A portable bi-polar millimetre-wave antenna near-field measurement system

Small millimetre-wave antenna designs present particular difficulties when measured. With most available antenna chambers and ranges originally designed for larger size and lower frequencies, physically smaller antennas are dwarfed by the large support structures and cannot be efficiently characterized. Modification of these existing ranges for small antennas and high frequencies may prove to be very difficult as large positional and RF equipment are not easily modified or replaced. Additionally, equipments associated with millimetre-wave antenna measurements such as vector network analysers, high frequency cable, and adapters, are typically very expensive and often exceed the cost of the rest of the system. With such difficulties, a custom antenna range, designed for the smaller size antennas operating at millimetre-wave frequencies and for lower cost is an attractive solution. In this presentation, a novel portable millimetre-wave bi-polar planar near-field antenna measurement system is presented. The system development, from the positional scanner design, measurement system software, and the post-processing options including phaseless measurements is discussed. Finally, representative measured results at Ka and W bands will be presented to demonstrate the functionality of this novel system.