Siliconp+-nn+trapatt diodes have been fabricated by integral-heat-sink (t.h.s.) technology. The gradedp+njunction has been formed by two methods; by deposition and by a low energy implantation, both of which were followed by a drive-in period. Oscillator efficiencies of 55% in L-band, and 35% in X-band were recorded. R.F. peak powers of up to 15 W in X-band have been observed. J-band operation has been obtained by 2nd-harmonic extraction, giving efficiencies of 13% to 16 GHz. Low steady-state thermal impedance has enabled operation with mean powers in excess of 1 W in X-band. Diodes with improved transient thermal impedance have enabled operation to be extended beyond 5 μs pulsewidth. Coaxial amplifier circuits produced small-signal gains of 9 dB and added-power efficiencies of 25% at 9 GHz. Large-signal gains of 4 dB with 1 dB bandwidths of 500 MHz with r.f. peak powers of over 12 W have been obtained. Amplifiers have been operated with a 1 dB variation in gain over a temperature range of 50 deg C.