Please use this identifier to cite or link to this item:
Title: A Wideband Resistive Beam-Splitter screen
Authors: Mahesh, Nivedita
Subrahmanyan, Ravi
Udaya Shankar, N.
Raghunathan, A.
Keywords: Radio interferometry
Mathematical model,
Antenna measurements
Issue Date: Nov-2015
Publisher: IEEE
Citation: IEEE Transactions on antennas and propagation, 2015, Vo. 63, p4835
Abstract: We present the design, construction, and measurements of the electromagnetic performance of a wideband space beam splitter. The beam splitter is a sheet in free space that is designed to divide incident radiation into reflected and transmitted components for interferometer measurement of spectral features in the mean cosmic radio background. Analysis of a two-element interferometer configuration with a vertical beam splitter between a pair of antennas leads to the requirement that the beam splitter be a resistive sheet with sheet resistance ηo/2, where ηo is the impedance of free space. The transmission and reflection properties of such a sheet are computed for normal and oblique incidences and for orthogonal polarizations of the incident electric field. We have constructed such an electromagnetic beam splitter as a square-soldered grid of resistors of value 180 Ohms (approximately ηo/2) and a grid size of 0.1 m. We measured the reflection and transmission coefficients over a wide frequency range between 50 and 250 MHz in which the wavelength well exceeds the mesh size. Measurements of the coefficients for voltage transmission and reflection agree to within 5% with physical optics modeling of the wave propagation, which takes into account edge diffraction.i
Description: Restricted Access. An open-access version is available at (one of the alternative locations)
ISSN: 0018-926X
1558-2221 (Online)
Alternative Location:
Copyright: 2013 IEEE
Appears in Collections:Research Papers (A&A)

Files in This Item:
File Description SizeFormat 
  Restricted Access
Restricted Access1.31 MBAdobe PDFView/Open Request a copy

Items in RRI Digital Repository are protected by copyright, with all rights reserved, unless otherwise indicated.