CMOS Tunable Channel-selection LNA Employing Active Feedback Technique and Gain-boosted N-path Bandpass Filter for Advanced Cellular Applications

In this paper, a CMOS tunable channel-selection low-noise amplifier (LNA) that employs an active feedback technique and gain-boosted N-path bandpass filter (BPF) is presented for advanced cellular applications. The proposed LNA achieves broadband input power matching and low noise figure (NF) performance by using the active feedback technique. The gain-boosted N-path BPF is also used to implement a high-Q RF fourth-order bandpass filtering. Simulated in a 65-㎚ CMOS process, the proposed LNA achieves a maximum voltage gain of 17 ㏈, minimum NF of 2.16 ㏈, maximum out-of-band blocker rejection ratio of 21 ㏈ at 80 ㎒ offset frequency. The center-frequency tuning range of the LNA is 0.1 ‒ 4 ㎓, which includes all FDD bands in the 3G/4G/5G sub-6 ㎓ cellular standards. It draws a DC bias current of 21 ㎃ from a supply voltage of 1.2 V. The active die area is 0.8 ㎟.