Potential Application of Pin-to-Liquid Dielectric Barrier Discharge Structure in Decomposing Aqueous Phosphorus Compounds for Monitoring Water Quality

Here, we proposed a pin-to-liquid dielectric barrier discharge (DBD) structure that used a water-containing vessel body as a dielectric barrier for the stable and effective treatment of aqueous solutions in an open atmosphere. To obtain an intense pin-to-liquid alternating current discharge using a dielectric barrier, discharge characteristics, including the area and shape of a ground-plate-type electrode, were investigated after filling the vessel with equivalent amounts of water. Consequently, as the area of the ground electrode increased, the discharge current became stronger, and its timing became faster. Moreover, we proposed that the pin-to-liquid DBD reactor could be used to decompose phosphorus compounds in water in the form of phosphate as a promising pretreatment method for monitoring total phosphorus in water. The decomposition of phosphorus compounds using the pin-to-liquid DBD reactor demonstrated excellent performance—comparable to the thermochemical pretreatment method—which could be a standard pretreatment method for decomposing phosphorus compounds in water.

Flat UWB antenna with optimized ground plate

The design of a broadband antenna based on a combination of electric and magnetic emitters is proposed. Antenna size ratios are proposed that provide a wide operating frequency band. The results of numerical modeling of the standing wave ratio and radiation patterns for a particular case with a matching range from 13 GHz to 27 GHz are presented.

Microstrip Antenna with High Gain and Strong Directivity Loaded with Cascaded Hexagonal Ring-Shaped Metamaterial

A new cascaded hexagonal ring-shaped metamaterial element is designed, which is arranged periodically and placed on the top of a traditional microstrip antenna to optimize the performance of the traditional antenna. The simulation results show that the new metamaterial microstrip antenna works at near 10 GHz, the impedance bandwidth is extended by 0.25 GHz and the gain is increased by 113.6% compared with a traditional microstrip antenna. Cross-shaped slots are etched on the ground plate of the microstrip antenna to widen the impedance bandwidth. It is shown that the impedance bandwidths at the resonant frequencies of 10 GHz and 14 GHz are broadened by 0.06 GHz and 0.56 GHz, respectively, and the gain of the slot-etched antenna is 13.454 dB. After the metamaterial unit structure is optimized, a nested double-hexagon ring-shaped electromagnetic metamaterial unit structure is proposed. The metamaterial slot microstrip antenna operates in two frequency bands of 10 GHz and 14 GHz; the relative bandwidths are increased to 16.9% and 19.4% with two working bandwidths of 1.74 GHz and 4.98 GHz, respectively; and the gain and directivity are also improved compared with the traditional microstrip antenna. The metamaterial unit structure proposed in this paper is of certain reference value for the variety of metamaterial and the application of metamaterial in traditional microstrip antennas.

Comparison of Two designs of Inverted F antenna in n78 band

This paper consists of comparison of design of two inverted F shape antennas in n78 band (3500 MHz). The antennas shown in this paper have rectangular ground plate. First design has a conducting surface over ground plate which has an inverted F shaped strip in the same plane. The other design of antenna which is considered here has vertical shorting strip placed on it, which again has a rectangular plate perpendicular to it. Considering different parameters like radiation pattern, gain, VSWR and reflection coefficient here we will see the best results of both the antennas in n78 band and talk about the design which can be used in most of our applications

A Compact Broadband Circularly Polarized Slot Antenna for Universal UHF RFID Reader and GPS

A novel compact printed broadband circularly polarized slot antenna is proposed in this paper. The antenna consists of an inverted L-shaped coplanar waveguide feed structure and a square ground plate loaded with three rectangular slots. The antenna achieves good impedance matching and circular polarization characteristics by adjusting the size of the L-shaped band and the rectangular slot. The simulation results show that the antenna has a 10-dB impedance bandwidth of 1360 MHz (690-2050 MHz) and a 3 dB axial ratio (AR) bandwidth of 490 MHz (770-1260 MHz). Additionally, the maximum gain reached 4.02 dBi. The antenna proposed in this paper can be applied to UHF RFID and GPS frequency bands.

