scispace - formally typeset
Search or ask a question
Author

一紘 平澤

Bio: 一紘 平澤 is an academic researcher. The author has contributed to research in topics: Slot antenna & Reconfigurable antenna. The author has an hindex of 1, co-authored 1 publications receiving 122 citations.

Papers
More filters
Book
01 Jan 1992
TL;DR: How to apply the moment method to wire antenna analysis evaluation of the basic performance of microstrip antennas and some considerations of small antenna measurements.
Abstract: How to apply the moment method to wire antenna analysis evaluation of the basic performance of microstrip antennas key points in the design and measurement of microstrip antennas analysis of planar inverted-F antennas and antenna design for portable radio equipment design and analysis of small-aperture antennas design and measurement of small AM broadcasting antennas mutual coupling effects between antenna elements on antenna performance some considerations of small antenna measurements.

124 citations


Cited by
More filters
Journal ArticleDOI
TL;DR: A new design for built-in handset antennas in that metal strips as additional resonators are directly connected with a feed strip and the size can be reduced by an order of 10/spl sim/20%, which is desirable since the size of mobile phones is becoming smaller according to consumer preferences.
Abstract: In this paper, we propose a new design for built-in handset antennas in that metal strips as additional resonators are directly connected with a feed strip. With the new design scheme, a quad-band antenna for covering GSM900, DCS1800, PCS1900, and UMTS2000 bands and a five-band antenna for covering GSM900, DCS1800, PCS1900, UMTS2000, and ISM2450 bands for use in mobile built-in handsets are experimentally carried out. Compared with the parasitic form with a shorted strip placed away from the main radiator in the open literature, the size of the proposed antennas can be reduced by an order of 10/spl sim/20%, which is desirable since the size of mobile phones is becoming smaller according to consumer preferences. Moreover, the impedance matching for each band of the new antennas becomes easy. The new quad-band and five-band built-in handset antennas are developed within the limits of a 36/spl times/16/spl times/8 mm/sup 3/ volume. The antennas are also analyzed using the finite-difference time-domain technique. A good agreement is achieved between measurement and simulation.

145 citations

Journal ArticleDOI
TL;DR: The Pare to GA, by which various Pareto-optimal solutions for each objective function (performance) can be obtained in a single trial of a numerical simulation and which enables the selection of parameters in accordance with the design requirement, is applied to the multiobjective optimization design of the Yagi-Uda antenna.
Abstract: An optimization method, such as the steepest gradient methods, could not easily obtain globally optimum solutions for devising antenna design parameters that allow the antenna to simultaneously improve multiple performances such as gain, sidelobe level, and input impedance. The genetic algorithm (GA) is suitable for empirically solving optimization problems and is effective in designing an antenna. In particular, this method can solve the multiobjective optimization problem using various Pareto-optimal solutions in an extremely efficient manner. In this paper, the Pareto GA, by which various Pareto-optimal solutions for each objective function (performance) can be obtained in a single trial of a numerical simulation and which enables the selection of parameters in accordance with the design requirement, is applied to the multiobjective optimization design of the Yagi-Uda antenna. The effectiveness of the Pareto GA was demonstrated by comparing the performances obtained by the Pareto GA with those of the previously reported values, which were obtained by the conventional GA, and with the values of the design benchmark reference.

139 citations

Journal ArticleDOI
TL;DR: In this article, the authors present the results concerning the input return loss, radiation characteristics and efficiency of novel internal, planar, multiband patch antennas for multistandard mobile phone devices.
Abstract: The advent of new, multistandard mobile phone devices is an important challenge for antenna designers, as they have to implement integrated antennas with multiband operation within a volume that is rapidly shrinking. In the paper, research results concerning the input return loss, radiation characteristics and efficiency of novel internal, planar, multiband patch antennas are presented.

125 citations

Journal ArticleDOI
TL;DR: In this article, a radio frequency microelectromechanical systems (RF MEMS)-based reconfigurable antenna operating in the United States Public Safety bands is presented, which has two modes of operation with central frequencies of 718 and 4960 MHz.
Abstract: The design methodology, analysis, and characterization of a radio frequency microelectromechanical systems (RF MEMS)-based reconfigurable antenna operating in the United States Public Safety bands are presented. It has two modes of operation with central frequencies of 718 and 4960 MHz, providing a high reconfigurable frequency ratio of $\sim {7}$ . This antenna is electrically small with lateral dimensions being $\sim \lambda/10 \times \lambda/10$ at 718 MHz. The reconfigurability between the modes is achieved by a single RF MEMS switch, which enables changing the length of the current flow path, thereby the resonance frequency is changed. The measurement results for impedance and radiation characteristics of the fabricated antenna prototype agree well with the simulations. The measured bandwidths of the antenna are 2.6% and 7.6% at 718 and 4960 MHz, respectively.

113 citations

Journal ArticleDOI
TL;DR: A new built-in quad-band handset antenna for covering GSM900, DCS1800, PCS1900, and UMTS2000 bands is presented and the simulation is based on the finite-difference time-domain (FDTD) method.
Abstract: A new built-in quad-band handset antenna for covering GSM900, DCS1800, PCS1900, and UMTS2000 bands is presented. Details of the antenna are discussed along with measured and simulated results. The simulation is based on the finite-difference time-domain (FDTD) method.

87 citations