The effect of dipole coupled impedances on open field range calibration

McConnell, R. A.

doi:10.1109/nsemc.1989.37142

Cited by 7 publications

(3 citation statements)

References 3 publications

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“…Therefore, it is reasonable to assume that the input impedance Z of an individual SLR at frequencies near its resonance is practically equal to that of the resonant dipole and can be approximated as Z ≈ R 0 (1 + β γ ), where β ≈59 and γ = ( ω − ω 0 )/ ω 0 is relative detuning (Kazempour & Begaud, ). Substituting this approximation for Z , for Z 13 and

Z_{M} \approx false(η false/ 24 πkd false) \exp false(- jkd false)

for two resonant half‐lambda dipoles (McConnell, ) into , we obtain the decoupling condition as

\frac{R_{0} η}{24 πkd} e^{- jkd} false(1 + βγ false) = {((), \frac{η L_{l}}{24})}^{2} \frac{e^{- 2 jkδ}}{2 π δ^{2}} .

In the case h ≪ d δ ≈ d /2 and complex exponentials cancel out that reduces to the simplest equation from which we find the detuning γ corresponding to the decoupling

βγ = ((), ηk L_{l}^{2} false/ d R_{0}) - 1 .

For d = 30 mm (in this case h = d /3) and L l =290 mm, yields γ ≈0.0423 that implies the decoupling at the upper edge of the resonance band—at 312.8 MHz. Meanwhile, using a passive resonant dipole we have obtained γ ≈0.007, that is, the decoupling holds at 302.8 MHz.…”

Section: Theory Of Decoupling By a Split‐loop Resonatormentioning

confidence: 97%

“…Therefore, it is reasonable to assume that the input impedance Z of an individual SLR at frequencies near its resonance is practically equal to that of the resonant dipole and can be approximated as Z ≈ R 0 (1 + ), where ≈ 59 and = ( − 0 )∕ 0 is relative detuning (Kazempour & Begaud, 2001). Substituting this approximation for Z, (8) for Z 13 and Z M ≈ ( ∕24 kd) exp (−jkd) for two resonant half-lambda dipoles (McConnell, 1989) into (1), we obtain the decoupling condition as…”

Section: Radio Sciencementioning

confidence: 99%

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Decoupling of Two Closely Located Dipole Antennas by a Split‐Loop Resonator

et al. 2018

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In this paper, we theoretically and experimentally prove the possibility of the passive electromagnetic decoupling for two parallel resonant dipoles by a split‐loop resonator having the resonance band overlapping with that of the active dipoles. We show that the replacement of the decoupling dipole suggested in the literature as a tool for decoupling of two closely located dipole antennas by our split‐loop resonator results in the twofold enlargement of the operation band.

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Z_{M} \approx false(η false/ 24 πkd false) \exp false(- jkd false)

for two resonant half‐lambda dipoles (McConnell, ) into , we obtain the decoupling condition as

\frac{R_{0} η}{24 πkd} e^{- jkd} false(1 + βγ false) = {((), \frac{η L_{l}}{24})}^{2} \frac{e^{- 2 jkδ}}{2 π δ^{2}} .

In the case h ≪ d δ ≈ d /2 and complex exponentials cancel out that reduces to the simplest equation from which we find the detuning γ corresponding to the decoupling

βγ = ((), ηk L_{l}^{2} false/ d R_{0}) - 1 .

Section: Theory Of Decoupling By a Split‐loop Resonatormentioning

confidence: 97%

“…Therefore, it is reasonable to assume that the input impedance Z of an individual SLR at frequencies near its resonance is practically equal to that of the resonant dipole and can be approximated as Z ≈ R 0 (1 + ), where ≈ 59 and = ( − 0 )∕ 0 is relative detuning (Kazempour & Begaud, 2001). Substituting this approximation for Z, (8) for Z 13 and Z M ≈ ( ∕24 kd) exp (−jkd) for two resonant half-lambda dipoles (McConnell, 1989) into (1), we obtain the decoupling condition as…”

