The Design of Wideband X -band Antenna for SAR onboard ... · antenna system consists of...
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0 100 200 300 400 500 600 -1.4 -1.2 -1 -0.8 -0.6 -0.4 -0.2 0 Travelling Distance (mm) Loss (dB) α = 0.0023 dB/mm 4.1 mm height of honeycomb 8.2 mm height of honeycomb 9.65 GHz [Honeycomb inserted in the WR90] L1 L2 p = 20 mm dx 0.5 p (fixed) Input port Output port PBC PBC Radiating slot with 50% coupling factor 0.5λg λp PMC PMC Output port Input port PBC PBC PBC PBC Parallel plate input port Satellite Body One Antenna Panel (current design is RHCP) Rectangular waveguide feeder to each panel [top view] [bottom view] Choke Flange x z y 70 cm 70 cm Input port x z y The Design of Wideband X-band Antenna for SAR onboard Small Satellite † Institute of Space and Astronautical Science - Japan Aerospace Exploration Agency (ISAS - JAXA) ‡ Tokyo Institute of Technology * University of Tokyo Abstract The design of an X-band antenna for small SAR sensor onboard a small satellite will be presented. The antenna system consists of rectangular waveguide as its feeder and parallel-plate waveguide as its radiating part. Here, the tournament feeding system with waveguide power divider is applied. The center frequency of antenna is designed at 9.65 GHz with vertical polarization. It is expected that 300 MHz operational bandwidth can be achieved. The recent design results of feeder system, power divider and parallel-plate of one antenna panel will be discussed further. Keywords : small SAR sensor, parallel-plate slot array antenna, X-band antenna Prilando Rizki Akbar † , Budhaditya Pyne*,Hirobumi Saito † , Miao Zhang ‡ , Jiro Hirokawa ‡ and Makoto Ando ‡ References 1. M.iao Zhang, Jiro Hirokawa and Makoto Ando, “Design of a partially-corporate feed double-layer slotted waveguide array antenna in 39 GHz band and fabrication by diffusion bonding of laminated thin metal plates,” IEICE Trans. Commun ., vol. E93-B, no.10, pp.2538-2544, Oct. 2010. 2. Tung Nguyen, Rushanthi J., K. Sakurai, J. Hirokawa, M. Ando, M. S. Castaner, O. Amano, S. Koreeda, T. Matsuzaki and Y. Kamata, “Propagation characteristics of honeycomb structures used in mm- wave radial laine slot antennas,” IEICE Trans. Commun , vol.E97-B, no.6, pp.1139-1147, June 2014. 3. Prilando Rizki Akbar, Hirobumi Saito, Miao Zhang, Jiro Hirokawa and Makoto Ando, “X-band Parallel- plate Slot Array Antenna for SAR Sensor onboard 100 kg Small Satellite,” in Proc . IEEE Int. Symposium on Antenna and Propagation , 2015, pp. 208-209. P-190 x z y Antenna panel (parallel-plate slot array antenna and its rectangular waveguide feeder) Choke Flange Satellite body Upper Aluminum plate Radiating slot Honeycomb core Adhesive sheet Adhesive sheet Lower Aluminum plate t s t g t c [Parallel Plate Structure] [bird view] Coupling slot Inductive wall Feeder Parallel-plate structure b a [single coupling slot] z x y [top view] Feeder PBC Input Port Port 3 Port 2 i l i w r s i p γ s w PBC s l Inductive wall z y x [one radiating slot pair ] Parameters Size (mm) Parallel-plate (W p x L p ) Feeder Length (L f ) Feeder inner size (a x b) Inductive wall width, i w Slot width, s w Slot round edge radius, r s Hardwall width, h w The thickness of - Aluminum skin sheet, t s - Adhesive sheet, t g - Honeycomb core (SAH-1/4-1.5) , t c - Hardwall - Feeder broad wall 657.2 x 700 678.4 22.86 x10.18 1 2 1 4.89 0.3 0.13 6 6.26 1 Item Mass (gram) Upper parallel aluminum plate Lower parallel aluminum plate Honeycomb core sheet Adhesive sheet Hard Surface wall Aluminum Frame Feeder waveguide (2x) Total antenna system 344 358 65 138 57 24 324 1310 Honeycomb core properties 60 80 100 120 140 160 180 -2200 -2000 -1800 -1600 -1400 -1200 -1000 -800 -600 Phase [deg] Position from center [mm] β = −11.92 60 80 100 120 140 160 180 -2200 -2000 -1800 -1600 -1400 -1200 -1000 -800 -600 Phase [deg] Position from center [mm] β = −11.92 W drection , 2 2 rc = π β λ ε 0 ε rc = 1.06 Future Research Aperture distribution Antenna pattern • The TE10 mode wave propagates in the feeder to y direction. • Then the wave in the feeder is coupled to the parallel plate by the coupling slots. • The coupled wave travels in the parallel plate to x and - x direction. • Then this wave is coupled to z direction by the radiating slots and becomes the radiated wave. Results of single coupling slot simulation are used in the design of feeder of one antenna panel. Spacing of coupling slots are adjusted to obtain optimum in-phase excitation Results of one radiating slot pair simulation are used in the design of one dimensional array of radiating slot. Spacing of radiating slot pair are adjusted to obtain optimum in-phase excitation. 