<s>
In	O
telecommunication	O
,	O
a	O
microstrip	B-Algorithm
antenna	I-Algorithm
(	O
also	O
known	O
as	O
a	O
printed	B-Algorithm
antenna	I-Algorithm
)	O
usually	O
means	O
an	O
antenna	O
fabricated	O
using	O
photolithographic	B-Algorithm
techniques	O
on	O
a	O
printed	O
circuit	O
board	O
(	O
PCB	O
)	O
.	O
</s>
<s>
An	O
individual	O
microstrip	B-Algorithm
antenna	I-Algorithm
consists	O
of	O
a	O
patch	O
of	O
metal	O
foil	O
of	O
various	O
shapes	O
(	O
a	O
patch	O
antenna	O
)	O
on	O
the	O
surface	O
of	O
a	O
PCB	O
,	O
with	O
a	O
metal	O
foil	O
ground	O
plane	O
on	O
the	O
other	O
side	O
of	O
the	O
board	O
.	O
</s>
<s>
Most	O
microstrip	B-Algorithm
antennas	I-Algorithm
consist	O
of	O
multiple	O
patches	O
in	O
a	O
two-dimensional	O
array	O
.	O
</s>
<s>
The	O
most	O
common	O
type	O
of	O
microstrip	B-Algorithm
antenna	I-Algorithm
is	O
commonly	O
known	O
as	O
patch	O
antenna	O
.	O
</s>
<s>
Common	O
microstrip	B-Algorithm
antenna	I-Algorithm
shapes	O
are	O
square	O
,	O
rectangular	O
,	O
circular	O
and	O
elliptical	O
,	O
but	O
any	O
continuous	O
shape	O
is	O
possible	O
.	O
</s>
<s>
Some	O
patch	O
antennas	O
do	O
not	O
use	O
a	O
dielectric	O
substrate	O
and	O
instead	O
are	O
made	O
of	O
a	O
metal	O
patch	O
mounted	O
above	O
a	O
ground	O
plane	O
using	O
dielectric	O
spacers	O
;	O
the	O
resulting	O
structure	O
is	O
less	O
rugged	O
but	O
has	O
a	O
wider	O
bandwidth	B-Algorithm
.	O
</s>
<s>
Microstrip	B-Algorithm
antennas	I-Algorithm
are	O
relatively	O
inexpensive	O
to	O
manufacture	O
and	O
design	O
because	O
of	O
the	O
simple	O
2-dimensional	O
physical	O
geometry	O
.	O
</s>
<s>
They	O
are	O
usually	O
employed	O
at	O
UHF	O
and	O
higher	O
frequencies	O
because	O
the	O
size	O
of	O
the	O
antenna	O
is	O
directly	O
tied	O
to	O
the	O
wavelength	O
at	O
the	O
resonant	B-Application
frequency	I-Application
.	O
</s>
<s>
Such	O
an	O
array	O
of	O
patch	O
antennas	O
is	O
an	O
easy	O
way	O
to	O
make	O
a	O
phased	O
array	O
of	O
antennas	O
with	O
dynamic	O
beamforming	B-Algorithm
ability	O
.	O
</s>
<s>
The	O
most	O
commonly	O
employed	O
microstrip	B-Algorithm
antenna	I-Algorithm
is	O
a	O
rectangular	O
patch	O
which	O
looks	O
like	O
a	O
truncated	O
microstrip	O
transmission	O
line	O
.	O
</s>
<s>
When	O
air	O
is	O
used	O
as	O
the	O
dielectric	O
substrate	O
,	O
the	O
length	O
of	O
the	O
rectangular	O
microstrip	B-Algorithm
antenna	I-Algorithm
is	O
approximately	O
one-half	O
of	O
a	O
free-space	O
wavelength	O
.	O
</s>
<s>
An	O
early	O
model	O
of	O
the	O
microstrip	B-Algorithm
antenna	I-Algorithm
is	O
a	O
section	O
of	O
microstrip	O
transmission	O
line	O
with	O
equivalent	O
loads	O
on	O
either	O
end	O
to	O
represent	O
the	O
radiation	O
loss	O
.	O
</s>
<s>
The	O
dielectric	O
loading	O
of	O
a	O
microstrip	B-Algorithm
antenna	I-Algorithm
affects	O
both	O
its	O
radiation	O
pattern	O
and	O
impedance	O
bandwidth	B-Algorithm
.	O
</s>
<s>
As	O
the	O
dielectric	O
constant	O
of	O
the	O
substrate	O
increases	O
,	O
the	O
antenna	O
bandwidth	B-Algorithm
decreases	O
which	O
increases	O
the	O
Q	O
factor	O
of	O
the	O
antenna	O
and	O
therefore	O
decreases	O
the	O
impedance	O
bandwidth	B-Algorithm
.	O
</s>
<s>
This	O
relationship	O
did	O
not	O
immediately	O
follow	O
when	O
using	O
the	O
transmission	O
line	O
model	O
of	O
the	O
antenna	O
,	O
but	O
is	O
apparent	O
when	O
using	O
the	O
cavity	O
model	O
which	O
was	O
introduced	O
in	O
1973	O
by	O
Itoh	O
and	O
Mittra	O
The	O
radiation	O
from	O
a	O
rectangular	O
microstrip	B-Algorithm
antenna	I-Algorithm
may	O
be	O
understood	O
as	O
a	O
pair	O
of	O
equivalent	O
slots	O
.	O
</s>
<s>
The	O
half-wave	O
rectangular	O
microstrip	B-Algorithm
antenna	I-Algorithm
has	O
a	O
virtual	O
shorting	O
plane	O
along	O
its	O
center	O
.	O
</s>
<s>
This	O
may	O
be	O
replaced	O
with	O
a	O
physical	O
shorting	O
plane	O
to	O
create	O
a	O
quarter-wavelength	O
microstrip	B-Algorithm
antenna	I-Algorithm
.	O
</s>
<s>
The	O
impedance	O
bandwidth	B-Algorithm
is	O
slightly	O
lower	O
than	O
a	O
half-wavelength	O
full	O
patch	O
as	O
the	O
coupling	O
between	O
radiating	O
edges	O
has	O
been	O
eliminated	O
.	O
</s>
<s>
The	O
shorting	O
plane	O
of	O
the	O
half-patch	O
is	O
reduced	O
in	O
length	O
which	O
decreases	O
the	O
resonance	B-Application
frequency	O
.	O
</s>
<s>
On	O
some	O
phones	O
,	O
grounded	O
parasitic	O
elements	O
are	O
used	O
to	O
enhance	O
the	O
radiation	O
bandwidth	B-Algorithm
characteristics	O
.	O
</s>
<s>
Defected	B-Algorithm
Ground	I-Algorithm
Structure	I-Algorithm
(	O
DGS	O
)	O
-integrated	O
microstrip	O
patch	O
has	O
been	O
popular	O
for	O
multiple	O
purposes	O
.	O
</s>
