Hiroyasu Matsui

On Analysis of Planar Antennas Using FDTD Method

The FDTD method is a powerful method for analysis of electromagnetic flelds in microwave circuits and devices, antennas, optical devices and transmission lines. In this paper, numerical conditions in analysis of planar antennas using the FDTD method are considered and found for a planar dipole antenna. The obtained results are compared with other and experimental results. DOI: 10.2529/PIERS061002234141 The planar antennas that are useful for mobile communications have been developed for many researchers. The FDTD method is a powerful method for analysis of planar antennas that are deflned as antennas that have planar shapes. We have analyzed several kinds of planar antennas for mobile communications. In this paper, numerical conditions in analysis of planar antennas using the FDTD method (3) are considered and found for a planar dipole antenna. In order to use the method, it is important to decide the number of layers of the PML and the distance between the antenna and the wall of the analytical area. If they are decided appropriately, the computational time and memories are saved. Therefore, the relation between them is discussed precisely. The FDTD method which used their numerical values are applied to several planar antennas (1,2). The obtained results are compared with other and experimental results. 2. FDTD METHOD

E-type planar antenna printed on dielectric substrate

An E-type planar antenna printed on a dielectric substrate is proposed for mobile and satellite communications. It is analyzed by the finite difference time domain (FDTD) method. The characteristics of the antenna such as return loss, far field patterns and current distribution are shown for structural parameters of the planar antenna. This antenna is of simple structure and is easily fabricated.

Characteristics of single-feed planar antenna for improvement of fading phenomenon

The characteristics of proposed antenna such as return loss and radiation patterns from both sides of measurement and calculation were obtained. From these results, it is understood that proposed antenna has both functions of the PMA and the PSA with single-feed structure. Therefore, it seems that proposed antenna is an effective planar antenna in order to improve the receiving signal quality. In future, an experimental system to confirm and verify the improvement of the deterioration of receiving signal quality will be considered.

Single-feed planar antenna for electric and magnetic fields reception

In this paper, a single-feed planar antenna for electric and magnetic fields reception (SPAEM) is proposed in order to decrease the change of received signal level and improve the receiving signal quality. The SPAEM is composed of a line element and a conducting ground plane with a slot which are printed on the dielectric substrate. The antenna has two functions. One is the function of a planar monopole antenna (PMA), and the other is the function of a planar slot antenna (PSA). Therefore, this antenna can receive both electric and magnetic fields by a single feed point. Return loss characteristics, current distribution, and radiation patterns are analyzed by the FDTD method. It is shown that the characteristics of the SPAEM combine those of the PMA with those of the PSA. The antenna keeps an independent resonant frequency even if the PMA and the PSA were combined using single feed structure. These results are described.

Broadband planar antenna with an offset elliptical element and a ground conductor plane with a slit

In this paper, we propose a planar antenna which has an elliptical element and a ground conductor plane which are printed on a dielectric substrate. The position of the feeding point of the antenna is offset from the center of the ground conductor plane with a slit. The characteristics such as return loss and radiation patterns of the proposed antenna are analyzed by using the FDTD method. From these results, it is found that it is effective in broadbanding of the antenna to offset the feeding point from the center of a ground conductor plane. And it turned out that it is effective in the improvement of radiation patterns to add a slit to a ground conductor plane. Moreover, these results confirmed that the proposed planar antenna is useful for broadband antenna.

Characteristics of a single-feed planar antenna for electric and magnetic fields reception

The fading phenomenon is enumerated in a factor of quality degradation in mobile communication technologies. In this paper, a single-feed planar antenna is proposed for electric and magnetic fields reception in order to improve the degradation of the received signal level due to a fading phenomenon. The proposed antenna has a line element and a conducting ground plane with a slot which are printed on the dielectric substrate. The antenna was analyzed by FDTD method. The characteristics of the single-feed antenna for electric and magnetic fields reception and its components: planar monopole antenna and planar slot antenna are described.

A Single-Feed Planar Antenna for Terrestrial Dtv Reception in Mobile Communication

Japanese terrestrial broadcasting was completely con- verted to digital television (DTV) broadcasting on 470{710MHz as of July 2011. However, fading phenomenon resulting from standing waves is a factor in quality deterioration in TV and mobile commu- nication technologies. Suppression of this is needed for many kinds of technologies. A broadband single-feed planar antenna composed of two antenna components, a Broadband Planar Monopole Antenna (B- PMA) and a Broadband Planar Slot Antenna (B-PSA), is proposed for reducing deterioration of reception due to the fading across the DTV band. Re∞ection coe-cients and radiation patterns analyzed by the Finite Difierence Time Domain (FDTD) method and compared with measured results indicate that the proposed antenna is broad- band compared with a conventional antenna studied previously. A fleld experiment is conducted in the DTV band. The results of the fleld experiment indicate clearly that the proposed antenna e-ciently suppresses fading resulting from standing waves across the band.

Single-Feed Planar Antenna for Electric and Magnetic Fields Reception for Mobile Communications

The fading phenomenon is enumerated in a factor of quality degradation in mobile communication technologies. In this paper, a single-feed planar antenna is proposed for electric and magnetic fields reception in order to improve the degradation of the received signal level due to a fading phenomenon. The proposed antenna has a line element and a conducting ground plane with a slot which are printed on the dielectric substrate. The antenna was analyzed by FDTD method. The characteristics of the single-feed planar antenna for electric and magnetic fields reception and its components (planar monopole antenna and planar slot antenna) are described.

Broadband Planar Antenna with an Elliptical Element and a Parasitic Element near Ground Conductor

The broadband planar antenna with a truncated elliptical element and a parasitic element near ground conductor which are printed on a dielectric substrate is proposed. The proposed antenna is analyzed by using the FDTD method, and return loss characteristics and radiation patterns are obtained and shown in figures. Effects of a parasitic element and a truncated elliptical element are considered. From the results, it is clear that radiation patterns are improved by locating a parasitic element and truncating an elliptical element.

Analytical study of broadbanding of a planar antenna for improving the deteriorated characteristics due to fading phenomenon

The fading phenomenon due to standing waves is one of the factors of quality deterioration in mobile communication technologies. A single-feed planar antenna which is suitable for receiving the terrestrial broadcasting in UHF (Ultra High Frequency) band is proposed in order to improve the deteriorated receiving characteristics due to the fading phenomenon. It has two antenna components; a B-PMA (Broadband Planar Monopole Antenna) which is an electric antenna and a B-PSA (Broadband Planar Slot Antenna) which is a magnetic antenna, and is composed of the two components by single-feed structure. The return loss characteristics of the proposed antenna and its components are analyzed by the FDTD (Finite Difference Time Domain) method, and declare that the bandwidth of the proposed antenna is broadened to receive the Japanese terrestrial DTV (Digital Television).