equiripple
从规范对象Equiripple单频冷杉过滤器
语法
equiFilt =设计(d,‘equiripple’,‘SystemObject’,真的)
equiFilt =设计(d ' equiripple designoption,价值,……,“SystemObject”,真的)
描述
equiFilt =设计(d,‘equiripple’,‘SystemObject’,真的)设计一个equiripple FIR数字滤波器使用规范提供的对象d。Equiripple滤波器设计最小化最大纹波在通带和阻带。
当你使用equiripple尼奎斯特过滤器规范对象,您可能会遇到设计滤波器设计不收敛的情况。收敛错误主要发生在大型过滤器订单,或小过渡宽度,或大型阻带衰减。这些规范,单独或结合,会导致设计失败。有关更多信息,请参考fdesign.nyquist在线帮助系统。
equiFilt =设计(d ' equiripple designoption,价值,……,“SystemObject”,真的)返回一个equiripple冷杉滤波器设计选项指定为输入参数。
确定可用的设计选项,使用designopts与规范的对象和设计方法作为输入参数如图所示。
designopts (d,“方法”)
关于使用完整的帮助equiripple,请参阅命令行帮助系统。例如,要获取特定信息使用equiripple与d输入以下规范对象,MATLAB提示。
帮助(d,“equiripple”)
例子
设计一个单频Equiripple过滤器
设计一个单频equiripple滤波器从halfband滤波器规范对象。注意到帮助命令用来了解规范对象的选择和方法。
d = fdesign.halfband (“tw, ast”,0.1,80);designmethods (d,“Systemobject”,真正的)
支持系统对象类fdesign的设计方法。金宝apphalfband (TW, Ast):黄油ellip iirlinphase equiripple kaiserwin
帮助(d,“equiripple”)
设计设计一个Equiripple冷杉过滤器。高清=设计(D, equiripple)设计equiripple过滤器D FDESIGN指定的对象,并返回DFILT / HD MFILT对象。高清=设计(D,…,“SystemObject”,true) implements the filter, HD, using a System object instead of a DFILT/MFILT object. HD = DESIGN(..., 'FilterStructure', STRUCTURE) returns a filter with the structure STRUCTURE. STRUCTURE is 'dffir' by default and can be any of the following: 'dffir' 'dffirt' 'dfsymfir' 'fftfir' Some of the listed structures may not be supported by System object filters. Type validstructures(D, 'equiripple', 'SystemObject', true) to get a list of structures supported by System objects. HD = DESIGN(..., 'MinPhase', MPHASE) designs a minimum-phase filter when MPHASE is TRUE. MPHASE is FALSE by default. HD = DESIGN(..., 'StopbandShape', SHAPE) designs a filter whose stopband has the shape defined by SHAPE. SHAPE can be 'flat', '1/f', or 'linear'. SHAPE is 'flat' by default. HD = DESIGN(..., 'StopbandDecay', DECAY) specifies the decay to use when 'StopbandShape' is not set to 'flat'. When the shape is '1/f' this specifies the power that 1/f is raised. When shaped is 'linear' this specifies the slope of the stopband in dB/rad/s. % Example #1 - Design a halfband lowpass equiripple filter with increased stopband attenuation. TW = 0.1; % Transition Width Ast = 80; % Stopband Attenuation (dB) h = fdesign.halfband('Type','Lowpass','TW,Ast',TW,Ast); Hd = design(h, 'equiripple', 'StopbandShape','linear','StopbandDecay',50); fvtool(Hd)
designopts (d,“equiripple”)
ans =结构体字段:FilterStructure:“dffir”MinPhase: 0 StopbandShape:“平”StopbandDecay: 0 SystemObject: 0
equiFilt =设计(d,“equiripple”,“stopbandshape”,“平”,“SystemObject”,真正的);fvtool (equiFilt);
的fvtool显示了过滤器的equiripple性质。
设计一个Equiripple冷杉滤波器的直接形式转置结构
这个例子中设计一个equiripple过滤器的直接形式转置结构通过指定“FilterStructure”的论点。设置过滤器的设计选项,使用designopts方法和选择对象选择。
d = fdesign.lowpass (“fp,置,美联社,ast”);选择= designopts (d,“equiripple”);opts.FilterStructure =“dffirt”;opts.DensityFactor = 20
选择=结构体字段:FilterStructure:“dffirt”DensityFactor: 20 MinPhase: 0 MaxPhase: 0 MinOrder:“任何”StopbandShape:“平”StopbandDecay: 0 UniformGrid: 1 SystemObject: 0
firFilt =设计(d,“equiripple”,“SystemObject”、真正的选择)
firFilt = dsp。FIRFilter属性:结构:“直接形式转置”NumeratorSource:“财产”分子:[-0.0024 -0.0021 0.0068 0.0167 0.0111 -0.0062 -0.0084 0.0093 0.0130 -0.0101 -0.0183 0.0114 0.0262 -0.0125 -0.0380 0.0134 0.0581 -0.0141 -0.1027 0.0145 0.3172 0.4854 0.3172 0.0145 -0.1027 -0.0141 0.0581 0.0134 -0.0380 -0.0125……]InitialConditions: 0显示所有属性
fvtool (firFilt);
的MaxPhaseequripple FIR滤波器的设计选择目前仅可用于低通,高通,带通和bandstop过滤器。
版本历史
介绍了R2011a
