Design guidelines for the SPICE parameters of waveform-selective metasurfaces varying with the incident pulse width at a constant oscillation frequency

Abstract

In this study, we numerically demonstrate how the response of recently reported circuit-based metasurfaces is characterized by their circuit parameters. These metasurfaces, which include a set of four diodes as a full wave rectifier, are capable of sensing different waves even at the same frequency in response to the incident waveform, or more specifically the pulse width. This study reveals the relationship between the electromagnetic response of such waveform-selective metasurfaces and the SPICE parameters of the diodes used. First, we show that reducing a parasitic capacitive component of the diodes is important for realization of waveform-selective metasurfaces in a higher frequency regime. Second, we report that the operating power level is closely related to the saturation current and the breakdown voltage of the diodes. Moreover, the operating power range is found to be broadened by introducing an additional resistor into the inside of the diode bridge. Our study is expected to provide design guidelines for circuit-based waveform-selective metasurfaces to select/fabricate optimal diodes and enhance the waveform-selective performance at the target frequency and power level.

Design of a Dual‐Band Waveform‐Selective Metasurface Absorber Based on the Combination of Two Resonator Structures Loaded with Nonlinear Circuits

“…The resistive component of the diodes exhibits significant variations in response to the power level of the incoming wave, making maintaining impedance matching imperative to achieve optimal absorption performance. [38] This means that the dual-band MSA has a finite dynamic range for exhibiting the nonlinear absorption mechanism.…”

“…To mitigate the impact of the resistive component of the diodes and address this concern, a potential solution is to introduce an additional series resistor R add inside the diode bridge, [38] as depicted in Figure 4a. Importantly, despite this modification, the resistive component of the diodes continues to exhibit variations in response to changes in the input power.…”

“…The induced current flows through the four diodes for full-wave rectification, and then, the input signal frequency is mostly converted into zero frequency or a static field as seen from the Fourier expansion of |sin|. [37][38][39][40] Compared with the half-wave rectification produced by a single diode, the full-wave rectification with the four diodes (i.e., the diode bridge) can accelerate the conversion of incident EM waves to static fields. For capacitorbased nonlinear circuits, induced electric charges are stored in a capacitor and then discharged into a parallel resistor.…”

“…[36] However, the current research on nonlinear circuit-based MSAs only involves selective absorption of specific waveforms at a single frequency. [37][38][39][40][41][42] In practice, many wireless communication devices simultaneously utilize signals at different frequencies (e.g., Wi-Fi routers using 2.4 and 5 GHz). In addition, the two frequencies used in this study belong to the S-band (2-4 GHz) and the C-band (4-8 GHz), which are both radio navigation bands and have a wide range of applications in radar and navigation systems as well as global positioning system (GPS).…”