Crossed Dipole

설계자: 남보한(2014)

1. Single dipole design 1

1.1 Geometry and dimensions:

Substrate: er = 3.5, tand = 0.0018, h = 0.79mm

Design 1
Parameters	Value [mm]
a	14
b	28.55
c	10.65
d	18.5
e	5.2
g	2.6
L	72.3
s	23
h	w+w/2 (2.5)
w	1.67
w0	1.67
w1	3.04
u	15.5
v	3
D	150

Design 2
Parameters	Value [mm]
a	14
b	28.5
c	12
d	18.5
e	5.1
g	2
L	71
s	13
h	w+w/2 (2.5)
w	1.67
w0	1.67
w1	3.04
u
v
D	150

Design 3
Parameters	Value [mm]
a	14
b	28.5
c	12
d	18.5
e	5.1
g	2
L	72
s	13
h	w+w/2 (2.5)
w	1.67
w0	1.67
w1	3.04
u	16
v	3
D	150

1.2 Results

Reflection coefficient. At 2.05-2.85GHz(33%), |S₁₁| < -20dB

Radiation pattern. Asymmetry in the gain pattern leads to high axial ratios at large angles. Peak gain = 8dB

1.3 Parameter study

- Dipole width: Controls the bandwidth

- Dipole height: Wrong figure

xxxxxx

Short circuit position: Affects the bandwidth and impedance matching

- Feeding point: Affects the impedance matching and bandwidth

- Feed line open stub length: Mildly affects the impedance matching.

- Dipole gap: Mildly affects the impedance matching.

- Dipole length: Affects the range of operating frequency and impedance matching

xxxx wrong results

- Dipole supporting strip width: Not sensitive

- Feed horizontal length: Not senstive

2. Single dipole design 2

Design 2
Parameters	Value [mm]
a	14
b	28.5
c	12
d	18.5
e	5.1
g	2
L	71
s	13
h	w+w/2 (2.5)
w	1.67
w0	1.67
W1	3.04
D	150

3. Design 3

Design 3
Parameters	Value [mm]
a	14
b	28.5
c	12
d	18.5
e	5.1
g	2
L	72
s	13
h	w+w/2 (2.5)
w	1.67
w0	1.67
w1	3.04
u	16
v	3
D	150

Conclusions: optimum values

a = 12-14, b= 27-30, c = 10-12, d = 19-20, e = 6-7, g = 2-3, u = 14-18, s = 15

[Crossed Dipole]

1. Design 3

ㅇ Geometry and dimensions

- Design idea:

Optimize the singla element → Apply it to the design of the crossed dipole.

When the short circuit position is same for fabrication purpose, the reflection coefficients are good at different frequencies.

Add a plane view of each dipole showing the slot to be removed for crossing.

Parameters	Value [mm]
a	14
b	28.5
c	12
d	18.5
e	5.1
g	2
L	72
s	13
h	w+w/2 (2.5)
w	1.67
w0	1.67
w1	3.04
u	16
v	3
D	150

ㅇ Results

Reflection coefficient: |S₁₁| < -20dB, |S₂₁| < -31dB over 2.15-2.75GHz

RHCP/ LHCP Pattern @2.15 Phi=45, Phi=0

RHCP/ LHCP Pattern @2.25 Phi=45, Phi=0

RHCP/ LHCP Pattern @2.5 Phi=45, Phi=0

RHCP/ LHCP Pattern @2.75 Phi=45, Phi=0

Axial Ratio @ 2.15GHz:

Axial Ratio @ 2.25GHz:

Axial Ratio @ 2.5GHz:

Axial Ratio @ 2.75GHz:

2. Design 2: 단일소자 design 2 사용