Semi-digital FIR DAC for low power single carrier IEEE 802.11ad 60GHz transmitter

Abstract

IEEE 802.11ad (WiGig) is an emerging multi-Gb/s wireless standard in the unlicensed 60GHz spectrum. This work presents system level validation of a Single Carrier (SC), QPSK modulated WiGig transmitter based on a semi-digital Finite Impulse Response (FIR) Digital-to-Analog Converter (DAC). The 1.76GS/s complex baseband input signal is upsampled by two to a clock frequency of 3.52GHz. In order to introduce channel shaping and meet the standard requirements, the structure implements a 16th-order direct-form Root-Raised Cosine (RRC) FIR filter. Transmit mask and EVM requirements are met with a large margin while allowing a 14% random mismatches on the current sources implementing the FIR DAC coefficients.