FREQUENCY-MODULATED TRANSCEIVER

A frequency-modulated transceiver in which modulation caused by the transmitter part of the transceiver in the output signal of the receiver i.f.-mixer is decreased. The transmitter comprises a frequency-modulated high-frequency oscillator (1) having a modulation input and an output, and the receiver comprises in a cascade: a high-frequency mixer (9) having a local oscillator input functionally connected to the output of the high-frequency oscillator (1) of the transmitter; a first intermediate filter (8); and an intermediate frequency mixer (7). The receiver further comprises a frequency-modulated local oscillator (4) having an output functionally connected to a local oscillator input in the intermediate frequency mixer (7), the local oscillator being modulated with the modulating signal of the transmitter. Modulation caused by the transmitter part of the transceiver in the output signal of the intermediate frequency mixer is decreased by time-delay means (3) connected in series with the local oscillator (4) before or after it, the time-delay means (3) compensating for the time difference between the modulation of the local oscillator signal of the intermediate frequency mixer (7) and the modulation caused by the transmitter part in the input signal of the intermediate frequency mixer (7).