Suppression of Spurious Emissions From a Spiral Inductor Through the Use of a Frequency-Selective Surface

In this paper, a new concept of adding a band-stop frequency-selective surface (FSS) to suppress spurious emissions from a spiral inductor is proposed. These emissions are especially serious, when the inductor has a wide impedance-matching band. The added FSS is designed to narrow the impedance-matching bandwidth, and lower the radiation efficiency without sacrificing the series inductance and quality factor of the inductor. In particular, an FSS-added spiral inductor is implemented and the measured results show that, all the objectives are achieved. A new FSS for this application is also proposed.