These sub-wavelength antennas employ composite nanowires that greatly improve magnetoelectric coupling to support ultra-compact designs that are tunable to different low frequency ranges. To achieve good performance, conventional antennas must be comparable in size to the wavelengths of the signals they transmit. Lower frequency wireless communication signals typically have longer wavelengths and, therefore, require bulkier antennas. Available antenna designs struggle to adopt smaller, sub-wavelength profiles while retaining good performance across tunable lower frequency ranges.
Researchers at the University of Florida have developed an antenna from magnetoelectric nanowire arrays that achieves sub-wavelength dimensions and works over tunable, low frequency ranges. The nanowire composition enhances magnetoelectric coupling, enabling the smaller antenna to operate using the mechanical resonance that occurs at lower frequencies.
Compact, sub-wavelength antennas for wireless communication over multiple low frequency ranges, such as FM, Ham radio, VLF, or VHF
The ultra-compact antenna achieves good performance even if its size is much smaller than the electromagnetic wavelength of the transmitted signal. The antenna utilizes biphasic magnetoelectric nanowires that combine piezoelectric and magnetostrictive materials to produce a material magnetoelectric effect. It receives and transmits signals through this effect at the nanowires’ mechanical resonance frequencies, which are much lower than electrical resonance frequencies. Since mechanical resonance requires less space, this low frequency antenna has a far more compact profile than standard low frequency antennas. The antenna’s electrodes have gaps that are similar in size to the lengths of the assembled magnetoelectric nanowires. The gaps and sizes of the nanowires are adjustable, allowing users to tune the resonance and operating region of the antenna.