Beam-Reconfigurable Antenna with Inductive Partially Reflective Surface
and Parasitic Elements
Abstract
A reconfigurable partially reflective surface (PRS) antenna can offer
low-cost and low-complexity beam steering, traditionally implemented
using a phased array with a bulky feeding network. This paper utilizes
ray-tracing to prove analytically that an inductive nonuniform PRS
facilitates larger beam deflection and lower sidelobe level (SLL) than a
capacitive one, given the same reflection phase difference. With a
suitable tradeoff in the beam deflection angle and gain variation
between the reconfigurable states, an inductive reconfigurable PRS is
designed for a ±13° steering range. To enhance the steering range with
minimal complexity, two parasitic elements loaded with PIN diodes are
added to the feeding source, resulting in the overall steering range of
±30°. The fabricated prototype verified that the pencil-shape beam can
be steered towards 0º and ±30º with SLLs of less than -19dB at 5.5GHz.
The antenna achieved peak realized gains of 9.5-10.4dBi for the three
states with gain variation of less than 0.9dBi. The measured overlapped
impedance band covers 5.41-5.63 GHz for all states.