scholarly journals Antenna Array with TEM-Horn for Radiation of High-Power Ultra Short Electromagnetic Pulses

Electronics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1011
Author(s):  
Vladimir M. Fedorov ◽  
Mikhail V. Efanov ◽  
Vasiliy Ye. Ostashev ◽  
Vladimir P. Tarakanov ◽  
Aleksander V. Ul’yanov
Keyword(s):  
Antenna Array ◽  
High Power ◽  
Electromagnetic Interference ◽  
Rise Time ◽  
High Efficiency ◽  
Ultra Wideband ◽  
Rectangular Plates ◽  
Antenna Aperture ◽  
Electromagnetic Pulses ◽  
Power Radiation

An antenna array with short shielded transverse electromagnetic horns (S-TEM-horns) for emitting high-power radiation of ultra-short electromagnetic pulses (USEMP) has been created and researched. The antenna unit consists of an ultra-wideband antenna array with four S-TEM horns, with each connected to a two-wire HF transmission line, and these four lines are connected to an antenna feeder. This feeder is connected to a semiconductor generator with the following parameters: a 50 Ohm connector, 10–100 kV high-voltage monopolar pulses, a rise time of about 0.1 ns, FWHM = 0.2–1 ns, and pulse repetition rates of 1–100 kHz. The antenna array was designed and optimized to achieve a high efficiency of about 100% for the antenna aperture by using a 2 × 2 array with S-TEM-horns, with shielding rectangular plates for the return current. The transient responses were studied by simulation using the electromagnetic 3D code “KARAT” at the time domain and experimentally with the use of our stripline sensor for measurement of the impulse electrical field with a 0.03 ns rise time and a 7 ns duration at the traveling wave. The radiators were emitting USEMP waves with a hyperband frequency spectrum of 0.1–6 GHz. The radiation with an amplitude of 5–30 kV/m of the E-field strength at a distance of up to 20 m was successfully applied to test the electronics for immunity to electromagnetic interference.

A Design of Multi-element Anti-jamming GPS Antenna

2020 ◽  
Vol 13 ◽  
Author(s):  
Xianquan Luo ◽  
Juwei Lv
Keyword(s):  
Antenna Array ◽  
Electromagnetic Interference ◽  
Single Mode ◽  
Development Trend ◽  
Antenna Aperture ◽  
Half Wavelength ◽  
Weak Intensity ◽  
Satellite Signal ◽  
L1 And L2 ◽  
The Development Trend

Background: With the development of the application of GPS satellite, the requirements of anti-jamming and integration for navigation receiving terminal are gradually raised. Methods: In terms of anti-jamming performance, because the satellite signal arrives at the ground with weak intensity and is vulnerable to electromagnetic interference, the positioning results are not available. Therefore, in complex electromagnetic environment, the anti-jamming navigation receiving terminal is needed, and the interference nulling or beam pointing can be achieved by using multi-array antenna array with anti-jamming algorithm. In terms of integration requirements, the development trend of navigation receiving terminal is from single mode to multi-mode and miniaturization. Results: In this paper, a miniaturized 7-element anti-jamming antenna array is given out. It mainly aims at GPS L1 and L2 frequency band. All elements adopt ceramic substrate microstrip antenna. Conclusion: The array elements adopt laminated design to effectively reduce the antenna aperture. The spacing between elements at two frequency points is not larger than half wavelength, which can ensure the back-end anti-jamming algorithm performance, and its performance and characteristics are verified through related experiments and simulations.

Radiation of Charge Moving Between Two Planar Periodic Wire Structures

2020 ◽  
Vol 23 (1) ◽  
pp. 66-71
Author(s):  
E. A. Gurnevich ◽  
I. V. Moroz
Keyword(s):  
Angular Distribution ◽  
Charged Particle ◽  
Research And Development ◽  
High Power ◽  
Free Electron ◽  
Radiation Intensity ◽  
Free Electron Lasers ◽  
Radiation Sources ◽  
Power Radiation ◽  
High Power Radiation

The Smith-Purcell radiation of a charged particle moving in a periodic structure is analysed theoretically. The considered structure consists of two planar diffraction gratings with different periods which are formed by parallel conducting wires. The analytical expression for the spectral-angular distribution of radiation is obtained. It is shown that the angular distribution of radiation can be made narrower by using two gratings instead of one, and radiation intensity can be manipulated by parallel relative shift of gratings. The obtained results are of great importance for the research and development of high power radiation sources based on volume free-electron lasers.

scholarly journals Ultra-Wideband Dielectric Lens Antennas for Beamsteering Systems

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Renan Alves dos Santos ◽  
Gabriel Lobão da Silva Fré ◽  
Luís Gustavo da Silva ◽  
Marcelo Carneiro de Paiva ◽  
Danilo Henrique Spadoti
Keyword(s):  
Antenna Array ◽  
Ultra Wideband ◽  
Printed Antennas ◽  
Lens Antennas ◽  
Dielectric Lens ◽  
Dielectric Lenses

This paper presents a high-directivity ultra-wideband beamsteering antenna array. An innovative beamsteering system based on hemispherical dielectric lenses fed by a set of different printed antennas is proposed. Diversity of signals in different spatial positions can be radiated at the same time. A prototype was manufactured and characterized, operating in a bandwidth varying from 8 GHz to 12 GHz with gain up to 13 dBi.

