Wideband micromachined broadside coupled Schiffman phase shifter

A 15-45 GHz broadside coupled rectangular coaxial line based phase shifter is demonstrated. An analysis, the design, fabrication, measurements and a sensitivity study are conducted and discussed. Amplitude and phase imbalances of <;0.25 dB and <;2.5°, respectively, are measured. Input port reflection coefficients <; -10 dB and an insertion loss below 0.6 dB are also obtained. A conducted sensitivity study shows the small dependence of the device performance on the process variations. The presented results may pave the way for multi-octave analogue phase shifters and beamformers throughout the millimetre-wave range.