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