Millimeter-Wave Tunable Phase Shifter on Silicon-on-Glass Technology

A low-loss, low-cost, and compact fully-dielectric phase shifter integrated on the corrugated Silicon-On-Glass (SOG) platform is presented for the first time. In the corrugated SOG platform, the glass substrate below the high-resistivity silicon (Si) components is etched in a periodic configuration to reduce the insertion loss and enhance the field confinement inside the Si. Measured phase shifts of 111 $^{\circ}$ and 129 $^{\circ}$ are achieved by a device length of 5 mm at the frequencies of 85 and 100 GHz, respectively. At 88 GHz, the maximum insertion loss over a phase shift of 114 $^{\circ}$ is only 0.6 dB.