fdesign.hilbert

Hilbert filter specification object

Syntax

d = fdesign.hilbert d = fdesign.hilbert(specvalue1,specvalue2) d = fdesign.hilbert(spec) d = fdesign.hilbert(spec,specvalue1,specvalue2) Fs d = fdesign.hilbert(…) d = fdesign.hilbert(...,MAGUNITS)

Description

d = fdesign.hilbertconstructs a default Hilbert filter designerdwithN, the filter order, set to 30 andTW, the transition width set to 0.1π radians/sample.

d = fdesign.hilbert(specvalue1,specvalue2)constructs a Hilbert filter designerdassuming the default specification'N,TW'. You inputspecvalue1和specvalue2forN和TW.

d = fdesign.hilbert(spec)initializes the filter designerSpecificationproperty tospec. You provide one of the following as input to replacespec. The specification options are not case sensitive.

Note

Specifications marked with an asterisk require the DSP System Toolbox™ software.

'N,TW'default specification option.
'TW,Ap'*

The filter specifications are defined as follows:

Ap— amount of ripple allowed in the pass band in decibels (the default units). Also called Apass.
N— filter order.
TW— width of the transition region between the passband and the stopband.

By default,fdesign.hilbert假设所有频率规格均以归一化频率单位提供。同样，分贝是所有级规范的默认值。

Different specifications may have different design methods available. Use设计methods(d)获取可用于给定规范的设计方法的列表。

d = fdesign.hilbert(spec,specvalue1,specvalue2)initializes the filter designer specifications inspecwithspecvalue1,specvalue2, and so on. To get a description of the specificationsspecvalue1和specvalue2, enter

get(d,'description')

at the Command prompt.

Fs d = fdesign.hilbert(…)adds the argumentFs, specified in Hz to define the sampling frequency. In this case, all frequencies in the specifications are in Hz as well.

d = fdesign.hilbert(...,MAGUNITS)specifies the units for any magnitude specification you provide in the input arguments.MAGUNITScan be one of

'linear'— specify the magnitude in linear units
'dB'— specify the magnitude in dB (decibels)
'squared'— specify the magnitude in power units

When you omit theMAGUNITSargument,fdesignassumes that all magnitudes are in decibels. Note thatfdesignstores all magnitude specifications in decibels (converting to decibels when necessary) regardless of how you specify the magnitudes.

Examples

collapse all

Hilbert Transformers

Open Live Script

设计30阶的希尔伯特变压器，其过渡宽度为0.2πRAD/样品。使用最小二乘最小化以获得等值的线性相位FIR滤波器。在间隔[–π，π）中绘制零相响应。

d = fdesign.hilbert('N,TW',30,0.2); Hd = design(d,'equiripple','SystemObject'，真的）;zerophase(Hd,'whole')

Figure Zero-phase Response contains an axes object. The axes object with title Zero-phase Response contains 2 objects of type line.

该均衡的3滤波器的脉冲响应是反对称的。

impz（高清）

Figure Impulse Response contains an axes object. The axes object with title Impulse Response contains an object of type stem.

ftype = firtype（HD）

ftype = 3

Design a minimum-order Hilbert transformer that has a sample rate of 1 kHz. Specify the width of the transition region as 10 Hz and the passband ripple as 1 dB. Display the zero-phase response of the filter.

fs = 1e3; d = fdesign.hilbert('TW,Ap',10,1,fs); hd = design(d,'equiripple','SystemObject'，真的）;Zerophase（HD，-FS/2：0.1：FS/2，FS）