scholarly journals Low-Profile Spidron Fractal Dipole Antenna with a Ferrite-Loaded Artificial Magnetic Conductor for Manpack Applications

2020 ◽  
Vol 10 (24) ◽  
pp. 8843
Author(s):  
Oh Heon Kwon ◽  
Keum Cheol Hwang
Keyword(s):  
High Frequency ◽  
Dipole Antenna ◽  
Magnetic Conductor ◽  
Very High Frequency ◽  
Artificial Magnetic Conductor ◽  
Received Power ◽  
Low Profile ◽  
Profile Characteristics ◽  
Very High ◽  
Good Agreement

In this paper, a Spidron fractal dipole antenna with a ferrite-loaded artificial magnetic conductor (AMC) is presented. By applying ferrite composed of nickel–zinc with a high permeability value, a compact AMC that operates in the broadband frequency range within the high-frequency/very-high-frequency/ultra-high-frequency (HF/VHF/UHF) bands was designed. A Spidron fractal-shaped dipole antenna with a quasi-self-complementary structure was designed and combined with a miniaturized ferrite-loaded AMC. This allowed the designed AMC-integrated dipole antenna to operate in a wide frequency band, covering the HF/VHF/UHF bands, with low-profile characteristics. A prototype of the proposed Spidron fractal dipole antenna with the AMC was manufactured and measured and found to meet low VSWR (voltage standing wave radios) specifications of <3.5 within the 20–500 MHz bandwidth range. The simulated and measured results are in good agreement. The size of the Spidron fractal dipole antenna with the AMC is 0.03×0.026×0.001λ3 relative to the wavelength of the lowest operating frequency. The received power of the Spidron fractal dipole antenna with the AMC was also measured when it was applied to relatively small applications, such as a manpack in this case.

scholarly journals A Low-Profile HF Meandered Dipole Antenna with a Ferrite-Loaded Artificial Magnetic Conductor

2021 ◽  
Vol 11 (5) ◽  
pp. 2237
Author(s):  
Oh Heon Kwon ◽  
Won Bin Park ◽  
Juho Yun ◽  
Hong Jun Lim ◽  
Keum Cheol Hwang
Keyword(s):  
High Frequency ◽  
Dipole Antenna ◽  
Unit Cell ◽  
Operating Frequency ◽  
High Permeability ◽  
Magnetic Conductor ◽  
Artificial Magnetic Conductor ◽  
Low Profile ◽  
Compact Size ◽  
Binary Genetic Algorithm

In this paper, a low-profile HF (high-frequency) meandered dipole antenna with a ferrite-loaded artificial magnetic conductor (AMC) is proposed. To operate in the HF band while retaining a compact size, ferrite with high permeability is applied to the unit cell of the AMC. The operating frequency bandwidth of the designed unit cell of the AMC is 1.89:1 (19–36 MHz). Thereafter, a meandered dipole antenna is designed by implementing a binary genetic algorithm and is combined with the AMC. The overall size of the designed antenna is 0.06×0.06×0.002 λ3 at the lowest operating frequency. The proposed dipole antenna with a ferrite-loaded AMC is fabricated and measured. The measured VSWR bandwidth (<3) covers 20–30 MHz on the HF band. To confirm the performance of the antenna, a reference monopole antenna which operates on the HF band was selected, and the measured receiving power is compared with the result of the proposed antenna with the AMC.

An efficient, low profile, electrically small, three-dimensional, very high frequency magnetic EZ antenna

2010 ◽  
Vol 96 (10) ◽  
pp. 104102 ◽  
Author(s):  
Chia-Ching Lin ◽  
Richard W. Ziolkowski ◽  
Jean A. Nielsen ◽  
Minas H. Tanielian ◽  
Christopher L. Holloway
Keyword(s):  
High Frequency ◽  
Three Dimensional ◽  
Very High Frequency ◽  
Low Profile ◽  
Very High

