Device system and method for low noise radio frequency transmission

摘要

A low noise transmitting device is disclosed. The transmitting device receives a modulated signal having a modulation bandwidth and an intermediate center frequency and generates a modulated transmit band signal at a carrier frequency. The transmitting device includes a first filter that receives the modulated signal and passes frequencies within the modulation bandwidth, producing a low noise filtered modulated signal, and a low noise frequency source that generates a low noise main synthesizer frequency. The filtered modulated signal and the main synthesizer frequency are then fed into a mixer that mixes the two signals (produces either the sum or difference). The output is a low noise modulated transmit band signal that may be amplified to transmit power levels without the need for power-inefficient post-amplification filtering.