Gyoo-Soo Chae

An Analysis of Direction Finding Accuracy of ELINT System

The technology of direction finding is very important to find the direction of emitters for ELINT(electronic intelligence) system. The principle of TDOA(time difference of arrival) is to receive an emitter signal with two antennas, measure the time difference between two antennas, and converse the time difference to direction difference. This technology can be used in broadband frequency system and make the system very simple because a phase-discriminator and a voltage comparator are not needed. For fine DF accuracy, high time resolution receiver and long basis line antennas are needed. The DF accuracy of noise added signals is simulated with different time

Novel S-DMB antenna design using modified QHA

A small QHA antenna for S-DMB (satellite digital multimedia broadcasting) is presented. The proposed antenna is based on the general QHA and modified the helix structure to improve the performance. According to our simulation results, a prototype antenna is manufactured and measured. The obtained antennas operate in S-DMB band (2.63 - 2.635 GHz) and can be adopted for various potable applications.

A small meander line antenna for T-DMB applications

A small meander line antenna for T-DMB (Terrestrial Digital Multimedia Broadcasting) is presented. The antenna proposed here is based on a typical planar meander line antenna and miniaturized by using a double-sided structure. A prototype antenna is manufactured based on the simulation results and the basic performances are measured. The presented antenna is designed within a dimension of 30×14mm and can be adopted for various mobile applications.

Analysis of Direction Finding Accuracy for Amplitude-Phase Comparison and Correlative Interferometer Method

In this paper, we present the direction finding accuracy of correlative interferometer method and amplitude-phase comparison method. Spiral antennas are used for amplitude-phase comparison method and blade antennas are used for correlative interferometer method. Those are made for uniform circular array (UCA) direction finding antenna systems. We simulate the accuracy of azimuth angle with 3 antennas UCA when SNR is 20 dB and baseline is 0.5 wave length. Correlative interferometer method has better accuracy than amplitude-phase comparison method.

A Design of a circularly polarized small UHF RFID antenna

=4.7). The simulation results shows that the antenna can be achieved a return loss of 12dB, gain of 3.46dBic over the UHF band of 902–928MHz. According to our simulation results, two prototype antennas are manufactured and measured. The obtained antennas operate in UHF RFID bands and can be adapted for various portable applications. In addition, a parametric study is conducted to facilitate the design and optimization processes.

An anti-ARM technique using decoy antennas

This paper describes an anti-ARM technique using multiple decoy antennas. We investigate the radar and decoy antenna signal received at the ARM receiver to verify the effect of decoy antennas. And we develop a simulation program using Matlab for optimum positions of the decoys and the effect of ARM by distance between decoys. We suggest optimum positions and distance between decoys based on our simulation results.

A Novel QHA for S-DMB Applications

A novel QHA (Quadrifilar helix antenna) for S-DMB (Satellite Digital Multimedia Broadcasting) is presented. The antenna proposed here is based on the general QHA and modified the feeding structure to simplify for manufacturing procedures. A prototype antenna is built based on the simulation results and the basic performances are measured. The presented antenna operates in S-DMB band (2630-2655 MHz) and can be adopted for various mobile applications.

Small printed antennas with a parasitic folded shorted-strip for dual-band WLAN

Small printed antennas with a parasitic folded shorted-strip for dual-band WLAN are presented. The proposed antennas are based on the parasitic shorted-patch structure which is a popular approach for further bandwidth improvement. According to our simulation results, two prototype antennas are manufactured and measured. The obtained antennas operate in IEEE802.11a/b/g bands (2.4-2.484GHz and 5.15-5.35GHz bands) and can be adopted for various potable applications.

An investigation of the Azimuth Error for Correlative Interferometer Direction Finding

In this paper, we present an azimuth error analysis for the correlative interferometer direction finding. The correlative interferometer is a direction finding method that compares the theoretical and measured phase differences. The direction of the radio transmitter can be estimated by obtaining the maximum correlation between two data sets. We used a 5-element circular array antennas arranged in a circle. To derive the correlation function between antenna elements, we assume that the incident plane wave arrives from a certain angle and the phase difference of each antenna can be derived by comparing with the reference. The suggested direction finding gives a relatively accurate result even if the radio transmitter is located in the higher altitude.

Position Fixing Accuracy of TDOA Direction Finding Method

Abstract The technology of direction finding is very important to make high position fixing accuracy. TDOA(time difference of arrival) direction finding technology is a high accuracy technology and is used in RF system from 1990. The principle of TDOA is to receive an emitter signal with two antennas, measure the time difference of received signal and then convert the time differences to azimuth angle. For high DF(direction finding) accuracy long basis line and high SNR at receiving system are needed. The DF accuracy and position fixing accuracy are simulated with different SNRs and antenna base lines. We obtain the DF accuracy of 0.51 o at 0 o incident azimuth angle in case of 50m base line and 40dB SNR. Key Words : Position Fixing, SNR, Direction Finding, TDOA, CEP, Position Error Received 27 September 2014, Revised 27 October 2014Accepted 20 November 2014Corresponding Author: Gyoo-Soo Chae(Baekseok University) Email: gschae@bu.ac.krⒸ The Society of Digital Policy & Management. All rights reserved. This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is ISSN: 1738-1916 properly cited.