Kinetic theory of high-frequency and low-pressure atomic discharges

1997 ◽  
Vol 58 (1) ◽  
pp. 123-143
Author(s):  
N. PEYRAUD-CUENCA ◽  
P. FAUCHER
Keyword(s):  
High Pressure ◽  
Kinetic Theory ◽  
High Frequency ◽  
Low Pressure ◽  
Plasma Phys ◽  
Numerical Results ◽  
Very High Frequency ◽  
Argon Discharge ◽  
Very High ◽  
Good Agreement

This paper gives a complete kinetic theory of atomic discharges whatever their parameters. Very high-frequency discharges and high-pressure continuous discharges were studied in an earlier paper by the same authors [J. Plasma Phys. 54, 309 (1995)]; in the present paper we study low-pressure continuous discharges or high-frequency discharges whose parameters satisfy different conditions and therefore cannot be described by the earlier model. Analytical results are applied to a high-frequency argon discharge and to a low-pressure continuous argon discharge. The results are in good agreement with the numerical results of Ferreira and co-workers.

Monocrystal elastic constants of orthotropic Y1Ba2Cu3O7: An estimate

1991 ◽  
Vol 6 (11) ◽  
pp. 2253-2255 ◽  
Author(s):  
Hassel Ledbetter ◽  
Ming Lei
Keyword(s):  
Elastic Constants ◽  
High Frequency ◽  
Stiffness Matrix ◽  
Phonon Dispersion ◽  
Elastic Stiffness ◽  
Tetragonal Symmetry ◽  
Very High Frequency ◽  
Analysis Theory ◽  
Very High ◽  
Good Agreement

For Y1Ba2Cu3O7, using only reported monocrystal measurements and some analysis–theory, we estimated the complete nine-component orthotropic-symmetry elastic-stiffness matrix, the Voigt Cij matrix. Comparison with very-high-frequency tetragonal-symmetry phonon-dispersion results shows good agreement (9% on average), except for C12.

scholarly journals Applications of AMC-based impedance surfaces

2018 ◽  
Vol 5 ◽  
pp. 3 ◽  
Author(s):  
Constantine A. Balanis ◽  
Mikal Askarian Amiri ◽  
Anuj Y. Modi ◽  
Sivaseetharaman Pandi ◽  
Craig R. Birtcher
Keyword(s):  
Anechoic Chamber ◽  
State University ◽  
Arizona State University ◽  
Leaky Wave ◽  
Magnetic Conductor ◽  
Artificial Magnetic Conductor ◽  
Full Wave ◽  
Low Profile ◽  
Low Profile Antennas ◽  
Good Agreement

The recent and major enhancements of artificial magnetic conductor (AMC) and their applications namely RCS reduction, low-profile antennas and holographic leaky wave antennas are reviewed. Full-wave simulations are compared to measurements of fabricated models, and a good agreement is attained. All of the measurement were conducted in the Arizona State University electromagnetic anechoic chamber (EMAC).

Kinetic theory of very high-frequency and high-pressure continuous atomic discharges

1995 ◽  
Vol 54 (3) ◽  
pp. 309-332
Author(s):  
N. Peyraud-Cuenca ◽  
P. Faucher
Keyword(s):  
High Pressure ◽  
Electric Field ◽  
High Frequency ◽  
Electron Distribution Function ◽  
Very High Frequency ◽  
High Frequency Electric Field ◽  
Analytical Approaches ◽  
Very High ◽  
Stationary Electron ◽  
Good Agreement

We derive the analytical solution of the Boltzmann equation for the stationary electron distribution function that is reached in a plasma generated on the application of a uniform very high-frequency electric field in an atomic gas. The theory includes all excitation transitions: ionization and electronic transitions. The analytic solution is also extended to continuous discharges with low electric field or high pressure in the gas. Then the electron rate coefficient for excitation of the first state (which is the most significant) is calculated analytically. We apply the results to the modelling of very high-frequency argon discharges and to high-pressure continuous discharges in argon and in sodium. The results are compared with numerical results of Ferreira and co-workers for argon and of LaVerne for sodium: in both cases we find good agreement between numerical and analytical approaches.

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