EQUAL POWER AMPLIFIER SYSTEM FOR ACTIVE PHASE ARRAY ANTENNA AND METHOD OF ARRANGING SAME

摘要

EQUAL POWER AMPLIFIERSYSTEM FOR ACTIVE PHASE ARRAYANTENNA AND METHOD OF ARRANGING SAMEABSTRACTAn equal power amplifier system (100) for amplifying aplurality of signals for transmission by an active phase array antenna(20), and a compact plural level beam-forming network (98) for forming aplurality of such signals, for example on excitation patterns for frequencyscanned virtual beams, are disclosed. The amplifier system uses at mostonly a few sizes of power amplifiers (130, 134) to amplify efficientlynumerous signals having significantly different amplitudes. This isaccomplished by distributing the task of amplifying signal pairs (Ai, Bi)composed of one large amplitude signal and one small amplitude signal toan equal power amplifying apparatus (130; 230), which includes two hybridcouplers (236, 238) and two equally sized power amplifiers (232, 234).The first hybrid coupler (236) divides the two signals (Ai, Bi) for inputinto the two power amplifiers. The second hybrid coupler (238) receivesthe intermediate amplified signals from the power amplifiers and throughconstructive and destructive interference produces amplified outputsignals (Ai*, Bi*) corresponding to the input signals. Also disclosed is amethod for properly selecting pairs of signals from an amplitudedistribution (200; 202) for application to such equal power amplifyingapparatuses of the amplifier system in order to operate the poweramplifiers therein at or near peak efficiency. The beam-forming network(98) is arranged on two levels to simplify interconnection of the selectedpairs of outputs of its line summers (176) for input into the equal poweramplifier system. The amplifier system and beam-forming network may beused together, for example, in the transmit antenna system of ageosynchronous satellite (10) or mobile earth station.