What is an Antenna Array?
An antenna array is a group of antenna elements, typically arranged as a circle,
within an outer enclosure such as a radome. The elements are often directional
antennas, with a centrally located omnidirectional antenna. The use
of multiple antenna elements within the array enables the user to transmit
and receive signals from all directions. This is also helpful for detecting
and locating signals, and for jamming signals.
Antenna Array Applications
There are 3 primary application areas in information warfare: signals intelligence
(SIGINT), direction-finding (DF) and electronic attack (EA).
These can be thought of as "listen, locate and respond".
Listen: In signals intelligence, the objective is to monitor the environment for signals of interest and collect the signal information.
Locate: In direction-finding, the objective is to determine the direction that the signal of interest is coming from.
Respond: In electronic attack, the objective is to jam the signal of interest.
An antenna array enables the user to "listen" in all directions, due to its multiple elements (and where applicable, its central omnidirectional element).
With respect to the Locate component of information warfare, because the elements point
in different locations, one can pinpoint the direction of signal origin more effectively with an antenna array than with a single antenna.
With respect to the Respond component of information warfare, electronic attack (jamming) can
also be facilitated by a high performance antenna array. Some antenna arrays are designed for both direction-finding and electronic attack.
With high performance antenna arrays, the end user can cover an ultra wideband
frequency range, with the ability to transmit and receive throughout that frequency range,
including the ability to transmit or receive ultra wideband (impulse-type) signals.
Custom Antenna Arrays
The information required to produce a custom antenna array is typically minimal:
all one needs is the volume (cylinder diameter and height) available for the array, the
maximum acceptable weight, number of elements (ports), whether an omnidirectional element
is needed, and whether the antenna array is for receive only, or for both receive
and transmit.
It is also helpful to know whether true spatial filtering
and amplitude and phase DF is required. If so, the array should have directional
elements, but may have an integral omnidirectional element as well. Based
on such specifications from the end user, very compact and light-weight antenna
arrays can be customized to the space available.
Summary
Antenna arrays are a vital tool for tactical communications and information warfare, including signals intelligence,
direction finding and electronic attack/information operations. An antenna array can be ultra wideband
to cover a wide range of narrowband frequencies while also being able to transmit and receive
ultra-wideband impuse-type signals. A custom antenna array can be designed around the end user’s requirements and specifications.
