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Cellular Basestation Antennas
MLS Azimuth Site (Taichung, Taiwan)
TACAN : L-Band Military Aid providing range and bearing
Secondary Surveillance Radar
S-band 3 Beam Primary Array Radar
Aerospace Products - quantities
Foreign Governments
US, Spain, PRC, Taiwan
Microwave Landing
Systems
10
Design and Manufacture
RAAF Electronic TACAN 10 Design and
manufacture
Alenia (Italy) SSR Antenna 22 Design and
manufacture
Alenia (Italy) S-band Primary Radar 2 Design and
manufacture
Racal (UK) Simple AMPS basestation
antenna
100 (manufacture only)
Typical Basestation Antenna using Patch Radiating Elements
Low-band Antenna with patches in boxes
Combined Phaseshifter and Power Divider
Use of Motor to Control Downtilt Remotely
Principle of Dielectric Phaseshifter
Operation of Dielectric Phaseshifter
Multibeam Antenna Array
Multibeam Antenna – Feed Network
Multibeam Stadium Antenna
-150 -100 -50 0 50 100 150-30
-25
-20
-15
-10
-5
0
Attachment 10.1-07: 1.920 GHz, DT=6.0
Rel Gain (dB)
Angle (deg)
High band and Low band Element Configuration
Driven
element
Parasitic
element
Special
‘long dipole’
340 mm wide (RVV)
Prototype dual band ultra-wide band antenna
Element Pattern of Crossed Dipoles => Squint problem
-1 -.8 -.6 -.4 -.2 0 .2 .4 .6 .8 1-1
-.8
-.6
-.4
-.2
0
.2
.4
.6
.8
1
-12
-9
-6
-3
For 10 deg downtilt, beam squints to the left by 10 deg
Low-band Element Configuration
Low-band Element Pattern
-1 -.8 -.6 -.4 -.2 0 .2 .4 .6 .8 1-1
-.8
-.6
-.4
-.2
0
.2
.4
.6
.8
1
-18
-15-1
2
-18
-15
-12
Co-Polar X-polar
Sledkov Radiating Element to minimise Squint
High-band (Sledkov) Element Pattern
-1 -.8 -.6 -.4 -.2 0 .2 .4 .6 .8 1-1
-.8
-.6
-.4
-.2
0
.2
.4
.6
.8
1
-12
-9
-6 -3
-1 -.8 -.6 -.4 -.2 0 .2 .4 .6 .8 1-1
-.8
-.6
-.4
-.2
0
.2
.4
.6
.8
1
-18
-18
-18
-18
Co-polar X-polar
High-band Radiating Elements
Low-band Azimuth Patterns – affected by high-band elements
-180
-170
-160
-150
-140
-130
-120
-110
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160
170
180
-30.00
-25.00
-20.00
-15.00
-10.00
-5.00
0.00
Bottom frequencies => Pattern distorted
Common mode dipole resonance
+ +
+ +
- -
-
LB Currents on HB Stalk cause minimum disturbance to VP Pattern
-180
-170
-160
-150
-140
-130
-120
-110
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160
170
180
-30.00
-25.00
-20.00
-15.00
-10.00
-5.00
0.00
LB Currents on HB Stalk cause significant distortion of HP Pattern
-180
-170
-160
-150
-140
-130
-120
-110
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160
170
180
-30.00
-25.00
-20.00
-15.00
-10.00
-5.00
0.00
Pattern distorted at low frequencies – Horizontal Polarization
Low band gain curve
698722
747771
790821
834862
880915
935960
14.40
14.60
14.80
15.00
15.20
15.40
15.60
15.80
16.00
16.20
16.40
16.60
Gain ‘suck out’ due
to HB dipole
resonance
Capacitance of
dipoles increased
with Cu tape
Frequency MHz
Ga
in (d
Bi)
Modelling to find Common Mode Resonance
Tuning common mode resonance to outside band
Starting point Tune up in frequency (reduce inductance)
Tune down in frequency (increase inductance)
High band and Low band Element Configuration
Driven
element
Parasitic
element
Special
‘long dipole’
340 mm wide (RVV)
Matching of Long Dipole
Choked dipole arm
Spherical Luneburg Lens- Matsing
Sperical Luneburg lens 0.8m dia (15kg) with patch feeds has a beamwidth at 2 GHz of about 11°
Principle of Luneburg Lens. Dielectric constant is higher near the centre
Artificial dielectric
6 mm cubes with wires are packed with random orientation in plastic casings.
Modifying Azimuth Beamwidth of Conventional Basestation Antenna
Multibeam Luneburg Lens Antenna
12-beam Luneburg Lens – Stadium Antenna 1710 MHz – 2690 MHz
Promising configuration for Basestation Antenna with reduced element count
Interaction with Government and Universities
R&D Tax Incentive
Export Market Development Grant
‘START’ programme grant
Equity to company staff – Tax treatment
Cooperation with University, CSIRO etc.
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