Low-insertion loss phase shifter for millimeter-wave phased array antennas

This paper proposes a compact, low-loss, and low-cost phase shifter for millimeter-wave/sub-THz applications. The basic idea is to perturb the propagation constant of a high resistivity silicon image guide by high-dielectric constant barium lanthanide tetratitanates (BLT) ceramic loading. Three different BLT ceramic samples have been tested. The measured maximum phase-shift variation reaches 150° at 100 GHz with an average insertion loss of 2.85 dB and an insertion loss variation <0.7 dB for a sample of a 5-mm length. The proposed phase shifter has a bandwidth from 95 to 105 GHz. A low-cost fabrication technology has been developed and used to realize this phase shifter.