A 2.4-GHz Front-end System Design for WLAN Applications using 0.35μm SiGe BiCMOS Technology

A 2.4GHz front-end system design for wide spectrum WLAN applications is presented in a 0.35 mu m SiGe BiCMOS Technology. This transceiver front-end contains a receive (Rx) chain with a two-stage cascode low noise amplifier (LNA) and an active down-conversion Rx mixer, and a transmit (Tx) chain composed of a Gilbert-Cell core up-conversion Tx mixer and a high-gain Driver Amplifier (DA). The high linear LNA shows a gain of 15.5 dB, an noise figure (NF) of 2.28 dB and an input-referred third-order intercept point (IP3) of +2.4 dBm with l-dB gain bandwidth (BW) of 1.5 GHz. The single-balanced Rx mixer exhibited a gain and l-dB gain BW of +6.8 dB and 1.5 GHz. Also a double-balanced Tx mixer with a gain and input/output return loss of -1.3dB and below -35dB, respectively, and a DA with a gain and output-referred IP3 of +29.2dB and +21.2dBm, respectively, is developed. The NF, input-referred IP3 and DC power consumption of Rx string (from antenna to Rx mixer) were achieved 4.4 dB, -15.4 dBm and 30mW respectively. The output-referred IP3 and power consumption of Tx chain were +20.5 dBm and 125mW, respectively.