Additive Phase-Noise Reduction in Microwave Regenerative Dividers

A detailed investigation of a method to effectively reduce additive phase noise in regenerative frequency dividers is presented. The approach enhances the sensitivity of conventional regenerative dividers and addresses start-up challenges while preserving low-additive phase noise and low power consumption. As a proof of concept, an integrated low-additive phase-noise regenerative divider with an octave-spanning frequency range was designed and fabricated using a 250-nm InP heterojunction bipolar transistor (HBT) process. The impact of the classes of operation for both the amplifier and the buffer, along with the effect of the phase shifter, on the divider’s overall phase-noise performance was analyzed and measured. The regenerative divider achieved additive phase noise below −163 dBc/Hz from a 7-GHz carrier at 10-kHz offset with more than 12-dB fundamental rejection and greater than −10-dBm output power at various frequencies. The presented results, with the full integration of the divider, address key challenges in low-additive phase-noise design, representing a significant advancement for low-noise applications, including communication and navigation systems.