Proposal of diagnosis technique for radiation of electromagnetic field generated by electronic device

We have been developing an electromagnetic field intensity measurement system using an absorption screen. In this developed system, a very small change of temperature on an absorption screen illuminated by the electromagnetic wave is measured using an infrared camera with 2-D lock-in image-processing technique. Here, we propose to apply this system to a diagnosis technique for radiation of electromagnetic field generated by the antenna. Ordinary, an antenna is used for measurement of electromagnetic field. However, an antenna always disturbs the electromagnetic field as the measurement subject. Since the electromagnetic field as the measurement subject is less disturbed by the screen even if the screen is placed near the wave source, this system is suitable for the measurement of it near the wave source that is difficult to measure by using a common antenna for telecommunications. To show the effectiveness of this system, we tried to measure the magnetic field of around 2.45GHz emitted from a dipole and a patch antennae. Furthermore, the theoretically numerical calculations for the electromagnetic field distribution around the antenna were also carried out. The measured magnetic field distributions are in good agreement with the calculated one.