A Low Phase Noise Frequency Synthesizer with a Fourth-Order RLC Loop Filter

The current work employs the HMC830 phase-locked loop chip to design a frequency synthesizer operating in L-band. can provide local oscillation signal for RF receiver front end. This article synthesis technique describe scheme. Due advantages of passive filters, such as simplicity, low cost, and phase noise, fourth-order RLC filter is proposed improve output quality reduce noise. performance this compared with RC filter. effects these two filters on capture time, spur suppression are analyzed. Subsequently, scheme, simulation analysis, test results presented under filters. indicate that outperforms filter; its noise higher than −100 dBc/Hz@1 kHz, time less 100 us, better 60 dBc. high-performance signals wireless communication equipment transmitters receivers. It meets application requirements many radio circuit structures has good prospects.