A saw-less receiver front-end employing body-effect control iip2 calibration

초록

An IM2 product cancellation technique that employs a body-effect control of transistors is presented by developing a design for low-cost and high-linearity receiver front-end in LTE/WCDMA applications. To accomplish a high IIP2 for strong out-of-band blockers, the body terminal voltage of the mixer switches is properly adjusted to provide intentional asymmetry and suppress the IM2 at the mixer output. Without the usage of inter-stage SAW filters, an out-of-band IIP2 of better than +60 dBm is consistently attained under different operating frequencies and channel bandwidths by applying this technique. Only 5-bits DAC calibration codes are utilized. The receiver front-end is implemented in a 65-nm CMOS technology and achieves out-of-band IIP3s of 3 dBm, 3.9 dBm and 5.4 dBm; in-band IIP3s of -8.4 dBm, -9.2 dBm and -10.5 dBm out-of-band P1dBs of -24 dBm, -22 dBm and -21 dBm peak gains of 42.5 dB, 41 dB and 42.2 dB and double side-band noise figures of 2.3 dB, 2.7 dB and 2.4 dB for Band 2 (LTE), Band 7 (LTE) and Band 1 (WCDMA), respectively. It operates at a nominal supply voltage of 1.2 V with bias currents of 15.1 mA, 17 mA and 14.2 mA, respectively. The active die area is 1.45mm2. © 2014 IEEE.

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