circuitry of claim 1 wherein said first means for adjusting further comprises means for variably amplifying the level of said signal having a first frequency.

4. The control circuitry of claim 1 wherein said second means for adjusting further comprises means for attenuating the level of said translated signal having a second frequency.

5. The control circuitry of claim 1 wherein said second means for adjusting further comprises means for variably amplifying the level of said translated signal having a second frequency.

6. The control circuitry of claim 1 wherein said means for translating further comprises means for generating a reference signal having a third frequency.

7. The control circuitry of claim 6 wherein said means for translating further comprises means for mixing said adjusted signal having a first frequency with said reference signal having a third frequency to produce said translated signal having a second frequency.

8. Power control circuitry for adjusting the power level of a radio frequency (RF) output signal, the power control circuitry having as input an intermediate frequency (IF) signal from a signal source, the power control circuitry comprising:

first means for adjusting a priori the power level of the IF signal to produce an adjusted IF signal;

means, coupled to said first means for adjusting, for translating said adjusted IF signal to the RF output signal;

second means, coupled to said means for translating, for adjusting a priori the power level of said RF output signal to produce an adjusted RF output signal;

means, coupled to said second means for adjusting, for amplifying said adjusted RF output signal to produce an amplified adjusted RF output signal;

means, coupled to said means for amplifying, for detecting a magnitude of said amplified adjusted RF output signal to produce a magnitude detection signal; and

means for controlling said first and second means for adjusting and said means for amplifying based on input from at least said magnitude detection signal and an adjustment control signal.

9. The power control circuitry of claim 8 wherein said means for translating further comprises means for generating a reference signal.

10. The power control circuitry of claim 9 wherein said means for translating further comprises means for mixing said adjusted IF signal with said reference signal to produce said RF output signal.

11. Power control circuitry for adjusting the power level of a radio frequency (RF) output signal over a predetermined power level range in a transmitter, the power control circuitry having as input an intermediate frequency (IF) signal from a signal source, the power control circuitry having the capability to adjust the RF output signal to a desired level and provide at least one adjustment control signal related to the RF output signal at a desired power level, the power control circuitry comprising:

means for providing an adjustment power level range less than or equal to the predetermined power level range;

means for generating a reference signal;

means for detecting a magnitude level of the RF output signal to produce a magnitude detection signal;

means for providing first and second adjustment control signals from the difference between the magnitude detection signal and a magnitude control signal;

first means, responsive to the first adjustment control signal, for adjusting the IF signal when the desired power level of the RF output signal is not within said adjustment power level range;

means, coupled to said first means for adjusting, for mixing said generated reference signal with said adjusted IF signal to produce the RF output signal; and

second means, responsive to the second adjustment control signal, for adjusting said RF output signal when said desired power level of said RF output signal is within said adjustment power level range to produce the RF output signal at the desired power level.

12. The power control circuitry of claim 11 wherein said first means for adjusting further comprises means for attenuating the power level of said IF signal when the desired power level of the RF output signal is not within said adjustment power level range.

13. The power control circuitry of claim 11 wherein said second means for adjusting further comprises means for attenuating the power level of said RF output signal when said desired power level of said RF output signal is within said adjustment power level range.

14. The power control circuitry of claim 11 wherein said second means for adjusting further comprises means for variably amplifying the power level of said RF output signal when said desired power level of said RF output signal is within said adjustment power level range.

15. A method of adjusting the level of an output signal comprising the steps of:

adjusting a priori the level of a signal having a first frequency to produce an adjusted signal having a first frequency;

translating said adjusted signal having a first frequency to a translated signal having a second frequency;

adjusting a priori the level of said translated signal having a second frequency to produce the adjusted output signal having a second frequency;

amplifying said adjusted output signal having a second frequency to produce an amplified adjusted output signal having a second frequency;

detecting a magnitude of said amplified adjusted output signal having a second frequency to produce a magnitude detection signal; and

controlling said steps of adjusting and said step of amplifying based on input from at least said magnitude detection signal and an adjustment control signal.

16. The method of claim 15 wherein said step of adjusting the level of a signal having a first frequency further comprises the step of attenuating the level of said signal having a first frequency.

17. The method of claim 15 wherein said step of adjusting the level of a signal having a first frequency further comprises the step of variably amplifying the level of said signal having a first frequency.

18. The method of claim 15 wherein said step of adjusting the level of said translated signal having a second frequency further comprises the step of attenuating the level of said translated signal having a second frequency.

19. The method of claim 15 wherein said step of adjusting the level of said translated signal having a second frequency further comprises the step of variably amplifying the level of said translated signal having a second frequency.

20. The method of claim 15 wherein said step of translating further comprises the step of generating a reference signal having a third frequency.

21. The method of claim 20 wherein said step of translating further comprises the step of mixing said adjusted signal having a first frequency with said reference signal having a third frequency to produce said translated signal having a second frequency.

22. A method of adjusting the power level of a radio frequency (RF) output signal, the method comprising the steps of:

adjusting a priori the power level of an IF signal to produce an adjusted IF signal;

translating said adjusted IF signal to a RF output signal;

adjusting a priori the power level of said RF output signal to produce an adjusted RF output signal;

amplifying said adjusted RF output signal to produce an amplified adjusted RF output signal;

detecting a magnitude of said amplified adjusted RF output signal to produce a magnitude detection signal; and

controlling said steps of adjusting and said step of amplifying based on input from at least said magnitude detection signal and an adjustment control signal.

23. The method of claim 22 wherein said step of translating further comprises the step of generating a reference signal.

24. The method of claim 23 wherein said step of translating further comprises the step of mixing said adjusted IF signal with said reference signal to produce said RF output signal.

25. A method of adjusting the power level of a radio frequency (RF) output signal over a predetermined power level range in a transmitter incorporating power control circuitry, the power control circuitry having as input an intermediate frequency (IF) signal from a signal source, the power control circuitry having the capability to adjust the RF output signal to a desired level and provide at least one adjustment control signal related to the RF output signal at a desired power level, the method comprising the steps of:

providing an adjustment power level range less than or equal to the predetermined power level range;

generating a reference signal;

detecting a magnitude level of the RF output signal to produce a magnitude detection signal;

providing first and second adjustment control signals from the difference between the magnitude detection signal and a magnitude control signal;

adjusting, based on the first adjustment control signal, the IF signal when the desired power level of the RF output signal is not within said adjustment power level range;

mixing said generated reference signal with said adjusted IF signal to produce the RF output signal; and

adjusting, based on the second adjustment control signal, said RF output signal when said desired power level of said RF output signal is within said adjustment power level range to produce the RF output signal at the desired power level.

26. The method of claim 25 wherein said step of adjusting the IF signal further comprises the step of attenuating the power level of said IF signal when the desired power level of the RF output signal is not within said adjustment power level range.

27. The method of claim 25 wherein said step of adjusting said RF output signal further comprises the step of attenuating the power level of said RF output signal when said desired power level of said RF output signal is within said adjustment power level range.

28. The method of claim 25 further comprising the steps of:

amplifying said RF output signal at a desired level; and

varying a current supplied at said step of amplifying when the desired power level of the RF output signal is within said adjustment power level range.