Novel analysis and optimization of gm-boosted common-gate UWB LNA

Abstract

This paper focuses on the design optimization of gm-boosted common gate (CG) CMOS low-noise amplifier (LNA) for ultra-wideband (UWB) wireless technology. In this regard, a detailed novel analysis of the UWB gm-boosted CG amplifier topology is presented, which includes the finite gds (=1/reds) effects. For UWB systems, signal-to-noise ratio (SNR) can be defined as the matched filter bound (MFB). Using this definition, the noise performance of the UWB CG LNA in the presence of the gm-boosting gain and the input noise-matching network are analyzed. It is found that the optimal noise factor of the UWB LNA collapses to the published narrowband gm-boosted CG LNA noise factor when an assumption of narrowband is applied. It is also proved that the noise performance of the gm-boosted UWB CG LNA is independent of the bandwidth of the input UWB signal. A new technique is presented for the design of optimal noise-matching network using passive components at the input of the UWB CG LNA. In this regard, role of the gm-boosting stage and its effect on the SNR and the gain of the overall system are analyzed, and, in addition, its non-idealities are simulated in detail.