A new 5-GHz ISM band CMOS doubly balanced sub harmonic mixer for direct conversion receiver

A new higb IIP2 low power doubly balanced subharmonic mixer for 5 GHz Industrial Scientific Medical (ISM) band direct conversion - zero IF receiver io an inexpensive 0.25-pm CMOS is presented. The sub-harmonic mixer, designed and fabricated, uses a power effcient IBX LO frequency generation scheme to overcome LO selfmixing problem common in conventional direct conversion receivers OCR). Simulated with 1% g, mismatch, 0.5% load mismatch and 2' LO phase error the mixer is able to achieve very good IIP2 of 55.3 dBm, IIP, of -6.5 dBm, and voltage conversion gain of 8 dB while consuming less than 1.75 mA from a single 3V supply. The mixer also achieves input compression, Plde of -12 dBm and an overall double side baud noise figure of 5.96 dB. The proposed mixer takes up less than lmm' of silicon real estate including die pads. The performance of the designed and fabricated mixer is believed to have the best FOM (Figure of Merit) when considering IIP2, lIP3, PldB, DSB NF, power consumption and gain performance parameter in 5 GHz ISM frequency band.