A quadrature LO-generator using an external single-ended clock receiver for dual-band WLAN applications

摘要

A low phase noise quadrature LO-generator for dual-band wireless local area network (WLAN) applications is presented. The quadrature LO-generator is composed of a clock receiver, a CML divider, and two quadrature dividers for the dual-band, respectively. A clock receiver converts the single-ended clock to a differential signal. Then a quadrature divider with a 25% duty cycle generates four quadrature signals for mixers. The split-grounded architecture and multiply ground pads decrease the inductive component of ground impedance as well as the ground bounce of the single-ended input. The phase noise is -143dBc/Hz and -149dBc/Hz at 1MHz offset in the 2.4-GHz and 5-GHz bands, respectively.