As mentioned in the previous newsletter, our anechoic chamber has undergone extensive upgrades. The goal was to increase the stability and repeatability of our antenna measurements as well as learn new measurement techniques and subtleties.
Some of the RF components we have implemented in our new chamber are an RF amplifier, rotating joints and new cables that are more phase stable than in the past. The amplifier will significantly increase the dynamic range of the chamber which improves pattern measurements, particularly if one is interested in side and back lobe levels. Phase stability allows for more accurate measurements of our circularly polarized antennas. The rotating joints give more repeatable measurements as there is less torsion on the cables when performing rotating pattern measurements.
We have also purchased new horn antennas for calibration of the chamber from 400-8000 MHz, and up to 18 GHz in the future.
An increase in performance below 800 MHz has been noted as well as a higher SNR over the entire measurement frequency range.
The ‘hands on’ experience gained from building the chamber, installing the RF components, and having the opportunity to refer to Dr Dirk Baker has been an invaluable experience.
The tests we will complete, will investigate the polarisation accuracy of the chamber, the repeatability and stability of our measurements and the size of our ‘quiet zone’ at various frequencies. The tests performed make use of the pairs of antenna horns we have purchased, a large amount of data collection and post processing using various spatial points in the test zone.
There have been delays on the horns required for the calibration of the chamber which has delayed the results from the initial calibration mentioned in the previous article.
This video gives an overview of the Anechoic Test Chamber Upgrades at Poynting Antennas