The free-field antenna measuring system AMA can be used to determine the radiation or reception characteristics of antennas in the far field. For this purpose, the test object is mounted on a rotating stand and the amplitudes and phases of the electric field are measured as a function of the angle of rotation. In this way, antenna pattern and gain can be recorded in a frequency range from 100 MHz to 110 GHz.
With the system AMA, own antenna developments are accompanied. The properties of such antennas installed on satellites, aircraft, rockets, motor vehicles or ships can also be examined and evaluated. The measurements can be carried out on the original object or on a scaled model.
The main components of the antenna measuring system are: a rotating stand with which the measuring object can be positioned and rotated around a horizontal or vertical axis for recording the diagrams, the rotating stand control which transmits the respective current angular position of the measuring object to the measuring room and precisely adjusts the rotating stand to the desired position manually or computer-controlled, as well as a stable measuring transmitter (synthesiser) which generates a signal with a predetermined frequency.
An automatic network analyser, which can also be operated as a microwave receiver, is used in the receiving device, which receives the signal emitted by the measuring object via a parabolic antenna and records its amplitude and phase with reference to the respective position. Objects weighing up to 1000 kg can be measured using various rotary stands. The positioning accuracy depends on the respective rotary stand used and is ±0.01° to ±1°.
The equipment has been used over many years in numerous projects to characterise single radiators and arrays developed for adaptive antennas for communication and navigation, mainly in the Ka and L bands. The AMA is also available for measurements by external clients.