• Title/Summary/Keyword: Tunnel diode

Search Result 27, Processing Time 0.023 seconds

Tunnel Diode Oscillator with a Moving Target as a Self-excited Mixer (이동물체 탐색을 위한 터넬다이오드 백여믹서)

  • Lee, Jong-Gak;Sim, Su-Bo;Yun, Hyeon-Bo
    • Journal of the Korean Institute of Telematics and Electronics
    • /
    • v.11 no.1
    • /
    • pp.40-46
    • /
    • 1974
  • This paper deals with the self-excited mixer using tunnel diode oscillator operated as a microwave source and Doppler signal detector. The system impedance, the oscillation condition and the frequency conversion theory including moving target are investigated. The oscillating frequency and the output of tunnel diode oscillator are 2.035 GHz and 0.1 mW. The input signal frequency which is equivalent to Doppler signal is lower than tunnel diode oscillator frequency by 125 MHz. TDe conversion loss has been investigated as a functicn of input signal level. This loss is greater than 67 db for the large pump mode.

  • PDF

Optimization of the tunnel Diode for GaAs/Ge Tandem Solar Cell (GaAs/Ge Tandem Solar Cell에 관한 터널 다이오드 최적화 연구)

  • Yang, S.M.;O, B.G.;Lee, M.G.;Cha, In-Su
    • Solar Energy
    • /
    • v.18 no.1
    • /
    • pp.35-43
    • /
    • 1998
  • In two terminals monolithic tandem solar cells, tunnel diode is an important variable to improve conversion efficiency depending on current matching between the top and the bottom cells. Especially, the GaAs/Ge tandem is one of the most interesting cells for its high potential efficiency. This paper shows that physical analysis about I-V specific character of the GaAs/Ge solar cell, which is grown by MOCVD for GaAs or CVD for Ge, using computer simulation and experimental results, varying with thickness of the tunnel diode layer and concentration.

  • PDF

Effect of Growth Factors in Doping Concentration of MBE Grown GaAs for Tunnel Diode in Multijunction Solar Cell

  • Park, Gwang-Uk;Gang, Seok-Jin;Gwon, Ji-Hye;Kim, Jun-Beom;Yeo, Chan-Il;Lee, Yong-Tak
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2012.08a
    • /
    • pp.308-309
    • /
    • 2012
  • One of the critical issues in the growth of multijunction solar cell is the formation of a highly doped Esaki interband tunnel diode which interconnects unit cells of different energy band gap. Small electrical and optical losses are the requirements of such tunnel diodes [1]. To satisfy these requirements, tens of nanometer thick gallium arsenide (GaAs) can be a proper candidate due to its high carrier concentration in low energy band gap. To obtain highly doped GaAs in molecular beam epitaxy, the temperatures of Si Knudsen cell (K-cell) for n-type GaAs and Be K-cell for p-type GaAs were controlled during GaAs epitaxial growth, and the growth rate is set to 1.75 A/s. As a result, the doping concentration of p-type and n-type GaAs increased up to $4.7{\times}10^{19}cm^{-3}$ and $6.2{\times}10^{18}cm^{-3}$, respectively. However, the obtained n-type doping concentration is not sufficient to form a properly operating tunnel diode which requires a doping concentration close to $1.0{\times}10^{19}cm^{-3}$ [2]. To enhance the n-type doping concentration, n-doped GaAs samples were grown with a lower growth rate ranging from 0.318 to 1.123 A/s at a Si K-cell temperature of $1,180^{\circ}C$. As shown in Fig. 1, the n-type doping concentration was increased to $7.7{\times}10^{18}cm^{-3}$ when the growth rate was decreased to 0.318 A/s. The p-type doping concentration also increased to $4.1{\times}10^{19}cm^{-3}$ with the decrease of growth rate to 0.318 A/s. Additionally, bulk resistance was also decreased in both the grown samples. However, a transmission line measurement performed on the n-type GaAs sample grown at the rate of 0.318 A/s showed an increased specific contact resistance of $6.62{\times}10^{-4}{\Omega}{\cdot}cm^{-2}$. This high value of contact resistance is not suitable for forming contacts and interfaces. The increased resistance is attributed to the excessively incorporated dopant during low growth rate. Further studies need to be carried out to evaluate the effect of excess dopants on the operation of tunnel diode.

  • PDF

광대역 고감도 DLVA 개발

  • 이두훈;김상진;김재연;조현룡;이정문;김상기
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.11 no.4
    • /
    • pp.39-52
    • /
    • 2000
  • A design of 2 stage S-DLVA(successive detector log video amplifier) was studied to detect wide dynamic radar pulse ranging from -70 ㏈m to 0㏈m. A basic design idea was focused on the linear detection in logarithmic scale of wide dynamic range radar pulses from nosie-like weak power of -70 ㏈m to relatively high power 0 ㏈m. It is highly formidable, since it requires high speed detection less than 10 nsec over the operating frequency ranges from 6 to 18 ㎓. A limiter diode, a tunnel diode and an L17-C were used as a protecting device, a detector diode and a log video amplifier in companion as a single stage detector to give voltage output proportional to the input power of about 35 ㏈ dynamic range. A protype of 2-stage DLVA having one more single stage detector was fabricated with a 32 ㏈ low noise amplifier and a 3 ㏈ hybrid coupler to provide total 70 ㏈ dynamic range detection. The logging characteristics were measured to have log slope of 25m.V/㏈ against 70 ㏈ logging range from -55 ㏈m to +15 ㏈m, the log linearity of within +/- 1.5 ㏈, and tangential sensitivity was at -63 ㏈m. The pulse dynamics of rise time and recovery time were measured as 50 nsec and 1.2 $\mu$sec, respectively. The reason might be due to the parasitic capacitances of packaged limiter, tunnel diode, and L17-C.

