• KIEE International Transactions on Electrophysics and Applications
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• v.4C no.6
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• pp.282-287
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• 2004

Since the manufacturing process in the LTCC process does not allow solid ground planes between ceramic layers to isolate the signal lines, the buried ground should be realized as a meshed ground plane. Both characteristic impedances of the signal lines and couplings between different signal layers are influenced by the properties of these meshed planes. In this paper, we propose a new analysis method for coupling behavior between internal transmission lines, which are isolated by the buried meshed-ground planes. The coupling behavior between layers isolated by meshed-ground planes is investigated by the coupled-transmission line model for the isolated layers. The coupling factors between isolated lines with the meshed-ground are extracted by 2-D FEM calculations.

• KIEE International Transactions on Electrophysics and Applications
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• v.4C no.6
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• pp.300-305
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• 2004

In this paper, new design equations based on the pole-zero analysis for multi-layered interdigital stripline linear group delay bandpass filter with tap input ports are presented. As a design example, a four-pole group delay filter with center frequency of 2.14GHz, bandwidth of 160MHz, and group delay variation of $\pm$0.1nS for LTCC technology or multilayered PCB technology is designed. In the design process, it is not necessary to simulate the entire structure, as the simulation of half structures is sufficient. Good results can be attained after the optimizing process was performed three times using the proposed equations and a commercial EM simulator.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.130-133
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• 2004

The characterization of interdigitated capacitors was investigated. The test structures are manufactured by low temperature co-fired ceramic(LTCC) process and their s-parameters were measured. The optimized equivalent circuit models for test structures were obtained using the partial element equivalent circuit(PEEC) method. Predictive modeling was performed on different test structures using optimized parameters to verify the circuit models. From this result, the manufacturability on the process can be improved through the predictive modeling for the characteristics of interdigitated capacitors.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.10 s.113
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• pp.967-975
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• 2006

In this paper, design and implementation of a very compact and cost effective front-end module are presented for IEEE 802.16 FWA(fixed Wireless Access) in the 40 GHz band. A multi-layer LTCC(Low Temperature Co-fred Ceramic) technology with cavity process to achieve excellent electrical performances is used to fabricate the front-end module. The wirebond matching circuit design of switch input/output port and waveguide transition to connect antenna are optimally designed to keep transmission loss low. To reduce the size of the front-end module, the dielectric waveguide filter is developed instead of the metal waveguide filter. The LTCC is composed of 6 layers(with the thickness of a layer of 100 um) having a relative dielectric constant of 7.1. The front-end module is implemented in a volume of $30{\times}7{\times}0.8mm^3$ and shows an overall insertion loss < 5.3 dB, and image rejection value > 49 dB.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.10 s.101
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• pp.1050-1058
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• 2005

This paper presents how to design and implement a very compact, cost effective and broad band receiver module for IEEE 802.16 FWA(Fixed Wireless Access) in the 40 GHz band. The presented receiver module is fabricated in a multi-layer LTCC(Low Temperature Cofired Ceramic) technology with cavity process to achieve excellent electrical performances. The receiver consists of two MMICs, low noise amplifier and sub-harmonic mixer, an embedded image rejection filter and an IF amplifier. CB-CPW, stripline, several bond wires and various transitions to connect each element are optimally designed to keep transmission loss low and module compact in size. The LTCC is composed of 6 layers of Dupont DP-943 with relative permittivity of 7.1. The thickness of each layer is 100 um. The implemented module is $20{\times}7.5{\times}1.5\;mm^3$ in size and shows an overall noise figure of 4.8 dB, an overall down conversion gain of 19.83 dB, input P1 dB of -22.8 dBm and image rejection value of 36.6 dBc. Furthermore, experimental results demonstrate that the receiver module is suitable for detection of Digital TV signal transmitted after up-conversion of $560\~590\;MHz$ band to 40 GHz.

