X-band 50 W high stability Gunn pulsed sources

A circuit structure readily adapted to combine the power of several pulsed diodes is presented. Herein the diodes have been mounted to stack up to a "Diodes Chain" in a full high WG. This approach does not suffer from multiple-modes, the diodes being in series along the same axis with the electric field. This method makes a feature of high active impedance, minor RF current, low loss and high Qex. As a result, high peak power and excellent frequency stability have been achieved. 50 W of peak power was measured from a two-diode pulsed Gunn source, the frequency stability being about 1-2 ppmspl deg/C and power\´s 0.01 dBspl deg/C for -20 to +60/spl deg/C. This may be one of the best performances published so far.<>