Design of Window Grille Shape-Based Multiband Antenna for Mobile Terminals

Combined with the classic Chinese window grille structure, this paper proposes and designs a multiband microstrip antenna that can be used in wireless mobile terminal equipment. The antenna radiator adopts a rectangular bending structure with four loops, which increases the effective current path of the antenna radiator in a limited space, so that the overall antenna is miniaturized. The branch structure of the four-ring phase set increases the current path of the antenna, making the antenna multiband. The electromagnetic simulation software HFSS was used for antenna modeling and parameter optimization, and the influence of the feed structure, feed mode, and ground plate shape on the antenna was compared and analyzed. The test results show that the antenna can cover four bands, 0.85–1.1 GHz, 1.2–1.8 GHz, 2.40–2.7 GHz, and 5.05–6.3 GHz, and produce 6 main frequency points, 0.9 GHz, 1.3 GHz, 1.6 GHz, 2.55 GHz, 5.3 GHz, and 6.05 GHz. The antenna can cover various navigation systems, Bluetooth, WLAN, ISM frequency band, and 5G (5.725–5.825 GHz).

6 Monopole Elements Array Intelligent Antennas for IoT Based Environmental Surveillance Network

Three types of 6 monopoles array intelligent antennas was numerically and practically examined. The main purposes of the investigation is to guarantee that those designed antennas are feasible to implement and to install in a particular IoT based environmental surveillance network configuration. The basic differences of the three intelligent antennas lied on the frequency operations (i.e. 433 MHz, 875-915 MHz and 2.5 GHz) and the actual environment operations (whether for indoor or outdoor). The extreme differences of such frequency operations, of course, affecting the differences on the whole antenna physical dimension. The higher the frequency operation determined then the smaller the physical size of the designed antennas produced. However, the deep intelligent antenna evaluations presented in the paper is the one that operated on frequency band of 875 -915 MHz. The intelligent electronic part of six monopole wire elements arrayed on a circular ground plate was composed of LoRa chip module, Android Uno microcontroller, and the switching network part. The three parts determined whole antenna operation throughout the IoT network. The results of whole antenna examinations are thoroughly discussed in the paper.

Modelling and optimization of the linear tapered slot antenna

A key component of any phased array or radar sensor is its antenna. For ultra wide band systems usually four types of antenna are being used: microstrip, tapered slot, sinuous and Yagi-Uda. The microstrip antenna generates two main lobes, which makes it a bidirectional antenna, like the tapered slot, sinuous, or Yagi-Uda antennae. Several efforts had been made to shift the bidirectional character of the microstrip antenna into unidirectional by placing a ground plate to absorb the undesirable main lobe. These efforts successfully eliminated the undesirable main lobe; however, side effects were introduced along the way, such as the remaining main lobe’s direction became frequency dependent. On the other hand, the sinuous antenna design is very complex when compared with the tapered slot antenna, involving multiple curvatures and angles. The Yagi–Uda antenna design, although less complex than the sinuous, still requires multiple segments and is more complicated than the tapered slot antenna. This study examined and analyzed primary parameters regarding their individual impact on linear tapered slot antenna design. The result is a set of recommendations for linear tapered slot antenna design to operate within the UWB frequency range. Unlike previous studies, which only focused on a certain set of these parameters, this paper provides a comprehensive recommendation for the parameters, which should result in a functional tapered slot antenna design. This set of recommendation can also serve as a base for further optimization, if desired. When used for optimization, the results from this study can guide the direction of changes when multiple parameters need to be adjusted simultaneously. Furthermore, this set of recommendations can be applied to other tapered slot antenna designs, as they all share, although are not defined completely, by these investigated parameters.

Co-Design and Control of a Magnetic Microactuator for Freely Moving Platforms

A current goal for microactuators is to extend their usually small working ranges, which typically result from mechanical connections and restoring forces imposed by cantilevers. In order to overcome this, we present a bistable levitation setup to realise free vertical motion of a magnetic proof mass. By superimposing permanent magnetic fields, we imprint two equilibrium positions, namely on the ground plate and levitating at a predefined height. Energy-efficient switching between both resting positions is achieved by the cooperation of a piezoelectric stack actuator, initially accelerating the proof mass, and subsequent electromagnetic control. A trade-off between robust equilibrium positions and energy-efficient transitions is found by simultaneously optimising the controller and design parameters in a co-design. A flatness-based controller is then proposed for tracking the obtained trajectories. Simulation results demonstrate the effectiveness of the combined optimisation.