Patent ID: 8095088

Claim:
A radio frequency transmitter comprising: an electronics rack having an electrical backplane; a plurality of radio frequency transmitters each operatively connected to said backplane, each transmitter comprising: a modem which receives one or more input data signals and an adaptive predistortion signal and provides a baseband in-phase (“I”) signal and a baseband quadrature (“Q”) signal; a power amplifier module which receives said I and Q signals and provides a radio frequency (“RF”) output signal; and a predistortion module which receives said RF signal, downconverts said RF signal to an intermediate frequency (“IF”) signal, downconverts said IF signal to a baseband feedback signal, and samples said feedback signal to thereby provide said adaptive predistortion signal to said modem; a local reference signal generator; and a frequency locking circuit; and a data processing unit (“DPU”) operatively connected to said backplane, said DPU having a first and a second common reference signal generator, wherein each said local reference generator is switchably connected to said first common reference signal generator via said frequency locking circuit.