Abstract:
Adaptive array antenna systems are currently the
subject of intense .interest and investigation I
development for radar and communications applications.
The principal reason for the use of adaptive arrays is
in their ability to "automatically steer nulls onto
undesired sources of interference, thereby reducing
output noise and enhancing the detection of desired
signals. These systems consist of an array of antenna
elements and an adaptive receiver processor which has
feedback control over the element weights. The concept
of the adaptive system works on the principle of
minimizing the output power under the constrained
response to specified directions.
The present work studies the behaviour of the
adaptive array system depending on the signal power of
the desired signal and the interference sources, and
also on the placement of directional c6nstraints ,in the
system. A brief theoretical analysis and intensive computer simulation on this directional constrained
system are presented. The results confirm that the
algorith~ used is able. to iteratively adapt variable
weights on the tap of the sensor array to minimize noise
power at the array output subject to certain constraints
on the mainlobe as well as on the sidelobes of the array
response pattern. A number of interesting observations
regardin~ the behaviour of this adaptiv~ antenna iystem
in presence of the desired signal and interfering noise
of varying power levels are also revealed. Detailed
discussion is held for all types of simulations and
inferences are drawn about the response of the array
under different signal environment as well as pattern
constraints.
