60 GHz 7-Bit Passive Vector-Sum Phase Shifter With an X-Type Attenuator

Abstract

This brief presents the design of a 60 GHz passive vector-sum phase shifter with 7-bit phase resolution. An analog X-type attenuator with complementary voltage control was used for vector modulation. The proposed attenuator is suitable for high-resolution phase shifter design because it is capable of phase inversion and shows a large attenuation range with low phase variation. The prototype phase shifter fabricated through the 65 nm CMOS process occupies an area of 0.24 mm(2) (excluding the bonding pads). The measurement results show that the proposed phase shifter achieves a phase resolution of 2.815 degrees while exhibiting an average insertion loss of 14 dB without DC power consumption. The calculated RMS gain and phase error were below 0.55 dB and 0.83-2.36 degrees, respectively, in the range of 57-67 GHz.