ANTENNA DESIGN & ANALYSIS
PATCH DESIGN BASED ON TRANSMISSION LINE MODEL
1) Wave length:
λ 
C
fo
λ is wavelength
Where,
C is Velocity of light (3 * 108 m/s)
f0 is Operating/ Resonant frequency (in GHz)
2) Width of the Patch (W):
W
Where,
C
2f o
2
r 1
εr is the relative permittivity of the substrate
3) Effective Dielectric Constant (εr eff):
ε reff 
Where,
 1
  2 
h
ε r 1 ε r 1 

1

12
w 
2
2 
h is the thickness of the substrate
√
4) Incremental Length (∆L):
 ε reff  0.3  *  wh  0.264
 ε reff  0.258 *  wh  0.8


ΔL  0.412h * 



5) Effective Length (Leff):
Leff 
C
ε reff
2f o
6) Length (L):
L  L eff - 2 L
7) Ground
Length
Lg  6h  L
Width
Wg  6h  W
8) Guided Wavelength (λg):
λg 
9) Radiation Box
g
λ
ε r eff
6
10)
Feed
Length Lf
Lf 
λg
4
Width Wf
{,
Where,
(
)
√
(
)- *
(
)
Z0 is Impedance (50Ώ)
(
)+}
11)
VSWR:
VSWR 
Where,
RL  20 log 
  10
12)
RL
20
Load impedance:
Z L  Z0
13)
1 
1 
1  L
1  L
Where,
  1  L
Quality Factor (under load):
Where,
f0 is resonant frequency
∆f is 3dB bandwidth
14)
Perfect matching condition
Insertion loss = Attenuation
15)
Loss tangent
In rectangular patch
( )(
)
( )(
)
CIRCULAR PATCH FORMULAS
1.
√
,
2.
*
+-
3.
,
4.
*
√
+-