Frequency-Hopped Quadrature Frequency Synthesizer in 0.13- m Technology Narasimha R. Lanka , Student Member , IEEE , Satwik A. Patnaik , Member , IEEE,a n d

Abstract

This paper presents a Wireless-USB/WiMedia-com- pliant fast-hopping frequency s ynthesizer architecture with quadrature outputs based on sub-ha rmonic injection-locking. The synthesizer features a cross-coup led quadrature digitally-con- trolled oscillator, that is injection-locked to a sub-harmonic frequency. An intuitive closed-form expression for the dynamic s of the quadrature injection-loc ked oscillator and a technique to achieve fast frequency-hopping, are presented. The overall architecture, based on this technique, is a CMOS-only imple- mentation and has been fabricated in a 0.13- m SiGe BiCMOS process. On-chip mixers have been implemented to measure the quadrature accuracy of the outputs. Measurement resu lts indicate lock-times of less than 2.5 ns, a locked phase noise of 114 dBc/Hz at 1 MHz offset and a quadrature accuracy of better than 0.5 . The frequency synthesizer (excluding output buffe rs) occupies an area of 0.27 mm and consumes 14.5 mW of power. The best and worst case spur suppression achieved are 47 and 31 dB, respectively. This is the lowest power fast-hopp ing quadrature frequency synthesizer that has been reported to date.