No abstract

In this paper, a two-stage concurrent dual-band low noise amplifier (DB-LNA) operating at 2.4/5.2-GHz is presented for Wireless Local Area Network (WLAN) applications. The current-reused structure using resistive shunt-shunt feedback is employed to reduce power dissipation and achieve a wide frequency band from low frequency to-5.5-GHz in the inverter-based LNA. The second inverter-based stage is employed to increase the gain and obtain a flat gain over the frequency band. An LC network is also inserted at the proposed circuit output to shape the dual-band frequency response. The proposed concurrent DB-LNA is designed for RF-TSMC 0.18-μm CMOS technology, which consumes 10.8 mW from a power supply of 1.5 V. The simulation results show that the proposed DB-LNA achieves a direct power gain (S 21) of 13.7/14.1 dB, a noise figure (NF) of 4.2/4.6 dB, and an input return loss (S 11) of −12.9/−14.6 dBm at the 2.4/5.2-GHz bands.

Design of high-efficiency visible-spectrum silicon nitride grating couplers, compatible with CMOS fabrication are proposed. The design is based on amorphous-silicon overlay and distributed-Bragg-reflectors. We simulated 74% and 79% efficiency for 638 nm and 780 nm.