Discrete-time, parallel structure filter
Hd = dfilt.parallel(Hd1,Hd2,...) returns a discrete-time filter, Hd, which is a structure of two or more dfilt filters, Hd1, Hd2, etc. arranged in parallel. Each filter in a parallel structure is a separate stage. You can display states for individual stages only. To view the states of a stage use
To append a filter (Hd1) onto an existing parallel filter (Hd), use
You can also use the nondot notation format for calling a parallel structure.
Using a parallel structure, create a coupled-allpass decomposition of a 7th order lowpass digital, elliptic filter with a normalized cutoff frequency of 0.5, 1 decibel of peak-to-peak ripple and a minimum stopband attenuation of 40 decibels.
k1 = [-0.0154 0.9846 -0.3048 0.5601]; Hd1 = dfilt.latticeallpass(k1); k2 = [-0.1294 0.8341 -0.4165]; Hd2 = dfilt.latticeallpass(k2); Hpar = parallel(Hd1 ,Hd2); gain = dfilt.scalar(0.5); % Normalize passband gain Hcas = cascade(gain,Hpar);
For details on the stages of this filter, use
To view this filter, use