• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.11A
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• pp.902-911
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• 2003

Using InGaP/GaAs HBT power cells with a 2.0${\times}$20$\mu\textrm{m}$$^2$ emitter area of a unit HBT, a two stage MMIC power amplifier has been developed for IMT-2000 handsets. An active-bias circuit has been used for temperature compensation and reduction in the idling current. Fitting on measured S-parameters of the HBT cells, circuit elements of HBT's nonlinear equivalent model have been extracted. The matching circuits have been designed basically with the extracted model. A two stage HBT MMIC power amplifier fabricated using ETRI's HBT process. The power amplifier produces an 1-㏈ compressed output power(P$\_$l-㏈/) of 28.4 ㏈m with 31% power added efficiency(PAE) and 23-㏈ power gain at 1.95 GHz in on-wafer measurement. Also, the power amplifier produces a 26 ㏈m output power, 28% PAE and a 22.3-㏈ power gain with a -40 ㏈c ACPR at a 3.84 ㎒ off-center frequency in COB measurement.quency in COB measurement.

• ETRI Journal
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• v.31 no.5
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• pp.601-603
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• 2009

This letter presents a high performance 2.4 GHz two-stage power amplifier (PA) operating in the temperature range from $-30^{\circ}C$ to $+85^{\circ}C$ for IEEE 802.11g, wireless local area network application. It is implemented in InGaP/GaAs hetero-junction bipolar transistor technology and has a bias circuit employing a temperature compensation technique for error vector magnitude (EVM) performance. The technique uses a resistor made with a base layer of HBT. The design improves EVM performance in cold temperatures by increasing current. The implemented PA has a dynamic EVM of less than 4%, a gain of over 26 dB, and a current less than 130 mA below the output power of 19 dBm across the temperature range from $-30^{\circ}C$ to $+85^{\circ}C$.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.10B
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• pp.1701-1706
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• 2000

In this work a 38 GHz hybrid 2-stage power amplifier module using GaAs pHEMTs and waveguide to microstrip transitions has been successfully developed. A 10 mil thickness duroid substrate was use for fabrication of the power amplifier and the waveguide to microstrip transitions. The fabricated waveguide to microstrip transition showed about 1 dB insertion loss(back to back) at 32-40 GHz. The measured results of power amplifier module showed 29 dBm output power(P1.5dB), 7,2 dB associated gain and 11.2% power-added efficiency(PAE) at 36.8-38.5 GHz.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.3
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• pp.135-140
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• 2019

In this paper, a frequency split type broadband drive amplifier operating in the L, S and C bands was designed and fabricated. Transistor is difficult to efficiently use when the fractional bandwidth of the drive amplifier is more than 100%, In particular, the characteristics of the driving amplifier are important for operating the power amplifier in which the characteristics of the output power and the efficiency are sensitively changed according to the frequency band. A frequency split methods was applied to maximize the bandwidth of a drive amplifier and to divide the output of the drive amplifier into low band and high band so that the transistor of the power amplifier located at the rear of the drive amplifier can be efficiently used. The designed drive amplifier was fabricated in GaAs HBT technology and 9-layer SiP, and verified by the measurements. The fabricated drive amplifier shows a gain of more than 8 dB and an output power of more than 15 dBm in the operating frequency range.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.11
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• pp.1081-1090
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• 2013

In this paper, a C-band 10 W power amplifier with internally matched input and output matching circuit is designed and fabricated. The used power transistor for the power amplifier is GaAs pHEMT bare-chip. The wire bonding analysis considering the size of the capacitor and the position of transistor pad improves the accurate design. The matching circuit design with the package effect using EM simulation is performed. To reduce the unsymmetry of IMD3 in 2-tone measurement due to the memory effect, the bias circuit minimizing the memory effect is proposed and employed. The measured $P_{1dB}$, power gain, and power added efficiency are 39.8~40.4 dBm, 9.7~10.4 dB, and 33.4~38.0 %, respectively. Adopting the proposed bias circuit, the difference between the upper and lower IMD3 is less than 0.76 dB.

