A continuous transverse stub array with parabolic reflector for Ka-band multibeam application

This paper proposes a compact continuous transverse stub (CTS) array that utilizes substrate integrated waveguide (SIW) technology. The CTS array includes six radiation slots and is powered by a novel linear source generator (LSG) with a parabolic reflector located on the bottom layer. The LSG converts the input wave into a planar wave that is subsequently coupled to the parallel-plate waveguide (PPW) of the CTS array through a coupling slot. By utilizing different input ports, the CTS array can produce planar waves in various directions, allowing for the production of beams with different pointing. The CTS array comprises four-layer substrates with a total thickness of only 0.24λ0. The measurement results show that the reflection coefficient of the array is below -10.9 dB in the operating range of 33-37 GHz. The array scanning angle theta can be up to about ±38°at the center frequency of 35 GHz, with a maximum gain of 20.9 dBi. When using the middle port feed, the measurement gain is superior to 20.1dBi and the radiation efficiency is above 87.1% in the 33-37 GHz range. Simulation and measurement results are in agreement, demonstrating that the proposed CTS array is suitable for multibeam applications in the Ka-band.