This invention discloses methods and circuits of wideband wireless transmitting and/or receiving by combining multiple RF transmitters and/or receivers, or multiple transceivers, each of which has a narrower bandwidth, e.g., producing a RF transmitter and receiver or a RF transceiver whose signal bandwidth is the sum or approximately the sum, e.g., slightly less than the sum, of the signal bandwidth of the multiple RF transmitters and/or receivers, or multiple RF transceivers. The embodiments apply in wireless communication systems with orthogonal or approximately orthogonal subcarrier type of modulation (OSM), e.g., Orthogonal Frequency Division Multiplexing (OFDM).