Design of a Ka Band Broadband 90° Phase Shifter Base on GGW

A low phase error broadband phase shifter based on the groove gap waveguide (GGW) is presented. In the proposed structure, unlike the way of quarter wavelength sections to obtain the phase shift, the phase shift can be obtained by stretching the broad side of the GGW and placing a stepped-ridge at the bottom layer, which are more suitable in development of symmetry and compact beam-forming networks of antennas. From fabrication point of view, the phase shifter based on the GGW is that it is removing the need for electrical contact between the different metal layers which considerably simplifies the manufacturing and assembly processes. The proposed phase shifter is designed to achieve 90° phase shift with the phase error less than 1.4° for a frequency range of 27-38 GHz compared to the equal length reference waveguide.