A Compact Component for Multi-Band Rejection and Frequency Coding in the Plasmonic Circuit at Microwave Frequencies

• Main Authors: Wenxuan Tang, Yujie Hua, Tie Jun Cui
• Format: Article
• Language: English
• Published: MDPI AG 2021-12-01
• Series: Electronics
• Subjects: band rejection; spoof surface plasmon polaritons; complementary resonator; compact circuit; coding metamaterials
• Online Access: https://www.mdpi.com/2079-9292/10/1/4

Plasmonic circuits, which support the propagation of spoof surface plasmon polaritons (SSPPs) at microwave frequencies, have been developed in recent years as an expected candidate for future highly integrated systems, mainly because of their extraordinary field confinements and sub-wavelength resolution. On the other hand, artificial electromagnetic (EM) resonators are widely adopted in metamaterial design for flexible resonance and band gaps. In this work, an electrically small complementary spiral, which is made up of six helix branches sculptured in the ground, is proposed to achieve independent resonances at six different frequency bands. Combined with the grounded corrugated transmission line (TL), the proposed component can provide designable multi-band rejection, and compose frequency coding circuits with a compact size (less than λ₀/4). The complementary spirals excited with the bending TL and the straight one are both investigated, and independence band rejections and designed 6-bit coding sequences in the frequency spectrum are demonstrated numerically and experimentally. Hence, it is concluded that such compact components can be adopted to flexibly control the rejection of waves in multi-frequency bands, and benefits the development of frequency-identification circuits and systems.