Abstract: In a microwave transceiver including a dielectric antenna and a self-oscillating semiconductor mixer stage for both generating a microwave signal to be transmitted via the antenna and mixing that microwave signal with reflected microwave signal components received by the antenna, the mixer stage being composed of a nonlinear microwave diode connected to give the stage a negative impedance to permit oscillation and to effect mixing, and a half-wavelength disc-type resonator providing a resonant circuit for the oscillator and having the form of a stripline piece element composed of two strip conductors between which the microwave diode is electrically conductively connected, the antenna being disposed on one of the strip conductors, the resonator and antenna are constructed to be axially symmetrical and are positioned coaxially to one another.