| 1. | Ultra - wideband electromagnetic radiation from gaas photoconductive switches 光电导开关的超宽带微波源 |
| 2. | Up to the present , there are no reliable theories that can correctly account for the observed transient characteristics produced by the lock - on effect 然而到目前为止,没有一种完善的理论模型,能对半绝缘gaas光电导开关中发现的lock - on效应进行较全面的解释。 |
| 3. | Being a source of microwave it is provided with merit of power and bandwidth at the same time , photoconductive semiconductor switches has unique predominance in the field of power pulse technology and thz sources 光电导开关作为兼顾脉冲功率和带宽的微波源,在thz电磁波的产生方面以及功率脉冲技术领域具有独特的优势。 |
| 4. | Especially the gaas pcss can take on particular phenomena of nonlinear characteristics ( also known as lock - on effect or high - gain mode ) witch made it be very availability . , convenience and f lexibleness 特别是在一定的触发光能和偏置电场阈值下,光电导开关存在的非线性工作模式(或lock - on效应) ,使得pcss ' s在高压超快功率脉冲系统中的应用更为有效、方便、灵活。 |
| 5. | Thus , space - charge field in excitated photoconductor can intensity influence not only the shape of photo - electric current of pcss ' s , but also the terahertz out put of photoconducting antenna . in this paper , the forming and movement of space - charge field are simulated by means of fdtd method 触发条件下光电导体内部电场不仅显著的影响光电导开关产生超快电脉冲的功率、波形,而且对thz偶极天线的辐射功率也有明显的影响。 |
| 6. | Based on the transferred - electron theory of the iii - v compound semiconductor and the research on the lock - on effect of the si - gaas pcss ' s , this paper proposes the monopole charge domain model similar to the guun or high - field domain to explain the peculiar switching phenomena occurring in the lock - on mode theoretically 本文基于gaas等?族化合物半导体的转移电子理论,结合半绝缘gaas光电导开关中特有的lock - on效应的研究,提出了类似于耿畴(高场畴或偶极畴)的单极电荷畴理论模型,对光电导开关lock - on效应的各种现象给出了理论解释。 |
| 7. | First , we think periodicity and weakening surge of the nonlinear waveform is caused by self - excitation of the circuit . the electric field thresholds ( et ) and maintenance field ( es ) of lock - on are modulated by the ac electric field ; the nonlinear waveform became two main modes of trans - electron oscillator , namely delay polar domain mode and quenched dipole domain mode 指出非线性波形周期性的减幅振荡,是由于光电导开关所处电路自激振荡形成的交流场对偶极畴的阈值电场e _ t和维持电场e _ s进行控制,从而形成转移电子振荡器的两种主要工作模式:延迟偶极畴模式和猝灭偶极畴模式。 |
| 8. | The electronic pulse waveform of linear , non - linear and the critically transiting switching modes outputted from the si - gaas pcss ' s was observed and measured . especially , we repeatedly measured the bias field thresholds and lock - on field of the critical transiting mode from the linear to non - linear state 作者测试了半绝缘gaas光电导开关在线性、非线性以及从线性到非线性过渡的临界状态模式下输出的电脉冲波形,特别是反复测量了开关在临界状态下的偏置电场阈值和lock - on电场强度。 |
| 9. | Duo to the intrinsic characteristics of the gaas material , serai - insulating ( si ) gaas photoconductive semiconductor switches ( pcss " s ) have more obvious advantages in the performance of both high power and ultra - fast switching than those pcss " s made of other materials and then can be widely used in ultrahigh speed electronics , field of high power microwave generation and pulse forming ( pulse sources of high power ultra - fast electromagnetism , ultra - wide - band microwave generator ) 半绝缘gaas光电导开关( photoconductivesemiconductorswitches简称pcss ' s )具有兼备宽频带和高功率容量特性,使其在超高速电子学和大功率脉冲产生与整形技术领域(大功率亚纳秒脉冲源、超宽带射频发生器等)具有广泛应用前景。 |
| 10. | They can dynamically change the distribution of electric field , carriers and current densities in pcss , caused output current to delay and also strengthen the local electric field enough to satisfy qualification of domain , and then cause avalanche . the time of delay is determined by the time of attaining the qualification of domain 非线性光电导开关的时间延迟效应则是由于半绝缘gaas材料中的el2深能级中心动态地改变开关中的电场、载流子浓度引起的;延迟时间的长短主要由满足成畴所需条件的时间决定。 |