0 10 20 30 40 50 0 5 10 15 20 -125 -100 -75 -50 -25 0 25 50 Coupling Factor [%] [mm] [deg] γ [deg] [mm] [mm] [mm] S l i p i l [deg] [deg] arg.S 21 arg.S 31 [Inner field measurement] , 4 eq wall ε ε λ − = 0 w h ( )( ) . 2 2 rg c rc g rg rc c g eq t t t t ε ε ε ε ε + + = ε rg = adhesive permittivity ε rc = honeycomb permittivity ε wall = hardwall permittivity λ 0 = free space wavelength x y z Coupling Slot Design z y x Short Input port d s (n, n-1) Hardwall Hardwall Coupling slot Inductive wall Impedance boundary Parallel-plate structure Feeder n = 1 n = N n = N n = 1 d s (n, n-1) Short Hardwall h w W p L p Hardwall z x y L f Antenna input Feeder Coupling slot Radiating slot Power divider λ p Antenna input Feeder Example of spacing adjustment result of coupling slot at antenna feeder Radiating Slot Design Radiating slot with 100% coupling factor a 0.5λg 0.85λo PBC PMC Input port PMC PBC PBC Short PBC λp x y z Parallel-plate structure d r (m, m-1) m = 1 m = M [1 dimensional array of radiating slot] a Power divider Design Additional walls to have wide bandwidth (double resonance) z x y Input port Output port b b c d g e e f Output port Output port Output port PMC PMC PBC PBC PBC PMC b = 1.56 mm c = 5.8 mm d = 11.1 mm e = 4 mm f = 16 mm g = 17. mm z y x Near Field Measurement Far Field Measurement 10 2 10 3 10 4 10 5 -20 -10 0 Precise Solution Far Field Estimation E-Field Intensity [dB] Distance [mm] Adjustment factor Far Field Measurement distance Short Short Center of power divider window Total Variation of Phase from Center of the Window to the end slot = 2.1 degrees This document is provided by JAXA.
Transcript of The Design of Wideband X -band Antenna for SAR onboard ... · antenna system consists of...
0 100 200 300 400 500 600-1.4
-1.2
-1
-0.8
-0.6
-0.4
-0.2
0
Travelling Distance (mm)
Loss
(dB
)
α = 0.0023 dB/mm
4.1 mm height of honeycomb 8.2 mm height of honeycomb
9.65 GHz
[Honeycomb inserted in the WR90] L1
L2
p = 20 mm
dx 0.5 p (fixed)
Input port
Output port PBC PBC
Radiating slot with 50% coupling factor
0.5λg
λp
PMC
PMC Output port
Input port
PBC
PBC
PBC
PBC
Parallel plate
input port
Satellite Body
One Antenna Panel (current design is RHCP)
Rectangular waveguide feeder to each panel
[top view]
[bottom view]
Choke Flange
x z
y
70 cm 70 cm
Input port
x z
y
The Design of Wideband X-band Antenna for SAR onboard Small Satellite
† Institute of Space and Astronautical Science - Japan Aerospace Exploration Agency (ISAS - JAXA)
‡ Tokyo Institute of Technology * University of Tokyo
Abstract The design of an X-band antenna for small SAR sensor onboard a small satellite will be presented. The antenna system consists of rectangular waveguide as its feeder and parallel-plate waveguide as its radiating part. Here, the tournament feeding system with waveguide power divider is applied. The center frequency of antenna is designed at 9.65 GHz with vertical polarization. It is expected that 300 MHz operational bandwidth can be achieved. The recent design results of feeder system, power divider and parallel-plate of one antenna panel will be discussed further. Keywords : small SAR sensor, parallel-plate slot array antenna, X-band antenna
Prilando Rizki Akbar†, Budhaditya Pyne*,Hirobumi Saito†, Miao Zhang ‡, Jiro Hirokawa ‡ and Makoto Ando ‡
References
1. M.iao Zhang, Jiro Hirokawa and Makoto Ando, “Design of a partially-corporate feed double-layer slotted waveguide array antenna in 39 GHz band and fabrication by diffusion bonding of laminated thin metal plates,” IEICE Trans. Commun., vol. E93-B, no.10, pp.2538-2544, Oct. 2010.
2. Tung Nguyen, Rushanthi J., K. Sakurai, J. Hirokawa, M. Ando, M. S. Castaner, O. Amano, S. Koreeda, T. Matsuzaki and Y. Kamata, “Propagation characteristics of honeycomb structures used in mm-wave radial laine slot antennas,” IEICE Trans. Commun, vol.E97-B, no.6, pp.1139-1147, June 2014.
