A 50MHz ~ 10GHz, 3.3dB NF, +6dBm IIP3 resistive feedback common source amplifier for cognitive radio application

Cognitive radio is a smart ultra-wideband wireless communication system that is capable of optimizing the usage of the available frequency spectrum. In this work, an ultra-wideband low noise amplifier with an operating bandwidth from 50 MHz to 10 GHz with integrated resistive feedback and π-matching network is presented. The amplifier is designed to self-bias via the feedback path to optimize the chip area consumption. The input signal is sourced to two common-source amplifiers to achieve the input matching configuration and subsequently cascaded to another common source amplifier with resistive termination in achieving the output matching. On-chip inductors were adapted to improve the high frequency response and to extend the bandwidth up to 10 GHz. Measured results show that the input and output matching are better than −10 dB with a gain variation of 10.32–13.28 dB, noise figure variation of 3.29–6 dB, and a third order intercept point ranging from −3.2 to +6 dBm in a frequency span of 50–10 GHz on a CMOS 0.13 µm platform. The physical layout occupies 0.77 mm2 chip area with the bondpads intact and consumes 31.2 mW of DC power from 1.2 V DC supply headroom.