Microwave equipment for MWD front-end radiolink in the borehole pipes

In this paper the X-band Gunn diode hybrid-integrated power amplifier-transmitter is proposed for the measurement-while-drilling (MWD) or logging-while-drilling (LWD) telemetry systems. This systems is a modern equipment for geophysics due transition from vertical to horizontal drilling. A review is presented of work on MWD, explaining the current high degree of interest in these subjects. The amplifier-transmitter operates in a new communication channel between drilling point to surface. This channel is characterized by high attenuation of signal. So main attention is paid to efficiently and low bias current. The transmitter design, simulated performances, and realized current-efficiently results are presented. The pulse output power is about 15-25 Watt in short-pulse mode, at 9 GHz central lobe. Measurement results are provided. Relation between measured output power and frequency of the center lobe as function of voltage and current of transmitter is determined. The aim of experiments is to test the effectiveness of the known voltage and current in order to increase output power. This work is carried out within a Microwave borehole project #13-02-98002 funded by the Russian Foundation for Basic Researches.