Single-Layer Electrically Small Antenna With Reconfigurable Radiation Pattern

A single-layer, ultra-low-profile, electrically small, pattern-reconfigurable antenna is presented. The antenna consists of electric and magnetic dipole elements and a reconfigurable driven element. Six p-i-n diodes are integrated into the driven element to obtain three switchable endfire radiation states, each state covers more than 120°, which covers the entire 360° azimuth plane. For verification, a pattern reconfigurable antenna was fabricated and tested. The antenna exhibits the following measured results:
$k_{a}= 0.75$
electrical size, 2.9% fractional impedance bandwidth, 4.17dBi peak gain, front-to-back ratios (FTRB) ~21.2dB, and radiation efficiencies (RE) ~82.6% for three switchable endfire radiation states.