In-Situ Measurement of Patch-Antenna Thermal Properties Using Fibers Bragg Grating in a Semi-Anechoic Environment

The performance of an antenna can be more or less sensitive to its thermal environment depending on its design. Indeed, the heating of an antenna mechanically deform all the parts constituting the antenna and also modify the electromagnetic and thermal properties of the materials used. In this paper, we present the first results of the evolution of the antenna return loss under thermal stress in a semi-anechoic environment made for 3D antenna measurements. A patch antenna was implement on a specific heating support localized at the center of a near-field 3D measurement facility. In particular, two fiber Bragg gratings were set up to achieve many acquisitions of the antenna temperature without disturbing its electromagnetic fields, and consequently its performances during the test. This work highlights a great compatibility between optic fibers and antenna, which could permit to acquire it RF characteristics under thermal stress with a high accuracy during the electromagnetic measurement.