Analysis of Dynamic Magnetoelastic Coupling in Mechanically Driven Magnetoelectric Antennas

Mechanically driven magnetoelectric antennas are a promising new technology that enable a reduction in antenna size by many orders of magnitude, as compared to conventional antennas. The magnetoelastic coupling in these antennas, a phenomenon playing a direct role in determining performance, has been modeled using approaches that are severely lacking in both accuracy and tractability. In response to this problem, we take a physics-based approach to the analysis of magnetoelastic coupling. We find that certain directions of applied stress will maximize the coupling and we derive general expressions to quantify it. Our results are applied in comprehensive simulations that demonstrate the dynamic nature of the coupling as well as the impact of various operating conditions and material properties. Our work contributes analytical expressions and associated insight that can serve not only as guidelines for the design of mechanically driven magnetoelectric antennas, but also as stepping stones towards the development of more accurate models.

A Miniaturized CSRR Loaded 2-Element MIMO Antenna for LTE Band

A miniaturized 2 x 1 multiple-input multiple-output (MIMO) antenna is presented in this paper. The designed antenna contains two circular patches with Complimentary Split-Ring Resonator (CSRR) that are etched in the ground which has a profound effect on antenna size reduction. It also helps in the reduction of isolation between two antennas. The maximum isolation between the two antennas is -84.62 dB at 2.8 GHz. The size of an antenna becomes more compact i.e., 40 x 20 x 1.6 mm3 after incorporating CSRR. The maximum gain of the designed antenna is 5.8 dBi at 4.3 GHz and the minimum reflection coefficient is -35.15 dB at 1.63 GHz. The operating band of an antenna is wide from 1.3 GHz to 4.3 GHz which covers Bluetooth, WiMax, and LTE applications. The proposed antenna is useful for various wireless applications.

2.4 GHz Microstrip Patch Antenna for S-Band Wireless Communications

For any wireless communication, the antenna plays a very important role. The request for this technology is reduced antenna size, weight, and cost with a low profile, high performance, and low return loss (RL). To meet these requirements, the microstrip patch antenna (MPA) can be used. This research represents the design and manufacture of the MPA for the 2.4 GHz applications with very low RL and perfect voltage standing wave ratio (VSWR). Computer simulation technology (CST) studio is used to design and simulation. The proposed MPA is fabricated on flame retardant (FR-4) material as a substrate. The results show that the MPA is capable to deal with RL of -38.86 dB at the frequency of 2.393 GHz with a bandwidth (BW) of 58 MHz and VSWR of 1.02. The volume of the antenna is 75.85 × 57.23 × 1.6 mm 3.

Dual-band Rectangular Microstrip Patch Antenna for WiMAX Wireless Communications by Chemical Method

The rectangular microstrip patch antenna (RMPA) had designed and manufactured to operate in two working areas of the worldwide interoperability for microwave access (WiMAX) communication system. Flame retardant (FR-4) material had used for implementation, and the total antenna size was 57.22 × 1.6 mm3. The chemical method was used to implement the RMPA. The proposed antenna is capable of working at frequencies 2.51 GHz and 3.87 GHz experimentally. The results were -21.62 dB of return loss, and 50 MHz of bandwidth for the first frequency. Also, for second frequency was -20.01 dB of return loss, and 80 MHz of bandwidth.

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.

An All-Textile Dual-Band Antenna for BLE and LoRa Wireless Communications

In this paper, a dual-band conductive textile-based wearable antenna operating at LoRa-868 MHz and BLE-2.4 GHz is presented. The proposed antenna is intended for accurate geolocation, tracking and communication applications in the military, industrial and telemedicine industries. The low-profile patch antenna is suitable for integrating into clothing. It is composed of three textile layers: top and bottom silver-ink-printed polystyrene fabrics, and a neoprene substrate. To utilize the flexible and restorable properties of these textile materials, the proposed antenna is directly fed by a flexible cable using an aperture-coupled feeding technique. This method not only eliminates the use of the conventional, bulky, and metallic SMA connector but also introduces a secondary resonance at 2.4 GHz, enabling the dual-band property. Using a thin coaxial cable fixed on the aperture slot for proximity coupling, a compact antenna size of 150 mm2 is obtained that can easily be attached and detached on existing cloths. The proposed structure has been fabricated and measured in an anechoic chamber to verify the performance. Measured gain of 3.28 dBi and 3.25 dBi was realized for LoRa and BLE at an antenna size of 0.61 λg × 0.61 λg × 0.012 λg (where λg is guided wavelength at 868 MHz) with a front-to-back ratio (FBR) of greater than 10 dBi.

A Flexible Single Loop Setup for Water-Borne Transient Electromagnetic Sounding Applications

Water-borne transient electromagnetic (TEM) soundings provide the means necessary to investigate the geometry and electrical properties of rocks and sediments below continental water bodies, such as rivers and lakes. Most water-borne TEM systems deploy separated magnetic transmitter and receiver loop antennas—typically in a central or offset configuration. These systems mostly require separated floating devices with rigid structures for both loop antennas. Here, we present a flexible single-loop TEM system, the light-weight design of which simplifies field procedures. Our system also facilitates the use of different geometries of the loop antenna permitting to adjust the depth of investigation (DOI) and the minimum sounding depth in the field. We measure the turn-off ramp with an oscilloscope and use the DOI to assess the minimum and maximum exploration depth of our single-loop TEM system, respectively. A reduction of the loop-antenna size improves early-time TEM data due to a reduced length of the turn-off ramp, whereas an increase of the loop-antenna size enhances the signal strength at late times, which allows to investigate deeper structures below the lake bed. We illustrate the capabilities of our system with a case study carried out at Lake Langau in Austria. Our results show that our system is capable of reaching a DOI of up to 50m (with a maximum radius of the circular loop of 11.9m), while it also resolves the water layer down to a minimum thickness of 6.8m (when the radius is reduced to 6.2m).

NEW DESIGN OF MICRO-STRIP PATCH ANTENNA FOR WI-FI APPLICATIONS

In this research, a new design of a semi-star patch antenna is simulated for Wi-Fi applications. The antenna is operated at 2.4GHz, which is modified by inserting rectangular slots in the ground layer. Copper is used for the patch and ground layers, while FR-4 epoxy is used for the substrate layer. FR-4 epoxy has a Ԑr=4.3 and a loss tangent (tanδ) of 0.025. The antenna size is (45x48x1.6) mm³. The proposed antenna provides a reflection coefficient of -41.5 dB and a gain of 2.8 dB at the operating frequency. The proposed antenna is simulated by CST STUDIO SUITE 2019.