Abstract
For an antenna-like-element model appearing in a configuration of printed circuit boards consisting of a driver and a receiver boards separated by spacers on the chassis of which signal is connected each other through a semi-rigid cable, an equivalent circuit model is proposed and then the relation between input impedance and radiated emission characteristics is studied. By making a measurement of the radiated emission from the assembly and comparing the measured and the computed results of the input impedance of the concerned signal-ground containing the metal spacers, it is shown that the resonance frequencies in the input impedance characteristics and the peak frequencies in the radiated emission are in a good agreement. This means that the signal-ground system having the metal spacers results in a serious role of antenna. The equivalent circuit model proposed here is effective to estimate the peak frequencies in the radiated emission in addition to the evaluation of the input impedance characteristics.