We have developed transmitter and receiver RF circuit in 38GHz band for ESK radio communication system, where all the RF active circuits are constructed by multi-functional MICs using the pseudomorphic Hetero-Junction FETs (HJ-FET). A transmitter saturated output power of more than +18dBm and a receiver NF of less than 5dB is achieved over the 280MHz frequency band with synthesized local oscillators.