• 한국정보통신설비학회:학술대회논문집
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• 2009.08a
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• pp.215-218
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• 2009

In this paper, Dual-band bandpass filter studied design using Parallel Coupled SIR(Stepped Impedance Resonator). This Dual-band bandpass filter design SIR of half-wavelength by Parallel-coupled type that is available to RFID system and Changed structure in Meander form by size reduce. Because seen Dual-band bandpass filter is designed so that is applicable for frequency 433MHz and 2.45GHz of RFID system is very wide distance between two pass-band, establish 433MHz by fundamental frequency and controlled 2.45GHz by 2st spurious resonance frequency bandstop filter of 1st spurious resonance frequency and Parallel coupled SIR Combine to remove 1st spurious resonance frequency.

• Journal of Positioning, Navigation, and Timing
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• v.12 no.2
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• pp.157-166
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• 2023

Several experiments were carried out to analyze the impact of the modernized Global Positioning System (GPS) L2C signal on pseudorange-based point positioning. Three dual-frequency positioning algorithms, ionosphere-free linear combination, ionospheric error estimation, and simple integration, were used, and the results were compared with those of Standard Point Positioning (SPP). An analysis was conducted to determine the characteristics of each dual-frequency positioning method, the impact of the magnitude of ionospheric error, and receiver grade. Ionosphere-free and ionospheric error estimation methods can provide improved positioning accuracy relative to SPP because they are able to significantly reduce the ionospheric error. However, this result was possible only when the ionospheric error reduction effect was greater than the disadvantage of these dual-frequency positioning algorithms such as the increment of multipath and noise, impact of uncertainty of unknown parameter estimation. The RMSE of the simple integration algorithm was larger than that of SPP, because of the remaining ionospheric error. Even though the receiver grade was different, similar results were observed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.9
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• pp.1733-1740
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• 2011

In this research, a MEMS vibratory gyroscope with dual-mass system in the sensing mode has been proposed to increase the stability of the device using wide bandwidth. A wide flat region between the two resonance peaks of the dual-mass system removes the need for a frequency matching typically required for single mass vibratory gyroscopes. Bandwidth, mass ratio, spring constant, and frequency response of the dual-mass system have been analyzed with MATLAB and ANSYS simulation. Designed first and second peaks of sensing mode are 5,917 and 8,210Hz, respectively. Driving mode resonance frequency of 7,180Hz was located in the flat region between the two resonance peaks of the sensing mode. The device is fabricated with anodically bonded silicon-on-glass substrate. The chip size is 6mm x 6mm and the thickness of the silicon device layer is $50{\mu}m$. Despite the driving mode resonance frequency decrease of 2.8kHz and frequency shift of 176Hz from the sensing mode due to fabrication imperfections, measured driving frequency was located within the bandwidth of sensing part, which validates the utilized dual-mass concept. Measured bandwidth was 768Hz. Sensitivity calculated with measured displacement of driving and sensing parts was 22.4aF/deg/sec. Measured slope of the sensing point was 0.008dB/Hz.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.67 no.2
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• pp.82-89
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• 2018

This paper presents a novel prototype of dual mode control based phase shift ZVS PWM high frequency load resonant inverter with lossless snubber capacitors in addition to a single active auxiliary resonant snubber for electromagnetic induction heating(IH) foam metal based consumer fluid dual packs(DPA) heater. The operating principle in steady state and unique features of this voltage source soft switching high frequency inverter circuit topology are described in this paper. The lossless snubber and auxiliary active resonant snubber assisted constant frequency phase shift ZVS PWM high frequency load resonant inverter employing IGBT power modules actually is capable of achieving zero voltage soft commutation over a widely specified power regulation range from full power to low power. The steady state operating performances of this dual mode phase shift PWM series load resonant high frequency inverter are evaluated and discussed on the basis of simulation and experimental results for induction heated foam metal heater which is designed for compact and high efficient moving fluid heating appliance in the consumer pipeline systems.

