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LaminateDielectric constant
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Relative cost
Ceramic:AluminaSapphire
9.89.4, 1.6
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Semiconductor:Silicon 11.9 0.0004 Excellent High
Ferrimagnetic:Ferrite 9.0 0.001 Excellent Medium
Synthetic:PTFEPolyphenylene oxide
2.12.55
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Composite material:PTFE-glass, wovenPTFE-ceramic, composite
2.17 –2.5510.2
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Microstrip Feed Types
Characteristics Coaxial-probe feed
Radiating Edge
Coupled
Non-radiating
Edge Coupled
Gap Coupled
Inset Feed
Proximity Coupled
Aperture Coupled
CPW Feed
Configuration Non planar Coplanar Coplanar Coplanar Coplanar Coplanar Coplanar Coplanar
Spurious feed radiation
More Less Less More More More More Less
Polarization Purity
Poor Good Poor Poor Poor Poor Excellent Good
Ease of fabrication
Soldering and drilling
needed
Easy Easy Easy Easy Alignment required
Alignment required
Alignment required
Reliability Poor due to soldering
Better Better Better Better Good Good Good
Impedance matching
Easy Poor Easy Easy Easy Easy Easy Easy
Bandwidth 2-5% 9-12% 2-5% 2-5% 2-5% 13% 21% 3%
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Antenna
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Name of Project Frequency
of operation
Antenna Type Gain Beamwidth (degrees)
Az Ele
NASA AIRSAR P-bandL-bandC-band
All Microstrip 14dBi18dBi24dBi
198
2.5
384450
CCRS C/X SAR C-bandX-band
All Horn 26.0dBi28.5dBi
3.31.4
2526
DLR E-SAR P-bandL-bandS-bandC-bandX-band
MicrostripMicrostripMicrostripMicrostripHorn
12dBi17dBin.a.17dBi17.5dBi
3018201917
6035353330
NASDA X/L-band SAR
L-bandX-band
MicrostripWaveguide-slot
18dBi 26.5dBi
2.32.3
4040
DCRS EMISAR L-bandC-band
All Microstrip 17.1dBi26.0dBi
102.4
4231
Lynx Ku-band Horn-fed dish n.a. 3.2 7
PHARUS SAR C-band Microstrip n.a. 2.3 24
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Patch substrate
Feed line substrate
Aperture Patch
ProbeMicrostrip lines
SMA connector
Metal back plane
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Width of patch, W 16.476 mm
Length of patch, L 12.611 mm
Feeding point offset from edge, xf 3.97 mm
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1.5
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3
3.5
4
4.5S tanding Wave Ra tio (S WR) at Input P ort
Frequency (GHz)
Magnitude of S
WR
5.890 GHz 6.106 GHz
6.054 GHz 5.939 GHz
216 MHz
115 MHz
Simulation Measured
At 6GHz
Standing wave ratio 1.21 1.41
Reflection coefficient -20.5dB -15.319dB
Gain 5.86dBi 5.7dBi
Bandwidth
For SWR<1.5 115MHz 92.4MHz
For SWR<2.0 216MHz 206MHz
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1 2 3 4 5
Magnitude 2.4000 3.8249 2.8908 0.6649 1.0000
Phase (deg) -164.23 -161.13 -155.69 -119.79 0
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90.31Ω -50Ω λ/4
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71.80Ω -40Ω λ/4
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40Ωtransmissi
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50Ω line to patch 1
50Ω line to patch 2
103.75Ω -50Ω λ/4
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65.10Ω -50Ω λ/4
transformer
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50Ωtransmission line as phase
shifter50Ω - 40Ω
λ/4 transformer
102.61Ω -50Ω λ/4
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65.55Ω -50Ω λ/4
transformer
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50Ωtransmission line as phase
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101.56Ω -50Ω λ/4
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65.99Ω -50Ω λ/4
transformer
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1.5
2
2.5
3
3.5S tanding Wave Ratio (SWR) at input port
Frequency (GHz)
Magnitude of S
WR
6.082 GHz 5.949 GHz
5.983 GHz 6.046 GHz
133 MHz
63 MHz
Simulation Measured
At 6GHz
Standing wave ratio 1.29 1.16
Reflection coefficient -17.83dB -22.632dB
Gain 16.2dBi 15.8dBi
Bandwidth
for SWR<1.5 63MHz 83.9MHz
for SWR<2.0 133MHz 135.9MHz
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ideal
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0 20 40 60 80 100 120 140 160 180-50
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Angle (degrees )
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s imulation(co-pol)
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s imulation (cros s -pol)
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Excitation coefficient
1.3732 0.8610 1.1009 1.3600 1.6322 1.9103 2.1866
Element no. 8 9 10 11 12 13 14
Excitation coefficient
2.4528 2.7003 2.9211 3.1078 3.2540 3.3543 3.4054
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At 6GHzStanding wave ratio 1.11 1.22Reflection coefficient -25.50dB -20.097dB
Gain 17.0dBi 16.6dBi
Bandwidth for SWR<1.5 145.1MHz 168.1MHz
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Frequency (GHz)
Magnitude
145.1 MHz
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0 20 40 60 80 100 120 140 160 180-40
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SWR < 1.5 168MHz (2.8% of f0)
SWR < 2.0 224MHz (3.7% of f0)
Measured gain, G 21.2dBi
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)Characteristics Targeted Achieved
Centre frequency 6GHz 6GHz
Beamwidth AzimuthElevation
30
240 (shaped)2.940
240 (rms error 0.43dB)
Bandwidth (SWR < 1.5) 20MHz 168MHz
AASR (at prf = 1000Hz) < -20dB -26.9dB
SidelobeAzimuth
Elevation
-30dB (all)
-15dB (all)
-16.2dB (peak), ≤ ±0 from broadside-20dB (peak)
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0 = transmitted signal
= received signal from a scatterer at R
= received signal from a scatterer at R with an
aircraft LOS displacement of δR
01
/
"!#
6 &789:; !#
" !$#
!! ( "$!
% <;;;8$9#
//
01!"$ %#
#
$($$#
/
7
$$%"#
*!$&!$#