Progress in high-power high-efficiency VCSEL arrays

2009 ◽  
Author(s):  
Jean-Francois Seurin ◽  
Guoyang Xu ◽  
Viktor Khalfin ◽  
Alexander Miglo ◽  
James D. Wynn ◽  
...  
Keyword(s):  
High Power ◽  
High Efficiency ◽  
Vcsel Arrays

scholarly journals Near-field thermophotovoltaics for efficient heat to electricity conversion at high power density

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Rohith Mittapally ◽  
Byungjun Lee ◽  
Linxiao Zhu ◽  
Amin Reihani ◽  
Ju Won Lim ◽  
...  
Keyword(s):  
Power Density ◽  
High Power ◽  
High Efficiency ◽  
Near Field ◽  
Electrical Power ◽  
Photovoltaic Cells ◽  
High Power Density ◽  
Pv Cell ◽  
Electrical Power Output ◽  
Power Densities

AbstractThermophotovoltaic approaches that take advantage of near-field evanescent modes are being actively explored due to their potential for high-power density and high-efficiency energy conversion. However, progress towards functional near-field thermophotovoltaic devices has been limited by challenges in creating thermally robust planar emitters and photovoltaic cells designed for near-field thermal radiation. Here, we demonstrate record power densities of ~5 kW/m2 at an efficiency of 6.8%, where the efficiency of the system is defined as the ratio of the electrical power output of the PV cell to the radiative heat transfer from the emitter to the PV cell. This was accomplished by developing novel emitter devices that can sustain temperatures as high as 1270 K and positioning them into the near-field (<100 nm) of custom-fabricated InGaAs-based thin film photovoltaic cells. In addition to demonstrating efficient heat-to-electricity conversion at high power density, we report the performance of thermophotovoltaic devices across a range of emitter temperatures (~800 K–1270 K) and gap sizes (70 nm–7 µm). The methods and insights achieved in this work represent a critical step towards understanding the fundamental principles of harvesting thermal energy in the near-field.

scholarly journals Realizing UWB Antenna Array with Dual and Wide Rejection Bands Using Metamaterial and Electromagnetic Bandgaps Techniques

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 269
Author(s):  
Ayman A. Althuwayb ◽  
Mohammad Alibakhshikenari ◽  
Bal S. Virdee ◽  
Pancham Shukla ◽  
Ernesto Limiti
Keyword(s):  
Antenna Array ◽  
Ground Plane ◽  
Ultra Wideband ◽  
Dual Band ◽  
Area Network ◽  
Electromagnetic Bandgap ◽  
Uwb Antenna ◽  
Average Gain ◽  
Left Handed ◽  
Notched Band

This research article describes a technique for realizing wideband dual notched functionality in an ultra-wideband (UWB) antenna array based on metamaterial and electromagnetic bandgap (EBG) techniques. For comparison purposes, a reference antenna array was initially designed comprising hexagonal patches that are interconnected to each other. The array was fabricated on standard FR-4 substrate with thickness of 0.8 mm. The reference antenna exhibited an average gain of 1.5 dBi across 5.25–10.1 GHz. To improve the array’s impedance bandwidth for application in UWB systems metamaterial (MTM) characteristics were applied it. This involved embedding hexagonal slots in patch and shorting the patch to the ground-plane with metallic via. This essentially transformed the antenna to a composite right/left-handed structure that behaved like series left-handed capacitance and shunt left-handed inductance. The proposed MTM antenna array now operated over a much wider frequency range (2–12 GHz) with average gain of 5 dBi. Notched band functionality was incorporated in the proposed array to eliminate unwanted interference signals from other wireless communications systems that coexist inside the UWB spectrum. This was achieved by introducing electromagnetic bandgap in the array by etching circular slots on the ground-plane that are aligned underneath each patch and interconnecting microstrip-line in the array. The proposed techniques had no effect on the dimensions of the antenna array (20 mm × 20 mm × 0.87 mm). The results presented confirm dual-band rejection at the wireless local area network (WLAN) band (5.15–5.825 GHz) and X-band satellite downlink communication band (7.10–7.76 GHz). Compared to other dual notched band designs previously published the footprint of the proposed technique is smaller and its rejection notches completely cover the bandwidth of interfering signals.

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