2017年3月22日 · Typically I have seen the "passband ripple" and "stopband attenuation" expressed in dB as shown in the picture translating the magnitude of the ripples to dB using $20log_{10}$ as shown. So the passband ripple is the amount of variation in the amplitude, within the designated passband of the filter, and stop band attenuation is the minimum ...

I understand that the stopband ripple can be given by the following: Stopband ripple = −20log10(δs) 40 = −20log10(δs) δs=0.01. Where does that come from? I have never heard the term "stopband ripple". Stopband attenuation of 40 dB means that in the stop band any level of -40dB OR LESS is allowed. How much less than -40dB or where it hits ...

2025年2月13日 · The edges there are often defined as the end of the passband spec (where the passband ripple is still in effect) and the start of the stopband spec (where the stopband ripple is at some dB attenuation). This “usable transition region” in a practical filter shape is narrower than “just up to the first DTFT zero” of the window transform.

2024年3月23日 · If implementing an IIR filter, performance for passband and stopband will be greatly improved within the constraint of order =5, but the further choice would be in filter type (Chebychev, elliptic, Butterworth etc) where other design trades come into play beyond order and attenuation (notably group delay distortion).

2022年5月14日 · For data sampled at 1000 Hz, design a lowpass filter with no more than 3 dB of ripple in a passband from 0 to 40 Hz, and at least 60 dB of attenuation in the stopband. Find the filter order and cutoff frequency.

2015年5月24日 · edit: This is for passband edge frequency. One Way the cutoff frequency can be calculated as: consider H(jw) normalized filter transfer function $$ H(jw)=\frac{V_0(jw)}{V_i(jw)} $$ Here the 3dB frequency is when H(jw) is 1/sqrt(2) time the max value.Then it is finiding the values omega which satisfies the below equation $$ H(jw)=\frac{1}{\sqrt2} $$ This we can see when we take logarithm of 1 ...

2024年1月10日 · The target gain for the stopband is $0$ or $-\infty$ dB. That is also the minimum amplitude of the stopband. The maximum amplitude of the stopband is $\delta_s$ (the deviation from $0$) or $20 \log_{10}(\delta_s)$ dB. The target gain of the passband is $1$ or $0$ dB.

2020年7月11日 · Stopband attenuation is actually a function of frequency, but very often the term is used to refer to the minimum stop band attenuation, which is usually achieved at the stop band edge(s). The term stopband ripple is used for filters with a non-monotonic behavior in the stopband. These filters usually have several local maxima of the magnitude ...

The last stage, 32kHz to 16kHz is the only non half-band filter, as the transition needs to be wholly within the lower half of the frequency range to prevent aliasing. I'm using 14-bit data so I went for 90dB stopband attenuation. An FFT on the coefficients mostly concurs with the output of PyFDA. I am not scaling the FFT output at all.

2017年12月26日 · The Paley-Wiener criterion does not say anything about the sharpness of the transition band, which is what the OP seems to be about. The Paley-Wiener criterion does not preclude the existence of a filter with a stopband attenuation of 500dB and an infinitely sharp transition from passband to stopband. $\endgroup$ –