滤波器基于matlab GUI高通+低通+带通+带阻FIR滤波器设计【含Matlab源码 699期】.zip

%-------------------------------------------------------------------------- %利用kaiser窗设计带阻滤波器 %默认输入参数： N=64 % beta=5.568 % wl=0.2 % wh=0.8 %输出参数： 低通带边界（wlp） % 低阻带边界（wls） % 高通带边界（whp） % 高阻带边界（whs） % 通带波纹 % 阻带衰减 %-------------------------------------------------------------------------- function varargout = bbfilter(varargin) % BBFILTER M-file for bbfilter.fig % BBFILTER, by itself, creates a new BBFILTER or raises the existing % singleton*. % % H = BBFILTER returns the handle to a new BBFILTER or the handle to % the existing singleton*. % % BBFILTER('CALLBACK',hObject,eventData,handles,...) calls the local % function named CALLBACK in BBFILTER.M with the given input arguments. % % BBFILTER('Property','Value',...) creates a new BBFILTER or raises the % existing singleton*. Starting from the left, property value pairs are % applied to the GUI before bbfilter_OpeningFunction gets called. An % unrecognized property name or invalid value makes property application % stop. All inputs are passed to bbfilter_OpeningFcn via varargin. % % *See GUI Options on GUIDE's Tools menu. Choose "GUI allows only one % instance to run (singleton)". % % See also: GUIDE, GUIDATA, GUIHANDLES % Edit the above text to modify the response to help bbfilter % Last Modified by GUIDE v2.5 29-Jun-2007 13:18:51 % Begin initialization code - DO NOT EDIT gui_Singleton = 1; gui_State = struct('gui_Name', mfilename, ... 'gui_Singleton', gui_Singleton, ... 'gui_OpeningFcn', @bbfilter_OpeningFcn, ... 'gui_OutputFcn', @bbfilter_OutputFcn, ... 'gui_LayoutFcn', [] , ... 'gui_Callback', []); if nargin & isstr(varargin{1}) gui_State.gui_Callback = str2func(varargin{1}); end if nargout [varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:}); else gui_mainfcn(gui_State, varargin{:}); end % End initialization code - DO NOT EDIT % --- Executes just before bbfilter is made visible. function bbfilter_OpeningFcn(hObject, eventdata, handles, varargin) % This function has no output args, see OutputFcn. % hObject handle to figure % eventdata reserved - to be defined in a future version of MATLAB % handles structure with handles and user data (see GUIDATA) % varargin command line arguments to bbfilter (see VARARGIN) % Choose default command line output for bbfilter handles.output = hObject; % Update handles structure guidata(hObject, handles); % UIWAIT makes bbfilter wait for user response (see UIRESUME) % uiwait(handles.figure1); %-------------------------------------------------------------------------- %设置滤波器长度，beta和截止频率编辑框的初始值 %设置窗体的标题 set(handles.figure1,'name','FIR带阻滤波器'); set(handles.edit_N,'string','64'); set(handles.edit_beta,'string','5.568'); set(handles.edit_wl,'string','0.2'); set(handles.edit_wh,'string','0.8'); %-------------------------------------------------------------------------- %由设置的初始值求取滤波器的理想单位脉冲响应 handles.wl=0.2*pi; handles.wh=0.8*pi; handles.M=64; handles.hd=ideal_bb(handles.wl,handles.wh,handles.M); %-------------------------------------------------------------------------- %绘制滤波器的理想单位脉冲响应 axes(handles.axes_hd); n=[0:1:handles.M-1]; plot(n,handles.hd); title('滤波器理想脉冲响应'); axis([0 handles.M-1 min(handles.hd) max(handles.hd)]); xlabel('n'); ylabel('hd(n)'); grid on; guidata(hObject,handles); % --- Executes on button press in plot. function plot_Callback(hObject, eventdata, handles) % hObject handle to plot (see GCBO) % eventdata reserved - to be defined in a future version of MATLAB % handles structure with handles and user data (see