EFFICIENT HF/VHF POWER AMPLIFIERS (INTEGRATED HF/VHF POWER CIRCUITS)

THE RESEARCH PROPOSED FOR THIS SBIR FOCUSES ON MODIFYING A NEW CLASS OF POWER AMPLIFIER, THE SM CLASS, FOR OPERATION IN THE RANGE OF 100400 WATTS AND 1-400 MHZ. THE SM POWER AMPLIFIER OPERATES BY COMBINING THE OUTPUTS OF DISCRETE SETS OF SWITCHING TRANSISTORS, WITH EACH SET OF TRANSISTORS OPERATING IN SATURATION AS THE INPUT SIGNAL MOVES THROUGH ITS THRESHOLD RANGE. AS EACH TRANSISTOR SET CONDUCTS, THE REMAINING SETS ARE CUTOFF. THE COMBINED OUTPUT WAVEFORM REPRESENTS AN ACCURATE, BUT AMPLIFIED, REPLICA OF THE INPUT WAVEFORM. THE BASIC SM DESIGN WAS DEVELOPED BY SCS TELECOM, INC AND INITIAL CALCULATIONS INDICATE THAT EFFICIENCIES OF UP TO 80-90% AND SPURIOUS NOISE COMPONENTS NEAR ZERO ARE ACHIEVABLE WITH THIS DESIGN. THIS WILL RESULT IN LOW WEIGHT, EXTREMELY EFFICIENT POWER AMPLIFIERS FOR A WIDE RANGE OF MILITARY COMMUNICATIONS AND ELECTRONIC WARFARE SYSTEMS. COMMERCIAL COMMUNICATIONS SYSTEMS WILL ALSO BENEFIT FROM THIS DESIGN AS COSTS DROP WITH THE INCREASED AVAILABILITY OF HIGH POWER IC'S.