7 bit phase shifter using SiGe BiCMOS technology for X band phased array applications
Phase array T/R modules achieve high performance with III V technologies. However, the cost of III V technologies is high. Recent developments in SiGe BiCMOS technology show us that III V technology can be replaced with SiGe BiCMOS. Moreover, thanks to the integration of the CMOS, digitally controlled T/R modules can be realized with that technology. Power dissipation, area, and integration complexity can be reduced with SiGe BiCMOS technology. Also, the number of radiating elements and the cost of T/R module can be reduced with phase shifters with high phase resolution. In the light of these trends, this thesis presents a 7 bit low insertion loss SiGe X band (8 12 GHz) passive phase shifter, realized in IHP 0.25 m SiGe BiCMOS process. The phase shifter is based on high pass/low pass lter topology with a new proposed switching technique. This technique decreases the number of series switch by dividing each phase into 4 arms instead of two arms. Also, in this technique, instead of using two single pole switches consecutively, multiple pole switches are realized. Thanks to the IHP SiGe BiCMOS technology, isolated NMOSs are used which improve insertion loss of the phase shifter. The overall phase shifter is composed of BALUN, SP4T, DP4T, 4P4Ts, and phase blocks to create a phase shift for achieving 7 bit phase resolution. The return loss of each state is better than 10 dB and the phase shifter has an average of 14.5 dB insertion loss. Minimum 1 RMS phase error is obtained at 10 GHz. RMS phase error is better than 6 at 9 11 GHz band. The phase shifter occupies an area of 6 mm2 and it has no DC power consumption. The thesis also summarizes the work that was contributed as part of the complete TR Module generation. These include active and passive gain equalizers that are utilized in the Module to generate desired slope in the receiver transmitter chain.