• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.10
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• pp.1477-1482
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• 2012

This paper deals with a new variable microwave power distributor and a connector between a deck plate and a input power waveguide for indoor microwave wireless power transmission. We design a new type connector built in the 3-stage coaxial line structure, and calculate the return loss of the connector at 2.45GHz. Newly designed connector shows the excellent return loss performance less than -30dB at the operating frequency of 2.45GHz. And we show a power distributor in which the dividing ratio of the power is controlled mechanically by three rotary fins. The distributor can control the dividing power from 4.5% to 58% with the variance of 5% output power. The experimentally tested results of the distributor are good agreement with the simulation within the return loss of 1%.

• Journal of the Semiconductor & Display Technology
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• v.18 no.1
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• pp.21-24
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• 2019

In this paper, 5.8GHz 25W microwave wireless power transmission system was developed. The transmission system is composed of a signal generator, a 1W drive amplifier, a 25W power amplifier, and a circularly polarized transmission antenna. The receiving system was fabricated with an integrated receiver that combines a circularly polarized receiving antenna, a pass band filter, and an RF-DC converter. And a multi-integrated receiver had twelve parts, including an integrated receiver. Under the conditions, voltage and current were measured for the system at 5cm intervals from a minimum distance of 5cm to a maximum distance of 80cm. The power was calculated for the system. The results of the system are shown in tables and graphs. The power decreases with distance, but the power does not drop sharply due to a multi-integrated receiver.

• Journal of the Semiconductor & Display Technology
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• v.13 no.4
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• pp.59-63
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• 2014

Previous studies have selected wireless power transmission system using 2.45 GHz of ISM band, but the researches for 5.8 GHz microwave wireless power transmission have been relatively rare. The 5.8 GHz has some advantages compared with 2.45 GHz. Those are smaller antenna and smaller integrated system for RFIC. In this paper, the 5.8 GHz wireless power transmission system was developed and transmission efficiency was measured according to the distance. A transmitter sent the amplified microwaves through an antenna amplified by a power amplifier of 1W for 5.8 GHz, and a receiver was converted to DC from RF through a RF-DC Converter. In the 1W 5.8GHz wireless power transmission system, the converted currents and voltages were measured to evaluate transmission efficiency at each distance where LED lights up to 1m. The RF-DC Converter is designed and fabricated by impedance matching using full-wave rectifier circuit. The transmission-efficiency of the system shows from 1.05% at 0cm to 0.095% at 100cm by distance.

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

• Journal of the Semiconductor & Display Technology
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• v.15 no.4
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• pp.16-21
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• 2016

In this paper, we have designed and fabricated a receiver module for 5.8GHz Microwave Wireless Power Transmission. The receiver module was composed of an antenna, BPF (Band Pass Filter) and RF-DC converter. The antenna was designed to RHCP (Right Hand Circular Polarization). And we used ${\lambda}g/2$ open-circuited stubs for the BPF. In addition, the RF-DC converter used the tripler voltage circuit for voltage multipliers. The integrated receiver RF module for 5.8GHz Microwave Wireless Power Transmission has been designed and fabricated. The voltage was measured to the distance of 50cm.

• Journal of the Semiconductor & Display Technology
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• v.14 no.4
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• pp.88-91
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• 2015

In this paper, we have designed and fabricated a BPF (Band Pass Filter) for 5.8GHz Microwave Wireless Power Transmission. We $used{\lambda}g/2$ open-circuited stubs in addition to T-shaped transmission lines for the BPF. This BPF removes harmonics caused by diodes of RF-DC converter, and thus the RF-DC converter converts more RF power to the DC. The performance of the BPF was measured and shown through direct comparison of voltages converted by the doubler as a RF-DC Converter with and without the BPF.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.881-885
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• 2008

Wireless energy transmission system to a Micro Aerial Vehicle is now under development. A 5.8 GHz microwave phased array antenna and rectenna array receiver have been developed. An electric motor on a circling MAV model was driven by the transmitted power. In addition, 140GHz millimeter-waves of up to 1MW was beamed to a "Microwave Rocket" and its thrusting has been successfully demonstrated.

• Journal of the Semiconductor & Display Technology
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• v.14 no.4
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• pp.84-87
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• 2015

We have designed and fabricated two different RF-DC Converters called doubler for 5.8GHz Microwave Wireless Power Transmission. The doubler as RF-DC Converter makes the rectified voltage be doubled. We measured and compared voltages of the doublers with those of the previous full-wave rectifying RF-DC Converter. The doublers show rectified double voltages. However, the full-wave rectifying converter has a high efficiency due to the suppression of reflecting harmonics. The other fabricated doublers causes so many harmonics that they can't convert the low-power RF to the full DC. In this paper, we show that the different doublers doesn't double the rectifying voltages compared with those of the full-wave rectifying converter and give a reason about that.

• Proceedings of the IEEK Conference
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• 2002.06a
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• pp.439-442
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• 2002

We present in this Paper a microwave Power sensor fabricated by a standard CMOS process and a bulk micromachining process. The sensor consists of a CPW transmission line, a resistor as a healer, and thermocouple arrays. An input microwave heater, the resistor so that the temperature rises proportionally to the microwave power and tile thermocouple arrays convert it to an electrical signal. The sensor uses air bridged 8round of CPW realized by wire bonding to reduce tile device size and cost and to improve the thermal impedance. Al/poly-Si junctions are used for the thermocouples. Poly-Si is used for tile resister and Aluminium is for transmission line. The resistor and hot junctions of the thermocouples are placed on a low stress silicon nitride diaphragm to minimize a thermal loss. The fabricated device operates properly from 1㎼ to 100㎽\ulcorner of input power. The sensitivity was measured to be ,3.2～4.7 V/W.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.8
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• pp.1125-1131
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• 2013

Wireless power transmission technology has been studied variety. Recently, wireless power transmission technology used by resonance and magnetic induction field is applied to various fields. However, magnetic resonance and inductive coupling are have drawbacks - power transmission distance is short. Microwave transmission and accept techniques have been developed to overcome short distance. However, improvement in efficiency is required. This paper, propose a high-efficiency microwave energy acceptor IC(EAIC). Suggested EAIC is consists of RF-DC converter and DC-DC converter. Wide Input power range is -15 dBm ~ 20 dBm. And output voltage is boosted up to 5.5 V by voltage boost-up circuit. EAIC can keep the output voltage constant. Available efficiency of RF-DC converter is 95.5 % at 4 dBm input. And DC-DC efficiency is 94.79 % at 1.1 mA load current. Fully EAIC efficiency is 90.5 %.