• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.9
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• pp.992-999
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• 2008

This paper describes the design of SPST PIN diode switch which has a 2 kW high power handling capability within $50{\mu}s$ switching speed in $20{\sim}100$ MHz VHF-band. Design factors were investigated and it was confirmed by simulation that the characteristics of insertion loss, VSWR, and isolation met design goal. Also, the capability to handle 2 kW high power with maximum fast switching speed less than $20{\mu}s$ was confirmed and insertion loss less than 0.2 dB, VSWR less than 1.17:1, and isolation higher than 40 dB were obtained by experiments.

• Journal of the Microelectronics and Packaging Society
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• v.12 no.2 s.35
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• pp.105-109
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• 2005

A compact antenna switch module for GSM/DCS dual band applications based on multilayer low temperature co-fired ceramic (LTCC) substrate is presented. Its size is $4.5{\times}3.2{\times}0.8 mm^3$ and insertion loss is lower than 1.0 dB at Rx mode and 1.2 dB at Tx mode. To verify the stability of the developed module to the process window, each block that is diplexer, LPF's and bias circuit is measured by probing method in the variation with the thickness of ceramic layer and the correlation between each block is quantified by calculating the VSWR In the mean while, two types of bias circuits -lumped and distributed - are compared. The measurement of each block and the calculation of VSWR give good information on the behavior of full module. The reaction of diplexer to the thickness is similar to those of LPF's and bias circuit, which means good relative matching and low value of VSWR, so total insertion loss is maintained in quite wide range of the thickness of ceramic layer at both band. And lumped type bias circuit has smaller insertion itself and better correspondence with other circuit than distributed stripline structure. Evaluated ceramic module adopting lumped type bias circuit has low insertion loss and wider stability region of thickness over than 6um and this can be suitable for the mass production. Stability characterization by probing method can be applied widely to the development of ceramic modules with embedded passives in them.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.1 s.343
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• pp.143-148
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• 2006

This paper presents a high isolation and power-handling single-pole double-throw(SPDT) switch for dual band wireless LAN applications. The switch circuit has asymmetric topology which uses stacked-gate to have high power-handling and isolation for the Tx path. The proposed SPDT switch has been designed with optimum gate-width, bias, and number of stacked-gate FET. This SPDT switch has been implemented with $0.25{\mu}m$ GaAs pHEMT process which has Gmmax of 500mS/mm and fmax of 150GHz. The designed SPDT switch has the measured insertion loss of better than 0.9dB and isolation of better than 40dB for the Tx path and 25dB for the Rx path and the high power handling capability with PldB of about 23dBm for control voltage of -3/0V. The fabricated SPDT switch chip size is $1.8mm{\times}1.8mm$.

• Electronics and Telecommunications Trends
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• v.37 no.5
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• pp.11-21
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• 2022

GaN (Gallium-Nitride) is a promising candidate material in various radio frequency applications due to its inherent properties including wide bandgap, high carrier concentration, and high electron mobility/saturation velocity. Notably, AlGaN/GaN heterostructure field effect transistor exhibits high operating voltage and high power-density/power at high frequency. In next-generation radar systems, GaN power transistors and monolithic microwave integrated circuits (MMICs) are significant components of transmitting and receiving modules. In this paper, we introduce technological trends for C-/X-/Ku-band GaN MMICs including power amplifiers, low noise amplifiers and switch MMICs, focusing on the status of GaN MMIC fabrication technology and GaN foundry service. Additionally, we review the research for the localization of C-/X-/Ku-band GaN MMICs using in-house GaN transistor and MMIC fabrication technology. We also discuss the results of C-/X-/Ku-band GaN MMICs developed at Defense Materials and Components Convergence Research Department in ETRI.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.2
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• pp.36-44
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• 2016

