提供RC和LC低通滤波器计算界面的开源代码 - 知乎专栏

... 掉高频辐射信号，常常会使用无源的低通滤波器，其中包括RC低通滤波和LC低通滤波。

RC低通滤波其截止频率的计算公式为： F_{cutoff}=1/2πRC 2. LC… 无障碍写文章登录/注册笔者在做硬件工程师的工作过程中，发现对于EMC工程师来说，为了滤掉高频辐射信号，常常会使用无源的低通滤波器，其中包括RC低通滤波和LC低通滤波。

RC低通滤波1.1RC低通无源滤波其截止频率的计算公式为：F_{cutoff}=1/2πRC2.LC低通滤波2.1LC低通无源滤波其截止频率的计算公式为：F_{cutoff}=1/2π\sqrt{LC}对于高频信号（例如1GMHz以上的）来讲，常常需要使用到各种pF，nH级别的电容电感进行无源滤波，有绝对值很大的指数，但是电脑自带的计算器有比较呆板，所以常常会有计算错误的情况发生，于是笔者就旨在设计一款专门运用于高频无源滤波调试的开源脚本来进行计算RLC的参数：3.RC滤波计算界面脚本#RC_Filterimporttkinterastkimporttkinter.messageboximportmathwindow=tk.Tk()window.title('RCFilterCalculator')window.geometry('450x300')#VarDefinitionR_insert_var=tk.DoubleVar()C_insert_var=tk.DoubleVar()F_insert_var=tk.DoubleVar()#function#YouknowCandcutofffrequency,soyouwanttocalculateR.defcalculate_R():C_insert=C_insert_var.get()F_insert=F_insert_var.get()ifC_insert>0andF_insert>0:R_calculation=float('%0.4f'%(1/(2*math.pi*F_insert*C_insert)*1e6));tk.messagebox.showinfo(title='Result',message='Youneeda{}Ωresistor'.format(R_calculation))else:tk.messagebox.showerror(title='Error',message='Pleaseinsertvalidvalueofcapacityandgoalfrequency.');#YouknowRandcutofffrequency,soyouwanttocalculateC.defcalculate_C():R_insert=R_insert_var.get()F_insert=F_insert_var.get()ifR_insert>0andF_insert>0:C_calculation=float('%0.4f'%(1/(2*math.pi*F_insert*R_insert)*1e6));tk.messagebox.showinfo(title='Result',message='Youneeda{}pFcapacitor'.format(C_calculation))else:tk.messagebox.showerror(title='Error',message='Pleaseinsertvalidvalueofresistanceandgoalfrequency.');#YouknowLandC,soyouwanttocalculatecutofffrequency.defcalculate_F():R_insert=R_insert_var.get()C_insert=C_insert_var.get()ifR_insert>0andC_insert>0:F_calculation=float('%0.4f'%(1/(2*math.pi*C_insert*R_insert)*1e6));tk.messagebox.showinfo(title='Result',message='Thecutofffrequencycalculationresultis{}MHz'.format(F_calculation))else:tk.messagebox.showerror(title='Error',message='Pleaseinsertvalidvalueofresistancenandcapacity.');#Widgetpackl_R=tk.Label(window,text='Pleaseinserttheresistancevalue',font=('Arial',12),width=30,height=2)l_R.place(x=-5,y=20,anchor="nw")R_insert=tk.Entry(window,textvariable=R_insert_var)R_insert.place(x=255,y=30)l_C=tk.Label(window,text='Pleaseinsertthecapacityvalue',font=('Arial',12),width=30,height=2)l_C.place(x=-5,y=80,anchor="nw")C_insert=tk.Entry(window,textvariable=C_insert_var)C_insert.place(x=255,y=90)l_F=tk.Label(window,text='Pleaseinsertthegoalfrequency',font=('Arial',12),width=30,height=2)l_F.place(x=-5,y=140,anchor="nw")F_insert=tk.Entry(window,textvariable=F_insert_var)F_insert.place(x=255,y=150)b_R=tk.Button(window,text='CalculateR',command=calculate_R)b_R.place(x=60,y=200,anchor="nw")b_C=tk.Button(window,text='CalculateC',command=calculate_C)b_C.place(x=160,y=200,anchor="nw")b_F=tk.Button(window,text='CalculateFrequency',command=calculate_F)b_F.place(x=260,y=200,anchor="nw")l_ohm=tk.Label(window,text='Ω',font=('Arial',12),width=5,height=2)l_ohm.place(x=380,y=20,anchor="nw")l_pf=tk.Label(window,text='pf',font=('Arial',12),width=5,height=2)l_pf.place(x=380,y=80,anchor="nw")l_MHz=tk.Label(window,text='MHz',font=('Arial',12),width=5,height=2)l_MHz.place(x=380,y=140,anchor="nw")window.mainloop()4.LC滤波计算界面脚本#LC_Filterimporttkinterastkimporttkinter.messageboxfrommathimport*window=tk.Tk()window.title('LCFilterCalculator')window.geometry('450x300')#VarDefinitionL_insert_var=tk.DoubleVar()C_insert_var=tk.DoubleVar()F_insert_var=tk.DoubleVar()#functiondefcalculate_L():C_insert=C_insert_var.get()F_insert=F_insert_var.get()ifC_insert>0andF_insert>0:L_calculation=pow(1/(2*pi*sqrt(C_insert)*F_insert),2)*1e9L_calculation=float('%0.4f'%L_calculation);tk.messagebox.showinfo(title='Result',message='Youneeda{}nHinductor'.format(L_calculation))else:tk.messagebox.showerror(title='Error',message='Pleaseinsertvalidvalueofcapacityandgoalfrequency.');defcalculate_C():L_insert=L_insert_var.get()F_insert=F_insert_var.get()ifL_insert>0andF_insert>0:C_calculation=pow(1/(2*pi*sqrt(L_insert)*F_insert),2)*1e9C_calculation=float('%0.4f'%C_calculation);tk.messagebox.showinfo(title='Result',message='Youneeda{}pFcapacitor'.format(C_calculation))else:tk.messagebox.showerror(title='Error',message='Pleaseinsertvalidvalueofinductanceandgoalfrequency.');defcalculate_F():L_insert=L_insert_var.get()C_insert=C_insert_var.get()ifL_insert>0andC_insert>0:F_calculation=1/(2*pi*sqrt(L_insert*1e-9*C_insert*1e-12)*1e6)F_calculation=float('%0.4f'%F_calculation);tk.messagebox.showinfo(title='Result',message='Thecutofffrequencycalculationresultis{}MHz'.format(F_calculation))else:tk.messagebox.showerror(title='Error',message='Pleaseinsertvalidvalueofinductanceandcapacity.');#Widgetpackl_L=tk.Label(window,text='Pleaseinserttheinductancevalue',font=('Arial',12),width=30,height=2)l_L.place(x=-5,y=20,anchor="nw")L_insert=tk.Entry(window,textvariable=L_insert_var)L_insert.place(x=255,y=30)l_C=tk.Label(window,text='Pleaseinsertthecapacityvalue',font=('Arial',12),width=30,height=2)l_C.place(x=-5,y=80,anchor="nw")C_insert=tk.Entry(window,textvariable=C_insert_var)C_insert.place(x=255,y=90)l_F=tk.Label(window,text='Pleaseinsertthegoalfrequency',font=('Arial',12),width=30,height=2)l_F.place(x=-5,y=140,anchor="nw")F_insert=tk.Entry(window,textvariable=F_insert_var)F_insert.place(x=255,y=150)b_L=tk.Button(window,text='CalculateL',command=calculate_L)b_L.place(x=60,y=200,anchor="nw")b_C=tk.Button(window,text='CalculateC',command=calculate_C)b_C.place(x=160,y=200,anchor="nw")b_F=tk.Button(window,text='CalculateFrequency',command=calculate_F)b_F.place(x=260,y=200,anchor="nw")l_nH=tk.Label(window,text='nH',font=('Arial',12),width=5,height=2)l_nH.place(x=380,y=20,anchor="nw")l_pf=tk.Label(window,text='pf',font=('Arial',12),width=5,height=2)l_pf.place(x=380,y=80,anchor="nw")l_MHz=tk.Label(window,text='MHz',font=('Arial',12),width=5,height=2)l_MHz.place(x=380,y=140,anchor="nw")window.mainloop()5.界面展示5.1LC滤波界面如图，当你需要滤波的通路上已经有68nH的电感，你需要滤除掉300MHz的噪声，这个时候你就可以输入你设定的值，然后点击“CalculateC”就会得到一个结果如图所示：5.2LC滤波器计算功能展示同理可运用在RC滤波计算。

发布于2020-12-1420:17无源网络​赞同4​​添加评论​分享​喜欢​收藏​申请转载​