Abstract:
This paper presents a wide signal bandwidth Cartesian loop transmitter (CLT) IC for off-chip PA linearization. The CLT can linearize a 10 MHz bandwidth signal by using a ...Show MoreMetadata
Abstract:
This paper presents a wide signal bandwidth Cartesian loop transmitter (CLT) IC for off-chip PA linearization. The CLT can linearize a 10 MHz bandwidth signal by using a feedforward technique to avoid instability caused by a time delay of an RF path. The transmitter is fabricated in 0.13 m CMOS technology. ACLR is improved from 30.2 dB to 38.4 dB and EVM is improved from 5.9% to 1.6% by using the feedback loop when 10 MHz OFDM signal is applied. The fabricated IC also realizes automatic phase and amplitude calibration by using on-chip amplitude and phase difference detector and external controller and result storage. The controller and result storage are realized by the FPGA. The calibration can be finished in 14 sec.
Published in: IEEE Journal of Solid-State Circuits ( Volume: 45, Issue: 12, December 2010)