A new power amplifier based on an extended resonance technique is pres
ented. This technique produces high power through multiplying the powe
r handling capability of a single device by the number of devices empl
oyed white maintaining the gain of a single-device amplifier. An X-ban
d power combining amplifier employing four 100 mW MESFET's was designe
d and constructed. The small signal gain was measured at 11.5 dB, and
a maximum of 480 mW was obtained at 9.57 GHz with a power-added effici
ency of 30.8%.