[Show abstract][Hide abstract] ABSTRACT: This paper describes a 2.5G cellular transceiver with standard DigRF interface, implemented in a low-cost 0.13mum CMOS process. This is the first CMOS single-chip, polar closed-loop transmitter, excluding the power amplifier (PA). This transmitter achieves an efficiency of 26% in EDGE mode by linearizing a saturated PA in a closed-loop feedback system. This is much higher than the typical 15-to-18% efficiency of systems using a linear PA. Typical high-band/low-band performance of -62/-64Bc in 30 kHz for 400 kHz offset spectral mask and 1.4/1.7% EVM in EDGE mode are significantly better than those reported earlier. Using a low-noise quadrature mixer topology, the receiver, including T/R switch and SAW filters, achieves a sensitivity of -110 dBm. The RF solution, consisting of PAs in a multi-chip integrated antenna switch module, SAW filters with integrated matching components and the transceiver is the smallest form factor available in the market today.
[Show abstract][Hide abstract] ABSTRACT: There has been an increased demand for 3G cell phones that support multiple bands of operation and are backward compatible with the 2G/2.5G standard to provide coverage where 3G networks have not yet been fully deployed. The transceiver design for such a handset becomes complicated with the need for separate transceivers for 3G and 2G/2.5G or for multiple inter-stage receive / transmit SAW filters. A single-chip transceiver that operates as a multimode multiband radio and eliminates the inter-stage receive/transmit SAW filters is presented. The transceiver has 7 primary and 4 diversity bands in WCDMA, and quad band in GSM. The transceiver is designed to operate in any of the UTRA bands 1 to 10, with the exception of band 7. It supports HSDPA (Cat 1-12), HSUPA (Cat 1-6), EGPRS (Classes 1-12, 30-39), and compressed mode of EGPRS / WCDMA operation. The transceiver is compliant with 3G DigRF interface 3.09.