• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.3
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• pp.171-175
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• 2013

In this paper was The dielectric constant of 4.4 and thickness of 0.6mm FR-4 substrate were implanted including the L-Slot in microstrip patch antenna to design a microstrip patch antenna for LTE. The proposed antenna is $180{\times}180$ compact and $46{\times}36$ lightweight compared to existing antenna and This antenna can be used as transmission ommidirectional radiation pattern of propagation was compared to the input return loss than -10dB (VSWR 2:1) to allow communication from the resonant frequency band.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.5
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• pp.703-711
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• 2013

In this paper, we have proposed high power generator with Induction Voltage Adder of three cells. IVA which has n cells can generate n-th times high power pulse, is a more stable system than Marx generator in the view of breakdown. We applied amorphous metal magnetic cores as an energy storing material for IVA rather than ferrite cores because of their higher magnetic flux swing to make it more compact system and the loss of it was also considered in the design. For driving the IVA, we design Blumlein pulse generators which are filled with pure water for high dielectric constant and high breakdown field strength, and triggered by single Marx generator. We have presented the PSPICE simulation and its test result.

• Journal of Advanced Navigation Technology
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• v.16 no.2
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• pp.227-233
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• 2012

This paper presents a bandpass fitler of GPS and WLAN band based on LTCC. The structure of bandpass fitler consists of a Butterworth lowpass fitler and highpass filter using CRLH (Composite Right/Left-Handed) transmission line. Using green sheet with dielectric constant 7.2, we fabricated the bandpass filter that satisfied GPS and WLAN band characteristics. We are implemented the bandpass filter at center frequency 1.5 GHz (GPS) and 2.4 GHz (WLAN). Its insertion loss are 1.66 dB at GPS and 3.20 dB at WLAN respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.8
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• pp.1313-1321
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• 2000

This paper presents a novel HTS microstrip pseudo-lumped element resonator for the compact and simple filter design. A 7-pole bandpass filter with quasi-elliptic response is designed and fabricated using non-adjacent couplings between resonators. A seven-pole quasi-elliptic filter is fabricated using double sided YBCO on a LaAlO$_3$ substrate with thickness of 0.5 mm and dielectric constant of 23.5. The filter has an insertion loss of 0.8 dB at 20K, a bandwidth of 8 MHz at the center frequency of 1774 MHz, and an attenuation of 33 dB for the cut-off-band of 1 MHz.

• Electrical & Electronic Materials
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• v.9 no.2
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• pp.132-137
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• 1996

Pb(Zr$_{x}$Ti$_{1-x}$ )O$_{3}$ solutions prepared by sol-gel processing with different Zr/Ti ratio were coated on Pt/SiO$_{2}$/Si substrates using spin coating method. Coated films were annealed by rapid thermal annealing at 650.deg. C for 20sec to fabricate Pb(Zr, Ti)O$_{3}$ ferroelectric thin films. Electrical properties of the films such as dielectric constant and loss, ferroelectric hysteresis, fatigue, switching time, and leakage current were measured. Hysteresis of the films with different Zr/Ti ratio yield Pr ranging 10-21.mu.C/cm$^{2}$, E$_{c}$ ranging 37.5-137.5kV/cm. Hysteresis curve was changed from square-type to slim type according to increasing Zr contents. Switching time was faster than 180ns, and leakage current was about 20.mu.A/cm$^{2}$. The film underwent above 10$^{8}$ cycles of reversed polarization showed fatigue with increased coercive field and decreased remnant polarization.tion.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.724-726
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• 1992

In this paper, the permeability ($\mu_{\tau}'$, $\mu_{\tau}''$), dielectric constants($\varepsilon_{\tau}'$, $\varepsilon_{\tau}''$) and absorbption characteristics of Ferrite/Rubber 0-3 composites were investigated. The composite specimens were prepared by molding and curing the mixtures of matrix rubber and Ni-Zn ferrite powders which were synthesized by wet-direct method. The permeability ($u_{\tau}'$) of specimen was decreased from 2.58 to 0.7 in the range of 1$\sim$7(GHz) and kept constant 0.7$\sim$0.8 at higher than 7(GHz), the higher the frequency was, the less the valves of $u_{\tau}"$ was from 1.57 to 0.03. The optimum thickness of microwave absorber, utilizing the Smith chart, was 5(mm). The reflection loss shows over than 20(dB) from 5.5(GHz) to 7.5(GHz) at 5(mm) thickness and relative band width(B/fm) was about 30%.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.4
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• pp.549-554
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• 2017

In this paper, we studied the design and fabrication of $2{\times}2$ microstrip array antenna at around 5 GHz band.. To improve of frequency properties of antenna, feed microstrip patch antenna was simulated by HFSS(High Frequency Structure Simulator). A $2{\times}2$ array antenna was designed and fabricated by photolithograph on an FR4 substrate (dielectric constant of 4.4 and thickness of 1.6 mm). The fabricated $2{\times}2$ array antenna showed a center frequency, the minimum return loss and bandwidth were 5.3 GHz, -24dB, and 390MHz, respectively.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.4
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• pp.9-17
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• 1998

BiNbO$_{4}$ ceramics with 0.07wt% V$_{2}$O$_{5}$ and 0.03wt% CuO (BNC3V7) sintered at 900 .deg. C where it is possible for these to be co-fired with ag electronde. Dielectric constant of 44.3 TCF (Thermal Coefficient of resonance Frequency) of 2 ppm/.deg. C and Qxf value 22,000 GHz can be obtained from BNC3V7. the laminatedchip LC filter is indispensible to the minimaturization of PCS (Personal Communication System) terminals. Therefore, multilayer type BPF has been fabricated by screen-printing with silver electrode after tape casting. The simulated characteristics of the fabricated filters sintered at 900.deg. C werecomparedwith the designed ones. for Band Pass Filter widths was similar that ofdesigned ones. For Low Pass Filter (LPF), insertion loss value of band pass widths (2.4 dB) which is a few higher than that of designed (1dB), but characteristization of band pass widths was similar that of designed ones.s.of designed ones.s.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.11
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• pp.1245-1250
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• 2015

In this paper, a compact CPW-fed antenna for 2.45 GHz band WLAN applications is presented. The proposed antenna which has a geometry of folded stub and slot is fabricated into an inexpensive FR-4 substrate that has a dielectric constant of 4.2 and a thickness of 1.0 mm with optimized parameters obtained by simulation, and then measured. From measured result, we confirmed available operation as antenna for WLAN applications by obtaining the return loss level of < -10 dB in the frequency band of 2.4-2.484 GHz.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.1003-1008
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• 2017

In this paper, we studied the design and fabrication of double T Structure with CPW antenna at around 5 GHz band.. To improve of frequency properties of antenna, Double T Structure with CPW antenna was simulated by HFSS(: High Frequency Structure Simulator). A double T Structure with CPW antenna was designed and fabricated by photolithograph on an FR4 substrate (dielectric constant of 4.4 and thickness of 1.6 mm). The fabricated A double T Structure with CPW antenna showed a center frequency, the minimum return loss and impedance were 5.29GHz, -34dB, and 390MHz, $49.6{\Omega}$ respectively.