• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.30A no.11
• /
• pp.40-47
• /
• 1993

In this paper, a method for analyzing coaxial collinear antenna for base station of mobile communications using the moment method and the transmission line theory is presented. The excited voltages at the junctions between elements are expressed as the matrix with transmission parameters and these voltages are applied to the integral equation for calculating current distribution. Here, the current distributions, input admittances, radiation patterns and gains are calculated. Calculated values of the current distributions and the input admittances show good agreement with measured values. In case of beamtilted collinear antenna, radiation pattern is simialar to measured result except side lobe.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.33A no.12
• /
• pp.9-15
• /
• 1996

An electric field induced by a point dipole soruce within a conductor-backed lossy dielectric slab above the earth is calculated by anumerical method. the calcualtion is peformed on the plane which is parallel to the conductor plane and containing the point dipole soruce. Computed S$_{21}$ values of two parallel planar dipole antennas and two collinear planar dipole antennas are compared against each other, as well as the electic field magnitudes in those arrangements.

• Journal of electromagnetic engineering and science
• /
• v.2 no.2
• /
• pp.87-92
• /
• 2002

A short-ended electromagnetically coupled coaxial dipole array antenna is investigated theoretically. The antenna has an advantage of structural simplicity. The integral equations are derived for the proposed structure by use of the Fourier transform and mode expansion, and the simultaneous linear equations are obtained. The slot electric field and strip current are obtained by solving the simultaneous linear equations. The effects of slot and strip numbers on the radiation efficiency, beamwidth and directivity gain of the antenna are presented.

• Journal of Multimedia Information System
• /
• v.5 no.2
• /
• pp.91-98
• /
• 2018

We devised a bird-borne transceiver unit for S-band packet radio communications based on the CC2500 transceiver, a device manufactured by Texas Instruments (TI). Our assessments determined the optimal parameters needed to achieve successful bird-to-center communication over a distance of 18 km and bird-to-bird communication over a distance of 200 m. These parameters included optimal modulation methods, transmission rates, and antennas. We equipped the transceiver unit with a modified dipole antenna (collinear antenna), which we tested in a 10 m anechoic chamber. Our experimental assessments and circuit design review identified the following parameters: 2FSK modulation method; 14.28 kHz frequency shift; 101.56 kHz IF reception bandwidth; and Manchester encoding (+). Our assessments showed bird-to-bird communications could be achieved over a distance of 200 m assuming MSK, FEC (+), and 500 kbps. Following tests by an official body, we obtained 28 sets of a type approval license for 2.4 GHz. In cooperation with the Yamashina Institute for Ornithology, we attempted to tag and release six or more swans. This unit gives us the ability to obtain vital data on swans. We expect this data to provide significant benefits, including clues on improving screening for infected individuals.