GUIDATA) %-------------------------------------------------------------------------- %从编辑框获取滤波器长度，beta和截止频率的值 handles.M = str2double(get(handles.edit_N,'String')); handles.beta = str2double(get(handles.edit_beta,'String')); handles.wl = str2double(get(handles.edit_wl,'String'))*pi; handles.wh = str2double(get(handles.edit_wh,'String'))*pi; %求取滤波器的理想单位脉冲响应 handles.hd=ideal_bb(handles.wl,handles.wh,handles.M); %绘制滤波器的理想单位脉冲响应 axes(handles.axes_hd); plot(0,0); n=[0:1:handles.M-1]; plot(n,handles.hd); title('滤波器理想脉冲响应'); axis([0 handles.M-1 min(handles.hd) max(handles.hd)]); xlabel('n'); ylabel('hd(n)'); grid on; %-------------------------------------------------------------------------- %求取kaiser窗函数 handles.w_kai=(kaiser(handles.M,handles.beta))'; %绘制kaiser窗函数 axes(handles.axes_wkai); plot(n,handles.w_kai); title('kaiser窗'); axis([0 handles.M-1 min(handles.w_kai) max(handles.w_kai)]); xlabel('n'); ylabel('w(n)'); grid on; %-------------------------------------------------------------------------- %求取滤波器的实际单位脉冲响应 handles.h=handles.hd.*handles.w_kai; %绘制滤波器的实际单位脉冲响应 axes(handles.axes_h); plot(n,handles.h); title('滤波器实际脉冲响应'); axis([0 handles.M-1 min(handles.h) max(handles.h)]); xlabel('n'); ylabel('h(n)'); grid on; %-------------------------------------------------------------------------- %求取滤波器的频率特性，并绘制幅频特性（转换到0—pi） [H,w] = freqz(handles.h,[1],handles.M*6,'whole'); % freqz(handles.h,[1],handles.M*6); H=(H(1:1:handles.M*3))'; w=(w(1:1:handles.M*3))'; mag=abs(H); db=20*log10((mag+eps)/max(mag)); % pha=angle(H); %绘制幅频特性（转换到0—pi） axes(handles.axes_bb); plot(w/pi,db); title('FIR滤波器的幅频特性（0-pi）'); axis([0 1 min(db) max(db)]); xlabel('Frequency in pi units'); ylabel('Decibels'); grid on; guidata(hObject,handles); %-------------------------------------------------------------------------- %由求得幅频特性计算通带边界，阻带边界，通带纹波和阻带衰减 %由beta值计算阻带衰减As if handles.beta<4.5513 As=fzero(@myfun,20,[],handles.beta)+21; else As=handles.beta/0.1102+8.7; end %计算通带边界wlp，whp,阻带边界wls,whs w_w=(As-7.95)/((handles.M-1)*14.36)*2; wls=0.5*(w_w+2*handles.wl/pi); wlp=0.5*(2*handles.wl/pi-w_w); whp=0.5*(w_w+2*handles.wh/pi); whs=0.5*(2*handles.wh/pi-w_w); % mag=(mag+eps)/max(mag); %计算通带纹波rp % deta_w=2*pi/(handles.M*6); % w_temp=mag(floor(ws/deta_w)); % mag_temp=abs(mag(1:floor(ws/deta_w))-w_temp); rp=20*log10(max(mag)); %-------------------------------------------------------------------------- %在相应的编辑框中显示通带边界，阻带边界，通带纹波和阻带衰减 str=sprintf('%.2f',wlp); set(handles.edit_wlp,'string',str); str=sprintf('%.2f',wls); set(handles.edit_wls,'string',str); str=sprintf('%.2f',whp); set(handles.edit_whp,'string',str); str=sprintf('%.2f',whs); set(handles.edit_whs,'string',str); str=sprintf('%.4f',rp); set(handles.edit_rp,'string',str); str=sprintf('%.2f',-As); set(handles.edit_As,'string',str); % --- Executes on button press in exit. function exit_Callback(hObject, eventdata, handles) % hObject handle to exit (see GCBO) % eventdata reserved - to be defined in a future version of MATLAB % handles structure with handles and user data (see GUIDATA) close(handles.figure1); %自定义函数，计算理想带阻滤波器的单位脉冲响应 function hd=ideal_bb(wl,wh,M); alpha=(M-1)/2; n = [0:1:(M-1)]; m=n-alpha+eps; hd=sin(wl*m)./(pi*m)+sin(pi*m)./(pi*m)-sin(wh*m)./(pi*m); % --- Outputs from this function are returned to the command line. function varargout = bbfilter_OutputFcn(hObject, eventdata, handles) % varargout cell array for returning output args (see VARARGOUT); % hObject handle to figure % eventdata reserved - to be defined in a future version of MATLAB % handles structure with handles and user data