As the number of drones continues to increase and their applications become more widespread, the importance of neutralizing drones is becoming increasingly important. Despite the existence of studies on neutralizing drones, only a few studies exist on jammer antennas for antidrone systems. Handheld antidrone jammer antennas require high gain directivity beam patterns with narrow half-power beamwidths (HPBWs), while also covering multiple frequency bands used by drones. In this letter, we propose a broadband gain enhanced narrow beam vivaldi antenna with directors for a handheld antidrone system. The proposed antenna can cover GPS L1, ISM 2.4 GHz, ISM 5.8 GHz, and remotely piloted aircraft system bands. A multilayer ground plane is proposed to fix the radiation angle at the GPS L1 band, while a metallic ring is proposed to enhance bandwidth and gain at the GPS L1 band. Directors are also proposed to enhance the gain of the antenna and decrease the HPBW of the radiation pattern. The total size of the antenna is 140 mm × 90 mm × 270 mm, and the measured peak gain is 10 dB with a narrow HPBW of 20.9°. The proposed antenna would be suitable for use in portable handheld antidrone jamming.

Enzyme production by microorganisms on an industrial scale has demonstrated technical bottlenecks, such as low efficiency in enzyme expression and extracellular secretion. In this study, as a potential tool for overcoming these technical limits, radio-frequency electromagnetic field (RF-EMF) exposure was examined for its possibility to enhance production of an enzyme, α-amylase, in a filamentous fungus, Aspergillus oryzae. The RF-EMF perfectly resonated at 2 GHz with directivity radiation pattern and peak gain of 0.5 dB (0.01 Watt). Total protein concentration and activity of α-amylase measured in media were about 1.5–3-fold higher in the RF-EMF exposed (10 min) sample than control (no RF-EMF) during incubation (the highest increase after 16 h). The level of α-amylase mRNA in cells was approximately 2–8-fold increased 16 and 24 h after RF-EMF exposure for 10 min. An increase in vesicle accumulation within fungal hyphae and the transcription of some genes involved in protein cellular trafficking was observed in RF-EMF-exposed samples. Membrane potential was not changed, but the intracellular Ca²⁺ level was elevated after RF-EMF exposure. Our results suggest that RF-EMF can increase the extracellular level of fungal total proteins and α-amylase activity and the intracellular level of Ca²⁺.

Deep core temperature is the most basic and important information about health conditions. Non-contact infrared thermometers are widely used for human body temperature measurement. However, infrared thermometers are not suitable for deep core temperature measurement. To overcome this limitation, measuring deep core temperature with a microwave radiometer is gaining attention. In this study, we propose a dual-band on-body near-field antenna for measuring deep core temperature with a microwave radiometer application. The proposed antenna has a compact size of 20 mm $\times30$ mm $\times1.52$ mm. The negative (−) radiator is located at the top of the substrate and the positive (+) radiator is located at the bottom of the substrate. The dual-band is proposed for high temperature resolution and is achieved by a meander slot on the radiator. The antenna is fabricated on a high dielectric substrate and the stubs are proposed to reduce the size of the proposed antenna so that it can be used on various human body parts.

In this study, we proposed an indoor broadband dual-polarized 2 × 2 MIMO (multiple-input and multiple-output) antenna having dimensions of 240 mm × 200 mm × 40 mm, for application in 5G wireless communication systems. The proposed antenna comprised two vertically polarized circular monopole antennas (CMAs), two horizontally polarized modified rectangular dipole antennas (MRDAs), and a ground plane. The distance between the two MRDAs (MRDA1 and MRDA2) was 70.5 mm and 109.5 mm in the horizontal (x-direction) and 109.5 mm vertical (y-direction) directions, respectively. Conversely, the distance between the two CMAs (CMA1 and CMA2) was 109.5 mm and 70.5 mm in the horizontal (x-direction) and vertical (y-direction) directions, respectively. While the CMAs achieved broadband characteristics owing to the optimal gap between the dielectric and the driven radiator using a parasitic element, the MRDAs achieved broadband owing to the optimal distance between the dipole antennas. The observations in this experiment confirmed that the proposed could operate in the 5G NR n46 (5.15–5.925 GHz), n47 (5.855–5.925 GHz), n77 (3.3–4.2 GHz), n78 (3.3–3.8 GHz), and the n79 (4.4–5 GHz) bands. Moreover, it exhibited a wide impedance bandwidth (dB magnitude of $S_{11}$) of 101% in the 2.3–7 GHz frequency range, high isolation (dB magnitude of $S_{21}$), low envelope coefficient correlation (ECC), gain of over 5 dB, and average radiation efficiency of 87.19%, which verified its suitability for application in sub-6 GHz 5G wireless communication systems.

Human deep core temperature is a vital health condition parameter. Human body temperature change begins from the deep core followed by change in skin temperature. Measuring deep core temperature is the first action for rapid detection of health condition. Infrared thermometer can measure temperature; however, the only measures the skin temperature. The use of microwave radiometer for measuring deep core temperature has garnered attention. The antenna, an important component of the microwave radiometer, has rarely been focused upon in studies on measurement of deep core temperature. This study proposed compact dual-band on-body near field antenna with a reflector for measuring deep core temperature using a microwave radiometer. The proposed antenna size is 13 mm × 13 mm with a 20 mm × 20 mm reflector 3 mm above the radiator. The proposed antenna was simulated and designed on a full 3D body model and simplified flat phantom and measured on real human wrist. It achieved sufficient bandwidth and volume loss density can be used in microwave radiometers for measuring deep core temperature.