  • PDF

Analysis of a Tunnel-Diode Oscillator Circuit by Predictor-Corrector Method (프레딕터.코렉터방법에 의한 터널다이오드 발진회로의 해석)

  • 이정한;차균현
    • Journal of the Korean Institute of Telematics and Electronics
    • /
    • v.10 no.6
    • /
    • pp.45-55
    • /
    • 1973
  • This paper discusses the nonlinear time-invarient circuit composed of a tunnel diode. Prior to determine the solution of the nonlinear network which has negative resistance elements, the static characteristics of the nonlinear resistance elements need to be represented by function. Polynomial curve fitting is discussed to represent the static characteristies by least squares approximation. In order to solve the nonlinear network, the state equations for the networks are set up and solved by prediction corrector method. Finally, the limit cycle is plotted to discuss the stability of the nonlinear network and the oscillation condition.

  • PDF

A Full Adder Using Schottky-Barrier Diodes and a Tunnel Diode (쇼트키-배리어 다이오드와 터넬다이오드를 사용한 전가산기)

  • 박인칠
    • Journal of the Korean Institute of Telematics and Electronics
    • /
    • v.9 no.3
    • /
    • pp.22-28
    • /
    • 1972
  • A new full-adder is proposed and it's operation-characteristic is described. The circuit proposed here was improved in operational stability and cicuit-configuration. The circuit is composed of a tunnel diode, Schottky-barrier diodes. The circuit design and it's opration is explained by considering the change of the load line when the input current is applied. The explanations are proved by experimental details.

  • PDF

Analysis of a Two Stable Multi-Vibrator using a Tunnel Diode Pair Circuit (2안정 멀티바이브레이터 터널 다이오우드 대회로의 해석)

  • 이광형
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.8 no.1
    • /
    • pp.38-42
    • /
    • 1983
  • The characteristic of a Tunnel Diode(TD) is approximated by the summation of two exponential terms, obtained from the haracteristic curves displayed on the curve tracer. Using this result, static characteristic of a TD pair was plotted by a computer programming. From these static characteristic curves, the triggering behavior of TC pair multi-vibrators was described graphically. Two stable characteristics were analyzed by piecewise linear Method. Theoritical switching Theoritical switching times of a TD pair flip-flop(F-F) circuits were compared with experimental results.

  • PDF

Analysis of Negative Resistance Maximum Oscillating Frequeney (부저항발진기의 최대주파수 해석(I보))

  • 김영권;서정홍
    • Journal of the Korean Institute of Telematics and Electronics
    • /
    • v.6 no.2
    • /
    • pp.6-20
    • /
    • 1969
  • Tunnel diode oscillator consisting of a tunnel diode(negative-resistance element) and a passive linear load. In this paper maximizing the frequeney of a negative reistance oscillator with varying a passive linear load is investigated. The method of theoretical analysis, utiliying impedance loei in the complex plane and experimental data shows that the maximum frequencies of quasi-harmonic oscillation is higher in the parrallal-RL load than in the resistive load.

  • PDF

Analysis of the Thermoelectric Devices' Power Generation Performance for Utilizing the Waste Heat of LED Tunnel Lighting Module (LED터널등 모듈의 폐열활용을 위한 열전소자의 발전 성능 분석)

  • Jeong, Ji-Young;Her, In-Sung;Lee, Se-Il;Kim, Myeong-Ho;Yu, Young Moon
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.29 no.8
    • /
    • pp.1-6
    • /
    • 2015
  • In this paper, we propose the LED(Light-Emitting-Diode) emergency lighting in a tunnel by using the thermoelectric devices. To achieve high generated power, thermoelectric device should be have high Seebeck coefficient and small contact area. Also, we reveal that a moderate heatsink required for high generated power. From the waste heat of LED tunnel lighting module (25W), the generated power was 0.062W by thermoelectric device, and it could illuminate for 1hour after charge the battery of emergency lighting during about 101hours.

Negative Differential Resistance Devices with Ultra-High Peak-to-Valley Current Ratio and Its Multiple Switching Characteristics

  • Shin, Sunhae;Kang, In Man;Kim, Kyung Rok
    • JSTS:Journal of Semiconductor Technology and Science
    • /
    • v.13 no.6
    • /
    • pp.546-550
    • /
    • 2013
  • We propose a novel negative differential resistance (NDR) device with ultra-high peak-to-valley current ratio (PVCR) by combining pn junction diode with depletion mode nanowire (NW) transistor, which suppress the valley current with transistor off-leakage level. Band-to-band tunneling (BTBT) Esaki diode with degenerately doped pn junction can provide multiple switching behavior having multi-peak and valley currents. These multiple NDR characteristics can be controlled by doping concentration of tunnel diode and threshold voltage of NW transistor. By designing our NDR device, PVCR can be over $10^4$ at low operation voltage of 0.5 V in a single peak and valley current.