Improving the linearity of wideband receiver systems by component IM3 phasor manipulation

A linearity improvement technique for receiver systems is presented and verified on a 130nm CMOS high-IF upconverter with 470 –790MHz input and 2.4–2.6 GHz output frequency range, enabling WLAN and LTE transceivers to be used as TV White Space Devices. The upconverter reaches a stable IIP3 of 15 dBm, NF of 8 dB and Gain of 7 dB. A linearized LNA and mixer are used as a composite architecture to combine low NF with, even though, high IIP3. Instead of further maximizing the linearity of the components, the overall performance is optimized on the system level by manipulation and complementary exploitation of the remaining third order intermodulation products of the components.