1.问题的提出滤波器分模拟滤波器与数字滤波器。LC滤波器与有源运放滤波器都属于模拟滤波器,但模拟滤波器体积大、受外界温度环境及老化的影响大,在技术飞速发展的今天已越来越显出其不足之处,而数字滤波器技术作为新兴的技术得到了快速发展,代表着滤波器的发展方向,目前已在许多领域得到了应用。在铁道信 1. The question proposed filter sub-analog filters and digital filters. Both the LC filter and the active operational amplifier filter belong to the analog filter. However, the analog filter is large in volume and greatly affected by the external temperature environment and aging. Today, the rapid development of the technology has shown its shortcomings. The digital filter technology as a new technology has been rapid development, represents the direction of filter development, has been applied in many fields. In the railway letter