上海天文台 Shanghai Astronomical Observatory RFI Environment at the Shanghai Sheshan Site Zhi-Qiang Shen, Bin Li, and Tao An (Shanghai Astronomical Observatory)

上海天文台Shanghai Astronomical Observatory

RFI Environment at the Shanghai Sheshan Site

Zhi-Qiang Shen, Bin Li, and Tao An (Shanghai Astronomical Observatory)

“RFI2010 - RFI Mitigation Workshop” 29 - 31 March, 2010, Groningen (NL)


Major Facilities for RA in China

Delingha 13.7m

21CMA


Telescope site（ 30-40 km

away）

Headquarter of ShAO

Location of the Shanghai Sheshan SiteLocation of the Shanghai Sheshan Site


Diameter: 25m

Band: L, S/X, C, K

VLBI Recording system: MK4, MK5A, MK5B

Shanghai Sheshan 25m RT (1987)


Location

5多波束射电接收时代的天体物理南京 2009年 9 月

6.1 KM

4 KM

2.4 KM

25m RT

65m RT


Shanghai 65m Radio Telescope

65-m in diameter fully steerable radio telescope Active surface Cover 1.4 – 46 GHz with 8 bands ：

L(1.6GHz) S/X(2.3/8.4GHz) C(5GHz) Ku(15GHz) K(22GHz) Ka(30GHz) Q(43GHz)

General-purpose (radio astronomy, geodynamics, single-dish, VLBI )

6


Frequency coverage: 1.4~46 GHz Aperture Efficiency ：

L/S/C >60%, X >55%, Ku >40%, K >20% Ka >50%, Q >45% (with active surface)

Surface accuracy ： 0.6mm RMS (without active surface) 0.3mm RMS (with active surface)

Pointing accuracy ： 3 arcsec (wind < 4m/s) 10 arcsec (wind < 10m/s) 30 arcsec (wind < 20m/s)

First secondary lobes: <20 dB under main Elevation limits: 5~90 degree Slew rates: 0.5 degree/s (azimuth), 0.3 degree/s

(elevation)

Telescope Specifications

7


Receiver Specifications

BandFrequency Range

(GHz)Bandwidth

(GHz)BW/CF

(%)Polarization

TREC

(K)TLNA

(K)

L (18 &21cm) 1.25～ 1.80 0.50 32 Lin/Circ 10 < 5

S (13cm) 2.15～ 2.45 0.30 13 Circ 12 < 5

C (5 &6cm) 4.50～ 7.00 2.50 43 Lin/Circ 16 < 5

X (3.6cm) 8.00～ 9.00 1.00 12 Circ 15 < 5

Ku(2.2cm) 12.00～ 15.50 3.50 25 Circ 15 < 6

K (1.3cm) 18.00～ 26.50 8.50 38 Circ 21 < 10

K a(9mm) 30.00～ 34.00 4.00 13 Circ 25 < 12

Q(7mm) 40.00～ 46.00 6.00 14 Circ 40 < 18

Note: S/X and X/Ka are dual-frequency bands

8


2008： funded, contract to CETC54 for the antenna construction

2009: complete design, start manufacturing

2010: foundation completed 2011: antenna completed 2012: L/S/C/X band test observations, ready

for participation in the Chinese Lunar Mission

2013-14: active surface tested, Ku/K/Ka/Q band test observations 2015: project finished

Project Timeline

9


10多波束射电接收时代的天体物理南京 2009年 9 月


: 1200 MHz; : 1520MHz; : 10 kHz; : 10 kHz : 0 dB; ; (dBm) LNA40dB, 2dB, , By: @ 65m2009- 10- 09起始频率终止频率分辨率带宽视频带宽衰减天线出处读数电缆损耗波脊喇叭李建斌韩金林上海HN

-140-135-130-125-120-115-110-105-100-95-90-85-80-75-70

1200 1220 1240 1260 1280 1300 1320 1340 1360 1380 1400 1420 1440 1460 1480 1500 1520

Max (dBm)Mean (dBm)

: 1200 MHz; : 1520MHz; : 10 kHz; : 10 kHz : 0 dB; ; (dBm) LNA40dB, 2dB, , By: @ 65m2009- 10- 09起始频率终止频率分辨率带宽视频带宽衰减天线出处读数电缆损耗波脊喇叭李建斌韩金林上海HE

-140-135-130-125-120-115-110-105-100-95-90-85-80-75-70

1200 1220 1240 1260 1280 1300 1320 1340 1360 1380 1400 1420 1440 1460 1480 1500 1520

Max (dBm)Mean (dBm)

