Asymptotic formulas for coupling between two antennas in the Fresnel region

Pace, J.R.

doi:10.1109/tap.1969.1139444

Cited by 26 publications

(17 citation statements)

References 9 publications

(6 reference statements)

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“…Note that the adjusted gain G A is recommended after an empirical case studies. It is also verified that the proposed method in (13) also exhibits similar convergence to the result of (12). It implies that the empirical coefficient α for (13) can be obtained as α = 0.06 for the class of the various antennas.…”

Section: Gain Reduction Factor In the Fresnel Regionsupporting

confidence: 62%

“…Those methods are different with respect to (a) possible antenna geometries, (b) required information, and (c) computational resources. The Friis formula can be expressed with a correction term of [11][12][13][14][15][16][17][18]. The formula can accommodate the instant computation with the basic information, such as gain at bore-sight and operational frequency while its effectiveness is confined within the Fresnel region.…”

Section: Friis Formula With a Correction Termmentioning

confidence: 99%

“…7and (8) assumes that it is possible to separate the gain reduction factor for each individual antenna, and they can be obtained through analytical derivation, full-wave simulations or measurements of the antenna gain pattern. [12] suggested that an antenna gain in the Fresnel region can be approximated with a quadratic form of variation in terms of its far-field gain:…”

Section: Friis Formula In the Fresnel Regionmentioning

confidence: 99%

“…The defocusing effect in a Fresnel region was derived in the gain reduction factor of uniform and tapered apertures [11]. An asymptotic series with Friis formula and correction term computed on-axis power transmission in a Fresnel region [12]. Gaussian approximation composed of effective aperture area shows its effectiveness for practical use in a Fresnel region [13].…”

Section: Friis Formula With Correction Term 41 Introductionmentioning

confidence: 99%

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Electromagnetic Computation of the Short-range Wireless Linkbuget for Biomedical Communication

Kim¹

2018

Emerging Microwave Technologies in Industrial, Agricultural, Medical and Food Processing

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The biomedical monitoring and imaging system requires data and power transmission through short-range communication, and the interference between large antennas placed within near-field region becomes the important consideration in designing an entire system. For the short-range communication, the electromagnetic computation becomes more complex, which requires huge computational resources. The efficient numerical methods that can be used in short-range communication are (1) Friis formula with correction term and (2) integral coupling formula. Both formulas are similar in an aspect that far-field gain pattern is used to calculate the link budget in a short range. The range of the communication link between two antennas can be defined as reactive nearfield, radiating near-field including Fresnel region, a far-field region in the order of nearest distance. Friis formula with correction term can be useful for the simple on-axis antenna displacement in Fresnel region. The integral coupling formula is flexible to compute the mutual coupling of diverse antenna geometries within an entire radiating near-field and a far-field region. Those two methods are evaluated using several examples of short-range communication and interference, and indoor measurement evaluates the validity of the calculated results.

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Section: Gain Reduction Factor In the Fresnel Regionsupporting

confidence: 62%

Section: Friis Formula With a Correction Termmentioning

confidence: 99%

Section: Friis Formula In the Fresnel Regionmentioning

confidence: 99%

Section: Friis Formula With Correction Term 41 Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Electromagnetic Computation of the Short-range Wireless Linkbuget for Biomedical Communication

Kim¹

2018

Emerging Microwave Technologies in Industrial, Agricultural, Medical and Food Processing

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“…Several attempts have been made to accurately predict the power transmission between closely spaced antennas, in particular, within a radiating near-field region. A common technique that has been studied for estimating the coupling can be defined in three ways: (i) integral form of the coupling equation [11][12][13], (ii) Friis formula including a correction term [14][15][16][17][18][19][20][21] and (iii) numerical evaluation using a full-wave simulation. Fig.…”

Section: Introductionmentioning

confidence: 99%

Generalised correction to the Friis formula: quick determination of the coupling in the Fresnel region

Kim

Rahmat‐Samii

2013

IET Microwaves, Antennas & Propagation

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A simple yet effective correction term to the Friis formula is presented to improve its accuracy in the Fresnel region. Based on the concept of gain reduction factor, the proposed asymptotic term with an empirical coefficient can be widely applied to a variety of antennas without lengthy calculations. The information required in the computation is only the antenna gain, separation and wavelength for the boresight scenarios. Case studies of several representative antennas using full-wave simulations show that the accuracy of the estimated power transmission levels between two antennas in the Fresnel region can be improved by up to 2-5 dB, for both boresight and off-axis cases. Measurement results using two horn antennas also confirm the validity of the proposed correction term.

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Microwave Antenna Theory

Kizer

2013

Digital Microwave Communication

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Asymptotic formulas for coupling between two antennas in the Fresnel region

Cited by 26 publications

References 9 publications

Electromagnetic Computation of the Short-range Wireless Linkbuget for Biomedical Communication

Electromagnetic Computation of the Short-range Wireless Linkbuget for Biomedical Communication

Generalised correction to the Friis formula: quick determination of the coupling in the Fresnel region

Microwave Antenna Theory

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