By dielectrically embedding monopole elements in low loss
material, compact electronically steerable antennas can be
fabricated with good mechanical stability. Electronically
steerable antennas can provide beam scanning in azimthal and
elevation planes without moving parts, adding to their
reliability under severe weather conditions. Such an antenna has
been developed based on a monopole center feed, an eight-
monopole main ring, and 16 monopoles in two parasitic rings. The
monopoles are embedded in dielectric to achieve a size
reduction. The parasitic elements are connected to a controller
circuit via a PIN diode and feedthrough capacitor. The
controller switches between conductive or nonconductive behavior
for the parasitic elements to steer the antenna beam. Demand has
increased for reliable two-way data-and voice-communication
systems to support public safety, emergency-response teams'
security due to terrorism, and various government and
nongovernment agencies. Kumar1-3 has reported several low-
profile mi