Time-domain front-end for short time windowing UWB WLAN transform-domain receiver

This paper addresses the selectivity problem, for the ultra-wide band (UWB), transform-domain receiver loss of orthogonality. A novel selective time-domain direct-sequence front-end for transform-domain ultra-wideband (UWB) wireless local area network (WLAN) receiver is proposed. The architecture comprises a multi-block, linear, dynamic feedback low-noise amplifier (LNA), quadrature mixer, and baseband filter. The dynamic feedback with inductive output load reduces the LNA to a simple second-order filter, with zero at the origin, while improving the conversion gain (CG) and noise figure (NF). Thus, the CG is further maximized when limiting the two poles within the 5-6 GHz frequency band. The mixer, based on a merged quadrature topology, employs single-peak notch network, with benefits to the NF and IIP3 of CG at 5.6 GHz. The front-end dissipates a 19.6 mW from 1.8 V supply voltage and achieves at 5.6 GHz 34.8 dB conversion gain, 6.42 dB NF, and 1-dB gain desensitization with -8 dBm interferer power at 7 GHz. Other simulation results are -2.35 dBm minimum IIIP3, and -35 dBc rejection at the UWB group #3.