In this proposal new trapezoidal patch microstrip feed
antenna array with ground defected by square shape is designed
for detailed antenna parameter study in terms of return loss,
VSWR, gain and radiation pattern for S band applications from 2
to 3 GHz. The bandwidth and radiation properties of four
radiating element arranged in 2 x 2 array has been improved by
defecting half of the ground by etching square shape opposite to
the vertical feed point. 30 x 70 x 1.6 mm dimension structure has
been fabricated in FR4 substrate for low cost applications and
performance analyzed in three different planes. With comparison
of four element array with full ground, the proposed array with
defected ground has proved the improvement in behavior with
return loss of -34.687 dB and ideally fit with VSWR of 1.038.
Parametric study with feed length and substrate thickness has also
been performed optimized decision of structure dimension. This
study reveals that by reducing the substrate thickness and
increasing the feed length, we can improve the performance of
loss reduction. The front view has been simulated with full ground
and defected ground for comparison and the compared results
shows that the loss reduction of -22 dB has been achieved with
VSWR value of 1.03 from 2.28 for defected ground structure. The
designed structure has been simulated with CST software and the
comparison of simulated results has conform that the proposed
structure can be used for S band application like airport
surveillance radars with wide bandwidth of 120 MHz and gain of
3.52 dBi. Comparison has been made between the proposed
antenna array and the antennas available in literature with
respect to bandwidth gain, reflection coefficient and defection type
for better understanding.
DESIGN AND PERFORMANCE ANALYSIS OF UWB CIRCULAR RING ANTENNA WITH DEFECTED GROUND STRUCTURE