Three variations of a pattern-reconfigurable microstrip parasitic array

This work describes three variations of pattern-reconfigurable microstrip parasitic arrays (RMPAs) and provides measured results for each. Variation 1 uses two switches to reconfigure the radiation pattern into three directions in the H-plane. Variation 2 uses two varactors to scan the radiation pattern between -27° and 27° in the H-plane by controlling the value of the varactors. Variation 3 uses two inductors and varactors in series so that the scannable range of the H-plane pattern is from ±32° to ±54°. Each variation has a common 2:1 VSWR bandwidth throughout the switching and/or scanning of the radiation pattern. Copper strips or capacitors are used instead of switches or varactors for proof of concept. These three variations have potential applications in both mobile-communication devices and multiple-input multiple-output (MIMO) systems.