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

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° 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°, respectively, in the range of 57–67 GHz.