A 6.3–6.8GHz LNA with noise cancelling and adjacent channel rejection for wideband mobile communication

Abstract

This paper discusses a 6.3-6.8GHz single-ended-to-differential LNA with noise-cancelling and adjacent channel rejection for wideband mobile communication. Different from traditional noise-cancelling LNA, this circuit includes local feedback, current reuse and considering bond-wire effect. Besides, this design utilizes a couple of differential-to-single buffers to reduce the mismatch of the differential signal output from single-ended-to-differential LNA. Bond-wire inductance and ESD is inevitable for the chip, but they usually bring about some negative effects. However bond-wire inductance can also be used for impedance matching and acting as current-source. To boost the LNA performance, the layout should be optimized to minimize the device and interconnection parasitic effects. Fabricated in a TSMC 0.13μm RF CMOS process, the LNA achieves a gain of 25dB and a NF of 2.0 dB over the band. It consumes 7.8mA from 1.2V supply and occupies an area of 0.5mm2.