Broadband Design of Microwave Power MESFET Amplifiers using Negative Feedback Techniques

A new method is presented which allows the design of a medium power MESFET amplifier stage in the 3.7 - 4.2 GHz communication band using a simple and universal feedback network. Using a commercially avalaible Nippon Electric Co. NE-464194 MESFET, an amplifier stage has been constructed using-thick-film microstrip circuitry. A gain of 8±0.3 dB has been obtained, with input and output VSWR less than 2. Power output at 1 dB compression is 22.5 dBm with an 3er O.I.P. of 33 dBm. Noise figure is 4.7 dB. The method is applicable to other types of MESFET.