An Ultra-Low Noise Microwave Synthesizer

A silicon bipolar transistor together with a barium titanate dielectric resonator were used to design a low noise microwave synthesizer. The oscillator was phase locked to a low-frequency (LF) reference with microwave frequency selection provided by a high-speed digital programmable divider within the phase-locked loop. The resulting FM noise Delta f_rms was 0.0003 Hz in a 1-Hz band greater than 1000 Hz from the 1-GHz carrier.