• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2004.11a
• /
• pp.5-8
• /
• 2004

In this paper, a novel 400MHz band small meander microstrip antenna is proposed the shape of the proposed antenna is a waved meander microstrip with a pair rf short pins on th￡ edge. the length of waved meander microstrip is $\lambda_g/4$ but it bends to half its size. Therefore, the total size of the proposed antenna is reduced to about 1/20 which is compared with a square patch antenna the simulated antenna gain is about 3dBi at 424MHz. the proposed antenna of -10dB impedance bandwidth is measured about $1.4\%$.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.56 no.4
• /
• pp.768-772
• /
• 2007

Integration of RF front end module(FEM) into the antenna has been investigated in USPCS band (1.88GHz-1.99GHz). The FEM consists of input filter, power amplifier, coupler, power detector, bias switch and duplexer. The antenna was designed in planar inverted F antenna(PIFA) structure to implement it inside the handset. In order to avoid strong coupling between the antenna and FEM, a shielding ground layer was placed between them. The antenna size is 19mm by 10mm by 6mm under which FEM whose size is 8mm by 5mm by 1.5m locates. The antenna impedance was selected to match to FEM having better efficiency rather than gain since FEM has enough gain whose system spec is minimum of 20dB. The antenna patterns are shown with and without FEM.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.46 no.1
• /
• pp.60-63
• /
• 2009

In this paper, Designed and implemented about module that generate division signal for uplink section and downlink section for controlling Tx/Rx antenna of 2.3-2.7GHz WiMAX TDD repeater. It is consisted of RF block and Baseband block, and because function of this module is that synchronize with WiMAX signal and create division signal for uplink section and downlink section, this module was designed only received path. And because of manufacturing of most RF block by one chip, this module could minimize area. And in baseband block, used the WiMAX Modem to detect Preamble and DL-MAP information of WiMAX signal. This design can process about 2.3-2.7GHz WiMAX.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.20 no.8
• /
• pp.777-783
• /
• 2009

In this paper, we implemented a wireless power transmission system at 2.45 GHz. The transmission power is limited within 20 dBm according to the ISM frequency regulations. We used two zero-bias Schottky diode and optimized the RF-DC converter for working a clock at 80 cm distance using a receiver with a single antenna and an Rf-DC converter to reduce parts and cost compared to previously reported literatures.

• Journal of Satellite, Information and Communications
• /
• v.10 no.1
• /
• pp.88-91
• /
• 2015

Wireless power transmission (WPT) is a technology using free space as a conductor for transmitting electric power, which aims to transfer not just the transmission signal but also the electrical energy itself. This paper takes issue with the microwave wireless transmission technology utilizing in long-distance transmission. To construct the WPT system, several components are needed, such as RF Oscillator which converts AC power to RF through DC status, high gain antenna and RF rectifier that converts RF back to DC. The array topology is good a candidate for wide use. The objective of this research is to study the efect of the WPT systmem on electric power system.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.21 no.4
• /
• pp.427-432
• /
• 2010

To reduce the outage probability and to increase the transmission capacity, the importance of repeaters in cellular systems is increasing. But a RF(Radio Frequency) repeater has a problem that the output of the transmit antenna is partially feedback to the receive antenna, which is feedback interference. In this paper, we proposed adaptive Sign-Sign LMS(Least Mean Square) algorithm using correlations for the performance enhancement of RF repeater. The weight vector is updated by using sign of input signal and error signal to the least squared error of the conventional algorithms. When compared with the conventional method, the proposed canceller achieves the maximum 10 dB performance gain in terms of the MSE(Mean Square Error).

• Proceedings of the IEEK Conference
• /
• 2002.06b
• /
• pp.201-204
• /
• 2002

A large area inductively coupled plasma which is applicable to LCD processing is built with a modified single loop RF antenna. Combination of parallel and series paths of RF current through the antenna induces local enhancement of plasma density, which in turn provides uniform plasma density near the substrate. The plasma density distribution is measured and compared with that of the conventional single loop antenna. Aisotropic etching of photoresist is performed, and it is found that etch uniformity is improved by 3％ from 15% of the conventional etcher over 350$\times$300mm glass substrates. Photoresist etching rate and uniformity can be further improved by applying a periodic weak axial magnetic fieid.

• Proceedings of the KIEE Conference
• /
• 2007.11a
• /
• pp.222-223
• /
• 2007

In 6.6kV Rotary Machine Stator Windings, Corona Discharge, Discharge at Conductor Surface, Slot Discharge and Endwinding Discharge is happended by electronic degradation. Also, if Partial Discharge cause in inner-part of Rotary Machine Stator Windings, it will be happended voltage and current pulse. In case of discharge spark, RF electromagnetic wave, which tranmits at discharge position, can happen. To detect this kind of RF electromagnetic wave efficiently, we have designed Planar Antenna Sensor with the CST MWS simulation program. Also we have confined the application possibility, which can analize the partial discharge in Rotary Machine Stator Windings. In the Future, sample of planar antenna sensor will be able to compare with the data of simulation by CST MWS program.

• Proceedings of the IEEK Conference
• /
• 2000.06b
• /
• pp.282-285
• /
• 2000

Four helical resonators are distributed in a 2 ${\times}$ 2 array by modifying upper part of the conventional reactive ion etching(RIE) type LCD etcher in order to prepare a large area plasma source. Since the resonance condition of the RF signal to the helical antenna, one RF power supply is used for delivering the power efficiently to all four helical resonators without an impedance matching network Previous work of 2 ${\times}$ 2array inductively coupled plasma(ICP)requires one matching circuit to each ICP antenna for more efficient power deliverly Distributions of ion density and electron temperature are measured in terms of chamber pressure, gas flow rate and RF power . By adjusting the power distribution among the four helical resonator units, argon plasma density of higher than 10$\^$17/㎥ with the uniformity of better than 7％ can be obtained in the 620 ${\times}$ 620$\textrm{mm}^2$ chamber.

• Proceedings of the KIEE Conference
• /
• 1998.07g
• /
• pp.2430-2432
• /
• 1998

Generally, in the best-known Pulse-type type and Frequency Modulated Continuous Wave(FM/CW)-type RF range measurement systems, the nearest measurable distance between antenna of system and targets is limited to several tens of meters. Moreover, in case of high-speed targets it is more difficult to measure the distance precisely. In this paper we design our own RF(X-band) range(up to 15 meters) measurement system usi code correlation for high- speed targets. It 0 the correlation value between transmitting receiving PN (Pseudo -Noise) codes. So we determine the distance between antenna of s and targets using this correlation value. We fabricated it using MIC techniques and experimental results show that the proposed syste fully qualified for a short range measurement syste