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Author

Esin Chang

Bio: Esin Chang is an academic researcher from Shell Oil Company. The author has contributed to research in topics: Microstrip & Radiation pattern. The author has an hindex of 1, co-authored 1 publications receiving 336 citations.

Papers
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Journal ArticleDOI
TL;DR: In this paper, the electromagnetic properties of rectangular microstrip antennas were investigated experimentally, and the bandwidth was calculated as a function of electrical thickness and the antenna radiation patterns were measured.
Abstract: The electromagnetic properties of electrically thick rectangular microstrip antennas were investigated experimentally. Antennas were fabricated with different patch sizes and with electrical thicknesses ranging from 0.03 to 0.23 wavelengths in the dielectric substrate. The resonant frequencies were measured and compared to existing formulas. The bandwidth was calculated as a function of electrical thickness and the antenna radiation patterns were measured.

347 citations


Cited by
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Journal ArticleDOI
TL;DR: In this paper, the characteristics of a rectangular microstrip antenna with an L-shaped probe are investigated and a foam layer with a thickness of around 10% of the wavelength is used as the supporting substrate.
Abstract: The characteristics of a rectangular microstrip antenna with an L-shaped probe are investigated. A foam layer with a thickness of around 10% of the wavelength is used as the supporting substrate. An impedance bandwidth of 35% and an average gain of 7.5 dBi can be achieved. The radiation pattern is stable across the passband.

455 citations

Journal ArticleDOI
TL;DR: In this paper, the analysis of resonant-type antennas based on the fundamental infinite wavelength supported by certain periodic structures is presented, and the analysis and design of the required unitcell is discussed based upon field distributions and dispersion diagrams.
Abstract: The analysis of resonant-type antennas based on the fundamental infinite wavelength supported by certain periodic structures is presented. Since the phase shift is zero for a unit-cell that supports an infinite wavelength, the physical size of the antenna can be arbitrary; the antenna's size is independent of the resonance phenomenon. The antenna's operational frequency depends only on its unit-cell and the antenna's physical size depends on the number of unit-cells. In particular, the unit-cell is based on the composite right/left-handed (CRLH) metamaterial transmission line (TL). It is shown that the CRLH TL is a general model for the required unit-cell, which includes a nonessential series capacitance for the generation of an infinite wavelength. The analysis and design of the required unit-cell is discussed based upon field distributions and dispersion diagrams. It is also shown that the supported infinite wavelength can be used to generate a monopolar radiation pattern. Infinite wavelength resonant antennas are realized with different number of unit-cells to demonstrate the infinite wavelength resonance

451 citations

Journal ArticleDOI
TL;DR: In this article, the authors proposed broadband impedance matching as a natural way to increase the bandwidth of conventional microstrip patch antennas and found that by using an optimally designed impedance-matching network, the bandwidth can be increased by a factor of at least 3.9, the exact value depending on the degree of matching required.
Abstract: The nature of the inherent narrow bandwidth of conventional microstrip patch antennas is considered. It is observed that, except for single-feed circularly polarized elements, their bandwidth is limited only by the resonant behavior of the input impedance and not by radiation pattern or gain variations, which usually are negligible over a moderate 10 to 20% bandwidth. Therefore, broadband impedance matching is proposed as a natural to increase the bandwidth. The maximum obtainable bandwidth is calculated using Fano's broadband matching theory. It is found that by using an optimally designed impedance-matching network, the bandwidth can be increased by a factor of at least 3.9, the exact value depending on the degree of matching required. A transmission-line prototype for a proper matching network is developed. The translation of this prototype network into a practical structure (e.g. a microstrip or stripline circuit) is considered. Practical design examples and experimental results which clearly show the validity of the technique are given. >

388 citations

Journal ArticleDOI
TL;DR: In this paper, the L-shaped probe is shown to be an attractive feed for the thick microstrip antenna (thickness around 10% of the operating wavelength), and a parametric study on the rectangular patch antenna is presented.
Abstract: The L-shaped probe is shown to be an attractive feed for the thick microstrip antenna (thickness around 10% of the operating wavelength). A parametric study on the rectangular patch antenna is presented. It is found that the antenna attains 36% impedance bandwidth (SWR/spl les/2) as well as gain bandwidth and about 7-dBi average gain. A two-element array fed by L-probes is also proposed. Experiments show that the array design can substantially suppress the cross polarization of the proposed antenna. Both the antennas have stable radiation patterns across the passband. Moreover, the measured resonant frequencies of the proposed antenna agree well with an existing formula and the L-probe does not have much effect on the resonant frequency.

382 citations

Journal ArticleDOI
TL;DR: In this article, a microstrip feedline on a substrate proximity-coupled to a rectangular microstrip patch on a covering superstrate is constructed, and a small open-circuit tuning stub is connected in shunt with the feed line.
Abstract: The letter presents experimental results for a proximity-coupled microstrip patch antenna capable of 13% bandwidth. The impedance match (VSWR ≤ 2), copolarised radiation patterns and crosspolarised radiation were measured over this bandwidth to confirm operation. The construction is quite simple, consisting of a microstrip feedline on a substrate proximity-coupled to a rectangular microstrip patch on a covering superstrate; a small open-circuit tuning stub is connected in shunt with the feed line.

301 citations