Daniel B. Schwartz

Single-Chip Multiband EGPRS and SAW-Less LTE WCDMA CMOS Receiver With Diversity

A single-chip multimode multiband receiver is designed and implemented in a 90-nm CMOS process for fourth-generation mobile platforms. The receiver includes nine primary low-noise amplifier (LNA) and five secondary LNA input ports, and supports long-term evolution (LTE)/WCDMA/ehanced general packet radio serve (EGPRS) standards for four gobal system for mobile communications bands, ten WCDMA bands, 14 frequency division duplex LTE band, and two time division duplex LTE bands. From antenna to RX digital signal processing output, the receiver achieves a typical 3-dB noise figure for all standards and bands. The RF front-end includes a matching network with 12-dB transducer gain, an inductively degenerated common-source LNA, passive mixers driven by a 25% duty-cycle local oscillate, and a current conveyor followed by a baseband filter. This receiver RF/analog front-end meets surface-acoustic-wave-less linearity requirements for all LTE/WCDMA bands and employs digital calibration to adjust the baseband low-pass filter cutoff frequency, mixer image rejection, second-order intermodulation intercept point performance and to perform in-phase/quadrature equalization.

A SAW-less CMOS TX for EGPRS and WCDMA

A 90 nm CMOS TX path architected for operation without inter-stage SAW filters is shown. The SAW elimination strategy is purely low noise design but the architecture still achieves DG.09 weighted TX current drain of 50 mA from the battery. The combination of a passive interleaved switching mixer plus digital gain control allows 2% EVM at 2 dbm and 4.2% at −78 dbm.

Single-chip multi-band SAW-less LTE WCDMA and EGPRS CMOS receiver with diversity

A single-chip multi-mode multi-band saw-less 90nm CMOS receiver is designed and implemented for 4G mobile platform. It supports LTE/WCDMA/EGPRS standards and supports 4 GSM bands (GSM850, EGSM900, DCS1800, PCS1900), WCDMA (Bands I, II, III, IV, V, VI, VIII, IX, X and XI) and LTE (FDD Bands 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 17 and TDD bands 38 or 40). The receiver achieves a typical 3dB and maximum 4dB noise figure (NF) in all standards and bands. By using inductive source degeneration LNA architecture with 24dB passive matching voltage gain, the receiver radio frequency (RF)/analog front-end meets noise and linearity requirements for all modes and all bands with small power consumption. For example, the whole main receiver RF and analog blocks in band1 LTE 20MHz mode operate at 1.8V supply and draw total only 24mA current at maximum TX output power condition. It also automatically calibrates baseband low-pass filter cut-off frequency, mixer image rejection and IIP2 performance.

Multi-mode cellular transceivers for LTE and LTE-Advanced.

This paper presents some of the challenges unique to a multi-mode transceiver supporting LTE and LTE-Advanced. Implications of combining 2G, 3G and 4G in a single lineup are discussed. RF problems specific to 4G support are discussed and technical examples are given. Specific technical solutions are provided for duplex offset IIP2 in the receiver using calibration. Multiple transmit solutions are shown for the counter intermodulation issue resulting from the inherent single sideband transmit problem caused by low RB count signaling.