3. Prilando Rizki Akbar, Hirobumi Saito, Miao Zhang, Jiro Hirokawa and Makoto Ando, “X-band Parallel-plate Slot Array Antenna for SAR Sensor onboard 100 kg Small Satellite,” in Proc. IEEE Int. Symposium on Antenna and Propagation, 2015, pp. 208-209.
P-190
x z
y
Antenna panel (parallel-plate slot array antenna and its rectangular waveguide feeder)
Choke Flange
Satellite body
Upper Aluminum plate
Radiating slot
Honeycomb core
Adhesive sheet
Adhesive sheet Lower Aluminum plate
ts
tg tc
[Parallel Plate Structure]
[bird view]
Coupling slot
Inductive wall
Feeder Parallel-plate structure
b
a
[single coupling slot]
z
x
y
[top view]
Feeder
PBC
Input Port
Port 3
Port 2
il
i w rs ip
γ
sw
PBC sl
Inductive wall z
y
x
[one radiating slot pair ]
Parameters Size (mm) Parallel-plate (Wp x Lp) Feeder Length (Lf) Feeder inner size (a x b) Inductive wall width, iw Slot width, sw Slot round edge radius, rs Hardwall width, hw The thickness of - Aluminum skin sheet, ts - Adhesive sheet, tg - Honeycomb core (SAH-1/4-1.5) , tc - Hardwall - Feeder broad wall
657.2 x 700 678.4
22.86 x10.18 1 2 1
4.89
0.3 0.13
6 6.26
1
Item Mass (gram) Upper parallel aluminum plate Lower parallel aluminum plate Honeycomb core sheet Adhesive sheet Hard Surface wall Aluminum Frame Feeder waveguide (2x) Total antenna system
344 358 65 138 57 24 324 1310
Honeycomb core properties
60 80 100 120 140 160 180-2200
-2000
-1800
-1600
-1400
-1200
-1000
-800
-600
Phas
e [d
eg]
Position from center [mm]
β = −11.92
60 80 100 120 140 160 180-2200
-2000
-1800
-1600
-1400
-1200
-1000
-800
-600
Phas
e [d
eg]
Position from center [mm]
β = −11.92
W drection
,2
2
rc
=
πβλε 0
εrc = 1.06
Future Research
Aperture distribution
Antenna pattern
• The TE10 mode wave propagates in the feeder to y direction.
• Then the wave in the feeder is coupled to the parallel plate by the coupling slots.
• The coupled wave travels in the parallel plate to x and - x direction.
• Then this wave is coupled to z direction by the radiating slots and becomes the radiated wave.
Results of single coupling slot simulation are used in the design of feeder of one antenna panel.
Spacing of coupling slots are adjusted to obtain optimum in-phase excitation
Results of one radiating slot pair simulation are used in the design of one dimensional array of radiating slot.
Spacing of radiating slot pair are adjusted to obtain optimum in-phase excitation.
0 10 20 30 40 500
5
10
15
20
-125
-100
-75
-50
-25
0
25
50
Coupling Factor [%]
[mm
] [deg]
γ [deg] [mm] [mm] [mm]
Sl
ip
i l
[deg] [deg]arg.S21
arg.S31
[Inner field measurement]
,4 eqwall εε
λ−
= 0wh
( )( ).
22
rgcrcg
rgrccgeq tt
ttεεεε
ε+
+=
εrg = adhesive permittivity εrc = honeycomb permittivity εwall = hardwall permittivity λ0 = free space wavelength
x y
z
Coupling Slot Design
z
y
x
Short
Input port
ds(n, n-1)
Hardwall
Hardwall
Coupling slot
Inductive wall
Impedance boundary
Parallel-plate structure
Feeder
n = 1
n = N
n = N
n = 1
ds(n, n-1)
Short Hardwall
hw
Wp
Lp
Hardwall
z x
y
Lf
Antenna input Feeder
Coupling slot
Radiating slot
Power divider
λp
Antenna input
Feeder
Example of spacing adjustment result of coupling slot at antenna feeder
Radiating Slot Design
Radiating slot with 100% coupling factor
a
0.5λg
0.85λo
PBC
PMC Input port
PMC
PBC
PBC
Short
PBC
λp
x y
z
Parallel-plate structure
dr (m, m-1)
m = 1
m = M
[1 dimensional array of radiating slot]
a
Power divider Design
Additional walls to have wide bandwidth (double resonance)
z
x
y
Input port
Output port
b
b
c
d
g
e
e
f
Output port
Output port
Output port
PMC
PMC
PBC
PBC
PBC
PMC
b = 1.56 mm c = 5.8 mm d = 11.1 mm e = 4 mm f = 16 mm g = 17. mm
z y
x
Near Field Measurement
Far Field Measurement
102 103 104 105
-20
-10
0
�Precise Solution Far Field EstimationE
-Fie
ld In
tens
ity [d
B]
Distance [mm]
Adjustment factor
Far Field Measurement distance
Short Short
Center of power divider window
Total Variation of Phase from Center of the Window to the end slot = 2.1 degrees
This document is provided by JAXA.
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