Concurrent Dual-Band Low Noise Amplifier for 802.11a/g WLAN applications

A concurrent dual-band low noise amplifier (LNA) for the 802.11a/g WLAN applications is presented. The circuit is designed in standard SiGe BiCMOS process from STMicroelectronics. The LNA circuit is a cascade topology with inductively degeneration transistor. A new input impedance matching network based on monolithic transformers was proposed to overcome to the problem of dual-band matching without degrading the noise performance and power delivery. The dual-band LNA provides a narrow band gain of 18.3 dB and 15.2 dB at 2.45 GHz and 5.5 GHz, simultaneously. It achieves input returns losses of -24 dB and -28 dB, a noise figure of 2.26 dB and 3.2 dB at these two bands, respectively. The LNA consumes 12 mW from a single 2 V supply.