• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.26 no.9
• /
• pp.806-813
• /
• 2015

In order to satisfy several conditions with respect to size, weight, and costs, automotive radars use an antenna consisting of a small number of receiving channels. If RELAX technique is applied to the automotive radars, angles of targets located in antenna beam can be estimated as well as the number of the targets. However, a small number of receiving channels in the antenna leads to inaccurate spectral estimation in angle domain, which in turn degrades performance of RELAX technique. Therefore, in this study, root-MUSIC technique coupled with MDL criterion is introduced to decide accurate angles of targets in antenna beam. In simulations, we show superior performance of proposed scheme using simulation results when three point targets are located in antenna beam.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.29 no.12
• /
• pp.924-934
• /
• 2018

This paper describes the development and measurement results of C-band planar active phase array antenna for detecting and tracking radar(weapon-locating radar). The antenna is designed with 14 sub-arrays(12 main channels and 2 sidelobe blanking channels and approximately 3,000 elements of transmit-receive channel) to generate transmit and digital receive patterns. Using a near-field measurements facility, G/N, transmit patterns, and received patterns are measured. Receive patterns are implemented with digital beamforming by signal processing. The measurement results demonstrate that antenna design specifications were fulfilled.

• Journal of Sericultural and Entomological Science
• /
• v.43 no.2
• /
• pp.77-82
• /
• 2001

This study was investigated to know the effects of diflubenzuron(DFB) on the larval silkgland development of the silk-worm, Bombyx mori (L.). It has been known as a prohibitor of chitin synthesis mostly on the species of the Order Lepidoptera. In this work, the effects of the DFB concentrations (2.5$\times$10$\^$-1/,2.5$\times$10$\^$-2/, and 2.5$\times$10$\^$-3/$\mu\textrm{g}$/$\mu$l on the various larval stages, were investigated in terms on the silkgland. The macro- and microstructure of cell membrane of silkgland, and the differences of silkgland weight and water contents treated by DFB are also surveyed. As the tesults, the silkgland weight depended sensitively on not the DFB concentration but the DFB treatment period. The longer DFB treatment period, the lighter dried silkgland weight and the heavier water content of the silkgland. White opaque(WO) emerged in the middle silkgland of DFB treated larva. From the scanning election microscope observation, the cell membrane of silkgland of DFB treated larva was distinctly more compact compared to that of control. The WO was evidently resulted from the obstacles of normal transformation of silk protein through the cell membrane of middle silkgland.