Fractal log-periodic Antenna

Strycek, Michal; Hertl, I.

doi:10.1109/radioelek.2007.371701

Cited by 8 publications

(1 citation statement)

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“…So, we explored the possibility of utilizing the same design concept for a CLPDA that can work in the lowfrequency regime with a low PI; additionally, we intended to reduce, as much as possible, the dimensions of the CLPDA with respect to its conventional design in order to minimize the fabrication and installation complexities, costs, efforts, etc., without compromising its reception characteristics. As far as the miniaturization of an LPDA is concerned, techniques such as Koch fractalization (Puente-Baliadra & Pous 1996;Strycek & Hertl 2007;Anagnostou et al 2008), meandering (Rashed & Tai 1991;Best 2002;Geethan & Anagnostou 2008;Lee et al 2010), meta-material (Greiser 1964;Breed 2008;Ripin et al 2013;Zhai et al 2019), top-loading (DiFonzo 1964Simpson 1971;Gong et al 2012;Kyei et al 2017), the hybrid (Genetic Algorithm and Nelder-Mead simplex) optimization (Chung & Haupt 2001;El-Khamy et al 2004), and dual-band dipoles (Kyei & Jung 2018) are being used to design LPDAs for high-frequency communication applications. The fractalization method reduces the transverse dimensions of an LPDA by ≈10%-17%; however, its directivity may vary by a factor of 2 or higher (Qiu et al 2005;Moallemizadeh et al 2012), and its operating bandwidth may also be reduced (Anagnostou et al 2008;Jingjing et al 2008).…”

Section: Introductionmentioning

confidence: 99%

Solar Radio Spectro-polarimeter (50–500 MHz). I. Design, Development, and Characterization of a Cross-polarized, Log-periodic Dipole Antenna

Kumari,

Gireesh,

Kathiravan

et al. 2023

ApJ

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The Zeeman effect has been routinely used to image and quantify the solar photospheric magnetic field (B). Such a direct measuring technique is not yet available for the corona (Lin et al. 2004). Since almost all transient nonthermal radio emissions from the corona are either partially or fully circularly polarized, observing their polarization signatures over broad frequency ranges would be of help to estimate B as a function of heliocentric height. This article aims to describe the design and development of a Cross-polarized Log-Periodic Dipole Antenna (CLPDA), an integral part of a radio spectro-polarimeter, which works in the 50–500 MHz frequency-range and to explain the tests that were carried out to characterize it. The above frequency range corresponds to a heliocentric height range ≈1.03 < r < 2.5 R ⊙ (R ⊙ = photospheric radius), wherein the numerous coronal nonthermal transients associated with space-weather effects are observed to originate. The CLPDA is used to determine the strength and sense of polarization of the received radio signal. The uncertainty involved in the determination depends on the polarization-isolation (PI) between the two orthogonal components of a CLPDA. Some of the recent advancements made in the antenna design concepts at high frequencies (∼GHz) were adopted to reduce the PI at low frequencies (∼MHz). Throughout the above frequency range, the CLPDA has a gain, return loss, and PI of ≈6.6 dBi, ≲−10 dB, and ≲−27 dB, respectively. The average PI of the CLPDA varies from −30 to −24 dB over an azimuthal angle range 0° to ±45° within which the observations are performed regularly.

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Section: Introductionmentioning

confidence: 99%

Solar Radio Spectro-polarimeter (50–500 MHz). I. Design, Development, and Characterization of a Cross-polarized, Log-periodic Dipole Antenna

Kumari,

Gireesh,

Kathiravan

et al. 2023

ApJ

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Small artificial magnetic conductor backed log‐periodic microstrip patch antenna

Almutawa

Mumcu

2013

IET Microwaves, Antennas & Propagation

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An artificial magnetic conductor (AMC) backed reduced‐size log‐periodic microstrip patch antenna (LPMA) is presented. To maintain the broadband performance of the LPMA, the AMC ground plane was modified to exhibit a log‐periodic structure. Specifically, an AMC ground plane configuration was realised over 0.889 mm thick εr = 10.2 Rogers 6010.2LM substrate for an LPMA printed over 1.524 mm thick εr = 2.94 Rogers 6002 substrate. The AMC‐backed LPMA is measured to operate from 5.3 to 8 GHz with linearly polarised broadside radiation, performing with 21% reduced size as compared with a conventional LPMA designed over the identical substrate stack‐up.

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