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In-Depth Information
Radiating slots
L
W
∆L
Patch
Fig. 2.
Electric field distribution in mi-
crostrip patch antenna
Fig. 3.
Top view of patch antenna
As shown in Fig. 4, the normal and tangential components of the electric field
at the edge can be resolved with respect to ground plane. As the length of the
patch antenna is
ʻ/
2, the normal components of the electric field will cancel out
and the tangential component will add up to give maximum radiation pattern
perpendicular to the surface [1] as shown in Fig. 4. Thus the electrical patch will
increase and is greater than the physical length. The increase in length is given
by Hammerstad [2] as
ʔL
=0
.
412
h
reff
+0
.
3
reff
−
W/h
+0
.
264
W/h
+0
.
813
(2)
0
.
258
Hence the effective length is given by
L
eff
=
L
+2
ʔL
(3)
At given resonant frequency
f
0
, the effective length is given [9] as
Fig. 4.
Side view of patch antenna [1]
