• Title/Summary/Keyword: Fundamental Circuit

Search Result 199, Processing Time 0.021 seconds

Design and fabrication of the MMIC frequency doubler for 29 GHz local oscillator application (29GHz 국부 발진 신호용 MMIC 주파수 체배기의 설계 및 제작)

  • Kim, Jin-Sung;Lee, Seong-Dae;Lee, Bok-Hyoung;Kim, Sung-Chan;Sul, Woo-Suk;Lim, Byeong-Ok;Kim, Sam-Dong;Park, Hyun-Chang;Park, Hyung-Moo;Rhee, Jin-Koo
    • Journal of the Institute of Electronics Engineers of Korea TC
    • /
    • v.38 no.11
    • /
    • pp.63-70
    • /
    • 2001
  • We demonstrate the MMIC (monolithic microwave integrated circuit) frequency doublers generating stable and low-cost 29 GHz local oscillator signals from 14.5 GHz input signals. These devices were designed and fabricated by using the M MIC integration process of $0.1\;{\mu}m$ gate-length PHEMTs (pseudomorphic high electron mobility transistors) and passive components. The measurements showed S11 or -9.2 dB at 145 GHz, S22 of -18.6 dG at 29 GHz and a minimum conversion loss of 18.2 dB at 14.5 GHz with an input power or 6 dBm. Fundamental signal of 14.5 GHz were suppressed below 15.2 dBe compared to the second harmonic signal at the output port, and the isolation characteristics of fundamental signal between the input and the output port were maintained above :i0 dB in the frequency range 10.5 GHz to 18.5 GHz. The chip size of the fabricated MMIC frequency doubler is $1.5{\times}2.2\;mm^2$.

  • PDF

Design of Metal-Slit Fresnel Lens for Enhanced Coupling Efficiency (광 결합 및 집속도 향상을 위한 금속 슬릿 프레넬 렌즈의 설계)

  • Park, Dong-Won;Jung, Young-Jin;Koo, Suk-Mo;Yu, Sun-Kyu;Park, Nam-Kyoo;Jhon, Young-Min;Lee, Seok
    • Korean Journal of Optics and Photonics
    • /
    • v.20 no.1
    • /
    • pp.1-5
    • /
    • 2009
  • Recently, much research has been done for to realizeing nano-scale photonic circuits based on photonic crystal, plasmonics and silicon photonics in order to overcome fundamental limits of electronic circuits. These limits include such as bottleneck of speed, and size that cannot be reduced. Even though several kinds of coupling schemes have been reported, coupling structures are still large when it is compared with the nano-scale optical circuit. In this paper, we proposed using a very thin Fresnel lens while shortening the focal length of the Fresnel lens as much as possible. We proposed, for the first time, to utilize metal slits that are able to use the optical coupling system between a nano-scale optical circuit and the standard single mode optical fiber for overcoming the limitation of focal length shortening of the Fresnel lens. Comparative study has been carried out with a FDTD simulation between normal and metal slit assisted Fresnel lens. From the result of simulation, we can achieve 65% coupling efficiency for the metal-slit Fresnel lens when the focal length of metal-slit Fresnel lens is just $4{\mu}m$. On the other hand, the coupling efficiency of the normal Fresnel lens is about 43%.

Electrical and Fire Prevention Measures through Improvement of Indoor Wiring, Outlets and Plugs (옥내배선, 콘센트 및 플러그 개선을 통한 전기화재 예방대책)

  • Jeung, Sueng Hyo;An, Hui-Seok;Lee, Yong-Su;Kim, Chang-Eun
    • Journal of the Korea Institute of Construction Safety
    • /
    • v.1 no.1
    • /
    • pp.31-39
    • /
    • 2018
  • It is reported that about 20 % of all fires in Korea are caused by the electric equipment and installations. In complex and large-scale buildings, the sizes of electric fires are becoming larger as property damage and casualties increase. Among the causes of various electric fires, fire by short circuit accounts for about 71.5% of overall fires, and in the classification by electric equipment and installation, fire caused by wiring and wiring equipment accounts for approximately 38.3% of overall fires. The purpose of this study is to propose methods to prevent electric fires due to short circuit by improving indoor wiring currently in use and to find the fundamental measures to prevent wiring equipment caused fires by improving the socket and plug which are commonly used in wiring equipment. It is expected that the electric fire prevention measures presented through this study can be used as a measure to protect many people and properties by eliminating the root cause of electric fire.

