Double-Gilbert mixer with enhanced linearity in 65 nm low-power CMOS technology

An innovative double-Gilbert-type down-conversion mixer is presented. It is designed and fabricated in a 65 nm low-power digital CMOS process. The mixer is based on the simple Gilbert-type mixer and utilizes a second mixer as active load. A second parallel mixer branch with switchable RC elements enables a high gain or a high linearity setting. A high 3rd-order input referred intercept point of +11.1 dBm is measured at a clock frequency of 1.5 GHz. A maximum conversion gain of 10.9 dB is achieved. A total power consumption of 6.0 mW from a 1.2 V supply is measured at the high-gain setting.