• Journal of the Microelectronics and Packaging Society
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• v.28 no.3
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• pp.25-32
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• 2021

In this paper, the Magneto-Electric(ME) dipole array antenna with dual-polarization in the X-Band is proposed and it is implemented and measured. The proposed array antenna is composed of 32 single ME dipole antenna and a Teflon PCB. 1 × 1 ME dipole antenna is implemented dual-polarization by radiating vertical polarization and horizontal polarization from two pairs of radiators. 2-port feeding structures are realized by lamination process using LTCC. And, each port independently feeds the radiator through a Γ-shaped feeding strip with isolation between ports. The Teflon PCB used in the antenna array has a 4-layer structure, and 2-port is fed through the top and bottom layers. The λ_g/4 transformer is applied to the transmission line of the Teflon PCB for impedance matching of the arrayed antenna and the Teflon PCB, and the optimal parameters are obtained through simulation. The measured maximum antenna gains of port 1 was 18.2 dBi, Cross-pol was 1.0 dBi. And the measured maximum antenna gains of port 1 was 18.1 dBi, Cross-pol was 3.2 dBi.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.288-289
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• 2006

We studied the effect of sol-gel processing and sintering temperature on the microwave properties of $MgCo_2(VO_4)_2$ system(MCV) which is applicable to LTCC(low-temperature cofired ceramics). The MCV was synthesized by sol-gel process using solution that contains precursor molecules for Mg, Co, and V. SEM analysis shows that the average particle size is ${\sim}1{\mu}m$ and size distribution is very uniform compared to the one prepared by conventional solid-state reaction process. Highly dense samples were obtained at the sintering temperature range of $750^{\circ}C{\sim}930^{\circ}C$. The maximum $Q{\times}f_0$ value of 55,700GHz, dielectric constant(${\varepsilon}_r$) of 10.41 and temperature coefficient(${\tau}_f$) of $-85ppm/^{\circ}C$ was obtained at the sintering temperature of $930^{\circ}C$. The superior microwave properties of sol-gel processed MCV relative to conventional solid-state reaction processed one is remarkable especially at lower sintering temperatures such as $750^{\circ}C$ and $800^{\circ}C$.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.5
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• pp.541-546
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• 2008

A novel, simple and broadband $90^{\circ}$ phase shifter was proposed and fabricated by the LTCC process. It is composed of a $180^{\circ}$ transmission line between two $90^{\circ}$ shorted transmission lines. Design equations for the proposed $90^{\circ}$ phase shifter are derived by the method of admittance parameter analysis. Based on design equations, $90^{\circ}$ phase shifter was designed and fabricated to operate in the C-band with ${\pm}2^{\circ}$ of phase deviation.

• Journal of IKEEE
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• v.16 no.2
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• pp.121-126
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• 2012

In this paper, a push-push VCDRO (Voltage Controlled Dielectric Resonator Oscillator) with a modified frequency tuning structure is investigated. The push-push VCDRO designed at 16GHz is manufactured using a LTCC (Low Temperature Co-fired Ceramic) technology to reduce the circuit size. The frequency tuning structure is embedded in intermediate layer of A6 substrate by an advantage of LTCC process. Experimental results show that the fundamental frequency suppression is above 30dBc, the frequency tuning range is 0.43MHz over control voltage of 0 to 12V, and phase noise of push-push VCDRO presents a good performance of -103dBc/Hz at 100KHz offset frequency from carrier.

• Journal of information and communication convergence engineering
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• v.13 no.2
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• pp.139-143
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• 2015

A push-push voltage controlled dielectric resonator oscillator (VCDRO) with a modified frequency tuning structure using broadside couplers is investigated. The push-push VCDRO designed at 16 GHz is manufactured using a low temperature co-fired ceramic (LTCC) technology to reduce the circuit size. The frequency tuning structure using a broadside coupler is embedded in a layer of the A6 substrate by using the LTCC process. Experimental results show that the fundamental and third harmonics are suppressed above 15 dBc and 30 dBc, respectively, and the phase noise of push-push VCDRO is -97.5 dBc/Hz at an offset frequency of 100 kHz from the carrier. The proposed frequency tuning structure has a tuning range of 4.46 MHz over a control voltage of 1-11 V. This push-push VCDRO has a miniature size of 15 mm×15 mm. The proposed design and fabrication techniques for a push-push oscillator seem to be applicable in many space and commercial VCDRO products.