Patent ID: 8838049

Claim:
A direct-conversion transmitter comprising: a transmit synthesizer common to a plurality of radio interfaces of the direct-conversion transmitter and configured to generate a mixing signal; a controllable low-pass filter common to the plurality of radio interfaces of the direct-conversion transmitter, the controllable low-pass filter configured to perform filtering of an analog baseband transmission signal using a controllable cut-off frequency according to which one of the plurality of radio interfaces of the direct-conversion transmitter is selected; a frequency divider common to the plurality of radio interfaces of the direct-conversion transmitter and configured to divide a frequency of the mixing signal at least by two, wherein the dividing produces two mixing signal components having a 90-degree phase difference; and a controllable gain transmitter amplifier common to the plurality of radio interfaces of the direct-conversion transmitter and configured to amplify a carrier-frequency signal from a mixer of the direct-conversion transmitter at a gain controlled according to which one of the plurality of radio interfaces of the direct-conversion transmitter is selected, wherein at least one of the plurality of radio interfaces of the direct-conversion transmitter comprises a modulation, a channel spacing, and a channel bit rate that at least one other of the plurality of radio interfaces does not have.