Patch antennas on ferromagnetic substrates

Brown, Andrew R.; Gong, Jian Ping; Kempel, Leo C.; Volakis, John L.

doi:10.1109/aps.1997.631534

Cited by 27 publications

(48 citation statements)

References 19 publications

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“…Since the practical magnetic materials themselves have a resonant magnetic permeability, the antenna system with such a filling becomes a dual-resonant structure whose behavior cannot be properly understood using a single-resonance model of the antenna filled by a nondispersive material. Patch antennas with resonant magnetized ferrite substrates have been studied in [8], where the magnetic filling was used as a means to provide electrical control of the resonant frequency and the antenna pattern, but not as a means to reduce the antenna size. In this paper, the effective-medium model is used to study the effect of dispersive magnetic-material fillings upon the performance of PIFAs.…”

Section: Introductionmentioning

confidence: 99%

Numerical study of a PIFA with dispersive material fillings

Kärkkäinen¹,

Tretyakov²,

Ikonen³

2005

Microw. Opt. Technol. Lett.

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01 mode than that of the same-size patch antenna without the notches. Therefore, the resonant frequencies of TM 10 and TM 01 are moved to lower and higher frequencies, respectively; that is, the frequency ratio of the proposed dual-frequency antenna can be controlled by d and w. RESULTSAt the beginning, the square patch antenna without notches was constructed as a reference [3]. In this case, the coplanar microstrip feed line is directly connected to the edge of the patch, and the measured resonant frequencies of ports 1 and 2 are 2450 and 2550 MHz, respectively, where the resonant frequency is defined as the frequency with minimum return loss. The reason why the two resonant frequencies have such a small difference is that the two ports use different matching designs to obtain 50⍀ input impedance. Then, several prototypes of the proposed dual-frequency antennas with different notch sizes were constructed and measured. Figure 2 shows the measured return loss at each port and isolations between the two ports for the cases of d ϭ 2, 8, and 10 mm when w is fixed to be 3 mm. From the results, it can be observed that the resonant frequencies of ports 1 and 2 have a 455-MHz decrease (Ϫ19%) and a 90-MHz increase (ϩ3.5%), respectively, when the inset length is increased from 2 to 10 mm. It means the larger the inset length, the higher the frequency ratio of the two resonant frequencies. Comparing to the results of the same-size square patch antenna without the notches, the frequency ratio is increased from 1.04 to 1.36 when the inset length of the coplanar microstrip line is 10 mm. In addition, the higher frequency ratio of the dual-frequency antenna would reduce the coupling strength of the two resonant modes, which results in a higher isolation between the two ports. With regard to the effects of the notch width w on the resonant frequencies, Figure 3 presents the measured return loss and isolation for the three cases of w ϭ 3, 5, and 7 mm when d is fixed to be 2 mm. It can be found that ports 1 and 2 have a 40-MHz decrease (Ϫ1.7%) and a 25-MHz increase (ϩ1%), respectively, which are relatively smaller than those of the case the inset length was changed. These measured results are also summarized in Table 1.For the prototype with notch dimensions of d ϭ 8 mm and w ϭ 3 mm, Figure 4 plots the measured E-plane and H-plane radiation patterns at 2090 MHz for port 1 and 2630 MHz for port 2. Good broadside radiation patterns are obtained, and the peak gains are 2.6 and 3.1 dBi for ports 1 and 2, respectively. Cross-polarization levels of less than Ϫ25 dB in the broadside direction are also observed. CONCLUSIONThe design of a dual-frequency microstrip antenna for operation at different frequency ratios has been presented. By adjusting the inset length of coplanar microstrip feed line, the frequency ratio can be varied from 1.04 to 1.36, and an isolation level of less than Ϫ27 dB is also obtained. The antenna's structure makes it suitable as an array element.

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Section: Introductionmentioning

confidence: 99%

Numerical study of a PIFA with dispersive material fillings

Kärkkäinen¹,

Tretyakov²,

Ikonen³

2005

Microw. Opt. Technol. Lett.

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“…A thicker substrate can be used to increase the bandwidth of the patch, but it will suffer from increased surface excitation, which will lower the efficiency [3]. The use of materials with relative permeability (µ r ) greater than one can also lead to antenna miniaturization in addition to enhanced bandwidths, tunable operation frequency, polarization diversity and beam steering [4][5][6][7]. Bulk ferrite materials [6], composites of ferrite particles in a polymer matrix [8] and metamaterials with embedded metallic circuits [9] have all been used as antenna substrates to achieve µ r > 1.…”

Section: Introductionmentioning

confidence: 99%

“…This property is necessary for microwave devices [12,13]. In the literature, ferromagnetic thin films have been utilized in order to tune the operating frequency of a patch antenna [6,7,11,13], and to obtain enhanced bandwidth [11] and increased gain [13].…”

Section: Introductionmentioning

confidence: 99%

Utilization of Screen Printed Low Curing Temperature Cobalt Nanoparticle Ink for Miniaturization of Patch Antennas

Nelo¹,

Palukuru²,

Juuti³

et al. 2012

PIER

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Abstract-This investigation is one of the first steps towards the realization of low-cost, mass producible, miniaturized antenna solutions utilizing screen printed magnetic thick films of cobalt nanoparticle ink. The ink has a curing temperature lower than 125 • C, feasible printing characteristics and metal loading higher than 85 wt.%. The properties are achieved by using an oxidatively polymerising natural fatty acid, linoleic acid, both as a surfactant and a binder. DSC-TGA-MS-analysis, TEM and SEM microscopies were utilized to investigate ink composition, nanoparticle coating and print quality. The resonant frequency of a microstrip patch antenna was tuned by screen printing of cobalt nanoparticle ink with different layer thicknesses on top of the antenna element. The influence of magnetic layers on resonance frequency, return loss, total efficiency and radiation pattern was measured and compared with a reference antenna without the magnetic films. For example, five layers of magnetic film (52 µm total thickness) tuned the resonance frequency (2.49 GHz) of the patch antenna by 68 MHz. The radiation efficiency of the patch antenna was increased from 39% to 43% by the loading of a 52 µm thick magnetic film compared to the reference antenna. The radiation patterns remained essentially unchanged, despite the presence of the magnetic thick films.

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“…Ferrite materials have found application in microwave components [4][5][6]. The magnetodielectric substrates also been used to achieve impedance matching [7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Perturbation of Emc Microstrip Patch Antenna for Permittivity and Permeability Measurements

Kulkarni¹,

Puri

2009

PIER Letters

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Abstract-The complex permittivity and permeability of barium hexaferrite in the 8-12 GHz range was determined by using perturbation of electromagnetically coupled Ag thick film patch antenna due to overlay. In this technique even minor change in the overlay material properties changes the antenna response. The power gain of the EMC patch antenna was enhanced by 50% due to barium hexaferrite overlay. Barium hexaferrite was synthesized by co precipitation method and their fritless thick films were fabricated by screen printing technique. The properties were found to depend on the synthesis conditions such as Fe/Ba molar ratio, pH of the solution.

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Patch antennas on ferromagnetic substrates

Cited by 27 publications

References 19 publications

Numerical study of a PIFA with dispersive material fillings

Numerical study of a PIFA with dispersive material fillings

Utilization of Screen Printed Low Curing Temperature Cobalt Nanoparticle Ink for Miniaturization of Patch Antennas

Perturbation of Emc Microstrip Patch Antenna for Permittivity and Permeability Measurements

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