An X-Band 5 Bit Phase Shifter With Low Insertion Loss in 0.18 $\mu{\rm m}$ SOI Technology

This letter presents a 5 b phase shifter using a commercial 0.18 <formula formulatype="inline"><tex Notation="TeX">$\mu{\rm m}$</tex></formula> SOI process for X-band phased array antenna. The phase coverage of 360<formula formulatype="inline"><tex Notation="TeX">$^{\circ}$</tex></formula> with the LSB of 11.25<formula formulatype="inline"><tex Notation="TeX">$^{\circ}$</tex> </formula> is achieved at 8–12 GHz. The RMS phase error and amplitude variation are less than 6.5<formula formulatype="inline"><tex Notation="TeX">$^{\circ}$</tex> </formula> and 0.5 dB, respectively. The measured insertion loss is less than 10.8 dB, and the input and output return losses are over 12 dB at 8–12 GHz. The current consumption is nearly zero with 1.8 V supply. The chip size is <formula formulatype="inline"><tex Notation="TeX">$1.14\times 0.78\ {\rm mm}^{2}$</tex></formula> excluding pads. To the authors' knowledge, this is the first demonstration of X-band phase shifter using a commercial SOI technology.