A 360° High‐Resolution Single‐Port Reflection‐Type Phase Shifter for Reconfigurable Reflectarray Antennas

ABSTRACT This letter presents a novel generalized single‐port phase shifter topology utilizing a 360° high‐resolution reflection‐type phase shifter (RTPS), which can be applied for reconfigurable reflectarray antenna (RRA) applications. First, we propose a novel single‐port RTPS topology for the first time. Compared with the traditional dual‐port phase shifter topology, the proposed single‐port phase shifter topology can be applied in RRA elements. Moreover, a detailed theoretical analysis is conducted by establishing an equivalent topology. Second, to improve design and test efficiency, we utilize the two‐step phase extraction method. This method can reduce the required tunable states from 2 2 n to 2 n +1 for an n ‐bit varactor. Additionally, to minimize the phase step, a phase step optimization theory based on load optimization is proposed. Finally, to validate the design concept, a prototype was fabricated using low‐cost PCB technology. By utilizing the two‐step phase extraction method, the required tunable states for a 6‐bit varactor are reduced by 97%. Experimental results show that the proposed 7‐bit single‐port RTPS achieves high resolution and a full 360° phase shift range with an insertion loss of 2.54 ± 1.24 dB at 2.45 GHz. Thus, the proposed single‐port RTPS topology has the potential to be applied in RRA applications.