Wide-Band Frequency Synthesizer and Ka-band Tunable Filter for Flexible Communications Payloads

摘要

This paper presents designed results of a fractional-N frequency synthesizer in CMOS Technology and measured results of a Ka-band tunable high pass filter for next generation flexible communication payload, respectively. A tuning range from 8 GHz to 12 GHz is achieved using two integrated voltage-controlled oscillator, which enables all frequencies generation bellows 6 GHz by frequency division. Using current mismatch compensation circuit in charge pump, in-band phase noise of-95 dBc/Hz is achieved at 100 kHz offset in fractional-N mode. Also, a Ka-band tunable high pass filter using TE0n mode is designed and fabricated. Unlike a conventional tunable filter using TE0n mode, the tunable filter has additional configurations for suppression of degenerate modes and spurious modes near the TE0n mode and has no conductive elastomer acting as a piston ring. The study shows how to maintain coupling values and filter performance over the wide tuning frequency range. This paper presents the design and test results of the tunable filter.