Design and implementation of a 16-channel amplitude tunable two-tone digital phase shifter

In this paper, an amplitude tunable two-tone digital phase shifter is designed, fabricated, and measured. This phase shifter has 16 channels and every channel is able to output arbitrary amplitude below 0 dBm and arbitrary phase among 360°. The two-tone output frequencies are 810 MHz and 4.5 GHz which are possibly used in 5G as phase changeable local oscillator (LO) frequency for up conversion to practical wireless communication frequency. High resolution (14 bits over 360° and 10 bits for amplitude), low phase noise, low spurious and convenient switch by program are achieved based on direct digital synthesis (DDS) technology. System architecture, channel element design and synchronization method are presented in this paper. The measured phase noise is −126.18 dBc/Hz@100KHz at 810 MHz and −128.10 dBc/Hz@100Khz at 4.51 GHz. The variance of phase is 1.2°in 64 times average.