Simple antenna characterisation using multiple VNAs: Page 3 of 7

May 25, 2017 //By Ing. C. Culotta-Lopez, Dipl.-Ing. T. Dallmann, IHF RWTH, Aachen, Germany and Dipl.-Ing. F. Gerhardes, Anritsu, Germany
This article shows how a set of two single-port vector network analysers (VNAs) that can be remotely operated via a LAN interface can be used for low-cost scalar transmission measurements for simple antenna characterisation. Practical results are included to show how antenna pattern and antenna gain measurements can be carried out with a very limited investment.

Antenna characteristics

The key antenna characteristics to be measured (Figure 1) are:

  • Radiation pattern;
  • Antenna half power beamwidth;
  • Antenna sidelobes;
  • Antenna gain.


Figure 1: Key antenna characteristics.

Gain measurements require essentially the same environment as their corresponding pattern measurements. To measure the gain of antennas operating above 1 GHz, anechoic chambers are usually used. Between 0.1 GHz and 1 GHz, ground-reflection ranges are used.

Within the scope of this project, three different gain-measurement techniques are available. The first two are so-called “absolute gain” measurements: the two-antenna method and the three-antenna method, while the third is the gain-transfer (or gain-comparison) method.

Design category: