Modified Wideband Tandem Couplers with Arbitrary Coupling Coefficient and its Implementation in Beam-Forming Networks

2018 ◽  
Author(s):  
He Zhu ◽  
Y. Jay Guo
Keyword(s):  
Coupling Coefficient ◽  
Beam Forming ◽  
Arbitrary Coupling

Novel rat-race coupler design of arbitrary coupling coefficient using substrate integrated waveguide cavity

2018 ◽  
Vol 10 (8) ◽  
pp. 861-869 ◽  
Author(s):  
Min-Hua Ho ◽  
Yi-Hao Hong ◽  
Jen-Chih Li
Keyword(s):  
Transmission Lines ◽  
Coupling Coefficient ◽  
Substrate Integrated Waveguide ◽  
Cavity Field ◽  
Arbitrary Coupling ◽  
Degenerate Mode ◽  
Quarter Wavelength ◽  
Small Phase ◽  
Hybrid Coupler ◽  
Degenerate Modes

AbstractThe contribution of this paper is to propose a novel rat-race hybrid coupler of arbitrary coupling coefficient. Traditionally, the rat-race hybrid couplers are built by various loop-alike transmission-lines of multiple quarter-wavelength, and in this paper, we approach the coupler design by using a circular substrate integrated waveguide (SIW) cavity (SIWC). The employed SIWC supports two mutually orthogonal degenerate modes, and cavity field is formed by the two modes in an arbitrary weighting ratio which defines the proposed rat-race coupler's coupling coefficient. The cavity is excited by a microstrip combined coupling slot with the microstrip along a specifically chosen direction. The energy of each degenerate mode can be solely extracted by an associated subminiature version A (SMA) whose position is carefully determined. The isolation between the coupling slots is assured by their perpendicular layout, and the isolation between the SMA probes is obtained by the orthogonality of the two degenerate modes. Experiments are conducted on the 3- and 10-dB coupling coefficient samples to verify this novel rat-race coupler design. The measurements agree well with the simulations, and circuit's good performance is observed in terms of coupling precision, isolations, and small phase imbalances.

scholarly journals Chebyshev-Response Branch-Line Couplers with Enhanced Bandwidth and Arbitrary Coupling Level

Electronics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1828
Author(s):  
Robert Smolarz ◽  
Krzysztof Wincza ◽  
Slawomir Gruszczynski
Keyword(s):  
Chebyshev Polynomial ◽  
Coupling Coefficient ◽  
Center Frequency ◽  
Electrical Parameters ◽  
New Approach ◽  
Branch Line ◽  
Design Procedures ◽  
Arbitrary Coupling

A new approach to the synthesis of broadband branch-line couplers with arbitrary coupling level was investigated in this paper. It was shown that the operational bandwidth of a classic branch-line coupler can be increased by utilizing N-section impedance transformers added to each of the coupler’s ports. Furthermore, the obtained response can be approximated by the Chebyshev polynomial. Moreover, it was proven that for such couplers a range of coupling coefficient values can be obtained by the modification of classic branch-line topology. The analysis of the electrical parameters of the proposed branch-line couplers was comprehensively investigated. To verify the correctness of the proposed design procedures, 3-dB, and 6-dB broadband branch-line couplers operating at the center frequency of 2 GHz having return losses greater than 20 dB were designed, fabricated, and measured.

Creation of Nonconformal Particles from Vacuum by A Test-Model Isotropic Gravitational Field

1997 ◽  
Vol 12 (03) ◽  
pp. 145-154 ◽  
Author(s):  
V. B. Bezerra ◽  
V. M. Mostepanenko ◽  
C. Romero
Keyword(s):  
Gravitational Field ◽  
Scalar Field ◽  
Coupling Coefficient ◽  
Quantum Effects ◽  
Test Model ◽  
Arbitrary Coupling

The quantized scalar field with arbitrary coupling in a nonstationary isotropic gravitational field evolving between two singularities is investigated. The number of pairs created from vacuum is demonstrated to have a very drastic dependence on the value of the coupling coefficient ξ. In other words the vacuum quantum effects of nonconformal field may be important in the early cosmology.

scholarly journals HAMILTONIAN DIAGONALIZATION FOR A NONCONFORMAL SCALAR FIELD IN AN ISOTROPIC GRAVITATIONAL BACKGROUND

1998 ◽  
Vol 07 (02) ◽  
pp. 249-259 ◽  
Author(s):  
V. B. BEZERRA ◽  
V. M. MOSTEPANENKO ◽  
C. ROMERO
Keyword(s):  
Wave Equation ◽  
Gravitational Field ◽  
Scalar Field ◽  
Coupling Coefficient ◽  
Vacuum State ◽  
Oscillator Frequency ◽  
Arbitrary Coupling ◽  
Spatially Homogeneous ◽  
Bogoliubov Transformations ◽  
Gravitational Background

The metrical Hamiltonian is investigated for a nonconformal scalar field with arbitrary coupling in a nonstationary spatially homogeneous isotropic gravitational field. It is shown that this Hamiltonian may be diagonalized by the canonical Bogoliubov transformations of creation-annihilation operators only for the values of coupling coefficient 0 ≤ ξ ≤ 1/6. The quasienergy of quasiparticles diagonalizing the Hamiltonian is shown to differ for the nonconformal case from the effective oscillator frequency of the wave equation. Different definitions of the initial vacuum state for the nonconformal scalar field are discussed.

Scaling Law of Coupling Coefficient and Coil Size in Wireless Power Transfer Design via Magnetic Coupling

2017 ◽  
Vol 137 (4) ◽  
pp. 326-333
Author(s):  
Chiaki Nagai ◽  
Kenji Inukai ◽  
Masato Kobayashi ◽  
Tatsuya Tanaka ◽  
Kensho Abumi ◽  
...  
Keyword(s):  
Coupling Coefficient ◽  
Scaling Law ◽  
Magnetic Coupling ◽  
Wireless Power Transfer ◽  
Power Transfer ◽  
Wireless Power ◽  
Coil Size
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