Compact Range Systems

ORBIT/FR offers a variety of Compact Range systems based on in-house expertise and manufacturing capabilities of all system components, i.e. reflectors, feeds, positioners, software and absorbers.

ORBIT/FR's Compact Range systems cover very low frequency applications (eg. mobile communcation baseband antenna testing at GSM frequencies) as well as very high frequency applications (e.g. automotive radar testing at 77 or 94 GHz). Due to very flexible and cost efficient manufacturing technologies, ORBIT/FR offers the optimized system configurations for any application: floor fed or side-wall fed systems, long or short focal length, serrated or rolled edge on single or double reflector systems. Reflectors are typically machined with an accuracy according to the application (frequency range) and can be extremely high (better than 10 micrometers for very high frequency applications). Small systems can be mobile, with all critical components mounted on a frame with wheels (eg. automotive radar systems).


One line of Compact Range products results from a cooperation between ORBIT/FR and Dornier Satellitensysteme (DSS), a corporate unit of Daimler-Chrysler Aerospace. DSS developed reflector manufacturing technology of casted iron reflectors the surface of which is milled using a high-accuracy 5-axis milling machine. This machine has been licenced to ORBIT/FR. This technology delivers the most accurate compact range reflectors available on the market today. Such compact ranges can be used for frequencies up to 300 GHz. ORBIT/FR also offers the DSS-developed double reflector compensated Compact Range, the system of choice if the lowest possible cross-polarization is required. All compact ranges based on steel reflectors have a horizontal symmetry plane. This results in side-fed systems. The feed, near one of the side walls, is at the same height as the center of the quiet zone. For single reflector systems this configuration allows for long focal lengths, resulting in excellent cross-polarization and low amplitude taper characteristics.
A second line of compact range products is based on an ORBIT/FR-developed aluminum technology, which offers excellent performance at lower cost and much lower weight. The aluminum technology allows for both side-fed and floor-fed configurations. Though the side-fed configuration is optimal for most applications, there are some applications where a floor-fed configuration is advantageous. Standard designs are equipped with serrations. Reflectors can also be equipped with rolled edges. Serrations offer the most cost effective edge treatment to minimize diffraction. Rolled edges offer lower diffraction, especially at lower frequencies, but with a higher cost.
Unique Reflector Manufacturing Technology Manufacturing technology is based on accurate machining of each individual reflector. Reflectors are made from either steel (DSS technology) or aluminum alloys, depending on the requirements. By varying the size of the serrations, or by replacing the serrated edge with a rolled edge of any size, ORBIT/FR can offer a range optimized for both the required performance and the available budget.
Serrated Edge Reflectors Serrated edge reflectors offer the lowest cost solutions, but have limited low frequency and sidelobe performance. The size of serrations can be tailored to the specific requirements and frequency range of the application. For RCS applications the serrated edge reflector is the preferred choice because of its low wall illumination, and sidelobe performance is of less importance.
Rolled Edge Reflectors Rolled Edge reflectors offer superior performance for almost any antenna measurement application. The edge size can be selected for best price / performance trade-off. Typical applications for small rolled edge compact ranges are millimeter wave Compact Ranges for automotive radar. Large rolled edge compact range systems are applicable for mobile communications, in particular baseband antenna testing. Very high-accuracy rolled edge reflectors can be found for very low sidelobe applications. Small size compact ranges (up to 3 ft quiet zone) are typically delivered as rolled edge only. Ranges up to 2 ft are mounted on a frame which includes reflector and feed system. For larger ranges the reflector and feed pedestal are typically installed as separate items at the customers site.
ORBIT/FR's reflector technology offers: Proven compact range design and manufacturing technology Excellent cross-polar and amplitude taper performance Superior high frequency performance Surface accuracy is based on requirements. Better than 10 microns for high Frequency applications available. Excellent long term electrical and mechanical stability
Feed Systems A large number of feed systems are available based on application, requirement and budget. Low cost solutions rely on simple horn constructions; high-end solutions are based on corrugated horns. Single and dual linear feeds can be supplied. For wide band applications, wide band single and dual linear horns are available. Large frequency bands can be covered by using feed caroussels and RF switching, without the need to exchange feeds.
AUT Positioners Antenna test positioners for compact range applications do not differ from any other far field application. The positioner system will be driven entirely by the application. The selection criteria for the antenna positioner includes configuration (e.g. azimuth over elevation or roll over azimuth), number of axes, size of the antenna (which is related to the size of the quiet zone), maximum weight of the test antenna, required accuracy (high resolution encoders, counterweights), etc. Feed Positioners All compact range systems include a feed positioner. As a minimum, standard feed positioners have a polarization positioner. Depending on the application, this positioner can be installed on a linear slide with an alignment jig. Sophisticated high-end feed positioners may include an automated feed exchange system.