摘要
基于OPA695、VCA821、MMG3H21NT1以及AT89S52设计的一款增益可控射频宽带放大器.此放大器以2级OPA695作为射频宽带放大器的前级;中间级以压控放大器VCA821,通过DA控制压控电压可完成放大以4d B为变化增益,在0d B^52d B增益范围可调;末级选用MMG3H21NT1,可实现输出电压有效值大于2V;制作40MHz至200MHz带通滤波器,当频率f_1=20MHz、f_2=270MHz时,衰减32d B;并以AT89S52为主控芯片,调节射频宽带放大器的增益.
A gain controlled RF broadband amplifier based on VCA821, MMG3H21NT1, OPA695 and AT89S52. The amplifier, with OPA695 level 2 as RF broadband amplifier proceding stage, the middle level to pressure controlled amplifiers VCA821, can realize the effective values of the voltage output of more than 2V by DA control voltage controlled voltage can be complete amplifier to 4dB gain variation 0dB-52dB gain range can be adjustable, and the final selection MMG3H21NT1; making the 40MHz to 200MHz Band Pass Filter, when the frequency fl=20MHz f2=270MHz, attenuation 32dB; and with AT89S52 microcontroller as the main control chip, adjusting the gain of the RF broadband amplifier.
出处
《玉林师范学院学报》
2016年第5期37-41,48,共6页
Journal of Yulin Normal University
基金
玉林师范学院教育教学改革工程一般项目(14YJJG16)