: 1200 MHz; : 1520MHz; : 10 kHz; : 10 kHz : 0 dB; ; (dBm) LNA40dB, 2dB, , By: @ 65m2009- 10- 09起始频率终止频率分辨率带宽视频带宽衰减天线出处读数电缆损耗波脊喇叭李建斌韩金林上海HS

-140-135-130-125-120-115-110-105-100-95-90-85-80-75-70

1200 1220 1240 1260 1280 1300 1320 1340 1360 1380 1400 1420 1440 1460 1480 1500 1520

Max (dBm)Mean (dBm)

: 1200 MHz; : 1520MHz; : 10 kHz; : 10 kHz : 0 dB; ; (dBm) LNA40dB, 2dB, , By: @ 65m2009- 10- 09起始频率终止频率分辨率带宽视频带宽衰减天线出处读数电缆损耗波脊喇叭李建斌韩金林上海HW

-140-135-130-125-120-115-110-105-100-95-90-85-80-75-70

1200 1220 1240 1260 1280 1300 1320 1340 1360 1380 1400 1420 1440 1460 1480 1500 1520

Max (dBm)Mean (dBm)

L 波段的详细测试图 LNA =40dB. 1200MHz~1520MHz，测试天线水平极化，以下四附图依次为天线指向东南西北四个方向测到的频谱图L 波段的详细测试图 LNA =40dB. 1200MHz~1520MHz，测试天线水平极化，以下四附图依次为天线指向东南西北四个方向测到的频谱图

L: 1.25～ 1.80GHz

1.25—1.52 GHz

East

South

West

North


: 1520 MHz; : 1840MHz; : 10 kHz; : 10 kHz : 0 dB; ; (dBm) LNA40dB, 2dB, , By: @ 65m2009-10-09起始频率终止频率分辨率带宽视频带宽衰减天线出处读数电缆损耗波脊喇叭李建斌韩金林上海HN

- 140- 135- 130- 125- 120- 115- 110- 105- 100- 95- 90- 85- 80- 75- 70

1520 1540 1560 1580 1600 1620 1640 1660 1680 1700 1720 1740 1760 1780 1800 1820 1840

Max (dBm)Mean (dBm)

: 1520 MHz; : 1840MHz; : 10 kHz; : 10 kHz : 0 dB; ; (dBm) LNA40dB, 2dB, , By: @ 65m2009- 10- 09起始频率终止频率分辨率带宽视频带宽衰减天线出处读数电缆损耗波脊喇叭李建斌韩金林上海HE

-140-135-130-125-120-115-110-105-100-95-90-85-80-75-70

1520 1540 1560 1580 1600 1620 1640 1660 1680 1700 1720 1740 1760 1780 1800 1820 1840

Max (dBm)Mean (dBm)

: 1520 MHz; : 1840MHz; : 10 kHz; : 10 kHz : 0 dB; ; (dBm) LNA40dB, 2dB, , By: @ 65m2009-10-09起始频率终止频率分辨率带宽视频带宽衰减天线出处读数电缆损耗波脊喇叭李建斌韩金林上海HS

- 140- 135- 130- 125- 120- 115- 110- 105- 100- 95- 90- 85- 80- 75- 70

1520 1540 1560 1580 1600 1620 1640 1660 1680 1700 1720 1740 1760 1780 1800 1820 1840

Max (dBm)Mean (dBm)

: 1520 MHz; : 1840MHz; : 10 kHz; : 10 kHz : 0 dB; ; (dBm) LNA40dB, 2dB, , By: @ 65m2009-10-09起始频率终止频率分辨率带宽视频带宽衰减天线出处读数电缆损耗波脊喇叭李建斌韩金林上海HW

- 140- 135- 130- 125- 120- 115- 110- 105- 100- 95- 90- 85- 80- 75- 70

1520 1540 1560 1580 1600 1620 1640 1660 1680 1700 1720 1740 1760 1780 1800 1820 1840

Max (dBm)Mean (dBm)

L: 1.25～ 1.80GHz

1.52—1.80 GHz


: 2000 MHz; : 5200MHz; : 100 kHz; : 100 kHz : 0 dB; : - 20. 0dBm; (dBm) LNA40dB, 2dB, , By: @ 65m2009- 10-起始频率终止频率分辨率带宽视频带宽衰减参考电平天线出处读数电缆损耗波脊喇叭李建斌韩金林上海09 HE

-130-120-110-100-90-80-70-60-50-40-30

2000 2100 2200 2300 2400 2500 2600 2700 2800 2900 3000 3100 3200 3300 3400 3500 3600 3700 3800 3900 4000 4100 4200 4300 4400 4500 4600 4700 4800 4900 5000 5100 5200