Design of Digital Phase-locked Loop based on Two-layer Frobenius norm Finite Impulse Response Filter (2계층 Frobenius norm 유한 임펄스 응답 필터 기반 디지털 위상 고정 루프 설계)

  • Sin Kim;Sung Shin;Sung-Hyun You;Hyun-Duck Choi
    • The Journal of the Korea institute of electronic communication sciences
    • /
    • v.19 no.1
    • /
    • pp.31-38
    • /
    • 2024
  • The digital phase-locked loop(DPLL) is one of the circuits composed of a digital detector, digital loop filter, voltage-controlled oscillator, and divider as a fundamental circuit, widely used in many fields such as electrical and circuit fields. A state estimator using various mathematical algorithms is used to improve the performance of a digital phase-locked loop. Traditional state estimators have utilized Kalman filters of infinite impulse response state estimators, and digital phase-locked loops based on infinite impulse response state estimators can cause rapid performance degradation in unexpected situations such as inaccuracies in initial values, model errors, and various disturbances. In this paper, we propose a two-layer Frobenius norm-based finite impulse state estimator to design a new digital phase-locked loop. The proposed state estimator uses the estimated state of the first layer to estimate the state of the first layer with the accumulated measurement value. To verify the robust performance of the new finite impulse response state estimator-based digital phase locked-loop, simulations were performed by comparing it with the infinite impulse response state estimator in situations where noise covariance information was inaccurate.

Design and Fabrication of the Push-push Dielectric Resonator Oscillator using a LTCC (LTCC를 이용한 push-push 유전체 공진 발진기의 설계 및 제작)

  • Ryu, Keun-Kwan;Oh, Eel-Deok;Kim, Sung-Chan
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.14 no.3
    • /
    • pp.541-546
    • /
    • 2010
  • The push-push DRO(dielectric resonator oscillator) using a multi-layer structure of LTCC(low temperature co-fired ceramic) fabrication is designed. After the single DRO of series feedback type in the center frequency of 8GHz is designed, the push-push DRO in the center frequency of 16GHz including the Wilkinson power combiner is designed. The bias circuit affecting the size of oscillator are embedded in the intermediate layer of the LTCC multi-layer substrate. As a result, the large reduction in the size of VCO is obtained compared to the general oscillator on the single layer substrate. Experimental results show that the fundamental and third harmonics suppression are above 15dBc and 25dBc, respectively, and phase noise characteristics of the push-push DRO presents performance of -102dBc/Hz@100KHz and -128dBc/Hz@1MHz offset frequencies from carrier.

A High Power 60 GHz Push-Push Oscillator Using Metamorphic HEMT Technology (Metamorphic HEMT를 이 용한 60 GHz 대역 고출력 Push-Push 발진기)

  • Lee Jong-Wook
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.17 no.7 s.110
    • /
    • pp.659-664
    • /
    • 2006
  • This paper reports a high power 60 GHz push-push oscillator fabricated using $0.12{\mu}m$ metamorphic high electron-mobility transistors(mHEMTs). The devices with a $0.12{\mu}m$ gate-length exhibited good DC and RF characteristics such as a maximum drain current of 700 mA/mm, a peak gm of 660 mS/mm, an $f_T$ of 170 GHz, and an $f_{MAX}$ of more than 300 GHz. By combining two sub-oscillators having $6{\times}50{\mu}m$ periphery mHEMT, the push-push oscillator achieved a 6.3 dBm of output power at 59.5 GHz with more than - 35 dBc fundamental suppression. The phase noise of - 81.5 dBc/Hz at 1 MHz offset was measured. This is one of the highest output power obtained using mHEMT technology without buffer amplifier, and demonstrates the potential of mHEMT technology for cost effective millimeter-wave commercial applications.

