A 16-element reflection grid amplifier with improved heat sinking

We present a 16-element hybrid grid amplifier with improved heat sinking. This is a higher-power version of a previously reported reflection grid amplifier. The grid uses custom-made differential-pair chips with TRW InP Heterojunction Bipolar Transistors (HBTs) as the active devices. We measure a peak gain of 15 dB at 8.4 GHz. Measured gain is consistent with theoretical predictions. The grid was able to dissipate up to 4 W of dc bias power without any apparent thermal damage. Measurements on passive resistor arrays demonstrate this architecture's superior thermal performance.