High temperature RF transceiver design for high-speed downhole communications

This paper presents a design of high-speed downhole system based on radio over fiber and frequency division multiplexing techniques. Furthermore, the design of a high temperature radio frequency (RF) transceiver for high-speed downhole communications is introduced. The designed transceiver provides full duplex communi-cations over the coaxial cable with high linearity, low noise, and reliable operation at room temperature and up to 230 degrees C. The proposed transceiver is designed based on commercial wide bandgap Gallium Nitride (GaN) high electron mobility transistor (HEMT) technology. Measurement results indicate that the transceiver can support data rate of 20 Mbps for uplink and 6 Mbps for downlink. The bit error rate of <10-6 and dynamic range of >55.0 dB at 230 degrees C are achieved through measurements.