SIGINT Annular Slot Antennas

Wide bandwidth and low noise amplifiers
result in uncovering signals overlooked
with many competitor products. The slot
antenna is unique in the fact that it can be
flush-mounted while providing 360 degrees
of azimuth coverage. The slot antenna has
extremely wide bandwidth, approaching
2 decades. The upper frequency limit is
reached when the slot diameter approaches
½ wavelength. Above this limit, the pattern
develops secondary lobes. There is no
sharp boundary on the lower limit, but the
sensitivity drops as the frequency is lowered.
In addition to the low drag and small diameter,
the slot antenna is very light. With an
on-board micro, this “smart” antenna
requires simple interfacing and offers
enhanced perfomance.