Evaluation of a Planar Reconfigurable Phased Array Antenna Driven by a Multi-Channel Beamforming Module at Ka Band

Abstract

In this paper, a planar active phased array antenna demonstration with linear polarization (LP) at Ka Band (28-30 GHz) is presented. The proof of concept is carried out to evaluate the possible problems that may arise, to analyze possible calibration stages and to assess the viability of the integration of an active system with a Multi-Channel Beamforming Module (MCBM). To fulfill this task an <inline-formula> <tex-math notation= LaTeX >$8\\times 8$ </tex-math></inline-formula>-element planar array arranged in column subarrays of <inline-formula> <tex-math notation= LaTeX >$1\\times 8$ </tex-math></inline-formula> elements for 1D beam steering is proposed. The single element consists of a printed circular patch connected to a microstrip feeding line through metallic vias in a multilayered structure. Both the amplitude and phase distributions are performed by a commercial integrated circuit (IC) designed for transmission purposes, from the common port to each of the 8 output ports. Thus, an evaluation of the IC performance is also included within this work. Despite the inherent amplitude and phase feeding errors of the IC, the beam-steering accuracy of the system is reasonable. A nice correspondence between the simulated and measured <inline-formula> <tex-math notation= LaTeX >$8\\times 8$ </tex-math></inline-formula>-element array beam steering directions is obtained, with errors below 1° in the steering of the beam.