Multi-mode multi-band transceiver, radio frequency front-end circuit and radio frequency system using the same

A transceiver, comprising:

• a controller used for providing a frequency selection signal;
• and
• a drive amplifier controlled by the controller and coupled to a signal transmitting port of the transceiver, wherein the drive amplifier comprises:
• a frequency dependent load set comprising a plurality of frequency dependent loads;
• a band selector switched between the frequency dependent loads in response to the frequency selection signal;
• and
• an amplifier circuit coupled to the band selector and electrically coupled to one of the frequency dependent loads through the band selector, wherein when the amplifier circuit is coupled to a first frequency dependent load of the frequency dependent loads, the amplifier circuit outputs a first RF signal to the signal transmitting port;
• when the amplifier circuit is coupled to a second frequency dependent load of the frequency dependent loads, the amplifier circuit outputs a second RF signal to the signal transmitting port.

An RF front-end circuit, comprising:

• a transmission path switch used for selectively and electrically coupling a signal transmitting port of a transceiver to one of a plurality of signal transmission paths;
• and
• an antenna switch coupled to the signal transmission paths for transmitting the signals coming from the signal transmission paths to an antenna module;
• wherein when the signal transmitting port transmits a first RF signal, the transmission path switch electrically couples the signal transmitting port to a first signal transmission path of the signal transmission paths to transmit the first RF signal to the antenna module;
• when the signal transmitting port transmits a second RF signal, the transmission path switch electrically couples the signal transmitting port to a second signal transmission path of the signal transmission paths for transmitting the second RF signal to the antenna module.