A novel topology of SiGe phase shifters using vector sum method with ultra-low power consumption for 5GHz applications

Abstract

A new type of an active phase shifter is proposed using a vector sum method that utilizes a cascode low-noise amplifier (LNA) circuit as a variable gain amplifier (VGA). The proposed configuration was designed and implemented using a Wilkinson power combiner/divider, a branch-line 3 dB quadrature hybrid coupler and variable gain amplifiers (VGAs) with 90° phase control and around 50-dB gain control. At 5 GHz, the module has a maximum gain of 6.8 dB. The chip is very small, operates with low voltage supplies, and is designed for wireless local area network applications and is fabricated using a commercial 0.35 μm SiGe HBT process.