21 cm 7 Beam (1290 - 1430 MHz, Primary Focus) Receiver

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Receiver Data

TypeHEMT, cooled
Channels14 in 7 beams
Receiver Noise Temperature10 K - 20 K (see below)
Frequency Range1260 - 1510 MHz
Bandwidth RF-Filters1260 – 1510 MHz
1380 – 1427 MHz
PolarizationCentre Horn: LHC and RHC
Outer Horns: Linear H and V
CalibrationNoise Diode
VTO: yes
Phaseshifterno
FeedCoaxial Horn
Beam separation0.25° = 1,6 beam widths
1. IF30 - 280 MHz
1. OscillatorULO1 or LO, upper side band, 1230 MHz


Block Diagram



Beam - Park Experiments

This is a receiver for the 21 cm Radioastronomy band. It is primarily built for the European Space Operation Centre (ESOC) for space debris measurements in Beam-Park Experiments (BPE). The Project is entitled „Multi-Beam Receiver for Beam-Park Experiments“, Contract No. 16173/02/D/HK, and pays all the material cost of the receiver while manpower is provided by MPIfR. Beam Park Experiments for space debris measurements are performed by a bistatic radar arrangement with the antenna beams parked at one certain point at the sky. The transmitting station is the TIRA antenna of FGAN in Wachtberg – Werthofen near Bonn, which is 21 km line of sight apart of the receiving Effelsberg telescope. In this configuration debris particles down to 9 mm diameter at 800 km to 1000 km height can be detected. This could be demonstrated in a first joint measurement in 1996: COBEAM.

A new backend was also developed for this receiver. It consists of seven commercially of the shelf dual channel sampling cards. The data is digitized with a sample rate up to 100 MHz and can be processed by a powerful FPGA. For BPE the sampled data is filed through the FPGA to a PCI system together with an accurate time stamp.

BPE are now performed on a regular basis since June 2006.



Radio Astronomy

The 21 cm seven beam receiver is operated in Effelsberg and can be used for radio astronomy purpose most of the time. Two filter bandwidths are available: the protected radio astronomy band 1380 MHz to 1427 MHz and the full receiver bandwidth 1260 MHz to 1510 MHz. The centre horn has circular polarization, the outer horns are linear polarized. The horns are arranged in an hexagonal package close together. The beam footprint at the sky is shown below.



Receiver Images

Dewar insight Receiver Box


Documentation

Technical data (preliminary):

Frequency range: 1260 MHz - 1510 MHz GHz (S14, S15 = 0)
1380 MHz - 1427 MHz GHz (S14, S15 = 1)
ULO frequencies: fULO1 = fsky – 150 MHz
fsky = fULO1 +150 MHz
fULO2 = not used
IF - bandwidth: 250 MHz at fIF = 155 MHz


Antenna Diagram and Beam Distribution:



Channels measured in the laboratory:

Channel Polarization (sky) S14, S15 = 0: 140 MHz bandwidth S14, S15 = 1: 47 MHz bandwidth
    TE  /K Tcal I/K Tcal II/K TE  /K Tcal I/K Tcal II/K
0A LHC 20,9 12,6 1,3 20,9 4,5 0,5
0B RHC 20,5 16,8 1,7 20,5 5,5 0,6
1A V 13,9 10,2 1,0 13,9 4,0 0,4
1B H 10,9 13,2 1,3 10,9 4,1 0,4
2A V 16,8 17,2 1,7 16,8 4,8 0,5
2B H 9,9 10,6 1,1 9,9 4,7 0,5
3A V 20,6 10,4 1,0 20,6 4,2 0,4
3B H 14,2 13,3 1,3 14,2 4,0 0,4
4A V 17,6 13,6 1,4 17,6 3,9 0,4
4B H 13,5 12,5 1,3 13,5 4,0 0,4
5A V 19,3 11,7 1,2 19,3 3,6 0,4
5B H 14,3 10,5 1,1 14,3 4,0 0,4
6A V 11,4 9,6 1,0 11,4 4,4 0,4
6B H 14,1 8,9 9,0 14,1 5,1 0,5

Report

PDF [5154 KB]

html version



Publications:

B. Klein, G. Bartsch, R. Keller, L. Leushacke: “Improved Systems for Bistatic Beam Park Experiments”; COSPAR Paris, July 2004