2-bit $X$-Band Reflective Waveguide Phase Shifter With BCB-Based Bias Circuits

The design and performance of a 2-bit p-i-n diode reflective <formula> <tex>$X$</tex></formula>-band phase shifter are described. This phase shifter uses the spiraphase principle of phase changing. Benzocyclobutene-based bias circuits are used to decrease the insertion loss level and to reduce the fabrication costs. It has been proven that the phase shifter demonstrates insertion loss better than 0.5 dB in the frequency band from 9.75 to 11.5 GHz for all four phase states. The phase shifter is characterized by maximum phase errors of 11<formula formulatype="inline"> <tex>$^{\circ}$</tex></formula> in the frequency band from 9.75 to 11.25 GHz. The measured switching time of the phase shifter is less than 150 ns.