高频小信号宽带直流放大器的电路设计.doc

高频小信号宽带直流放大器的电路设计 摘 要 随着微电子技术的发展，小信号的处理在通信和信息处理领域运用越来越广泛，宽带运算放大器广泛应用于A/D转换器、D/A转换器，有源滤波仪、波形发生器、广播、电视、通信、雷达等的接收机等电路中，然而对小信号的增益可控成为小信号放大的重点和难点。 本设计主要是运用模拟电子线路的知识，利用AD603为核心设计的宽带直流放大器。在介绍AD603的基础上，针对各种接收机对宽带直流放大电路的要求,设计实现了一种基于宽带放大器AD603 的AGC 放大电路对其整体结构进行了详细的设计,并根据电路要求设计了跟随器输出电路及取样反馈电路,该放大电路具有增益高、AGC 范围宽、负载能力强、输出幅度恒定、工作性能稳定等优点,能够满足一般接收机的使用场合，本文中所描述的AGC 具有理论上84dB 的动态范围，90MHz 的带宽，检波电路采用三极管检波，成本低，调试简单。 关键词：AD603；宽带直流放大器；AGC Abstract Along with the development of microelectronics technology, small signal processing in communication and information processing field is used widely, broadband op-amp are widely used in A/D converter, D/A converter, active filter apparatus, waveform generator, radio, television, communication, radar, etc, the receiver circuits to small signal gain, however small signal magnified controlled become important and difficult. This design is mainly using analog electronic circuit knowledge, use AD603 as the core design of broadband dc amplifier. On the basis of introduction AD603 receiver to broadband, according to various requirements of dc amplifier circuit, designed and implemented a AD603 based on broadband amplifier amplifier circuit of AGC of its whole structure carried on the detailed design, and according to the circuit design requirement for the output circuit and sampling followed device, the magnifying circuit feedback circuit with gain wide range, high, AGC output amplitude load ability, constant, work stable performance advantages, can satisfy the general use of occasions, this paper receiver described in the 84dB of AGC possesses the theoretical 90MHz dynamic range, the bandwidth, detection circuit USES triode detection, low cost, commissioning simple. Key Words：AD603 ; Wideband DC Amplifier ; AGC 目 录 第1章 ??论 ......................................................................................................................... 1 1.1宽带放大器的应用前景及研究意义 ..........................................