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, P_ldB, DSB NF, power consumption and gain performance parameter in 5 GHz ISM frequency band.