This paper is a report of the designing and making of a UWB pulse generator using SRD ( step recovery diode) and microwave transmission line and by means of intervention and elimination. 文中利用SRD(阶跃恢复二极管)与微波传输线,通过错位对消的方法设计与制作了UWB脉冲发生器。
A new ultra-wideband ( UWB) Gaussian pulse generator composed of a step recovery diode ( SRD), a field-effect transistor ( FET) and a Schottky diode was developed. 设计了一种超宽带高斯脉冲的脉冲发生器,此脉冲发生器主要由阶跃恢复二极管,FET管和肖特基二极管组成。
The duration of the quenching pulse should exceed the recovery time of the counter. 淬火脉冲的持续时间应当超过计数器的恢复时间。
Objective: To study the effects of the frequency selection pulse sequence and inversion recovery pulse sequence in the suppression of fatty tissue. 目的:研究频率选择脉冲序列与反转恢复脉冲序列对脂肪组织抑制的效果。
Many novel nanosecond pulse circuits with nanosecond rise time and high-repetition rate using step recovery diodes are discussed and recommended in this paper. 本文讨论了利用二极管由正向至反向恢复的阶跃特性所构成的多种新颖毫微秒脉冲电路;指出了阶跃恢复二极管在高重复频率毫微秒脉冲电路中应用的多种可能性;
The basic principles of π/ 4-DQPSK modulation and baseband difference demodulation are given firstly. Several important problems are settled, such as interpolation, pulse shaping, bit-timing recovery and so on. Then the whole communication system is simulated. 简略介绍了π/4-DQPSK调制和基带差分解调的工作原理,解决了内插、脉冲成形、位定时恢复等几个关键问题,在此基础上对整个通信系统进行了计算机仿真。
The thesis analyses the principles and characteristics of the pulse generator composing from avalanche transistor and step recovery diode ( SRD), the analysis provide the necessary theoretic bases for design and realization nanosecond and sub-nanosecond pulse circuit. 论文分析了由雪崩晶体管组成的窄脉冲发生电路和阶跃二极管组成的脉冲整形电路的原理与特性。为纳秒和亚纳秒级脉冲电路的设计与实现提供了必要的理论依据。
Other types of new pulse circuits using step recovery diodes with more detailed analysis and practical circuits will be reported in the near future. 在以后的论文中将探讨其它新型电路,并对某些电路作较详尽的分析,提供实际应用举例。
A post pulse recovery time of 2~ 3h and the use of sub inhibitory concentrations of antibiotics in the selective plates were very critical for electrotransformation. 同时,发现电击后的细胞必需在高渗培养基中才能存活,电击后2~3h的复苏表达期和用亚抑制抗生素浓度选择转化子,这些对电转化成功以及提高转化效率都是十分关键的。
METHODS: The indexes of the swimming athletes were recorded, including morning rate and individual subjective fatigue with morning rate timer after wake-up every morning; instant pulse after a group of training and the recovery pulse after rest for 2 minutes during training class. 方法:运动员每天早晨醒来利用晨脉表记录晨脉和个体主观疲劳,记录运动心率是在训练课中,一组训练内容结束后的即刻脉搏和休息2min后的恢复脉搏。
The rate of pulse recovery increases by an average of 20 per cent. 人的脉搏恢复率平均提高20%;
Effect of pulse electromagnetic field on the recovery of coxa function and on the level of inflammatory factors of old age women suffered from facture on neck of femur 脉冲磁场对中老年女性股骨颈骨折髋关节功能恢复及早期血清炎性因子的影响
This article briefly introduced the theory base of fast pulse recovery technique. According to the need of practice, we also designed a set of recovery system which can effectively prevent the batteries from being over charged or under charged. 本文简述了快速脉冲充电技术的理论基础,并根据需要设计了一套能有效防止过充和欠充的充电系统。
This paper introduces a kind of pulse tube regenerator, which can recover part of the lost acoustic power, and then analyzes it in two aspects: acoustic power recovery and phase angle adjustment. 本文介绍了一种带声功回收的脉管制冷机,从功回收和相位调节角度对它进行了分析。
Study on fast pulse recovery based on PIC singlechip 关于快速脉冲充电技术的研究
Result-contrast research of fat-suppression of pulse sequence used with frequency selection and inversion recovery 频率选择脉冲序列与反转恢复脉冲序列脂肪抑制效果对比研究
Application of low pressure pulse bag filter technique in valuable flue dust recovery system of argentum-converter 低压脉冲袋式收尘技术在银转炉有价烟尘回收系统中的应用
Through the theoretical research, pulse generation could be performed by direct synthesis, using step recovery diode and transmission line, however, the implement of the circuit is not easy for integration, low-cost, low-complexity purposes. 通过理论研究,用阶跃恢复二极管和传输线可以直接合成IR-UWB信号,然而,这样的电路实现起来不易集成、功耗大、电路复杂。
According to the design rule of the clamping circuit, an optimal parameter design method is introduced, and it reduces the minimum pulse width and speed up the dynamic recovery process. 根据曲线给出了优化参数的计算公式,不但大大简化了箝位电路的设计过程,而且降低了最小脉宽限制,提高了动态恢复速度。
The charging power supply takes high frequency switching mode power supply with half-bridge topology circuit, at the same time, for the fast charging strategies such as negative and positive pulse charge, a bidirectional DC-DC converter is designed for the battery discharge and energy recovery. 其中,充电电源设计采用以半桥电路作为拓扑结构的高频开关电源,同时,在输出滤波环节中加入双向半桥DC-DC变换器,以实现对电池的负脉冲放电及能量回收,提高了充电机的充电效率。