查询词典 high frequency amplifier

Through the noise analysis between circular oscillators composed of general differential amplifer element and of capacitive coupling differential amplifier element, it is found that the later,due to its band-pass and dynatron characteristics,provides a better anti-noise performance,which can be used in VCO circuits having a high requirement on frequency stability.

通过对采用由普通差分放大器单元和容性耦合差分放大器单元构成的环行振荡器的噪声分析得出，由容性耦合差分放大器单元构成的环行振荡器，因其带通特性和负阻特性而具有较好的抗噪声能力，可用于对频率稳定度有较高要求的VCO等电路中。

According to the demand of high magnetic field power supply, reference is increased with a set ramp rate and stops at a set stable value, so reference system is composed of digital setting and digit to analog converting circuit. But the stability of reference is mostly guaranteed by the performance of D/A circuit, so D/A circuit is particularly studied in reference system. The scheme of D/A circuit, the selection of DAC and its voltage reference, hardware anti-jamming design and PCB design are discussed in detail, and software of remote control and PLC are discussed in brief. Zero-flux DC current transformer well satisfies the demands of the high stability of Load current detection unit, so the principle of zero-flux DC current transformer is analyzed; in the mean time a project which detects the long term stability is designed. During 8 hours, analog signal which is detected with high precision digit multimeter is recorded in computer at 1HZ frequency by GPIB communication. The drift error source and related parameters are explained in the compare-amplify part. Detailed subtraction circuit is designed; also amplifier chip and periphery components are selected and verified according to the theory of error analysis.

根据强磁场电源的需求，参考源应按照软件设定的斜率逐渐上升到设定稳态值，则参考源系统应由数字给定和数模转换电路两大部分组成，而参考源的稳定度主要依靠完成数模转换功能的模拟电路的性能来保证，因此本文对参考源系统的研究以数模转换电路为重点，分别从电路方案的确定、数模转换芯片及其基准电压源的选取和验证、电路板硬件抗干扰和PCB设计几方面进行了论述，然后对数字给定部分的远控组态和PLC程序设计作了简要介绍；采用零磁通原理的直流电流转换器很好地满足了对负载电流检测单元高稳定度的需求，本文详细分析了零磁通检测的原理，并在选定此种类型电流转换器的基础上设计了一套检测长期稳定度的方案，8小时内以1秒为采样周期，通过计算机Labview程序和高精度数字电压表的GPIB通讯，将被高精度数字电压表数字化后的模拟信号采样值连续记录至计算机中；比较放大环节简要阐述了漂移产生的原因和相关参数指标，确定了具体的减法电路形式，并根据误差分析理论对运算放大器和外围元器件进行了选取和验证。

The signal amplifier should have features like low noise signal, zero drift, high precision, wide frequency band, high input resistance, and low output resistance.

信号放大器应该有特点，例如低噪声信号，零点漂移小，精度高，宽的频带，高输入电阻，低输出电阻。

By the pre-amplifier, the use of low-pass and high pass filter in series, the effective frequency of ECG interference from outside the filter.

经前置放大器后，运用低通和高通滤波器的串联，对心电信号有效频率外的干扰进行滤波。

In the research, a Low noise, Wide frequency band, High speed Pre-Amplifier was made, and the dynamic range of the lidar was pressed using high speed multiplier and it give the lidar system better specification.

在激光雷达系统的研制过程中，解决了低噪声、宽频带、高速前放的研制，首次使用高速乘法器进行了动态范围压缩，改善了激光雷达系统的性能。

Parametric amplifier is a high sensitive instrument with ultrahigh frequency.

参量放大器是一种灵敏度很高的超高频仪器。

Using 0.15-micron-gate-length GaAs pseudomorphic high-electron-mobility-transistor device technology, the power amplifier covers the 17 to 25 GHz frequency bands and has a signal gain of 20 decibels with +28 dBm P1dB compression point.

采用0.15微米的高电子移导率场效晶体管器件技术的这一功率放大器的频率范围为17～25 GHz，增益为20分贝(相对+28 dBm P1dB压缩点)。

There are three parts included. The first part is the prepositive-amplifier, it gets broadband high gain and flat frequency response. The second part is the U band quadrupler, which composed of two doublers using a PHEMT chip HMMC-5040, a Schottky diode of DMK-2790, a HMMC-5040 amplifier, and a fin-line transitional stage. Maximum output power higher than 60mW is obtained in V band. The third part is a 2nd harmonic gunn oscillator injection locked by the Fundamental Wave,which get about 2GHz locked bandwidth in W band.

电路主要由三部分组成，第一部分为采用HMMC-5618设计的前置放大器，实现了宽带高增益和平坦的频率响应；第二部分为设计的主体，由HMMC-5040设计的二倍频器、DMK-2790设计的二倍频器、HMMC-5040设计的放大器及鳍线过渡段组成的U波段四倍频器，在U波段实现了最高60mW以上的输出功率；第三部分为基波注入锁定谐波Gunn振荡器，在W波段实现了近2GHz锁定带宽。

She gently rebuff ed him, but agreed that they could be friends

她婉言拒绝了，但同意作为朋友相处。

If in the penal farm, you were sure to be criticized.

要是在劳改农场，你等着挨绳子吧！