An ultra-wideband 15–35 GHz phase-shifter for beamforming applications

An ultra-wideband Ku-, K- and Ka-band phase-shifter for beamforming applications is presented in this paper. A novel inductive load single ended input poly-phase filter is used for high I/Q accuracy quadrature generation. Sign-selection and vector addition is performed in two stages to lower supply voltage. The proposed phase-shifter is fabricated in 0.18 μm SiGe BiCMOS process and occupies an area of 520μm×370μm.The rms gain error is less than 2.2 dB and rms phase error is less than 12 ° over 15-35 GHz. The phase-shifter thus achieves a full 360 ° phase-shift range with 22.5 ° phase resolution. The total power consumption is 14 mA from a 1.8 V power supply. The phase shifter achieves an input P1dB of -6.25 dBm. The measured phase-shifting fractional bandwidth of 87% is the highest reported so far in literature for a SiGe BiCMOS implementation.