scholarly journals Design of Heterogenous Two-Element Array Antenna on an Electrically Thick Substrate for High Isolation and Low Pattern Correlation Using Modal Difference in Radiation Patterns

2020 ◽  
Vol 10 (11) ◽  
pp. 3916
Author(s):  
Tae Heung Lim ◽  
Byung-Jun Jang ◽  
Hosung Choo
Keyword(s):  
Elevation Angle ◽  
Array Antenna ◽  
Interference Signal ◽  
Radiation Patterns ◽  
Inversion Algorithm ◽  
High Isolation ◽  
Mode Decomposition ◽  
Thick Substrate ◽  
Power Inversion ◽  
Element Array

In this paper, we propose a novel design of a two-element array antenna on an electrical thick substrate with an extremely narrow array distance. The proposed array consists of a rectangular ring patch printed on a thick substrate and a monopole wire in the center of the substrate. Each element has a modal difference in the radiation pattern, causing high isolation and low correlation between the array elements. From the measurement results, the monopole and patch elements exhibit reflection coefficients of −10 dB and −10.7 dB with peak gains of 3.8 dBi and 6.1 dBi, respectively, at 1.6 GHz. The mutual coupling between the two elements is −20.7 dB. For modal analysis of the antenna pattern, spherical mode decomposition is performed on the radiation patterns of the two elements, and low envelope correlation coefficient levels below 16% are maintained. We also investigate the antijamming performance using a power inversion algorithm in a practical pattern nulling application; a null depth of −47.7 dB and a null width of 33.2° are obtained when the interference signal arrives at the elevation angle of 45°.

scholarly journals THE BROAD APPLICATION OF A DEPTH INVERSION ALGORITHM BASED ON THE DYNAMIC MODE DECOMPOSITION

2020 ◽  
pp. 50
Author(s):  
Matthijs Gawehn ◽  
Sierd de Vries ◽  
Stefan Aarninkhof
Keyword(s):  
The Netherlands ◽  
Wave Field ◽  
Dynamic Mode Decomposition ◽  
Dynamic Mode ◽  
Inversion Algorithm ◽  
Broad Application ◽  
Significant Wave ◽  
Mode Decomposition ◽  
Novel Algorithm

The technological boost of drones and satellites offers new and more flexible platforms for video-based depth inversion. It signals a desire to generate depth estimates on-the-fly, requiring more flexibility and high computational speeds. For this purpose, a novel algorithm was developed, which is based on the Dynamic Mode Decomposition. The analysis of video from three different field-sites in the Netherlands, Australia and US, suggests that 32 s of video are sufficient to correctly capture the significant wave components in the wave-field. It means that DMD-based depth inversion is suited for fast coastal reconnaissance.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/TcE13C1oTKw

Dual‐port planar MIMO antenna with ultra‐high isolation and orthogonal radiation patterns

2015 ◽  
Vol 51 (1) ◽  
pp. 7-8 ◽  
Author(s):  
Han Wang ◽  
Zhijun Zhang ◽  
Zhenghe Feng
Keyword(s):  
Radiation Patterns ◽  
Mimo Antenna ◽  
High Isolation

A Technique of Scan Blindness Elimination for Planar Phased Array Antenna using Miniaturized EBG

2014 ◽  
Vol 69 (2) ◽  
Author(s):  
M. S. M. Isa ◽  
R. J. Langley ◽  
S. Khamas ◽  
A. A. M. Isa ◽  
M. S. I. M. Zin ◽  
...  
Keyword(s):  
Surface Wave ◽  
Band Gap ◽  
Radiation Pattern ◽  
Phased Array ◽  
Elevation Angle ◽  
Array Antenna ◽  
Phased Array Antenna ◽  
Electromagnetic Band Gap ◽  
Novel Technique ◽  
Wave Effects

In this paper, the planar phased array antenna scan blindness characteristic has been analyzed and a novel technique of eliminating the scan blindness for the phased array antenna has been introduced. The scan blindness of the center element has been used to present the entire phased array characteristic. The array scan blindness characteristics have been simulated and analyzed using CST Microwave Studio (CST MWS). The 5×3 planar phased array antenna radiation patterns against the pattern elevation angle direction has been simulated and compiled. The array’s scan blindness has been determined at the angle of approximately 47⁰. The miniaturized capacitive loaded Electromagnetic Band Gap (EBG) has been developed and introduced between the array elements to eliminate the problem. Based on the simulated results, it is shown that the use of a miniaturized EBG is effective in reducing the surface wave effects and eliminates the scan blindness in the array radiation pattern. This novel finding is very useful to improve the antenna directive efficiency for the directional radar and satellite application.

