A Low Phase Noise Dual-Loop Dual-Output Frequency Synthesizer in SiGe BiCMOS

Abstract

In this article, a dual-loop dual-output frequency synthesizer designed for IEEE802.11aj (45 GHz) standard is presented. In order to support the super-heterodyne transceiver, the Loop1 output frequency is fixed for easy design of high-performance IF transceiver and filter, and the Loop2 output frequency varies for the channel selection according to the IEEE802.11aj (45 GHz) standard. The power hungry high-speed prescaler (or multi-modulus-divider) is replaced with a mixer in Loop2, thus the in-band phase noise and DC power consumption can be improved. The dual-loop dual-output synthesizer is fabricated in 0.13 µm SiGe BiCMOS technology, occupies an area of 2.7 mm × 2.4 mm, and consumes 610 mW DC power. Measured results show the phase noise of the frequency synthesizer are −79.3 dBc/Hz@10 kHz and −129.1 dBc/Hz@10 MHz at 12.96 GHz for Output1 and −76.6 dBc/Hz@10 kHz and −117.2 dBc/Hz@10 MHz at 32.535 GHz for Output2. The low-reference spur of −69.2 dBc and low-power level spurious tones at the outputs are observed during the measurement. To the best of our knowledge, this work is the first reported dual-loop dual-output synthesizer designed for IEEE802.11aj (45 GHz) standard.