an instrumental test observation for 22ghz and 43ghz quasi-optical circuit of kvn receivers march 18...
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An Instrumental test observation for22GHz and 43GHz quasi-optical
circuit of KVN receivers
March 18th 2009
Seog-Tae Han, Jung-Won Lee, Jiman Kang, Sang-Sung Lee, Do-young Byun,
Do-Heung Je, Moon-Hee Chung, Seog-Oh Wi.
Outline
- Eevaluation of Quasi-optical circuit for 22GHz and 43GHz bands
- Test observation for quasi-optics circuit
- Summary
Total Quasi-optical Circuit Evaluation
for 22GHz and 43GHz bands
Outline(I)
Quasi-optical circuit forMulti-band receivers
Frequency
(GHz)
Loss
(dB)
Cross-
Pol.
(dB)
Beam
Deviation
(mm)
LPF1 Transmission 22 0.2 35 <1mm
43 0.2 35 <1mm
Reflection 86 0.2 30 <1mm
129 0.1 30 <1mm
LPF2 Transmission 22 0.2 30 <1mm
Reflection 43 0.2 35 <1mm
LPF3 Transmission 86 0.1 30 <1mm
Reflection 129 0.1 30 <1mm
• It took about more than 4years for design and test Good results to be used quasi-optical components
Summary of the experimental results of LPFs
22/43GHz band Quasi-optics circuit for simultaneous observation.
HPBW at Cass. focus @ 43GHz : approx. 30mm @ 22GHz : approx. 60 mmBeam Deviation between two beams : less than 1mm
Beam deviation 22/43GHz for total Q.O circuit
Red : 22GHzGreen : 43GHz
Cass.focus
Comparison between theoretical and measuredbeam size at cassegrain focus
Beam radii near Cass. focus at 22GHz
2mm (2/50) differenceWithout LPF With LPF
49.4mm47.6mm
(Transmission through LPF2)
2mm (2/26.4) differenceWithout LPF With LPF
26.4mm 24.5mm
Beam radii near Cass. focus at 43GHz(Reflection by LPF2)
w0a=3λ
z
2000
22 )//(.)/(
4
abboazoboaab wwwwwwK
• Woa/Wob : 26.5/24.7 @ 43GHz : 49.5/47.4@22GHz 1.05 both 22/43GHz• Beam coupling loss due to mismatch both 22/43GHz apporxi. less than 1%
Evaluation axial beam mismatch between theo. and exp.
LPF Loss Measurement Setup
The additional Receiver Noise Temperature Due to the LPFs
LPF1 Contribution
0.0
5.0
10.0
15.0
20.0
9000 9200 9400 9600 9800 10000 10200 10400
FSyn [MHz]
Nois
e C
ontr
ibuti
on [
K]
22G LCP22G RCP43G LCP43G RCP
LPF2 Contribution
0.0
5.0
10.0
15.0
20.0
9000 9500 10000 10500
FSyn [MHz]
Noi
se C
ontr
ibut
ion
[K]
22G LCP22G RCP43G LCP43G RCP
Quasi-optical circuit forMulti-band receivers
Quasi-optical circuit at LabQuasi-optical circuit at Lab
LPF1
LPF2
LPF3M1
M2
M3
Flat MHorn 22G
M4
Flat M
M5Cal
chopper
Quasi-optical circuit installed at receiver room of antennaQuasi-optical circuit installed at receiver room of antenna
M5
Calchopper
22GHz RX
43GHz RX
M4 M1
M2M3
Outline(II)
Test observation forEvaluation of Quasi-optics Circuit
Contour Map of Jupiter for 22GHz and 43GHz bands
Contour Map of Jupiter for 22GHz and 43GHz bands
22GHz( Red )
43GHz( Black )
Bold lines show HPBW
22GHz( Red )
43GHz( Black )
The Pointing offset between 22GHz and 43GHz band at Jupiter
)9.2,"6.1(, ELAZ
October 28th 2008
43GHz( Black )
The Pointing offset between 22GHz and 43GHz band at Jupiter
)"7.0,"1.0(, ELAZ
22GHz( Red )
March 6th 2009
Radiation patterns of Jupiter for 22GHz and 43GHz bands
Orion-KL H2O and SiO Maser Line
Simultaneous Observation Results !!!!!on October 28th 2008
Aperture efficiencies at 22GHz/ 43GHz
Efficiency(%)
EL(°)
Remark TB*(K)
Aperture efficiencies at 22GHz
Venus 68(70) 30 LPF2 505+-25**
Aperture efficiencies at 43GHz
Venus 68.8(70) 32 LPF2 450+-32
Summary
Pointing offset between 22GHz and 43GHz - less than 1” ( Pointing error of KVN antennas : 4”) Successfully done simultaneous observation - 22GHz and 43GHz bands Aperture efficiency 68%(70%) at both 22/43GHz
Quasi-optical evaluation for 86GHz and 129GHz - must be harder than that of previous ones Development of 86GHz and 129GHz receiver optics - at least 2011.
Thanks for your attention
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