Section: Radio Sciencementioning

confidence: 99%

Decoupling of Two Closely Located Dipole Antennas by a Split‐Loop Resonator

et al. 2018

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“…A very simple relation for the mutual impedance of two parallel antennas performed of wires with radius r 0 < 10 −3 λ separated by a gap d < L was heuristically obtained in [21]. In our notations this relation can be written for both Z 12 = Z M and Z 13 = Z 23 as follows:…”

Section: Decoupling Of Two Half-lambda Dipolesmentioning

confidence: 99%

Passive Decoupling of Two Closely Located Dipole Antennas

Mollaei¹,

Hurshkainen²,

Kurdjumov³

et al. 2018

Preprint

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In this paper, we prove that two parallel dipole antennas can be decoupled by a similar but passive dipole located in the middle between them. The decoupling is proved for whatever excitation of these antennas and for ultimately small distances between them. Our theoretical model based on the method of induced electromotive forces is validated by numerical simulations and measurements. A good agreement between theory, simulation and measurement proves the veracity of our approach.

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A simple closed‐form formula for the mutual impedance of dipoles

Kazemipour

Begaud

2002

Micro & Optical Tech Letters

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facturing process may not seriously impair the deliverable bandwidth.The Bragg regime vanishes if c ϭ d even though a b c , as per Eq. (6). This condition denotes the pseudo-isotropic point, when the axially excited chiral STF effectively responds as an isotropic and homogeneous material (despite being anisotropic and unidirectionally nonhomogeneous), and does not distinguish between incident left and right circularly polarized light: R LL ϭ R RR , R LR ϭ R RL , T LL ϭ T RR and T LR ϭ T RL . Table 3 provides values of v and the consequent values of and a,b,c calculated for chiral STFs of the same three materials as in Table 1. Figure 4 presents contour plots of the differences ͉R RR Ϫ R LL ͉ and ͉T RR Ϫ T LL ͉ as functions of v and 0 for chiral STFs made of titanium oxide. In both contour plots, the cross marks the location of the center wavelength of the Bragg regime that is missing because v is at the pseudo-isotropic point. These plots show clearly the singularity of the pseudo-isotropic point, highlighting the potential for its disturbance by some perturbation, as mentioned earlier.As the requirements of maximum and null bandwidths are mutually exclusive, the same value of v cannot deliver both, according to Eq. (6). Significantly, as the maximum bandwidth and the pseudo-isotropic points turn out to be widely separated on the v axis, device designers with different objectives cannot confuse between the two. Furthermore, both points are realizable because the corresponding values of substantially exceed the lowest values of reported till date. The deliverable value of 0Br , for either of the two points, will require the selection of ⍀ during deposition; with postdeposition tuning possible perhaps with piezolelectric actuators [17]. INTRODUCTIONIn the design of antenna arrays or in the electromagnetic compatibility domain, coupling effects are very important phenomena. To have a good knowledge of coupling effects, it is necessary to use a full-wave method, but for an array with many radiating sources, or for a complex EMC environment, full-wave modeling leads to complex and lengthy numerical simulation. The idea is to achieve a simple and compact analytical formula for taking into account the coupling effects, to have real information quickly. As the basic radiator elements, linear dipoles could be used to investigate any complex form of antenna. For this reason and their simple physics, dipole antennas are largely studied and used [1]. Usually for calculating the self-impedance and mutual impedance of dipoles, one supposes one-term [2] sinusoidal current density or a combination of a few sinusoidal functions [3] along the dipole, making it possible to determine the impedances analytically in the form of S i or C i integrals. Using this well-known method permits having the mutual impedances of the dipoles in the near-or far-field region of each other. But the complexity of C i and S i integrals is a serious obstacle for considering this method to be useful one for the quick and simple expression of impedances...

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The effect of dipole coupled impedances on open field range calibration

Cited by 7 publications

References 3 publications

Decoupling of Two Closely Located Dipole Antennas by a Split‐Loop Resonator

Decoupling of Two Closely Located Dipole Antennas by a Split‐Loop Resonator

Passive Decoupling of Two Closely Located Dipole Antennas

A simple closed‐form formula for the mutual impedance of dipoles

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