A reconfigurable LNA with single switched input matching network for S-band (WiMAX/WLAN) applications

In this paper a reconfigurable Low Noise Amplifier (LNA) which works at 2.4 GHz and 3.5 GHz frequency bands is presented. In discrete approach for designing reconfigurable circuits the switch is an undeniable part. But the number of switches can make many problems such as amount of noise factor. Here, a LNA has been introduced which has only one switch and is designed with discrete tuning technique that can show good performance at mentioned frequencies. Besides, the input matching network uses a circuit that presents relatively fixed real part in input impedance, and therefore, input matching is satisfied. Using current reuse technique causes the overall gain is set in high amount. LNA is designed using 0.18μm CMOS technology and results of simulator express that its gain is 20.07dB and 21.08dB, s11s11 is –22.8dB and –28.86dB, s22s22 has −18.16dB and –27.37dB values, NF is 2.6dB and 3.1dB, and IP3 is equal to –2dBm and –2.1dBm in 2.4GHz and 3.5GHz, respectively. The proposed LNA consumes 11mA from a 1.8V supply voltage.