ORBIT FR Rolled Edge Reflectors User Manual

Compact Range Products

Compact Range Products

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 relati vel y uniform am plit ude and phase . R adi atio n effe ct s from the ed ge
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 reflecto r
surface. Illumination of the reflector edges, an d 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 regi on. 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 pr ovide s for equi valent or better performance
indoors than might otherwise be required on an outdoor range. This has the obvious
advantage of high up time, as logi stics and weath er are issue s that may impede range
usage on a long outdoor range. The compact range also has several advantages over
near field solutions. Th e first advantage is that it i s not required to collect a com plete
set of data over the aperture in order to evalu ate a single pattern cut. Using a compac t
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 out p ut of a compl ete syste m or p artial syste m can be ev alua ted
directly as a function of position, which is not possible with a near field test scenario.

ORBI T/FR offers a wide variety of com pact range systems, incl uding side and corner
fed geometries, se rrated and rol led ed ge refl ectors, and si ngle as well as dual polari zed
feeds, over both wave guide 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 system s. ORBIT/FR has delivered numer ous compact range systems
with quiet zone sizes ranging from 1 to 16 ft. and larger. F eed 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 specialize d requirements. ORBIT/FR can deliver a compact range solution
to meet your needs.

2006_1_v1 www.orbitfr.com

Compact Range Products

Rolled-Edge Reflectors

Corner-Fed

Rolled edge reflectors offer unique advantages over the serrated edge technology.
Rolled edge technol ogy is based on the premise of redirecti ng the energy illuminating
the edge of the reflector to non-critical areas of the anechoic chamber. Appropriately
redirected, the energy can be dissipated without exhibiting significant effects on the
quiet zone performance . This concept , while superior in performance, depen ds much
more on the quality of the anechoic chamber and absorber treatment in the room.
Limitations in the anechoic performance will result in negation of the rolled edge
advantages.

The rolled edge reflector system, by combining the parabolic central portion of the
reflector with a precisely defined edge surface designed to distribute the edge
currents in an optimal fashion to the benign sections of the room, requires a precisely
manufactured transition region from the core parab ola to the edge region. ORBIT/FR
offers the manufacturing technology required to successfully achieve this transition,
thereby avoiding any discontinuitie s that would result in diffraction which may materially
affect quiet zone performance.

The rolled edge compact range technology offers higher or equivalent level of
performance than serrated edge system at a higher cost than serrated edge
technology in the appropriate anechoic environment.

Consult your ORBIT/FR sales representati ve for applications information. An ORBIT/
FR applications engineer is available to discuss the comparisons in compact range
technology and offer a solution which will meets your needs.

AL-25000 Series

Quite Zone Shape CC CC CC CC CC CC CC CC
Frequency Range GHz 8 - 100 4 - 100 3 - 100 2 - 100 1.5 - 100 1 - 100 0.8 - 100 0.7 - 100
Quite Zone

Dimensions
(H x W x L)

Cross Polarization
(typ.)

Amplitude Total
Variation

Amplitude Taper dB 1.0 (> 18) 1.0 (> 8) 1.0 (> 6) 1.0 (> 4) 1.0 (> 3) 1.0 (> 2) 1.0 (> 2) 1.0 (> 1.5)
Amplitude Ripple dB

Phase Total
Variation

Phase Taper deg
Phase Ripple deg ± 3 (18-40) ± 3 (8-40) ± 3 (6-40) ± 3 (4-26) ± 3 (3-26) ± 3 (2-20) ± 3 (2-20) ± 3 (1.5-20)

AL-25101 AL-25202 AL-25303 AL-25404 AL-25606 AL-25808 AL-251010 AL-251212

m 0.3 x 0.3 x 0.3 0.6 x 0.6 x 0.6 0.9 x 0.9 x 0.9 1.2 x 1.2 x 1.2 1.8 x 1.8 x 1.8 2.4 x 2.4 x 2.4 3.0 x 3.0 x 3.0 3.6 x 3.6 x 3.6
ft 1 x 1 x 1 2 x 2 x 2 3 x 3 x 3 4 x 4 x 4 6 x 6 x 6 8 x 8 x 8 10 x 10 x 10 12 x 12 x 12

dB -30 -30 -30 -30 -30 -30 -30 -30
dB

±0.4 (40-100)

deg

0.25 * f (> 40)

1.9 (8 - 12)

1.7 (12 – 18)

±0.4 (18-26)
±0.3 (26-40)

12 (8 – 12)

10 (12 – 18)

± 3 (18-26)
± 2 (26-40)

1.9 (4 - 6)

1.7 (6 – 8)

±0.4 (8-12)

±0.3 (12-40)

±0.4 (40-100)

12 (4 – 6)
10 (6 – 8)

0.25 * f (> 40)

± 3 (8-12)

± 2 (12-40)

1.9 (3 - 4)

1.7 (4 – 6)

±0.4 (6-8)

±0.3 (8-40)

±0.4 (40-100)

12 (3 – 4)
10 (4 – 6)

0.25 * f (> 40)

± 3 (6-8)

± 2 (8-40)

1.9 (2 - 3)

1.7 (3 – 4)

±0.4 (4-6)

±0.3 (6-26)

±0.4 (26-100)

12 (2 – 3)
10 (3 – 4)

0.4 * f (> 26)

± 3 (4-6)

± 2 (6-26)

1.9 (1.5 - 2)

1.7 (2 – 3)

±0.4 (3-4)

±0.3 (4-26)

±0.4 (26-100)

12 (1.5 – 2)

10 (2 – 3)

0.4 * f (> 26)

± 3 (3-4)

± 2 (4-26)

1.9 (1 – 1.5)

1.7 (1.5 – 2)

±0.4 (2-3)

±0.3 (3-20)

± 0.4 (20-100)

12 (1 – 1.5)
10 (1.5 – 2)

0.5 * f (> 20)

± 3 (2-3)

± 2 (3-20)

1.9 (0.8 – 1.5)

1.7 (1.5 – 2)

±0.4 (2-3)

±0.3 (3-20)

±0.4 (20-100)

12 (1 – 1.5)
10 (1.5 – 2)

0.5 * f (> 20)

± 3 (2-3)

± 2 (3-20)

1.9 (0.7 - 1)

1.7 (1 – 1.5)

±0.4 (1.5-2)

±0.3 (2-20)

±0.4 (20-100)

12 (0.7 – 1)
10 (1 – 1.5)

0.5 * f (> 20)

± 3 (1.5-2)

± 2 (2-20)

1. Specifications apply to the full quiet zone at a 95% confidence level

2. () indicates applicable frequency range in GHz for specification

AL-251216

CC

1 - 40

3.6 x 4.8 x 4.8
12 x 16 x 16

-25

1.9 (1 - 2)

1.0 (> 2)

±0.4 (2-3)

±0.3 (3-20)

±0.4 (20-40)

12 (1 – 1.5)
10 (1.5 – 2)

0.5 * f (> 20)

± 3 (2-3)
± 2 (3-20)

± 3 (2-20)

AL-252020

1 - 40

6.0 x 6.0 x 6.0
20 x 20 x 20

1.9 (1 - 2)

1.0 (> 2)

±0.4 (2-3)

±0.3 (3-20)

±0.4 (20-40)

12 (1 – 1.5)
10 (1.5 – 2)

0.5 * f (> 20)

± 3 (2-3)
± 2 (3-20)

± 3 (2-20)

CC

-25

2006_1_v1 www.orbitfr.com