Broadband lumped-element X band GaAs f.e.t. amplifier

The design of a 2-stage broadband X band amplifier using GaAs Schottky field-effect transistors is described. The performance of the intrinsic device and the amplifier are summarised. The amplifier gives 9.5±1 dB gain over the frequency range 6.5¿12 GHz. The v.s.w.r. at the input and the output does not exceed 2.5:1. Practical wideband matching networks are described that minimise overall amplifier noise figure and maintain a constant gain over the design bandwidth, while including the effects of parasitics, loss and discontinuity capacitances.