TABLE VI: PERFORMANCE OF FOUR-ELEMENT LINEAR ARRAY
Four-Element Linear Array Conductor Pattern
(equal amplitude and phase to each element)
Four-Element Linear Array Conductor Current
19
(note equal amplitude and phase excitation)
Four-Element Linear Array Radiation Patterns
(note increased gain, EL beamwidth reduction and sidelobes)
Four-Element Linear Array Input Impedance
(note increase in impedance bandwidth versus single element)
TABLE 6 documents the performance of a Four-element linear array to which an amplitude taper has been applied.
As mentioned previously, the amplitude taper is utilized to reduce sidelobe levels. The amplitude taper is
implemented by changes to the impedance of the lines of the power divider in a manner that alters the impedance
at the principal junction of the power divider. A simple equation governs the power divider design under the
specified conditions.
20
19
The current density annotation feature available within the AXIEM EM analysis software provides significant physically
insightful information. The graphic indicates that the amplitude and phase of the individual element excitation are equal. This
feature is uniquely valuable in evaluation of proper amplitude and phase excitation of more complex array structures.
20
The unequal power divider is documented at the website: http://www.microwaves101.com/encyclopedia/calpowerdivider.cfm
1
0
-10
-20
-30
-40
-50
-60
-70
-80
- 9 0
-100
-110
-120
-130
-140
-150
-160
-170
180
170
160
150
140
130
120
110
100
9 0
80
70
60
50
40
30
20
10
Azimuth and Elevation Patterns
Mag Max
20 dB
Mag Min
-30 dB
10 dB
Per Div
p2 p1
Mag 11.72
Ang 0
DB(| PPC_EPhi(0,1,90,2,1)| )[3]
1_x_4_Array.$FSAMP
DB(| PPC_ETheta(0,1,0,2,1)| )[3]
1_x_4_Array.$FSAMP
p1: FREQ = 5.8 GHz
p2: FREQ = 5.8 GHz
0 1.0
1.0
-1.0
10.0
10.0
-10.0
5.0
5.0
-5.0
2.0
2.0
-2.0
3.0
3.0
-3.0
4.0
4.0
-4.0
0.2
0.2
-0.2
0.4
0.4
-0.4
0.6
0.6
-0.6
0.8
0.8
-0.8
Input Impedance
Swp Max
5.9GHz
Swp Min
5.7GHz
5.8 GHz
r 0.937847
x 0.262159
S(1,1)
1_x_4_Array.$FSAMP
Microstrip Antenna Design
17 www.cadence.com/go/awr
