High susceptibility of micro-phonic and phase-hit dual loop push-push synthesizer design for high modulation microwave digital radios

The susceptibility performance of microphonic and phase-hit over temperature transition for a synthesizer has become more critical. This paper describes simulation and prototype work done for a 38GHz 128QAM radio development, which requires low phase noise, high susceptibility of micro-phonic and phase hit performance over temperature. Push- Push dual loop synthesizer scheme has been used, one narrow band loop is designed for achieving low phase noise with small step size and the second loop is designed for a wide loop bandwidth achieving high susceptibility of micro-phonic and phase-hit over temperature. The simulation and prototype testing show good results.