Phase shifter based on the substrate integrated waveguide technology

Substrate integrated waveguide (SIW) technology is widely known transmission line technology adapted for use in various types of microwave circuits. This article deals with the analysis and design of a phase shifter based on the SIW technology. With simulation and measurement results obtained from the phase shifter with using air holes inside the structure, a test circuit was designed and manufactured. Results show that a phase balance of less than 10° is achieved with the experimental setup. The return loss value is better than 15 dB for working frequency band 8.85 GHz-9GHz. The main benefit of this work is the easy of implementation air holes inside the structure and also the easy of manufacture of the circuits for antenna arrays, where a certain number of identical circuits is usually needed.