A SAW-Less First Folded-Conversion Second Down-Conversion Receiver for Multistandard Broadcasting Radio Applications

Abstract

A surface-acoustic-wave-less first folded-conversion and second down-conversion receiver for the AM/FM/digital radio mondiale (DRM)/digital audio broadcasting (DAB) radio standards is presented. This architecture is more suitable for broadcasting radio with ultra-narrow signal bandwidth since it relaxes the requirement on the local area (LO) generator by decreasing its tuning range. To reduce the blockers and out-of-band (OB) interferers, current amplifying and polyphase filters are introduced simultaneously. An inverter-based switched capacitor array technique is proposed in voltage-controlled oscillator (VCO) design to isolate the noise from the substrate. With a single VCO, the receiver can cover the frequency range from 100 kHz to 1.5 GHz. Without the RF pre-filters, the in-band ${\rm IIP}_{3}$ is 1.5 dBm, and the OB ${\rm IIP}_{3}$ is up to 17.4 dBm. The LO phase noise in the worst case is $-$ 119 dBc/Hz@1 MHz. The chip is fabricated in a 0.18- $\mu{\hbox{m}}$ CMOS technology, and mounted on a QFN package. It consumes only 86.4 mW under 1.8-V supply. To our best knowledge, this is first receiver reported thus far that supports all four AM/FM/DRM/DAB standards.