Wideband Antenna Design for Millimeter-Wave Applications

Wideband antenna design in the millimeter-wave band addresses the growing demand for high-data-rate wireless links, sensor networks and emerging Internet of Things applications. At these frequencies (typically 24–100 GHz), antenna elements must combine broad impedance bandwidth, stable radiation patterns and compact form factors suited to mass-production. Techniques such as substrate-integrated waveguide (SIW), gap waveguide, coplanar-waveguide and microstrip feeding networks are widely adopted to suppress unwanted modes and extend usable bandwidth. Passive structures—including sequentially fed arrays, parasitic elements and dielectric resonators—further broaden operational bands and improve axial-ratio performance for circular polarisation. Meanwhile, integration of magneto-electric dipoles and multi-resonant stacks enables electrically small footprints without compromising gain. These advances underpin 5G base stations, vehicle radar systems and low-earth-orbit communication terminals, offering multi-gigabit capacity over congested spectra and ensuring robust links across varying device orientations.

Research from Nature Portfolio

Recent studies have introduced a printed planar antenna exploiting a coplanar-waveguide-fed modified microstrip monopole. By integrating capacitive stubs and phase-sequencing along the microstrip, the design achieves more than 8 GHz of bandwidth in the 25–33.5 GHz region with a sub-3 dB axial ratio across 26–33.5 GHz. The structure delivers an average realised gain of 10 dBic while maintaining a compact profile, demonstrating potential for Internet of Things deployments in satellite-oriented and remote sensor networks.

Wideband Antenna Design for Millimeter-Wave Applications publication trend

The graph below shows the total number of articles in wideband antenna design for millimeter-wave applications across all publications each year (not limited to Nature Index journals).

Technical terms

Millimeter-wave (mm-wave): Electromagnetic spectrum from 30 GHz to 300 GHz, enabling high-speed wireless links.

Impedance bandwidth: Frequency span over which the antenna’s input reflection (S₁₁) remains below –10 dB.

Circular polarisation (CP): Wave polarization in which the electric field rotates at a constant amplitude.

Axial ratio (AR): Measure of CP quality; ratios under 3 dB indicate near-ideal circularity.

Coplanar waveguide (CPW): Transmission line with ground planes on either side of a central conductor on the same substrate layer.

Magneto-electric (ME) dipole: Combined electric and magnetic radiators that enhance bandwidth and radiation diversity.

Characteristic mode analysis (CMA): Method to decompose antenna currents into orthogonal modes for targeted bandwidth and polarization control.

Dielectric resonator antenna (DRA): Radiator using a dielectric block to achieve high radiation efficiency and wide bandwidth.

References

1. Highly integrable planar-structured printed circularly polarized antenna for emerging wideband internet of things applications in the millimeter-wave band. Scientific Reports (2024).
2. Broadband Cross-Slotted Patch Antenna for 5G Millimeter-Wave Applications Based on Characteristic Mode Analysis. IEEE Transactions on Antennas and Propagation (2022).
3. Low-Profile and Wideband Circularly Polarized Magneto-Electric Dipole Antenna Excited by a Cross Slot. IEEE Access (2022).
4. Ultra-Wideband Hybrid Magneto-Electric Dielectric-Resonator Dipole Antenna Fed by a Printed RGW for Millimeter-Wave Applications. IEEE Access (2021).