24 GHz LNA and vector modulator phase shifter for phased-array receiver in CMOS technology

With the rapid development of the applications in short range communication, phased-array receiver working at 24 GHz can provide enhanced gain performance at desired transmission direction. Also there is the wide signal bandwidth, i.e. 250 MHz free licensed spectrum at this frequency. In the phased-array front-end, the key component is the phase shifter, which decides the tuning resolution of beam-forming. The challenge of the design work comes from the low-power, low-noise and low-cost requirement. This paper explores the design procedure of a Vector Modulation Phase Shifter (VMPS), consisting of a 90° hybrid, a variable gain amplifier and the Wilkinson combiner. The variable gain amplifier is fabricated in 90nm complementary metal-oxide-semiconductor technology, and the passive hybrid and the Wilkinson combiner are designed on the printed circuit board with RO4003 substrate. After combining the measurement results of each block, the VMPS shows 45° phase shifts with 7° phase error, and 9 mW consumption.