Max (dBm)Mean (dBm)

: 2000 MHz; : 5200MHz; : 100 kHz; : 100 kHz : 0 dB; : - 20. 0dBm; (dBm) LNA40dB, 2dB, , By: @ 65m2009- 10-起始频率终止频率分辨率带宽视频带宽衰减参考电平天线出处读数电缆损耗波脊喇叭李建斌韩金林上海09 HS

-130-120-110-100-90-80-70-60-50-40-30

2000 2100 2200 2300 2400 2500 2600 2700 2800 2900 3000 3100 3200 3300 3400 3500 3600 3700 3800 3900 4000 4100 4200 4300 4400 4500 4600 4700 4800 4900 5000 5100 5200

Max (dBm)Mean (dBm)

: 2000 MHz; : 5200MHz; : 100 kHz; : 100 kHz : 0 dB; : - 20. 0dBm; (dBm) LNA40dB, 2dB, , By: @ 65m2009- 10-起始频率终止频率分辨率带宽视频带宽衰减参考电平天线出处读数电缆损耗波脊喇叭李建斌韩金林上海09 HW

-130-120-110-100-90-80-70-60-50-40-30

2000 2100 2200 2300 2400 2500 2600 2700 2800 2900 3000 3100 3200 3300 3400 3500 3600 3700 3800 3900 4000 4100 4200 4300 4400 4500 4600 4700 4800 4900 5000 5100 5200

Max (dBm)Mean (dBm)

: 2000 MHz; : 5200MHz; : 100 kHz; : 100 kHz : 0 dB; : - 20. 0dBm; (dBm) LNA40dB, 2dB, , By: @ 65m2009- 10-起始频率终止频率分辨率带宽视频带宽衰减参考电平天线出处读数电缆损耗波脊喇叭李建斌韩金林上海09 HN

-130-120-110-100-90-80-70-60-50-40-30

2000 2100 2200 2300 2400 2500 2600 2700 2800 2900 3000 3100 3200 3300 3400 3500 3600 3700 3800 3900 4000 4100 4200 4300 4400 4500 4600 4700 4800 4900 5000 5100 5200

Max (dBm)Mean (dBm)

S: 2.15～2.45GHz C:4.5～7.0 GHz


: 5200 MHz; : 8400MHz; : 100 kHz; : 100 kHz : 0 dB; : - 20. 0dBm; (dBm) LNA40dB, 2dB, , By: @ 65m2009- 10-起始频率终止频率分辨率带宽视频带宽衰减参考电平天线出处读数电缆损耗波脊喇叭李建斌韩金林上海09 HE

-130-125-120-115-110-105-100-95-90-85-80

5200 5300 5400 5500 5600 5700 5800 5900 6000 6100 6200 6300 6400 6500 6600 6700 6800 6900 7000 7100 7200 7300 7400 7500 7600 7700 7800 7900 8000 8100 8200 8300 8400

Max (dBm)Mean (dBm)

: 5200 MHz; : 8400MHz; : 100 kHz; : 100 kHz : 0 dB; : - 20. 0dBm; (dBm) LNA40dB, 2dB, , By: @ 65m2009- 10-起始频率终止频率分辨率带宽视频带宽衰减参考电平天线出处读数电缆损耗波脊喇叭李建斌韩金林上海09 HS

-130-125-120-115-110-105-100-95-90-85-80

5200 5300 5400 5500 5600 5700 5800 5900 6000 6100 6200 6300 6400 6500 6600 6700 6800 6900 7000 7100 7200 7300 7400 7500 7600 7700 7800 7900 8000 8100 8200 8300 8400

Max (dBm)

Mean (dBm)

: 5200 MHz; : 8400MHz; : 100 kHz; : 100 kHz : 0 dB; : - 20. 0dBm; (dBm) LNA40dB, 2dB, , By: @ 65m2009- 10-起始频率终止频率分辨率带宽视频带宽衰减参考电平天线出处读数电缆损耗波脊喇叭李建斌韩金林上海09 HW

-130-125-120-115-110-105-100-95-90-85-80

5200 5300 5400 5500 5600 5700 5800 5900 6000 6100 6200 6300 6400 6500 6600 6700 6800 6900 7000 7100 7200 7300 7400 7500 7600 7700 7800 7900 8000 8100 8200 8300 8400

Max (dBm)Mean (dBm)

