Continuously tunable 360 degrees phase shifter based on planar waveguide technology for MM-wave applications

A continuously tunable phase shifter based on a substrate integrated waveguide (SIW) is proposed for high-performance applications at millimetre-wave frequencies. The proposed phase shifter consists of two slots cut on the SIW's broad wall and a high dielectric constant (HDC) slab over the slots. The phase shifting mechanism is based on perturbing the electric field of the SIW-slot by putting a HDC slab over two slots. The fabricated phase shifter exhibits linear phase-frequency response behaviour with an average insertion loss less than 2 dB over a phase shift range of 360 degrees in the operating frequency band (29-31 GHz).