Design and characterization of a novel toroidal split-ring resonator

Area of Science:

• Electromagnetics
• Resonator Design
• Metamaterials

Background:

• Conventional cylindrical split-ring resonators (SRRs) suffer from magnetic flux leakage into surrounding free space.
• This radiated power leads to energy losses, reducing the resonator's quality factor.
• External electromagnetic shielding is often required to mitigate these losses.

Purpose of the Study:

• To design and characterize a novel toroidal split-ring resonator (SRR).
• To investigate the advantages of toroidal SRRs over conventional designs regarding magnetic field confinement and energy loss.
• To analyze the dependence of resonant frequency and quality factor on inductive coupling.

Main Methods:

• Detailed design and construction of the toroidal SRR.
• Experimental characterization of the continuous wave (cw) response in the frequency domain.
• Time-domain response analysis to a radio frequency (rf) pulse.
• Theoretical and experimental investigation of inductive coupling effects.

Main Results:

• The toroidal SRR demonstrates strong confinement of magnetic field lines within its bore.
• High intrinsic quality factors and stable resonance frequencies were achieved.
• Reduced energy losses were observed compared to conventional designs, eliminating the need for additional shielding.
• The dependence of resonant frequency and quality factor on inductive coupling was quantified.

Conclusions:

• The toroidal SRR offers superior performance due to enhanced magnetic field confinement.
• This novel design provides a pathway to higher-efficiency resonant circuits.
• The findings have implications for advanced electromagnetic applications requiring high-Q resonators.