• Proceedings of the KIEE Conference
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• 2006.10d
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• pp.129-131
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• 2006

This paper presents a new ZVS-PWM high frequency inverter. The ZVS operation is achieved in the whole load range by using a simple auxiliary reverse blocking switch in parallel with series resonant capacitor. The operating principle and the operating characteristics of the new high frequency circuit treated here are illustrated and evaluated on the basis of simulation results. It was examined that the complete soft switching operation can be achieved even for low power setting ranges by introducing the high frequency dual duty cycle control scheme. In the proposed high frequency inverter treated here, the dual mode pulse modulation control strategy of the asymmetrical PWM in the higher power setting ranges and the lower power setting ones, the output power of this high frequency inverter could introduce in order to extend soft switching operation ranges. Dual duty cycle is used to provide a wide range of output power regulation that is important in many high frequency inverter applications. It is more suitable for induction heating applications the operation and control principle of the proposed high frequency inverter are described and verified through simulated results.

• 한국정보통신설비학회:학술대회논문집
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• 2006.08a
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• pp.179-182
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• 2006

This paper introduce a different-type voltage-controlled oscillator (VCO) for PLL frequency synthesizer, And also the architecture of a high speed low-power-consumption CMOS dual-modulus frequency divider is presented. It provides a new approach to high speed operation and low power consumption. The proposed circuits simulate in 0.35 um CMOS standard technology.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.5
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• pp.303-306
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• 2014

In this paper, by using a dual frequency liquid crystal material, we propose a liquid crystal device with a fast response characteristics. The dual frequency liquid crystal material has a positive dielectric anisotropy value at a low frequency. With a high frequency, the dielectric anisotropy becomes negative. Therefore, the relaxation process is governed by not only the elastic deformation, but also the dielectric interaction. The measured decay time and rise time were 0.88 ms and 0.33 ms, respectively.

• Journal of IKEEE
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• v.22 no.4
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• pp.1088-1092
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• 2018

In this paper, we propose a dual-mode frequency tripler using push-push and stacked FET structures. The proposed circuit can operate either in frequency multiplier mode or in amplifier mode. In the frequency multiplier mode, push-push frequency multiplication is achieved by allowing input signals with particular phase shifts. In the amplifier mode, the device operates as a distributed amplifier to obtain high gain. Also both modes were designed using stacked FET structure. The designed circuit showed frequency tripled output power of 9.7 dBm at 2.4 GHz with the input at 800 MHz. On the other hand, in the amplifier mode, the device showed 8.9 dB of gain to generate 19.5 dBm at 800 MHz.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.385-386
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• 2008

In this paper, a simple dual band filter chip is designed with 0603 case size using IPD technology. The dual-band filter achieves high frequency band at 2.5 GHz and low frequency band at 1.8 GHz. The insertion losses in high frequency band and low frequency band are -0.195 dB and -0.146 dB, respectively. The return losses in these bands are -22.7 dB and -22.8 dB, respectively. The simple dual-band filter based on SI-GaAs substrate is designed within die size of about 1.3 $mm^2$.

• Proceedings of the IEEK Conference
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• 2003.11c
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• pp.37-40
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• 2003

The 1.63㎓, 2.33㎓ dual-band PLL frequency synthesizer has been developed for applications to the miniature repeater. The miniature dual-band repeater will be used at shopping mall, basements and underground parking lots. The in-loop 1.63㎓, 2.33㎓ dual-band PLL frequency synthesizer has been developed by designing Si BJT VCO and PLL loop circuits with Colpitts. The prototype of 1.63㎓, 2.33㎓ dual-band PLL frequency synthesizer of size 19${\times}$19${\times}$8(mm) has shown operating frequencies of 1.63㎓, 2.33㎓ ranges, RF output of 1dBm(PCS), 1dBm(IMT-2000), phase noise of -100 dBc/Hz(PCS), -95dBc/Hz(IMT-2000) at 10KHz offset, harmonics suppression of -24dB c(PCS), -15dBc(IMT-2000).