Modelling of Tunable CPW Structure Dielectric Phase Shifters

The high performance phase shifter is of significant interest in the modern communication system. New type coplanar waveguide (CPW) structure dielectrics phase shifters are reported; the microwave characteristics of the devices are systematically studied by the FEA method basing on HFSS (ANSYS Electronics®). It is found that the proposed phase shifters can operate over 10 GHz. The influence of active varactor area, dielectric thickness and the matching of pads are analyzed. The tuning effects of the phase shifters are also investigated by changing the relative permittivity
$(\varepsilon_{r})$
of the dielectric layer. In order to increase the absolute phase shifting angle, assorted structures with multiple varactors are designed. By increasing the number of varactors, the phase angle shifting of the devices can be multiplied, but the insertion loss of the phase shifters will also increase. The proposed structures are compact and easy to fabricate, which can be used for the rapidly developing microwave industry.