What is a Compact Range System?

Antennas Test & Measurement 
When looking to test the far-field characteristics of a large antenna, I was told to use a compact range system. What is this and how does it work?
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Raghav Kapur - everything RF

Dec 9, 2016

A Compact Range system makes direct far-field measurements of electrically large antennas in a shielded anechoic chamber. It uses a large parabolic reflector to project a small radiating source (feed) into the far field. The reflector is used to transform a spherical wave into a plane wave with far-field characteristics. Multiple-feed systems may be used to improve the far-field characteristics.

The far field principle states that the distance between the Transmitter and Receiver (R) should be as follows:

Where D is the Diameter of the antenna and ? is the wavelength of the wave. For large antennas operating at high frequencies this far field distance is quite large and thus we need to test it in a compact range system. For example, an antenna with a diameter of 5 meters operating at a frequency of 10 GHz would have to be placed at a distance of a few km to simulate far field conditions. This is not very practical when conducting test, as a large antenna is not easy to move around. That is why compact ranges are used for testing electrically large antennas.

There is a white paper that talks more about the different types of compact ranges and how they work. You can read it here.

You can also see a list of companies that have or can help you develop Compact Range Systems in the everything RF Directory - https://www.everythingrf.com/directory/compact-range-systems