The Distributed Oscillator : A Solution for Power GaAs IMPATT Combining

Multidiode distributed oscillators allow combining several high power GaAs Impatt diodes in a compact module. According to this principle, the diodes are strongly coupled to a low-Q resonant circuit. The modes and resonant frequencies depend heavily upon the diode reactances. The flat cavity combiner which is described involves special techniques for suppressing unwanted parasitic modes without absorbing power on the desired TM 010 mode. A four diode structure delivers 5 W around 10 GHz, with a nearly 100% power adding efficiency and a 400 MHz locking bandwidth for a 10 dB gain. At Ku band, power combining of six 2.5 W nominal GaAs diodes inside a dielectric circular cavity, is presented.