A fully integrated 2×1 dual-band direct-conversion transceiver with dual-mode fractional divider and noise-shaping TIA for mobile WiMAX SoC in 65nm CMOS

Abstract

Mobile WiMAX complying with the IEEE 802.16e standard is one of the emerging standards and is achieving world-wide penetration. Low-cost implementation is essential and single-chip implementation is a straightforward approach. However, there are many technical challenges such as floor-planning, signal integrity and scalability of analog/RF circuits in an SoC, as well as power reduction in scaled CMOS technologies. In this work, we have designed and fabricated a fully-integrated 2RX × 1TX dual-band direct-conversion transceiver having digital interfaces for a mWiMAX SoC in a 65nm pure CMOS technology. To cope with the constraints of floor-planning while maintaining the signal integrity, inductorless local oscillator (LO) distribution using compact dual-mode fractional dividers is introduced, leading to the reduction of die area. Total noise figure of 3.8dB is achieved by a novel noise-shaping transimpedance amplifier to mitigate the flicker noise of a scaled CMOS device.