Synopsis: Superconducting Antennas Tune In

Metamaterials made of superconducting elements could lead to efficient antennas for wireless communications.
Synopsis figure
C. Kurter et al., Phys. Rev. Applied (2015)

Metamaterials have been used to build more efficient and directional radio-frequency (rf) antennas for wireless communications. Most schemes, however, work at one fixed frequency and require impractically large components for operation at a few megahertz (MHz)—a frequency range that can be reflected by the Earth’s ionosphere and is thus suitable for long-range communications. Now, a team led by Steven Anlage at the University of Maryland, College Park, has demonstrated a new metamaterial, made with superconducting elements, that could be used to build tunable and efficient rf antennas.

The device consists of two-dimensional arrays of spirals made of niobium, a superconductor with a critical temperature (Tc) of 9.2K. Several arrays are stacked on top of each other to form a three-dimensional structure, which was placed between transmitting and receiving antennas to study its electromagnetic response. Below Tc, each spiral acts like an inductor-capacitor circuit with a sharp resonance. In isolation, each spiral resonates at 25MHz, but the coupling between multiple spirals shifts the resonance of the entire structure to lower frequencies. The authors demonstrated that this resonance can be tuned over a 0.25-MHz range by varying the temperature by a few degrees. The effect occurs because temperature controls the density of superconducting electrons and thus the effective inductance of each resonator. The metamaterial structure could be placed near a radio-frequency source to improve the source’s coupling to free space and boost its efficiency.

This research is published in Physical Review Applied.

–Matteo Rini


More Announcements »

Subject Areas

MetamaterialsMaterials Science

Previous Synopsis

Quantum Information

Heralded Qubit Transfer

Read More »

Related Articles

Viewpoint: Relaxons Heat Up Thermal Transport
Materials Science

Viewpoint: Relaxons Heat Up Thermal Transport

A recasting of the theory that underlies thermal transport in electrical insulators relies on new vibrational modes called relaxons. Read More »

Viewpoint: Improving Electronic Structure Calculations
Materials Science

Viewpoint: Improving Electronic Structure Calculations

A new approach to calculating the properties of molecules and solids may offer higher accuracy at reasonable computational cost, accelerating the discovery of useful materials. Read More »

Synopsis: Jiggling Graphene

Synopsis: Jiggling Graphene

The random quivering of graphene membranes could be exploited to generate electricity. Read More »

More Articles