Introduction
Antenna measurements are usually expensive and complicated, and take a long time for results to be displayed. While the VNA is today’s standard tool for measuring frequency-dependent parameters, it does have the disadvantage that it is virtually impossible to extend the VNA ports to the desired antenna locations without incurring problems such as cable losses.
However, as the project described in this article shows, a VNA such as the Anritsu MS46121A single-port analyser can serve as a valuable and inexpensive tool for simple antenna measurements, with measured antenna characterisation close to the manufacturers’ specifications.
Student project
The background of this project is a student work at RWTH Aachen University’s Institute of High Frequency Technology that was supported by Anritsu GmbH.
The student task was to design and develop a stepper motor hardware concept and control software for the azimuthal rotation of the antenna under test. An additional requirement was for the visualisation of the antenna radiation pattern and antenna gain in a MATLAB environment.
Anritsu supported this project with the necessary VNA hardware, a stepper motor, anantenna tripod and a Schwarzbeck USLP 9142 antenna. RWTH Aachen University was responsible for the design, development and realisation of the project. After a successful demonstration at the 2015 German Microwave Conference, it was agreed to extend the project to produce some real results.