Antenna miniaturization technology has been a challenging problem in the field of antenna design. The demand for antenna miniaturization is even stronger because of the larger size of the antenna in the low-frequency band. In this paper, we consider MEMS magnetoelectric antennas based on mechanical resonance, which sense the magnetic fields of electromagnetic waves through the magnetoelectric (ME) effect at their mechanical resonance frequencies, giving a voltage output. A 70 μm diameter cantilever disk with SiO₂/Cr/Au/AlN/Cr/Au/FeGaB stacked layers is prepared on a 300 μm silicon wafer using the five-masks micromachining process. The MEMS magnetoelectric antenna showed a giant ME coefficient is 2.928 kV/cm/Oe in mechanical resonance at 224.1 kHz. In addition, we demonstrate the ability of this MEMS magnetoelectric antenna to receive low-frequency signals. This MEMS magnetoelectric antenna can provide new ideas for miniaturization of low-frequency wireless communication systems. Meanwhile, it has the potential to detect weak electromagnetic field signals.

Recently, the realization of electromagnetic wave signal transmission and reception has been achieved through the utilization of the magnetoelectric effect, enabling the development of compact and portable low-frequency communication systems. In this paper, we present a miniaturized low-frequency communication system including a transmitter device and a receiver device, which operates at a frequency of 44.75 kHz, and the bandwidth is 1.1 kHz. The transmitter device employs a Terfenol-D (80 mm × 10 mm × 0.2 mm)/PZT (30 mm × 10 mm × 0.2 mm)/Terfenol-D glued composite heterojunction magnetoelectric antenna and the strongest radiation in the length direction, while the receiver device utilizes a manually crafted coil maximum size of 82 mm, yielding a minimum induced electromagnetic field of 1 pT at 44.75 kHz. With an input voltage of 150 V, the system effectively communicates over a distance of 16 m in air and achieves reception of electromagnetic wave signals within 1 m in simulated seawater with a salinity level of 35% at 25 °C. The miniaturized low-frequency communication system possesses wireless transmission capabilities, a compact size, and a rapid response, rendering it suitable for applications in mining communication, underwater communication, underwater wireless energy transmission, and underwater wireless sensor networks.

This paper presents a guided-mode resonance (GMR) reflector for sapphire based Fabry-Perot (F-P) sensors that enables tunable or wideband high reflectance with high temperature resistance, which is expected to effectively regulate the performance of F-P sensors and offer a novel approach for designing F-P sensors in harsh environments. Intrinsic and extrinsic GMR gratings are proposed, and their optical and thermal properties are investigated and compared through numerical simulations, such as rigorous coupled-wave analysis and finite element analysis methods. The quantitative results indicate high feasibility for harsh environment applications and the potential for adopting different demodulation methods. Significant enhancement in the F-P sensor performance is obtained through analysis based on the F-P interference model, and the spectrum fineness and sensor sensitivity can be enhanced by at least one order of magnitude. The GMR reflector can be extended to other types of F-P sensors, demonstrating significant potential in high-temperature applications.