Design and Analysis of a Novel Compact Metamaterial Absorber Based on Double-Layer ITO Resistive Film for Improving Signal Integrity

Abstract

This paper presents a compact metamaterial absorber (MMA) based on double-layer ITO resistive film for suppression of electromagnetic interference (EMI) to improve signal quality and signal integrity (SI). In the design of MMA, based on the classic Jerusalem cross, circular and fan-shaped structures are combined to increase its equivalent capacitance to achieve frequency shift, and an equivalent circuit model is established to analyze the key factors affecting its absorption rate. At the same time, the full-wave simulation results show that more than 90&#x0025; absorption rate is achieved in the frequency range of 8.9 GHz-14.0 GHz, and the measurement results show that the absorption rate of MMA at different incident angles is consistent with the simulation. Moreover, microstrip antenna and differential microstrip transmission line are also designed as equivalent radiation sources. The co-simulation results show that the 3 m field radiation of the patch antenna is reduced by 10 <inline-formula> <tex-math notation="LaTeX">$dB\mu V$ </tex-math></inline-formula> at 10 GHz. At the same time, the eye height of the differential microstrip transmission line has increased from 68 mV to 340 mV, indicating that the signal integrity problem has been significantly improved. The size of the unit is only about 0.065 <inline-formula> <tex-math notation="LaTeX">$\lambda _{L}\times 0.065\,\,\lambda _{L}$ </tex-math></inline-formula> where <inline-formula> <tex-math notation="LaTeX">$\lambda _{L}$ </tex-math></inline-formula> is the wavelength of the lowest frequency, and the total thickness of the absorber is only 0.047 <inline-formula> <tex-math notation="LaTeX">$\lambda _{L}$ </tex-math></inline-formula>. The proposed MMA has the characteristics of miniaturization, ultra-wideband, high absorption rate, and polarization insensitivity, which provides a new suppression method for the radiation problem of gradually miniaturized electronic equipment.