Circuit and system design for fully integrated CMOS direct-conversion multi-band OFDM ultra-wideband receivers.

摘要

Ultra-WideBand (UWB) technologies are widely accepted as the center piece of ubiquitous wireless interconnects for next generation Wireless Personal Area Networks (WPAN). It finds potential exciting applications in high-connectivity and high-interoperability multimedia consumer products within personal operating space, such as wireless home video distributions systems, and high-speed, high-mobility cable replacement solutions, such as Wireless Universal Serial Bus (W-USB) and wireless IEEE-1394 Firewire. Many active academic and industrial works have been dedicated to the implementation of UWB transceivers, however, a monolithic UWB radio expanding across full 3.1--10.6 GHz UWB spectrum is yet to be accomplished.; Targeting Multi-Band Orthogonal Frequency Division Multiplexing (MB-OFDM) UWB, one of the two major competing industrial UWB standards, this dissertation focuses on system and circuit co-design of a fully integrated CMOS direct-conversion transceiver, with emphasis on architectural issue, frequency planning, and circuit topologies of its RF front-end and frequency synthesizer.; This dissertation extends prior wireless channel analysis on three mandatory frequency bands to full UWB spectrum, and derives general system parameters including sensitivity, system gain, noise figure, IIP3, IIP 2, local oscillator (LO) phase noise, and spurious tone rejections for UWB receivers. Subsequent receiver budget analysis leads to the specifications of each individual functional block along the analog signal receiving chain.; Based upon system-level design, two different RF front-end architectures are implemented using a 0.18-microm 1P6M CMOS technology. The first front-end consists of a single-ended common-gate low-noise amplifier (LNA) with tunable LC-tank load and a class-AB downconversion mixer with an embedded balanced-unbalanced converter (balun). In the second one, a classical inductively-degenerated common-source differential LNA with a bandwidth-expanding feedback loop is followed by a current-injected double-balanced mixer stage. The two structures clearly reflect the trade-offs in UWB RF front-end design.; A novel ""two-step"" frequency generation scheme and its associated frequency synthesizer architecture are also proposed in this dissertation. This scheme can provide all MB-OFDM UWB bands with only two frequency mixing steps. Analysis on its phase noise and parasitic frequency spur performance justifies its effectiveness.