9 GHz power amplifier-transmitter on Gunn diode for measurement-while-drilling system

This paper describes the power stage of downlink of measurement-while-drilling (MWD) telemetry system. Design of this system is modern direction in geo- and radiophysics due transition to a new communication channel between drilling point to surface. The device is the X-band Gunn diode hybrid-integrated power amplifier-transmitter. Its advantage is high efficiently and low current from bias. The pulse output power is about 15 Watt in short-pulse operating conditions, at 9 GHz central lobe frequency. Due to the MWD application, the special attention pays to circuit and repeatability of characteristics. Design and packaging is very tight and give a possibility to put device into the drilling gun. The experimental bench and some measurement results are presented in the paper. In particular, output power and frequency of the center lobe as function of voltage and current of transmitter is shown.