全国电子设计大赛LC谐振放大器的设计

摘要：本文是基于 LC 高频小信号放大电路的设计，它由前级衰减电路、LC 谐振放大电路、多级增益放大电路、电源电路组成。其中前级衰减电路用 π 型电阻网络实现 40dB 的衰减；核心LC 谐振放大器采纳三极管 2SC1815 构成的单调谐回路选频放大器，实现 15MHz 的谐振频率和300KHz 的带宽调节，增益放大电路由 SGM8067 组成的三级同相放大电路实现 15MHz 带宽 60dB放大倍数的放大，整个 LC 放大电路的带内波动不大于 2dB；电路所需的稳定电压由锂电池18650 提供。本设计很好实现谐振频率 15MHz、带宽 300KHz、增益 76dB 以及带内波动小于 1dB 的谐振放大电路，并且本设计采纳高频三极管 2SC1815 和高速高带宽运算放大器 SGM8067 联合组成 LC 谐振放大电路，比单纯用高频三极管组成的多级 LC 谐振放大电路要简单，调试起来也很容易。关键词：π 形网络；LC 谐振；SGM8067Design oftheLC resonantamplifierAbstract:This paper is based on LC high frequency amplifier circuit design of small signal, it by the former stage attenuation circuit, LC harmonic oscillator amplifier circuit, multi-level amplifier circuit, the power supply circuit. The top level with π attenuation circuit type resistance network realization of 40 dB attenuation; Core LC resonance with transistor amplifier 2 SC1815 consists of the single tuned circuit choose frequency amplifier, realize the resonance frequency of the 15 MHz of bandwidth and 300 KHz regulation, gain the SGM8067 amplifier circuit of the same phase 3 amplifier circuit realize 15 MHz bandwidth 60 dB magnification magnification, the whole LC amplifier circuit with the fluctuated in not greater than 2 dB; Circuit of 3.6 V voltage stability needed by the lithium battery 18650 provides. This design is very good realize the resonance frequency 15, 300 MHz bandwidth, gain 76 dB KHz and with less than 1 dB fluctuated in resonant amplifying circuit and the design USES high frequency transistor 2 SC1815 and hig...