20.7 A multi-band inductor-less SAW-less 2G/3G-TD-SCDMA cellular receiver in 40nm CMOS

The growing demand for high-speed wireless communication has driven the evolution of cellular phone networks. New-generation cellular standards use wider channel bandwidth and more sophisticated modulation to obtain higher data-rates. Due to various cellular standards, chip providers are required to offer highly integrated solutions that support 2G, 3G, and even 4G in one chip. This paper presents a receiver supporting 2G quad bands and 3G TD-SCDMA dual bands. Figure 20.7.1 shows the 2G/3G receiver, whose front-end current-mode outputs are combined at baseband CR filter and biquad PGA, which are shared between all bands. A dynamic gain-bandwidth-product-extension circuit technique is used to remove a transimpedance amplifier to save die area and current.