High-efficiency multimode HF/VHF transmitter for communication and jamming

The high-efficiency HF/VHF multimode transmitter described in this paper is based upon the Kahn EER (Envelope-Elimination-and-Restoration) technique. The major subsystems are a class-D RF power amplifier (PA), a class-S high-level amplitude modulator, a single-sideband modulator, a delay-compensation circuit, and a frequency translator. The efficiency is about 60 percent for all signal amplitudes, which makes its average efficiency about 60 percent for voice and noise signals about three times that of a transmitter with a conventional class-B PA. For voice-bandwidth signals, the IMD products are 43 cc dB or more below the peak output