As researchers around the world race toward the realization of 6G wireless communication systems, the need for antennas that can dynamically adapt to ever-changing signal environments has never been greater. A key requirement of 6G is intelligent beam control, which enables signals to be steered, shaped, and optimized in real time to support ultra-high data rates, low latency, and massive device connectivity.

In a new breakthrough, researchers from Tohoku University and the University of Surrey have successfully developed an innovative pattern-reconfigurable Yagi-Uda antenna integrated with a magnetic gear. The new design enables precise beam scanning while avoiding many of the drawbacks that have limited conventional reconfigurable antenna technologies.

Pattern-reconfigurable antennas are essential components for future 6G systems, as they can dynamically redirect radiation patterns toward desired users or devices. Existing approaches generally fall into two categories: electronic and mechanical. Both have significant trade-offs.

For example, electronic reconfigurable antennas, which rely on diodes and biasing circuits, offer extremely fast beam scanning on the order of microseconds but suffer from high insertion loss, nonlinearity, and non-reciprocal behavior. Mechanical approaches, on the other hand, provide linear and reciprocal responses but require complex mechanical connections and are prone to friction and wear.

To overcome these limitations, the research team proposed integrating a magnetic gear directly into the antenna system. A magnetic gear transmits torque without physical contact, using magnetostatic forces between arrays of small magnets. In the newly developed antenna, the lower part of the magnetic gear is mechanically driven, while the upper part--coupled magnetically--rotates in a fully contactless manner, even through the antenna's ground plane.

This contactless actuation eliminates the need for direct mechanical connections between the actuator and the antenna element, resulting in a system that is effectively free from friction and abrasion. Because the spacing between the magnetic gears remains constant during operation, the magnetostatic force is stable and highly linear. This makes multi-bit or even continuous antenna reconfiguration straightforward, without the nonlinear behavior seen in systems that rely on electromagnets with variable spacing.

The design also maintains low insertion loss, a critical requirement for high-frequency wireless systems. Dielectric losses can be minimized by optimizing the infill rate when fabricating the magnetic gear frame using a 3D printer, while magnetic losses remain low as long as the individual magnets are sufficiently small compared to the operating wavelength.

"By integrating a magnetic gear, we achieved stable, low-loss, and maintenance-free pattern reconfiguration, which could open new possibilities for adaptive antennas in future wireless networks," says Keisuke Konno, one of the lead researchers on the project.

Numerical simulations and experimental measurements confirmed that the proposed antenna delivers the expected radiation performance and successfully demonstrates clear advantages over conventional reconfigurable antennas.

The antenna builds on a rich legacy of innovation. The Yagi-Uda antenna, one of the most widely used directional antennas in the world, was originally invented at Tohoku University in the 1920s by Shintaro Uda, together with Hidetsugu Yagi. By combining this classic antenna architecture with modern magnetic-gear technology, the researchers have created a powerful new platform for next-generation wireless systems.

The research findings were published in IEEE Transactions on Antennas and Propagation on February 12, 2026.

Publication Details:

Title: Mechanically Pattern Reconfigurable Yagi-Uda Monopole Antenna Using Magnetic Gear

Authors: Keisuke Konno, Satoshi Yoshida, Sho Muroga, Nozomi Haga, Jerdvisanop Chakarothai, Qiang Chen, Gabriele Gradoni

Journal: IEEE Transactions on Antennas and Propagation

DOI: 10.1109/TAP.2026.3662161

Press release in Japanese