Waveguide-based Phased Array with Integrated Element-specific Electronics for 28 GHz

Scalable and beam-steerable phased antenna array prototype for wireless backhaul ommunication is presented for 28 GHz. The 16-element phased array onsists of low-loss waveguide power division network, waveguide-to-PCB transitions, phase shifters on PCB, and horn antenna elements fed from the PCB. The paper presents a state-of-the-art design where the electronically controlled phase shifters are implemented on the PCB right in immediate proximity of the radiating elements. Thus, the transmission losses are kept as low as possible, even though each element has their specific PCB-mounted electronics. Furthermore, novel matching steps with easy manufacturing are presented in the power division network. The simulated and measured results show good agreement. The measurement results show that grating lobe-free beam steering range is +/-20 degrees in both azimuth and elevation. The measured antenna gain at broadside is 11.3 dBi after element phase adjustment, and the majority of the losses are due to the implemented electronics, i.e. the phase shifters.