• Journal of electromagnetic engineering and science
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• v.4 no.1
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• pp.37-42
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• 2004

In this paper, LNB(low noise block) downconverter MMIC is designed for Ku-band satellite communication system using InGaP/GaAs HBT high linear process. Designed MMIC consists of low noise amplifier, double balanced mixer, and IF amplifier with a total chip area of 2.6${\times}$1.1 $\textrm{mm}^2$. Designed MMIC has the characteristics of over 37.5 ㏈ conversion gain, 14 ㏈ noise figure, ripple of 3 ㏈, and output-referred $P_{1dB}$TEX>(1 ㏈ compression power) of 2.5 ㏈m with total power dissipation of 3 V, 50 mA.

• Journal of electromagnetic engineering and science
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• v.9 no.4
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• pp.218-222
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• 2009

In this paper, we present a CPW-based 77 GHz 3-stage power amplifier MMIC for automotive radar systems. The power amplifier MMIC has been realized using a 130 nm $In_{0.88}$GaP/$In_{0.4}$AlAs/$In_{0.4}$GaAs metamorphic high-electron mobility transistors(mHEMTs) technology and an output stage with a cascode configuration. This produced a good output power and gain performance at 77 GHz. The fabricated power amplifier MMIC exhibited a small-signal gain of 18 dB, an output power of 17 dBm and 9 % power added efficiency(PAE) at 77 GHz with a total gate width of 800 ${\mu}m$ in the output stage. These performances could be useful to low-cost and small-sized components for 77 GHz automotive radar systems.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.9
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• pp.897-903
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• 2011

This paper presents a highly linear power amplifier MMIC, having an output power level of about 1 watt, based on InGaP/GaAs hetero-junction bipolar transistor(HBT) technology for the 900 MHz band. The active bias circuit is applied to minimize the effect of temperature variation. Ballast resistors are optimized to prevent a current collapse and a thermal runaway. The fabricated power amplifier exhibited a gain of 17.6 dB, an output P1dB of 30 dBm, and a PAE of 44.9 % at an output P1dB from the one-tone excitation. It also showed a very high OIP3 of 47.3 dBm at an average output power of 20 dBm from the two-tone excitation.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.609-610
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• 2006

A 77GHz MMIC transceiver module consisting of a power amplifier, a low noise amplifier, a drive amplifier, a frequency doubler and a down-mixer has been developed for automotive forward-looking radar sensor. The MMIC chip set was fabricated using $0.15{\mu}m$ gate-length InGaAs/InAlAs/GaAs mHEMT process based on 4-inch substrate. The power amplifier demonstrated a measured small signal gain of over 20dB from $76{\sim}77GHz$ with 15.5dBm output power. The chip size is $2mm{\times}2mm$. The low noise amplifier achieved a gain of 20dB in a band between $76{\sim}77\;GHz$ with an output power of 10dBm. The chip size is $2.2mm{\times}2mm$. The driver amplifier exhibited a gain of 23dB over a $76{\sim}77\;GHz$ band with an output power of 13dBm. The chip size is $2.1mm{\times}2mm$. The frequency doubler achieved an output power of -16dBm at 76.5GHz with a conversion gain of -16dB for an input power of 10dBm and a 38.25GHz input frequency. The chip size is $1.2mm{\times}1.2mm$. The down-mixer demonstrated a measured conversion gain of over -9dB. The chip size is $1.3mm{\times}1.9mm$. The transceiver module achieved an output power of 10dBm in a band between $76{\sim}77GHz$ with a receiver P1dB of -28dBm. The module size is $8{\times}9.5{\times}2.4mm^3$. This MMIC transceiver module is suitable for the 77GHz automotive radar systems and related applications in W-band.

• ETRI Journal
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• v.31 no.3
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• pp.247-253
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• 2009

We propose a Ku-band driver and high-power amplifier monolithic microwave integrated circuits (MMICs) employing a compensating gate bias circuit using a commercial 0.5 ${\mu}m$ GaAs pHEMT technology. The integrated gate bias circuit provides compensation for the threshold voltage and temperature variations as well as independence of the supply voltage variations. A fabricated two-stage Ku-band driver amplifier MMIC exhibits a typical output power of 30.5 dBm and power-added efficiency (PAE) of 37% over a 13.5 GHz to 15.0 GHz frequency band, while a fabricated three-stage Ku-band high-power amplifier MMIC exhibits a maximum saturated output power of 39.25 dBm (8.4 W) and PAE of 22.7% at 14.5 GHz.