Electric lines of force of an electrically small dipole-loop antenna array

Overfelt, P. L.

doi:10.1109/8.662665

Cited by 12 publications

(2 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A idéia de se combinar estes tipos de antenas para aumentar a largura de banda também foi utilizado em [12]. Neste trabalho, os autores utilizaram um modelo teórico aproximado de linhas de transmissão para os cálculos, e alimentaram cada dipolo separadamente, como num arranjo, com amplitudes e fases das fontes diferentes entre si (em [13], investigou-se também o efeito das fases das correntes nos dipolos). Os autores de [12] conseguiram obter alta largura de banda ajustando estes parâmetros como função da freqüência.…”

Section: Introductionunclassified

Combinações de Dipolos Elétricos e Magnéticos com Simples Alimentação para Aumento da Largura de Banda

Costa¹,

Dmitriev²

2004

Anais Do XXI Simpósio Brasileiro De Telecomunicações

View full text Add to dashboard Cite

Resumo-Este trabalho apresenta quatro tipos de antenas dipolo compostas de banda larga. Estas antenas são combinações de dipolos elétricos e magnéticos ortogonais entre si e com simples alimentação. Usando o método dos momentos, calculouse a impedância de entrada, o coeficiente de reflexão e os diagramas de radiação das antenas para diferentes geometrias. É mostrado que as antenas propostas podem ter largura de banda entre (80-90)% para um nível do coeficiente de reflexão de |Γ|<-10dB.Palavras-Chave-Dipolos de banda larga, antenas compostas, dipolos elétricos e magnéticos.

show abstract

Section: Introductionunclassified

Combinações de Dipolos Elétricos e Magnéticos com Simples Alimentação para Aumento da Largura de Banda

Costa¹,

Dmitriev²

2004

Anais Do XXI Simpósio Brasileiro De Telecomunicações

View full text Add to dashboard Cite

show abstract

“…This is the effect cited by Chu [1948] and, compared with results of section A3, is a simple example of how Q depends upon phasing. The field configuration and directivity of this case were recently detailed by Overfelt [1998].…”

Section: Dipole Combinationsmentioning

confidence: 99%

Radiation Q of dipole‐generated fields

Grimes¹,

Grimes²

1999

Radio Science

View full text Add to dashboard Cite

Abstract. The radiation Q of several dipole fields in free space are determined using the time-dependent Poynting theorem. Earlier works on this subject, recently summarized by McLean [1996], are based upon the complex Poynting theorem. It was previously shown [Grimes and Grimes, 1997] that the full complex Poynting theorem is correct only for single-mode radiation fields. The time-dependent theorem shows that three numbers are necessary to completely specify time-varying power, and complex numbers supply but two; the third piece of information, a phase, is discarded when complex notation is formed. Omissions inherent in the complex Poynting theorem affect the calculated value of standing energy about an antenna and hence the calculated value of Q. To avoid such omissions, we develop a method of determining Q based upon the time-dependent Poynting theorem that builds upon and extends our earlier work [Grimes and Grimes, 1997]. The purposes of this paper are to (1) provide a time domain basis for calculating Q in mixed modal radiation fields, (2) determine the Q of electric and magnetic dipoles, alone and in combination, and (3) demonstrate how source structure and relative phasing affect the physics of several combinations of electric and magnetic dipole radiation fields. The primary conclusion of this work is that the minimum possible Q of a radiation source established by Chu [1948] does not extend to properly mixed and phased multimodal radiation fields. A radiation source is presented for which, by our analysis, the radiation Q is zero. IntroductionThe purpose of this paper is to establish a lower limit on the Q of mixed modal dipole radiation fields in the external region about a virtual sphere of radius a, where a is the smallest radius that circumscribes The complex Poynting theorem is a mathematical identity that permits calculation of two numbers by integration over any enclosing surface. It takes three numbers, though, to completely specify power in a time-varying radiation field: Only for certain special cases are two numbers sufficient [Grimes and Grimes, 1997]. Complex notation suppresses a modal phase angle, and when multiple powers are combined it is essential to account for different angles. As an example, consider a center-driven, linear antenna that generates both dipolar and octupolar field modes.

show abstract

Coupling between elements of electrically small compound antennas

Tefiku

Grimes

1999

Microw. Opt. Technol. Lett.

View full text Add to dashboard Cite

Electric lines of force of an electrically small dipole-loop antenna array

Cited by 12 publications

References 17 publications

Combinações de Dipolos Elétricos e Magnéticos com Simples Alimentação para Aumento da Largura de Banda

Combinações de Dipolos Elétricos e Magnéticos com Simples Alimentação para Aumento da Largura de Banda

Radiation Q of dipole‐generated fields

Coupling between elements of electrically small compound antennas

Contact Info

Product

Resources

About