A Frequency- and Pattern-Reconfigurable Two-Element Array Antenna

2018 ◽  
Vol 17 (4) ◽  
pp. 617-620 ◽  
Author(s):  
Siti Nailah Mastura Zainarry ◽  
Nghia Nguyen-Trong ◽  
Christophe Fumeaux
Keyword(s):  
Array Antenna ◽  
Element Array

scholarly journals Four-Element Microstrip Patch Array Antenna with Corporate-Series Feed Network for 5G Communication

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Janam Maharjan ◽  
Dong-You Choi
Keyword(s):  
Microstrip Antennas ◽  
Array Antenna ◽  
Frequency Bandwidth ◽  
Microstrip Patch ◽  
Feeding Technique ◽  
Feed Network ◽  
Overall Performance ◽  
5G Communication ◽  
Element Array ◽  
Series Technique

The paper proposes a simple four-element microstrip patch array antenna fed with corporate-series technique. The paper compares the proposed design with four-element antennas fed with only series-fed and corporate-fed microstrip antennas. All three antenna designs use rectangular microstrip patch elements with two insets and slots on both sides of the patch. The patch elements are accompanied by Yagi elements: three director elements and two reflector elements. Through comparison of simulation results, the paper shows that four-element array antenna with combined corporate-series feeding technique performs better compared to antennas with only either series or corporate feeding network. The proposed corporate-series fed antenna achieves better performance with wide frequency bandwidth of 25.04–30.87 GHz and gain of 9.5 dB. The antenna has an end-fire radiation pattern. Overall performance shows that the proposed corporate-series-fed microstrip patch antenna with Yagi elements is suitable for next generation 5G communication.

Aircraft Mounted Neural Network Electrostatic Discharge (ESD) Location

2012 ◽  
Vol 721 ◽  
pp. 331-336
Author(s):  
Paul Ratnamahilan Polycarp Hoole ◽  
Nur Farah Aziz ◽  
Velappa Ganapathy ◽  
Kanesan Jeevan ◽  
Ramiah Harikrishnan ◽  
...  
Keyword(s):  
Neural Network ◽  
Electrical Activity ◽  
Electric Fields ◽  
Array Antenna ◽  
Lightning Activity ◽  
Electronic Systems ◽  
Distance Range ◽  
The Neural Network ◽  
Unique Shape ◽  
Element Array

Abstract. Cloud to ground and cloud to cloud lightning flashes pose a threat to the aircraft body and the electronic systems inside the aircraft. In this paper we present a single unit, as opposed to a three unit, lightning locator mounted on the aircraft that uses the wave-shapes of electromagnetic fields radiated by lightning and electrical activity ahead of the aircraft to locate the distance range of lightning activity. A three element array antenna scans the area ahead of the aircraft to narrow down the area ahead where the lightning or threatening electrical activity is. Moreover, the unique shape of the electric fields depending on the distance from the lightning activity is used by a neural network to train and recognize the distance range of the lightning activity from the aircraft on which the lightning detector is mounted. The combined use of the three element array antenna and the neural network provides the required knowledge of lightning activity for the pilot to take evasive action.

Tropospheric NO2 and HCHO derived from dual-scan MAX-DOAS measurements in Uccle (Belgium) and application to S5P/TROPOMI validation

2020 ◽  
Author(s):  
Ermioni Dimitropoulou ◽  
Francois Hendrick ◽  
Martine M. Friedrich ◽  
Gaia Pinardi ◽  
Frederik Tack ◽  
...  
Keyword(s):  
Vertical Profile ◽  
A Priori ◽  
Elevation Angle ◽  
Optical Absorption Spectroscopy ◽  
Azimuthal Direction ◽  
Inversion Algorithm ◽  
Vertical Column ◽  
Near Surface ◽  
Mixing Ratios ◽  
Horizontal Variation

<p>Ground-based Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) measurements of aerosols, tropospheric nitrogen dioxide (NO<sub>2</sub>) and formaldehyde (HCHO) have been carried out in Uccle, Brussels, during two years (March 2018 – March 2020). The MAX-DOAS instrument has been operating in both UV and visible (Vis) wavelength ranges in a dual-scan configuration consisting of two sub-modes: (1) an elevation scan in a fixed viewing azimuthal direction (the so-called main azimuthal direction) pointing and (2) an azimuthal scan in a fixed low elevation angle (2<sup>o</sup>). By applying a vertical profile inversion algorithm in the main azimuthal direction and an adapted version of the parameterization technique proposed by Sinreich et al. (2013) in the other azimuthal directions, near-surface  concentrations (VMRs) and vertical column densities (VCDs) are retrieved in ten different azimuthal directions.</p><p>The present work focuses on the seasonal horizontal variation of NO<sub>2 </sub>and HCHO around the measurement site. The observations show a clear seasonal cycle of these trace gases. An important application of the dual-scan MAX-DOAS measurements is the validation of satellite missions with high spatial resolution, such as TROPOMI/S5P. Measuring the tropospheric  VCDs in different azimuthal directions is shown to improve the spatial colocation with satellite measurements leading to a better agreement between both datasets. By using  vertical profile information derived from the MAX-DOAS measurements, we show that a persistent systematic underestimation of the TROPOMI  data can be explained by uncertainties in the a-priori NO<sub>2</sub> profile shape in the satellite retrieval. A similar validation study for TROPOMI HCHO is currently under progress and preliminary results will be presented.</p><p><strong>References:</strong></p><p>Sinreich, R., Merten, A., Molina, L., and Volkamer, R.: Parameterizing radiative transfer to convert MAX-DOAS dSCDs into near-surface box-averaged mixing ratios, Atmos. Meas. Tech., 6, 1521–1532, https://doi.org/10.5194/amt-6-1521-2013, 2013.</p>

Sign in / Sign up

Export Citation Format

Share Document