Thirty Years of Antenna Characterization in the Millimeter Wave Range at IETR

Since more than 30 years, IETR has been designing antennas for millimeter wave range applications. Coupled with this main topic, characterization capabilities have been developed in order to validate research work by measuring Electro-Magnetic radiation of the prototypes used as proof of concept. Of course, over such a long period of time, the different antenna test facilities have been improved, in correlation with the research needs and the evolution of the different equipment. In this paper, the different improvements performed are presented, as well as the objectives which shaped them. The guidelines cover the RFsystems, the measurement techniques, the different processing used, and the possible next steps. Indeed, to be consistent with research activities, the facilities must meet two main criteria: the systems have to be dimensioned to offer sufficient capabilities to characterize proof of concept prototypes; the versatility of the systems have to allow set-ups and measurement techniques to be tailored to short- and long- terms research needs. This historical overview of IETR millimeter wave range antenna test facilities shows the evolution of Vector Network Analyzers from the historic HP8510 to those of the latest generation, the integration of Compact Antenna Test Ranges eligible for millimeter and submillimeter wave characterization, the development of nearfield scanners for Electro-Magnetic probing or antenna characterization. For each category, a discussion is carried out to assess the advantages and disadvantages of the evolution choices made. To illustrate the key steps of these improvements, several experimental results are presented giving as well an overview of characterization needs in the millimeter wave-range.