Design and applications of 2-6.5 GHz transistor amplifiers

Using the microwave thin-film technology, the class-A common emitter transistor pre- and power amplifiers fabricated on a sapphire substrate were initially optimized for the gain and VSWR's simultaneously over the 2-6.5 GHz range and then adjusted for the large-signal conditions. The large-signal adjustments were proven to be quite beneficial in maximizing the power-handling capability and in minimizing the spurious signal content. The measured power gain of both amplifiers is 4 dB. The output power at the 1 dB gain compression level of pre- and power amplifiers is 13 and 16 dBm, respectively, while all spurious signals are at lease 20 dB down. Also, their applications in C-band test instruments are given.