Transmitter/receiver for transmitting and receiving of an RF signal in two frequency bands

A direct conversion transmitter/receiver which operates in two separate frequency bands, and in which the first frequency band comprises a first transmitting frequency band and a first receiving frequency band and the second frequency band comprises a second transmitting frequency band and a second receiving frequency band, and in which

• said receiver comprises at least one RX mixer for mixing a received signal into a baseband signal,
• said transmitter comprises at least one TX mixer for mixing a baseband signal into a carrier frequency transmitting signal, and
• the transmitter/receiver comprises synthesizer means (340) which outputs a synthesized signal for forming a first RX mixing signal (RXM1) to the RX mixer for mixing the signal (RXC1) received in the first receiving frequency band into a baseband signal (RXB1) and for forming a first TX mixing signal (TXM1) to the TX mixer (362, 382) for mixing the first baseband TX signal (TXB1) into the first carrier frequency TX signal (TXC1) which is in the first transmitting frequency band,
• wherein the transmitter/receiver comprises additionally:
• a first conversion means (311) for forming a second RX mixing signal (RXM2) from the synthesized signal for mixing the signal received in the second receiving frequency band into a second baseband RX signal (RXB2), and
• a second conversion means (361) for forming a second TX mixing signal (TXM2) from the synthesized signal for mixing the second baseband TX signal (TXB2) into a second carrier frequency signal (TXC2) which is in the second transmitting frequency band.