A 2.65 GHz Doherty Power Amplifier Using Internally-Matched GaN-HEMT (내부정합된 GaN-HEMT를 이용한 2.65 GHz Doherty 전력증폭기)

  • Kang, Hyunuk;Lee, Hwiseob;Lim, Wonseob;Kim, Minseok;Lee, Hyoungjun;Yoon, Jeongsang;Lee, Dongwoo;Yang, Youngoo
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.27 no.3
    • /
    • pp.269-276
    • /
    • 2016
  • This paper presents a 2.65 GHz Doherty power amplifier with internally-matched GaN HEMT. Internal matching circuits were adopted to match its harmonic impedances inside the package. Simultaneously, due to the partially matched fundamental impedance, input and output matching networks become simpler. Bond wires and parasitic elements of transistor package were predicted by EM simulation. For the LTE signal with 6.5 dB PAPR, the implemented Doherty power amplifier shows a power gain of 13.0 dB, a saturated output power of 55.4 dBm, an efficiency of 49.1 %, and ACLR of -26.3 dBc at 2.65 GHz with an operating voltage of 48 V.

Sensorless Precision Speed Control of PM BLDC Motor (PM BLDC 모터의 센서리스 정밀 속도 제어)

  • Won, Chung-Yuen;Kim, Yuen-Chung;Yoon, Yong-Ho;Kim, Hack-Seong;Lee, Byuong-Kuk;Chun, Jang-Sung
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.20 no.1
    • /
    • pp.48-56
    • /
    • 2006
  • This paper studies particularly applicable method for sensorless PM BLDC motor drive system. The waveform of the motor internal voltages(or back emf) contains a fundamental and higher order frequency harmonics. Therefore the third harmonic component is extracted from the stator phase voltage. The resulting third harmonic signal keeps a constant phase relationship with the rotor flux for any motor speed and load condition. Also because of low resolution of estimated signal obtained by the proposed sensorless algorithm, to improve the wide range of speed response characteristic more exactly, we propose the rotor position signal synthesizer using PLL circuit based on estimated signals. Some experimental results are provided to demonstrate the validity of the proposed control method.

Design of a Novel 2D-Metamaterial CRLH ZOR Antenna with a Microstrip Patch Capacitively Coupled to a Rectangular Ring (직각 링과 용량성 결합된 마이크로스트립 패치 구조의 새로운 2차원 메타 재질 구조 CRLH 0차 공진 안테나의 설계)

  • Jang, Geon-Ho;Kahng, Sung-Tek
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.21 no.2
    • /
    • pp.143-151
    • /
    • 2010
  • In this paper, a novel rectangular patch antenna is proposed to have Zeroth Order Resonance(ZOR) generated based on the Metamaterial Complosite Right- and Left-Handed(CRLH) structure. Making the in-phase electric field over the entire antenna other than a half-wavelength as the fundamental resonance mode of a standard microstrip patch or its positive multiple, the metallic patch is suggested to be capacitively coupled with only one surrounding rectangular ring, different from the previous 1D ZOR antennas commonly having several metal cells in line. The performance of the proposed antenna is simulated by a 3D field solver that inputs the sizes of the physical structure corresponding to the equivalent circuit designed to have ZOR at 2.4 GHz. Consequently, the resonance frequency, the gain and the antenna efficiency are observed 2.4 GHz, 5 dB and 98%, respectively. Besides, the important property of the proposed antenna is addressed as the combination of the low profile as an advantage of microstrip patch antennas, and the omni-directional field pattern typical of monopole antennas.

A Study on the Small Size Loudspeaker for Hi-Fi Low Frequency Sound Reproduction (저음재생용 소형 스피커의 개발에 관한 연구)

  • 남경준;이채봉;김천덕
    • The Journal of the Acoustical Society of Korea
    • /
    • v.20 no.8
    • /
    • pp.31-37
    • /
    • 2001
  • Following the recent trends of reducing the size of multimedia devices, we tried for the development of a compact-sized speaker to produce low-frequency sounds efficiently. For this work, equivalent-circuit analysis was used to get fundamental resonant frequency and then the structure of speaker components has been changed appropriately. As a result, an 80mm small-sized speaker was developed. The performance test showed that the resonant frequency of our system is 79 Hz while that of numerical analysis was 81Hz. At a distance of 1m from our speaker, the frequency ranges 80 Hz to 15kHz and the average sound pressure was found to be 84±2 dB. The second (at 400 Hz) and the third (at 100 Hz) high-frequency distortions of our system were 0.5% and 1.8% respectively, which is to be compared with the distortions of 0.9% and 6% in conventional speakers.

  • PDF