• ETRI Journal
• /
• v.35 no.3
• /
• pp.546-549
• /
• 2013

A Ka-band 6-W high power microwave monolithic integrated circuit amplifier for use in a very small aperture terminal system requiring high linearity is designed and fabricated using commercial 0.15-${\mu}m$ GaAs pHEMT technology. This three-stage amplifier, with a chip size of 22.1 $mm^2$ can achieve a saturated output power of 6 W with a 21% power-added efficiency and 15-dB small signal gain over a frequency range of 28.5 GHz to 30.5 GHz. To obtain high linearity, the amplifier employs a class-A bias and demonstrates an output third-order intercept point of greater than 43.5 dBm over the above-mentioned frequency range.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.8 no.2
• /
• pp.139-142
• /
• 2008

An X-band MMIC power amplifier for radar application is developed using $0.25-{\mu}m$ gate length GaAs pHEMT technology. A bus-bar power combiner at output stage is used to minimize the combiner size and to simplify bias network. The fabricated power amplifier shows 38.75 dBm (7.5 Watt) Psat at 10 GHz. The chip size is $3.5\;mm{\times}3.9\;mm$.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.15 no.4
• /
• pp.437-444
• /
• 2015

A high output power voltage controlled oscillator (VCO) in the U-band was implemented using a 65 nm CMOS process. The proposed VCO used a transmission line to increase output voltage swing and overcome the limitations of CMOS technologies. Two varactor banks were used for fine tuning with a 5% frequency tuning range. The proposed VCO showed small variation in output voltage and operated at 51.55-54.18 GHz. The measured phase noises were -51.53 dBc/Hz, -91.84 dBc/Hz, and -101.07 dBc/Hz at offset frequencies of 10 kHz, 1 MHz, and 10 MHz, respectively, with stable output power. The chip area, including the output buffer, is $0.16{\times}0.16mm^2$ and the maximum output power was -0.11 dBm. The power consumption was 33.4 mW with a supply voltage of 1.2-V. The measured $FOM_P$ was -190.8 dBc/Hz.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.11a
• /
• pp.408-409
• /
• 2008

In this paper the power divider is realized using the IPD processes for 900/1800 MHz; the designed power divider achieved the isolation of more than -24 dB. the insertion loss of nearly -3.5 dB, and the return loss of about -25 dB. The simple dual-band power divider based on SI-GaAs substrate is realized within the die size of about $2.5\times2mm^2$.

• Journal of the Semiconductor & Display Technology
• /
• v.9 no.2
• /
• pp.7-10
• /
• 2010

In this paper, we design a modem SoC (System on Chip) for low power consumption and high speed wireless communications. Among various schemes of high speed communications, an MB-OFDM (Multi Band-Orthogonal Frequency Division Multiplexing) UWB (Ultra-Wide-Band) chip is designed. The MB-OFDM uses wide-band frequency to provide high speed data rate. Additionally, the system imposes no interference to other services. The 90nm CMOS (Complementary Metal-Oxide Semiconductor) technology is used for the SoC design. Especially, power management mode is implemented to reduce the power consumption.

• Journal of IKEEE
• /
• v.22 no.4
• /
• pp.1050-1055
• /
• 2018

In this paper, we analyzed the sensitivity of matching elements for the dual-band operation of a power amplifier with composite right/left-handed (CRLH) transmission lines. Metamaterial theory enables CRLH transmission to support arbitrary impedance matching at dual frequencies. In general, at sub-GHz range, the CRLH matching networks are commonly implemented with lumped elements, which are prone to manufacturing distribution. In order to reduce the effect from the distribution of element values in design, we suggest a method to analyze the sensitivity of matching elements from the performance aspect of power amplifiers. Based on the analysis, a 40dBm dual-band power amplifier operating at 0.7GHz and 1.5GHz is designed.

• Proceedings of the IEEK Conference
• /
• 2002.07b
• /
• pp.1133-1136
• /
• 2002

We designed and fabricated a low local oscillation (LO) power V-band CPW mixer module using a CPW-to-waveguide transition technology for the application of millimeter-wave wireless communication systems. The mixer was designed using a unique gate mixing architecture to achieve simultaneously a low LO input power, a high conversion gain, and good LO-RF isolation characteristics. The fabricated mixer exhibited a high conversion gain of 2 dB at a low LO power of 0 dBm. For data transmission of the 60 ㎓ wireless LNA systems, we fabricated a CPW-to-waveguide converter module of WR-15 type and mounted the fabricated mixer in the converter module. The fabricated V-band mixer exhibited a higher conversion gain and a lower LO input power than other reported V-band mixers.

• Electronics and Telecommunications Trends
• /
• v.37 no.5
• /
• pp.11-21
• /
• 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 Satellite, Information and Communications
• /
• v.11 no.3
• /
• pp.127-132
• /
• 2016

This paper presents the design of a palm-sized metamaterial antenna system having reconfigurable polarization as well as dual-band characteristics. Basically, three antennas are laid by 45 degrees in order and excited by a compact metamaterial dual-band power-divider of the in-phase outputs, and the radiated fields of the antennas are mixed to turn the vector of the polarization to another. The validity of the proposed method is verified by observing the in-phase outputs from the odd-numbered power-dividing device for both 900 MHz and 2.4 GHz, and checking the changeable polarization with the antenna gain over 2 dBi for all the polarizations.

• Electrical & Electronic Materials
• /
• v.9 no.9
• /
• pp.969-977
• /
• 1996

본고에서는 여러가지 Wide Band-gap중에서 특히 최근에 많은 관심을 끌고 있는 GaN와 4H-SiC, 6H0SiC의 전자기적 물성을 소개하고 현재 이들로부터 제작된 prototype소자들의 성능을 비교함으로써 그 발전현황을 알아보기로 한다. 본고에서 관심을 두는 소자분야는 광전소자(optoelectronic devices)라기보다는 고주파 고출력용 전력소자임을 밝힌다. 아울러 GaN로부터 제작된 MESFET(MEtal Semiconductor Field-Effect Transistor)소자의 고주파 대역에서의 Large-Signal특성을 Device/Circuit Model을 통하여 실험치와 비교하여보고 이로부터 최적화된 channel 구조를 갖는 소자구조에서의 RF특성을 조사한다.