| This thesis presents the design, simulation, construction and evaluation of novel coplanar-waveguide (CPW) phase shifters for Local Multipoint Communication Service (LMCS) applications. To meet the LMCS system requirements, a 2 gigahertz (GHz) bandwidth, centered at 28 GHz, was required. Two design strategies were implemented: reflection and transmission phase shifters. The reflection phase shifters used branch-line coupler in conjunction with delay lines. The transmission phase shifter was based on two distributed-element filters. Both approaches took advantage of the uniplanar nature of CPW to simplify the fabrication process, which is described in some details.; Short-circuiting of the delay lines and switching between the filters is to be realized with micromachined (MEMS) switches, which are currently under development. The measurement results of the reflection phase shifter showed behaviour approaching that expected, but several fabrication problems caused significant deterioration of the results. In the case of the transmission phase shifter, the measured phase difference of 161° matched the simulated one of 176°. The results are explained in detail and suggestions for improving upon them are given. |
