Passband ripple formula

1. What is passband ripple?
2. What is the effect of ripple in passband?
3. What is ripple in low pass filter?
4. Is ripple and attenuation same?

What is passband ripple?

Passband Ripple and Stopband Attenuation. In many applications, you can allow the gain in the passband to vary slightly from unity. This variation in the passband is the passband ripple, or the difference between the actual gain and the desired gain of unity.

What is the effect of ripple in passband?

Passband ripple occurs in the high-gain region of a higher-order filter or amplifier's transfer function, and looks like some variations in the output gain. The same applies to the phase on the output. In effect, the two are not smooth functions of frequency. Ripple can also appear in the stopband in these circuits.

What is ripple in low pass filter?

Any realizable filter's passband will be only approximately flat; the deviation from flatness is called the ripple, and is often specified by giving the ratio between the highest and lowest gain in the passband, expressed in decibels. The ideal low-pass or high-pass filter would have a ripple of 0 dB.

Is ripple and attenuation same?

the ripple is a certain amount of amplification or attenuation tolerated in the pass band of the filter. So it depends if those effects are critical for your application or not. if you are doing a FFT and the amplitude of the spectrum is key, then a low or no ripple low pass filter is required.