Phase Control Block for high phase-shift precision and beam tuning resolution microwaves phase shifter

A 10-bits Phase Control Block (PCB) in 0.35 μm SiGe technology for active phased arrays is presented. The proposed PCB has been used instead of a DDS in an advanced DDS-PLLs microwaves phase shifter. The PCB is composed by a counter and a set of comparators. The clock frequency is 2GHz and the PCB output frequency is 1.953MHz. The block generates 1024 phase-shift values, each one corresponding to a given phase word. A DSP or a microcontroller can be used to set the desiderated phase values. Each block is designed in ECL logic with a 3.3V supply voltage. The phase shifted outputs of the PCB are used by the PLLs as references signals. The phase shifter output frequency is 2.4GHz. As expected from the theory, the rms phase error is less than 0.1° compatible with the 10-bits PCB resolution confirming the validity of the proposed solution.