Abstract: A millimeter-wave transceiver with two-receiver ways and one-transmitter way is designed. It can be used for a millimeter radar. The frequency of the two-ways receiver is converted to 50 MHz from Ka-band by twice mixing. Whereas in the transmitter way, two up-converters make 50 MHz signal transfer to millimeter-wave band. Based on the analysis about the design principle of T/R moudle and various kinds of scheme, the transceiver is fabricated and tested. The performance of a power output of 1.0 W at Ka-band, a noise figure of 4.5 dB, a receiver gain of 100 dB is achieved.