ORBIT FR Rolled Edge Reflectors - Manual

Compact Range Products
2006_1_v1 www.orbitfr.com
Overview
Compact ranges provide an efficient means of obtaining the illumination desired over a
specified test zone normally provided by a long far field range in a relatively short
distance. This is achieved by conversion of the spherical wave produced by the compact
range feed to a plane wave by the parabolic reflector assembly. Locating the test zone
at the appropriate distance from the reflector provides a high quality plane wave
illumination with relatively uniform amplitude and phase. Radiation effects from the edge
region of the reflector, however, introduces ripple in the quiet zone illumination which
degrades performance. These effects are greatly reduced by the use of serrated edges
on the reflector, or in some cases by using a rolled edge termination on the reflector
surface. Illumination of the reflector edges, and thus ripple, can be reduced by using a
more directive compact range feed; however, a trade-off exists in that use of a more
directive compact range feed will result in more taper over the quiet zone region. Thus,
proper edge design is required to optimize this trade-off. Consideration must also be
given to the absorber layout and separation distance between the absorber and the
reflector in the anechoic chamber. Careful analysis of these requirements and
implementation of the appropriate compact range system can result in a high
performance, efficient size test zone within a given anechoic chamber volume.
Compact ranges offer performance advantages over conventional far field and near
field ranges. In general, the compact range offers a much smaller test facility
implementation than far field ranges, and provides for equivalent or better performance
indoors than might otherwise be required on an outdoor range. This has the obvious
advantage of high up time, as logistics and weather are issues that may impede range
usage on a long outdoor range. The compact range also has several advantages over
near field solutions. The first advantage is that it is not required to collect a complete
set of data over the aperture in order to evaluate a single pattern cut. Using a compact
range the desired cut can be obtained directly, making possible the rapid evaluation of
antenna performance. Secondly, the compact range provides the capability for system
level testing, that is, the output of a complete system or partial system can be evaluated
directly as a function of position, which is not possible with a near field test scenario.
ORBIT/FR offers a wide variety of compact range systems, including side and corner
fed geometries, serrated and rolled edge reflectors, and single as well as dual polarized
feeds, over both waveguide bandwidths and broadband implementations. ORBIT/FR’s
reflectors are suitable for use up to 100 GHz and beyond, made possible by a special
machining technology. Precision installation, alignment, and field probe verification of
quiet zone quality are all services provided as standard elements of ORBIT/FR’s
compact range systems. ORBIT/FR has delivered numerous compact range systems
with quiet zone sizes ranging from 1 to 16 ft. and larger. Feed polarization rotators are
standard elements of the ORBIT/FR compact range systems; multi-feed carousels are
available as an option. Contact your ORBIT/FR sales representative for additional
details and specialized requirements. ORBIT/FR can deliver a compact range solution
to meet your needs.
Compact Range Products