A 5-13 GHz 6-Bit vector-sum phase shifter with+3.5 dBm IP1dB in 0.25-mu m 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 degrees phase range with 5.6 degrees phase steps between 5-13 GHz in a commercial 0.25-mu m SiGe BiCMOS technology. A transformer balun and an RC polyphase filter (PPF) are implemented for inphase 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 7.8 dB. Thus, the VSPS achieves 6-bit phase resolution. IP1dB for the 1st state of the VSPS at 10 GHz is measured to be +3.5 dBm. Overall chip size of the VSPS IC is only 1.22x0.59 = 0.71 mm(2), excluding the RF and the DC pads