A Highly-Integrated 3–8 GHz Ultra-Wideband RF Transmitter With Digital-Assisted Carrier Leakage Calibration and Automatic Transmit Power Control

Abstract

This paper presents a highly-integrated 3-8 GHz ultra-wideband (UWB) RF transmitter implemented in a 1.2 V 0.13m CMOS technology. The transmitter integrates an analog baseband (PGAs and filter), an IQ modulator, a variable gain amplifier (VGA), a differential-to-single-ended amplifier, a power amplifier, as well as a transmitted signal strength indicator (TSSI). The RF VGA and the TSSI cooperate to perform an automatic transmit power control. The IQ modulator and an off-chip digital circuit implemented by a FPGA perform a carrier leakage calibration. Measured maximum output power and OP1 dB are -5 and +1.5 dBm, respectively. Measured worst carrier leakage suppression is 21 dB (before calibration) at 6.6 GHz. Measured worst sideband suppression is 29.1 dB at 7.6 GHz. The high linearity and accurate IQ modulation lead to an error vector magnitude (EVM) of -28 dB under the data rate of 480 Mb/s in WiMedia Mode 1. The entire transmitter consumes 66 mW under supply voltage of 1.2 V.