Linear high-power transistor amplifiers
Abstract
It was found experimentally that predistorted AM and phase characteristics reduce the total intermodulation distortion (IMD) and that the low IMD results from a cancellation effect of the intermodulation products due to particular shapes of the amplitude and phase characteristics of the amplifier. Work performed with linear amplifiers operating in class B and AB showed that these amplifiers are particularly attractive not only because they provide higher efficiency and higher output power than class-A amplifiers operating with the same active devices, but also because they can be linearized by proper choice of RF tuning and bias supply voltages. Active broadband bias circuits were developed whose performance was superior to that of most common passive bias circuits. Amplifiers built with bipolar transistors provided 10 dB gain at 4 GHz, with an efficiency 5 to 6 times that of comparable class-A amplifiers, and a modulation bandwidth of 100 MHz.
- Publication:
-
Active semiconductor devices for microwaves and integrated optics
- Pub Date:
- 1975
- Bibcode:
- 1975asdm.proc..327S
- Keywords:
-
- Amplifier Design;
- Bipolar Transistors;
- Linear Amplifiers;
- Microwave Amplifiers;
- Power Amplifiers;
- Transistor Amplifiers;
- Amplitude Modulation;
- Intermodulation;
- Phase Modulation;
- Signal Distortion;
- Electronics and Electrical Engineering