: 5200 MHz; : 8400MHz; : 100 kHz; : 100 kHz : 0 dB; : - 20. 0dBm; (dBm) LNA40dB, 2dB, , By: @ 65m2009- 10-起始频率终止频率分辨率带宽视频带宽衰减参考电平天线出处读数电缆损耗波脊喇叭李建斌韩金林上海09 HN

-130-125-120-115-110-105-100-95-90-85-80

5200 5300 5400 5500 5600 5700 5800 5900 6000 6100 6200 6300 6400 6500 6600 6700 6800 6900 7000 7100 7200 7300 7400 7500 7600 7700 7800 7900 8000 8100 8200 8300 8400

Max (dBm)Mean (dBm)

C:4.5～ 7.0 GHz X:8.0～ 9.0 GHz


9.2 ~ 17.8 GHz : 9200 MHz; : 17800MHz; : 300kHz; : 300kHz : 0dB; : - 20. 0dBm; (dBm) LNA40dB, 2dB, , By: @ 65m2009- 10- 09起始频率终止频率分辨率带宽视频带宽衰减参考电平天线出处读数电缆损耗波脊喇叭李建斌韩金林上海

HE

-130-125-120-115-110-105-100-95-90-85-80

9000 9500 10000 10500 11000 11500 12000 12500 13000 13500 14000 14500 15000 15500 16000 16500 17000 17500

Max (dBm)Mean (dBm)

: 9200 MHz; : 17800MHz; : 300kHz; : 300kHz : 0dB; : - 20. 0dBm; (dBm) LNA40dB, 2dB, , By: @ 65m2009- 10- 09起始频率终止频率分辨率带宽视频带宽衰减参考电平天线出处读数电缆损耗波脊喇叭李建斌韩金林上海HS

-130-125-120-115-110-105-100-95-90-85-80

9000 9500 10000 10500 11000 11500 12000 12500 13000 13500 14000 14500 15000 15500 16000 16500 17000 17500

Max (dBm)

Mean (dBm)

: 9200 MHz; : 17800MHz; : 300kHz; : 300kHz : 0dB; : - 20. 0dBm; (dBm) LNA40dB, 2dB, , By: @ 65m2009- 10- 09起始频率终止频率分辨率带宽视频带宽衰减参考电平天线出处读数电缆损耗波脊喇叭李建斌韩金林上海HW

-130-125-120-115-110-105-100-95-90-85-80

9000 9500 10000 10500 11000 11500 12000 12500 13000 13500 14000 14500 15000 15500 16000 16500 17000 17500

Max (dBm)Mean (dBm)

: 9200 MHz; : 17800MHz; : 300kHz; : 300kHz : 0dB; : - 20. 0dBm; (dBm) LNA40dB, 2dB, , By: @ 65m2009- 10- 09起始频率终止频率分辨率带宽视频带宽衰减参考电平天线出处读数电缆损耗波脊喇叭李建斌韩金林上海HN

-130-125-120-115-110-105-100-95-90-85-80

9000 9500 10000 10500 11000 11500 12000 12500 13000 13500 14000 14500 15000 15500 16000 16500 17000 17500

Max (dBm)Mean (dBm)


Active surface control Compensate (repeatable) gravitational

deformations, to maintain the nominal shape of the primary reflector (to improve the efficiency at high frequencies)

Used on the USA GBT 100-m and Italy Noto 32-m

16


EMC testing with 300kg load

17


Results from EMC testing

18

Power-on & in motion Power-on & hold still


solutions

Administrative level: Shanghai Radio Administration Bureau Was done in 1990’s Good contact

Hardware: Superconductor filter Shielding etc

Software: learned from this workshop

19


Superconductor Filter Mitigate strong RFI which saturates

the first cryogenic LNA. Working at 10~20K, low loss, low

phase degeneration. Example

Frequency: 2.2~2.3GHz (3G mobile RFI@ 2.14GHz)

Style: hairpin, 12 sections Material: thin film TL-2212 Insertion loss: 0.05dB at 20K

20


Superconductor Filter

Provided by CETC-16 institute21


Conclusions and Future Work RFI has become an important issue to the sites of

radio telescopes in China

Observatory will pay close attention to both the technical and regulatory issues related to RFI Superconductor filter (considered for 65m) Shielding (under consideration) Softwares … Spectrum management at different levels Origins of RFI (Shanghai Radio Administration

Bureau)

More frequent RFI monitoring is necessary to ensure a reliable assessment at Shanghai Sheshan site

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Documents

上海天文台 Shanghai Astronomical Observatory RFI Environment at the Shanghai Sheshan Site Zhi-Qiang Shen, Bin Li, and Tao An (Shanghai Astronomical Observatory)