Polarimetric Bistatic X-Band Measurement Facility and its Applications

1
Polarimetric Bistatic X-Band Measurement Facility
and its Applications
Dr. Thomas Börner Deutsches Zentrum für Luft- und
Raumfahrt e.V. (DLR) Institut für
Hochfrequenztechnik und Radarsysteme P.O.-Box
1116, D-82230 Weßling, Germany Phone/Fax
49-8153-28-2368 / -1449, Email
Thomas.Boerner_at_dlr.de
Abstract The presentation will give an overview
about the current system design of the X-band
Measurement Facility of the Microwaves and Radar
Institute of the German Aerospace Center
Oberpfaffenhofen. The system consists of two
X-band broadband antennas (transmit and receive)
located in an anechoic chamber. An HP-VEE based
software is used to move the antennas and to
collect and store the measured data from a
network analyser. The system was originally
designed for the estimation of dielectric and
magnetic properties of materials. Therefore the
antennas have been moved synchronically to assure
that incident and reflection angle are the same.
Also the polarisation of the antennas can be
changed manually at arbitrary angles so that the
measurement of a full scattering matrix is
possible.
Anechoic chamber, two X-Band antennas and a table
for the targets.
System scheme
Center Frequency 9.6 GHz Frequency Range 8.2
to 12.4 GHz Useful Ranges 9.4 to 11.7
GHz 12.3 to 12.9 GHz 13.4 to 14.7
GHz Chamber Size 2.7m ? 2.1m Distance
Antenna - Table 1.2m Angular Range 12 -
70 Accuracy - Amplitude ? 0.1 dB - Phase
? 0.5 Polarisation can be adjusted
manually!
Bistatic measurement of a metal plate in VV
polarisaton. HP-VEE software is used to control
movements and to show phase and amplitude of the
measured signal provided by the network analyser.
One antenna is fixed to 46 incidence angle.
System specs

• Past and Current Applications
• Attenuation measurements of absorber materials.
• Estimation of dielectric and magnetic
  properties.
• Scattering from multi-layered dieletric targets.
  
• Future Applications
• Bistatic polarimetric measurements using canonic
  targets.
• Bistatic polarimetric scattering from moist
  rough soils/surfaces.
• Open Issues
• Bistatic and polarimetric calibration of the
  system.
• Theory and coherent models for canonic targets
  (partially available).
• Theory and coherent models for rough surfaces in
  the bistatic case.

Same measurement as above, but now the signal is
attenuated by an absorber plate above the metal
plate.