An x-band 6-bit active phase shifter

Official URL: http://dx.doi.org/10.1109/SiRF.2014.6828527

This paper presents a 6-bit active phase shifter using a new vector-sum method for X-band (8-12 GHz) phased arrays in 0.13 mu m SiGe BiCMOS process. An RC filter is used to generate two orthogonal vectors which are then fed into four VGAs, two using the common-base and two using the common-emitter topology. This generates 4 vectors of 0 degrees, 90 degrees, 180 degrees and 270 degrees which are scaled and added by varying the gains of the VGAs to generate any phase between 0-360 degrees. The gains of the VGAs are adjusted with analog voltage control using the current-steering method. The outputs of the VGAs are connected together with a common load in order to add the vectors in current-domain. The phase shifter achieves < 5.6 degrees RMS phase error over 8-12 GHz and < 3.1 degrees RMS phase error over 9-11 GHz. The phase shifter has a power consumption of 16.6 mW from a 2V supply. The chip size is 850 mu m x 532 mu m including the probing pads. These performance parameters are comparable with the state of the art of the technology in literature.