In this paper, an Impulse Radio-Ultra Wide band RF Transceiver for WBAN applications is implemented in $0.18{\mu}m$ CMOS technology. The designed RF transceiver support 3-5GHz UWB low band and employs OOK(On-Off Keying) modulation. The receiver employs non-coherent energy detection architecture to reduce complexity and power consumption. For the rejection of the undesired interferers and improvement of the receiver sensitivity, RF active notch filter is integrated. The VCO based transmitter employs the switch mechanism. As adapt the switch mechanism, power consumption and VCO leakage can be reduced. Also, the spectrum mask is always same at each center frequency. The measured sensitivity of the receiver is -84.1 dBm at 3.5 GHz with 1.579 Mbps. The power consumption of the transmitter and receiver are 0.3nJ/bit and 41 mW respectively.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.5
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• pp.461-466
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• 2012

This paper describes the development and test result of X-band Transmitter flight model(FM) of STSAT-3 by satellite research center(SaTReC), KAIST. The communication sub-system of STSAT-3 is consist of two different frequency band channels. S-band frequency is used for Telemetry & Command, and X-band frequency is used for mission data. Payload observations data in Mass Memory Unit (MMU) is modulated by QPSK modulator in X-band Transmitter, and then QPSK modulation signal is transmitted to antenna through transfer switch. In this Paper, we described the results of modulation, low-pass filter design, power amp development, and switch test. The FM XTU is delivered Spacecraft Assembly, Integration and Test(AIT) level through the completion of functional Test and environmental(vibration, thermal vacuum) Test successfully.

• Transactions on Electrical and Electronic Materials
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• v.14 no.5
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• pp.225-230
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• 2013

This paper presents a novel shunt radio frequency microelectromechanical system switch on a quartz substrate with stiff ribs around the membrane. The buckling effects in the switch membrane and stiction problem are the primary concerns with RF MEMS switches. These effects can be reduced by the proposed design approach due to the stiffness of the ribs around the membrane. A lower mass of the beam and a reduction in the squeeze film damping is achieved due to the slots and holes in the membrane, which further aid in attaining high switching speeds. The proposed switch is optimized to operate in the k-band, which results in a high isolation of -40 dB and low insertion loss of -0.047 dB at 21 GHz, with a low actuation voltage of only 14.6 V needed for the operation the switch. The membrane does not bend with this membrane design approach. Finite element modeling is used to analyze the stress and pull-in voltage.

• Journal of electromagnetic engineering and science
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• v.16 no.1
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• pp.29-34
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• 2016

This paper proposes a reconfigurable microstrip diplexer, also known as a switchplexer, for use with single-switch operation of frequency band and output path. The proposed switchplexer is composed of a rectangular ring resonator and a switch on a shorting pin, which is inserted between the ring resonator and the ground plane. The rotated main current distributions occurring at different switch statuses provide the diplexer's different operating bands and different output ports. The performance of the simply designed switchplexer is successfully demonstrated via simulation and measurement.

• Journal of the Korean Institute of Telematics and Electronics
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• v.19 no.6
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• pp.41-51
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• 1982

This paper proposes a method of analyzing the effect of non-ideal VIS (Voltage Inverter Switch) operation on SCF characteristics. In the special case of the VIS realized with only one switch, equivalent circuits of the elements proposed in [1]. [2]. [3] are obtained from the above results. Applying these results, SCF's operating at higher frequency than the conventional ones can be implemented and the equivalent circuits of most SC circuits can be obtained. Expermental results of a low-pass filter and a band-stop filter show good agreements with the theoretical characteristics.

• Journal of Satellite, Information and Communications
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• v.5 no.2
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• pp.97-103
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• 2010

In this paper, we present an efficient design scheme based on analysis of design requirements and considerations of baseband packet switch for S-band satellite/terrestrial hybrid multi-beam satellite communication systems. To establish design requirements and considerations, we analyze required functions of baseband packet switch, specifications of multi-beam satellite communications, communication services and performance requirements. And also we analyze and compare conventional layer-2 and layer-3 satellite baseband packet switching techniques, packet switching protocols and packet switch architectures, to apply from analyzed results. Finally, we propose a hardware design scheme of MPEG based layer-2 baseband packet switch using analyzed results.