Quasioptical power combining at millimetre waves

Quasioptical technique is used to combine CW Gunn sources at millimetre-wave frequencies using a Fabry Perot resonator. This resonator consists of two symmetrical highly polished reflectors with dielectric launchers to couple maximum energy from the sources. Experiments were caried out using two, three and four GaAs Gunn oscillators, at 94 GHz, to prove the power combining concept. Combining efficiency of about 50, 55 and 60%, respectively, with half-power bandwidth (HPBW) of 50 kHz has been achieved.