Hisamatsu Nakano

TL;DR: An antenna composed of a conducting body of revolution (BOR) and a parasitic ring shorted to a finite-sized ground plate, designated as the BOR-SPR, is designed for realizing a low-profile base station antenna with a wideband voltage standing wave ratio (VSWR) characteristic as discussed by the authors.

TL;DR: In this article, the effects of combining a steerable beam square loop antenna with various periodic high impedance surfaces (HISs) are investigated, and a hybrid HIS with vias between the plates and ground is designed.

TL;DR: In this paper, a comparison between monofilar and bifilar helix antennas is made, and a helical antenna with a parasitic helix (HAP) is proposed in order to enhance the power gain.

TL;DR: In this paper, a modified finite-difference formula is presented for the second derivative of a semivectorial field in a step-index optical waveguide, which achieves a truncation error of O(spl Delta/x/sup 2 ) provided the discontinuity coincides with a mesh point or lies midway between two mesh points.

TL;DR: In this article, the alternating direction implicit (ADI) method was applied to the analysis of three-dimensional optical fiber waveguides and it was numerically demonstrated that the ADI method offers higher computational efficiency and a larger propagation step length, as compared with the conventional beam propagation method which uses fast Fourier transformation.