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Author

Y. Mushiake

Bio: Y. Mushiake is an academic researcher. The author has contributed to research in topics: Dipole antenna & Directivity. The author has an hindex of 2, co-authored 2 publications receiving 11 citations.

Papers
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Journal ArticleDOI
TL;DR: In this article, a type of spherical triangular array composed of turnstile elements is numerically analyzed and discussed, and it is found that the spherical array proposed here is able to scan its beam up to large angle without variation of the directivity and the circular polarization property.
Abstract: Radiation characteristics of a type of spherical triangular array composed of turnstile elements are numerically analyzed and discussed. It is found that the spherical array proposed here is able to scan its beam up to large angle without variation of the directivity and the circular polarization property.

9 citations


Cited by
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Journal ArticleDOI
TL;DR: A full solid angle scanning cylindrical-and-conical (CYLCON) conformal phased array antenna (PAA) is designed and a microstrip Yagi antenna with low profile and small size is proposed and discussed.
Abstract: In this paper, a full solid angle scanning cylindrical-and-conical (CYLCON) conformal phased array antenna (PAA) is designed. First, a microstrip Yagi antenna with low profile and small size is proposed and discussed. Second, a cylindrical conformal Yagi antenna array consisting of 24 aforementioned 8-element Yagi antennas is designed and optimized. Simulation results show that the Yagi antenna array can realize low-elevation beam scanning in the region of $ 0 {^{\circ }} \le \theta \le 30 {^{\circ }}$ , $30 {^{\circ }} \le \varphi \le 150 {^{\circ }}$ with low sidelobe levels and sharp beams. Third, CYLCON conformal microstrip antenna arrays are developed to realize the broadside beam scanning. Afterwards, an integrated PAA by combining the aforementioned conformal arrays along with feeding networks is constructed to achieve full solid angle scanning. Finally, a prototype is fabricated, the measured results show that it can realize beam scanning in the regions of $ 0 {^{\circ }} \le \theta \le 30 {^{\circ }}$ , $30 {^{\circ }} \le \varphi \le 150 {^{\circ }}$ , and $30 {^{\circ }} \le \theta \le 180 {^{\circ }}$ , $60 {^{\circ }} \le \varphi \le 120 {^{\circ }}$ , which meet well with those of the simulated. By arranging proper number of arrays along the perimeter accompanied with the switchable feeding configurations, a full solid angle scanning can be achieved.

42 citations

Journal ArticleDOI
TL;DR: In this paper, the spherical-coordinate finite-difference time-domain method is applied to numerical analysis of phased array of monopoles distributed over a sphere, where the outer boundary of the given problem is modeled by accurate spherical coordinate anisotropic perfectly matched layer.
Abstract: In this paper, the spherical-coordinate finite-difference time-domain method is applied to numerical analysis of phased array of monopoles distributed over a sphere. Outer boundary of the given problem is modeled by accurate spherical- coordinate anisotropic perfectly matched layer. The problem of increased cell aspect ratio near the sphere poles causing degradation of results is solved by dispersion optimization through artificial anisotropy. The accuracy of the approach is verified by comparing a model case with an exact solution. Finally, radiation patterns obtained by frequency-domain near-to-far-field transform and s-parameters of the array elements are presented and validated by comparing with measurement data.

30 citations

Journal ArticleDOI
TL;DR: In this article, a type of spherical triangular array composed of turnstile elements is numerically analyzed and discussed, and it is found that the spherical array proposed here is able to scan its beam up to large angle without variation of the directivity and the circular polarization property.
Abstract: Radiation characteristics of a type of spherical triangular array composed of turnstile elements are numerically analyzed and discussed. It is found that the spherical array proposed here is able to scan its beam up to large angle without variation of the directivity and the circular polarization property.

9 citations

Dissertation
01 Jan 2005
TL;DR: This dissertation considers beamformer design and direction finding for a broadband source using concentric ring array (CRA), that contains many concentric rings of different radii that has several advantages including the flexibility in array pattern synthesis and adaptive array design.
Abstract: Sensor arrays have been used widely in applications including radar, sonar, seismology, biomedicine, communications and imaging. A very popular type of sensor array is circular array, which has almost invariant array pattern in azimuthal plane. This dissertation considers beamformer design and direction finding for a broadband source using concentric ring array(CRA) that contains many concentric rings of different radii. The multi-ring structure of a CRA has several advantages including the flexibility in array pattern synthesis and adaptive array design. We first proposed three CRA array pattern synthesis techniques, which can be used to control the sidelobe and/or mainlobe width of the array pattern of a deterministic broadband beamformer. We then proposed a flexible partially adaptive broadband beamformer design based on element-space approach. Finally, we proposed an efficient direction finding technique for broadband source using CRA. The proposed design techniques are corroborated by experiments from simulated as well as measured data.

8 citations

Journal Article
TL;DR: In this article, the radiation characteristics of a circularly polarized conical beam spherical slot array antenna for applying to the mobile satellite communication subscriber are presented. But the antenna is not suitable for the tracking system, since the azimuthal pattern is omnidirectional.
Abstract: SUMMARY This paper presents the radiation characteristics of a circularly polarized conical beam spherical slot array antenna for applying to the mobile satellite communication subscriber. The structure of the antenna is easy to fabricate i.e., a ring of perpendicular slot pairs cut on an outer surface of a concentric conducting spherical cavity enclosed by the conducting conical surface with the simple feeding structure, and a linear electric probe excited at the center of the inner surface of the cavity. Radiation fields of a spherical slot array antenna are calculated by superposing the patterns of all the slots. From the numerical results of the radiation pattern, in both elevational and azimuthal planes, it is obvious that the conical beam is realized. The elevational beam direction is low, which is suitable for installing in the land mobile subscriber unit located far from the equator. The tracking system is not necessary because the azimuthal pattern is omnidirectional. Directivity of the antenna for various spherical radii and angles of slot positions are illustrated as the guidelines for the design. Experimental results are in good agreement with the predictions.

6 citations