A 5–13 GHz 6-bit vector-sum phase shifter with +3.5 dBm IP1dB in 0.25-μm SiGe BiCMOS

This paper presents a wideband vector-sum phase shifter (VSPS) with high phase resolution and high input-referered 1 dB compression point (IP1dB) which covers the full 360° phase range with 5.6° phase steps between 5-13 GHz in a commercial 0.25-μm SiGe BiCMOS technology. A transformer balun and an RC polyphase filter (PPF) are implemented for in-phase and quadrature phase (I/Q) reference vector generation while the desired phase states are generated by an adder stage where the amplitudes of the I/Q reference vectors are manipulated with digitally controlled variable gain amplifiers (VGAs). The measured root mean square (RMS) phase error of the VSPS is <;2.8° between 7.4-10.3 GHz and <;5.6° between 5.4-11.9 GHz with a measured average insertion loss >7.8 dB. Thus, the VSPS achieves 6-bit phase resolution. IP1dB for the 1^st state of the VSPS at 10 GHz is measured to be +3.5 dBm. Overall chip size of the VSPS IC is only 1.22×0.59 = 0.71 mm², excluding the RF and the DC pads.