An interferer-tolerant receiver with active feedback for cognitive radio applications

A receiver architecture covering 54–864 MHz and suitable for tolerating large interferers is presented in 0.18 µm CMOS. It alleviates the problem of LO harmonics mixing with the aid of a heterodyne conversion, and by employing an active feedback, provides an IIP3 of better than +13.4 dBm, comparable with state-of-the-art. Noise canceling techniques are used to improve the NF of the receiver so that the receiver achieves NF of 8.6 and 18 dB in the absence, and presence of an interferer, as strong as 0 dBm, respectively.