Design of low noise and linear wideband CMOS transconductor for SAWless multi-standard mobile TV applications

Abstract

In this dissertation, a design of a wideband low noise transconductor for multistandard mobile TV system is presented. In mobile TV standards, the most dominant standards are DMB(Korea), DVB-H(Europe) and ISDB-T(Japan). Since the mobile terminal should provide interoperability with the European GSM band at 900MHz, which is very close to our mobile TV bands (170M~702MHz), a proper rejection is required to prevent from the severe linearity deterioration. With the help of off-chip notch filter at the input of the LNA and the Q-enhanced on-chip notch filter, the GSM band can be suppressed without external SAW filter. A direct-conversion architecture is adopted for its low cost and high integration characteristic which makes it more suitable for mobile applications. The proposed wideband low noise transconductor can possibly drive Multi-Tap Direct Sampling Mixer (MTDSM) in the spirit of being more digital where programmability can be added. The proposed low noise transconductor achieves wideband matching, NF of under 2.5dB and IIP3 of 0.5dBm.