Amplifying and processing apparatus for modulated carrier signals

• US 3,900,823 A
• Filed: 03/28/1973
• Issued: 08/19/1975
• Est. Priority Date: 03/28/1973
• Status: Expired due to Term

• Current Assignee: Alan D. Sokal, Nathan O. Sokal
• Original Assignee: Alan D. Sokal, Nathan O. Sokal
• Inventors: Sokal, Nathan O., Sokal, Alan D.
• Primary Examiner(s): Mullins, James B.
• Application Number:
  US05/345,509
• Time in Patent Office: 874 Days
• Field of Search: 330/149,127-129 332/18,37R,37D 328/162,163,155 325/475,476
• US Class Current: 330/149
• CPC Class Codes: H03F 1/0216 Continuous control
• CPC Class Codes: H03F 1/3223 using feed-forward H03F1/3211 takes precedence
• CPC Class Codes: H03F 3/217 Class D power amplifiers; Switching amplifiers
• CPC Class Codes: H03G 3/22 in amplifiers having discharge tubes
• CPC Class Codes: H03G 3/3042 in modulators, frequency-changers, transmitters or power amplifiers transmission power control in bidirectional transmission systems H04W52/04

Abstract

A power amplifying and signal processing system for modulated carrier signals separately processes the amplitude component of the system input signal and the component of frequency or phase or both frequency and phase, and later recombines the separately processed components to provide an output signal. The amplitude and phase transfer functions of the system can be accurately controlled. The input signal is fed to a power amplifier whose output provides the output for the system. The input and output signals of the system are fed by separate paths to a comparator which compares those signals and emits an error signal to a controller. The controller regulates the amplitude and phase, or both, of the power amplifier'"'"''"'"'s output to null the error signal. One or both of the signal paths to the comparator may have in it a non-linear function generator which acts upon the signal fed by that path to the comparator. The system may also have a frequency translator and phase shifter interposed between the system input terminal and the power amplifier'"'"''"'"'s input to shift the frequency or phase or both of the signal applied to the power amplifier'"'"''"'"'s input.

Claims

1. In a signal processing system of the type having 1. a system input terminal for receiving the signal to be processed, 2. a system output terminal at which the processed signal is provided, 3. a power amplifier having its output fed to the system output terminal, 4. means coupling the system input terminal to the input of the power amplifier, 5. control means for controlling the amplitude of the output of the power amplifier, 6. a differential amplifier having its output connected to the control means and emitting an error signal thereto in response to the input signals applied to the differential amplifier, 7. means providing a first signal path connecting the system input terminal to a first input of the differential amplifier, the first signal path having in it an amplitude detector, 8. means for sensing the output of the power amplifier and providing an electrical signal related thereto, and 9. means providing a second signal path connecting the output sensing means to second input of the differential amplifier, the second signal path having in it an amplitude detector, the improvement wherein at least one of the first and second signal paths has a nonlinear function generator in it which acts upon the signal fed by that path to the differential amplifier.

2. a system output terminal at which the processed signal is provided,

3. a power amplifier having its input connected to the system input terminal and having its output connected to the system output terminal,

4. means coupling the system input terminal to the input of the power amplifier,

5. control means for controlling the amplitude of the output of the power amplifier,

6. a differential amplifier having its output connected to the control means and emitting an error signal thereto in response to the input signals applied to the differential amplifier,

7. means providing a first signal path connecting the system input terminal to a first input of the differential amplifier,

8. means for sensing the output of the power amplifier and providing an electrical signal related thereto, and

9. means providing a second signal path connecting the output sensing means to a second input of the differential amplifier, the improvement wherein the means coupling the system input terminal to the input power amplifier includes a variable phase shifter and wherein the signal processing system further includes

10. means for controLling the variable phase shifter,

11. The improvement in a linear power amplifying system according to claim 10 wherein the control means includes a switching regulator comprising c. a switch connected in the d.c. supply voltage path to the at least one stage of the power amplifier, the switch controlling the application of the d.c. supply voltage to those stages, and d. a modulator governing and operation of the switch in response to the error signal emitted by the comparison means.

12. means for coupling the system input terminal and the system output terminal to different inputs of the phase detector, and

13. In a linear power amplifying system comprising

14. The improvement in a linear power amplifying system according to claim 13, wherein the apparatus which controls the a.c. cycle duty ratio causes the centroids of the individual a.c. cycles appearing at the system output terminal to be delayed a constant time from the centroids of the individual a.c. cycles appearing at the system input terminal.

15. A linear power amplifying system comprising a. a system input terminal for receiving the signal to be linearly amplified, b. a system output terminal at which the linearly amplified signal is provided, c. a power amplifier having its input connected to the system input terminal and having its output connected to the system output terminal, d. means for linearly combining the signals at the which are present at system input and output terminals, e. detection means fed by the output of the linear combining means, the output of the detection means being indicative of the difference between the amplitude of the signal at the system input terminal and the arithmetic product of the amplitude of the signal at the system output terminal and a constant factor, and f. control means responsive to the output of the detection means, the control means governing the amplitude of the output of the power amplifier in accordance with the output of the detection means.

16. The linear power amplifying system according to claim 15, wherein the detection means comprises a synchronous detector having as its analog signal input the output of the linear combining means and having as its reference phaSe input a signal of the same frequency as the signal at the system input terminal, and further comprising g. phase control means for controlling the relative phases of the signals applied to the linear combining means.

17. The linear power amplifying system according to claim 16, wherein the power amplifier includes a variable phase shifter, and wherein the phase control means comprises

18. The linear power amplifying system according to claim 15, wherein the constant factor in the aforesaid arithmetic product is substantially independent of the relative phase of the signals at the system'"'"''"'"'s input and output terminals.

19. The linear power amplifying system according to claim 18, wherein the linear combining means has two or more sections, each of which has means for linearly combining the signals applied to it, and wherein the detection means has two or more sections, each of which has means for detecting signals applied to it, and the detection means further comprises means for combining the outputs of the sections to provide the output of the detection means whereby the detection means yields an output that is substantially independent of the relative phase of the signals at the system'"'"''"'"'s input and output terminals.

20. The linear power amplifying system according to claim 19, wherein a first section of the detection means comprises a synchronous detector, the synchronous detector having as its reference phase input a signal whose fundamental frequency component is a linear combination of the signals at the system input and output terminals, and the synchronous detector having as its analog signal input the output of a first section of the linear combining means, and wherein another of the sections of the detection means is associated with a different section of the linear combining means, the combination thereof performing a function substantially equivalent to the function performed by the combination of the aforesaid first sections where one of the input signals to the latter combination is shifted 180* in phase.