Broadband High-SFDR Digital-IF Module for 5G Millimeter-wave Transmitters

A digital intermediate frequency (IF) transmitter module boasting a large bandwidth and high spurious-free dynamic range (SFDR) has been conceived and implemented. The transmitter module is equipped with dual independent output channels, and employs a direct radio frequency (RF) architecture to circumvent the issues associated with image rejection, local oscillator leakage, DC offset, and I/Q mismatch that are encountered with low-IF and zero-IF architectures. The integrated phase noise of the clock signal utilized in the module is less than -65 dBc/Hz. Additionally, the transmitter features spurious rejection exceeding 70 dBc for single-tone output, and output flatness superior to ±1 dB within 400MHz bandwidth. Moreover, the transmitter showcases an error vector magnitude (EVM) of less than 1% for single-carrier quadrature amplitude modulation (QAM-16) signals. The transmitter module is designed to serve as an IF constituent part in massive multiple-input multiple-output (MIMO) array systems operating in the millimeter-wave (mm-wave) band.