IDTF1320NBGI

DPD Demodulator for PA Linearization GENERAL DESCRIPTION This document describes the specification for the IDTF1320 Digital Pre-Distortion Demodulator for PA linearization. This device is one of 2 variants to cover common UTRA bands. See the Part# Matrix below for details. COMPETITIVE ADVANTAGE In typical basestation transmitters a digital pre-distortion loop is employed to improve the Transmitter performance. The signal coming out of the PA is sampled so that the I&Q data at Baseband can be predistorted before being sent to the Tx DAC to counteract the distortion inherent in the downstream PA. The signal coupled from the PA is adjusted via a digital step attenuator to a lower level and then sub-sampled at an IF frequency of ~200 MHz which necessitates the need for a highly linear demodulator to downmix to quadrature IF from the Transmit frequency. By sampling IF_I and IF_Q independently and then digitally combining these signals, an effective doubling of the sample rate can be achieved. Any distortion in this path will degrade the performance of the DPD algorithm. By utilizing an ultra-linear demodulator w/integrated DSA such as the IDTF1320, the ACLR and/or power consumption of the full Tx system can be improved significantly.  DPD full path ACLR:  1 dB  Icc: DPD function Power Consumption  40%  Zero-DistortionTM Demod eliminates 2 IF amps  Integrates 2 BPFs, 2 Baluns, 2 SP2Ts  Glitch-FreeTM gain control Glitch-FreeTTMM PART# MATRIX Part# F1320 F1370 RF rang...