• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.652-655
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• 2004

RF MEMS is a miniature device or an array of integration devices and mechanical components and fabricated with If batch-processing techniques. RF MEMS application area are in phased arrays and reconfigurable apertures for defence and telecommunication systems, switching network for satellite communication, and single-pole double throw switches for wireless application. Recently, RF MEMS switches have been developed for the application to the milimeter wave system. RF MEMS switches offer a substantilly higher performance than PM diode or FET switches. In this paper, SPDT(single-pole-double-throw) switch are designed to use 10 GHz. Actuation voltage and displacement are simulated by tool. And stress and distribution are simulated.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.4
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• pp.511-519
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• 2016

This paper proposes a CMOS 6-bit phase shifter with low RMS phase and amplitude errors for an X-band phased array antenna. The phase shifter combines a switched-path topology for coarse phase states and a switch-filter topology for fine phase states. The coarse phase shifter is composed of phase shifting elements, single-pole double-throw (SPDT), and double-pole double-throw (DPDT) switches. The fine phase shifter uses a switched LC filter. The phase coverage is $354.35^{\circ}$ with an LSB of $5.625^{\circ}$. The RMS phase error is < $6^{\circ}$ and the RMS amplitude error is < 0.45 dB at 8-12 GHz. The measured insertion loss is < 15 dB, and the return losses for input and output are > 13 dB at 8-12 GHz. The input P1dB of the phase shifter achieves > 11 dBm at 8-12 GHz. The current consumption is zero with a 1.2-V supply voltage. The chip size is $1.46{\times}0.83mm^2$, including pads.

• Journal of the Korean Vacuum Society
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• v.14 no.4
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• pp.207-214
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• 2005

This paper presents a channel structure for promising high performance pseudomorphic high electron mobility transistor(pHEMT) switching device for design and fabricating of microwave control circuits, such as switches, phase shifters, attenuators, limiters, for application in personal mobile communication systems. Using the designed epitaxial channel layer structure and ETRI's $0.5\mu$m pHEMT switch process, single pole double throw (SPDT) Tx/Rx monolithic microwave integrated circuit (MMIC) switch was fabricated for 2.4 GHz and 5 GHz band wireless local area network (WLAN) systems. The SPDT switch exhibits a low insertion loss of 0.849 dB, high isolation of 32.638 dB, return loss of 11.006 dB, power transfer capability of 25dBm, and 3rd order intercept point of 42dBm at frequency of 5.8GHz and control voltage of 0/-3V These performances are enough for an application to 5 GHz band WLAN systems.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.7 s.337
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• pp.57-62
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• 2005

This paper describes the design of a high performance microwave single pole double throw (SPDT) monolithic microwave integrated circuit switch using GaAs pHEMT process. The switch design proposes a novel coplanar waveguide (CPW) impedance transform network which results in the low insertion loss and high isolation by compensating for the FET parasitics to get the low on-resistance and low off-capacitance. The proposed switch has the measured isolation of better than 24 dB and insertion loss of less than 2.6 dB from 53 to 61 GHz. The chip is fabricated with the size of 2.2mm $\times$ 1.6 mm.

• ETRI Journal
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• v.31 no.3
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• pp.342-344
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• 2009

From a hydrodynamic device simulation for the pseudomorphic high electron mobility transistors (pHEMTs), we observe an increase of maximum extrinsic transconductance and a decrease of source-drain capacitances. This gives rise to an enhancement of the switching speed and isolation characteristics as the upper-to-lower planar-doping ratios (UTLPDR) increase. On the basis of simulation results, we fabricate single-pole-double-throw transmitter/receiver monolithic microwave integrated circuit (MMIC) switches with the pHEMTs of two different UTLPDRs (4:1 and 1:2). The MMIC switch with a 4:1 UTLPDR shows about 2.9 dB higher isolation and approximately 2.5 times faster switching speed than those with a 1:2 UTLPDR.

• ETRI Journal
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• v.28 no.1
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• pp.84-86
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• 2006

This letter presents a small-sized, high-power single-pole double-throw (SPDT) switch with defected ground structure (DGS) for wireless broadband Internet application. To reduce the circuit size by using a slow-wave characteristic, the DGS is used for the quarter-wave (${\lambda}$/4) transmission line of the switch. To secure a high degree of isolation, the switch with DGS is composed of shunt-connected PIN diodes. It shows an insertion loss of 0.8 dB, an isolation of 50 dB or more, and power capability of at least 50 W at 2.3 GHz. The switch shows very similar performance to the conventional shunt-type switch, but the circuit size is reduced by about 50% simply with the use of DGS patterns.

• Proceedings of the IEEK Conference
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• 2003.11c
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• pp.60-63
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• 2003

This paper describes the design and the simulation of a V-band single pole double throw (SPDT) FET switch fur millimeter-wave applications using drain impedance transformation network with CPW transmission line. The designed switch has about 10% bandwidth at 60GHz. Insertion loss is better than 3dB fur the ON state and Isolation is larger than 30dB fer the OFF state. The maximum isolation is 43.4dB at 60GHz with input power of 10dBm. The yield analysis is done considering the effects of pHEMT variations.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.10
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• pp.1567-1570
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• 2022

This paper, we presents a RF protection technique of antenna switch by improving the power handling capability in worst case environment mode for mobile phone applications without critical payment of circuit performances such as insertion loss, isolation and ACBV (AC breakdown voltage). By applying a additional capacitive path located in front of the antenna in cell-phone, it performs the effective reduction of input power in high voltage standing wave ratio (VSWR) condition. Under the all-path off condition which causes a high VSWR, it achieved 37.7dBm power handling level as high as 5.7dB compared to that of conventional one at 2GHz. In addition, insertion loss and isolation performances were 0.31dB and 42.72dB at 2 GHz, respectively which were almost similar to that of the conventional circuit. The proposed antenna switch was fabricated in 130nm CMOS SOI technology.

• Journal of Korea Multimedia Society
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• v.25 no.8
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• pp.1038-1048
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• 2022

Ultrasound is one of the effective methods for skin treatment. The skin penetration depth of the ultrasound depends on the ultrasonic frequency, that is, when the ultrasonic frequency is high, the depth is shallow. We have developed a transducer which can generate effectively 3 different ultrasonic frequencies removing interference between 3 types of frequencies according to impedance matching technology. The generated powers of transducer are 40.67W at 3.MHz, 17.46W at 11.7 MHz, and 14.79W at 21.5 MHz. The signal interference between the three frequencies is designed so that they do not interfere with each other by separating the signals using the SPDT (Single Pole, Double Throw) switch. The developed hybrid ultrasound transducer can be applied in skin care or skin treatment and beauty therapy.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.7
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• pp.613-619
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• 2015

In this paper, we proposed a paper-based pattern-switchable antenna using inkjet-printing technology. The proposed antenna is composed of two bow-tie antennas and a switching network. The bow-tie antennas are inkjet-printed on paper using a low cost home printer. The switching network is built on a printed-circuit-board(PCB) and consists of a single-pole-double-throw(SPDT) switch and balun element. A double-sided parallel-strip line(DSPSL) can convert the unbalanced microstrip mode to the balanced strip mode. Two bow-tie antennas have different radiation patterns because of the different orientation of the reflectors. It is demonstrated from EM simulation and measurement that the radiation patterns of the proposed antenna are successfully switched by the SPDT.