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ida_fahani
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help me guys...
i reall need the answer ASAP...
Thanx in advance..
i reall need the answer ASAP...
Thanx in advance..
ida_fahani said:thanx...really apperitiate if u guys can explain to me in deapth..
ida_fahani said:the question is:
why we choose -3db as a corner frequency?
why -3db show 45 degree phase shift?
The -3db frequency is the frequency at which the output power of a system is half of the input power. This frequency also represents the cutoff frequency of a filter. At this frequency, the output signal will have a phase shift of 45 degrees compared to the input signal. This is because the filter is attenuating the signal by half, which results in a 45 degree phase shift between the output and input signals.
The -3db frequency is the cutoff frequency of a filter, which is the frequency at which the output power is half of the input power. In a low pass filter, frequencies below the cutoff are allowed to pass through with minimal attenuation, while frequencies above the cutoff are significantly attenuated. Therefore, the -3db frequency is an important parameter for determining the bandwidth and filtering capabilities of a low pass filter.
No, a -3db frequency is not always associated with a 45 degree phase shift. The phase shift at this frequency depends on the type of filter being used. For example, a high pass filter will have a phase shift of -45 degrees at the -3db frequency, while a band pass filter will have a phase shift of 0 degrees at this frequency. It is important to consider the type of filter and its characteristics when determining the phase shift at the -3db frequency.
The phase shift at the -3db frequency can significantly impact the frequency response of a system. In some cases, a 45 degree phase shift can result in a phase cancellation between the input and output signals, leading to a weaker overall signal. Additionally, the phase shift at the -3db frequency can affect the slope of the filter's frequency response curve, which can impact the filtering capabilities of the system.
In most cases, the -3db frequency is determined by the design and characteristics of the filter being used. However, there are certain filters, such as state-variable filters, that allow for the adjustment of the -3db frequency and therefore the phase shift. In general, it is not recommended to adjust the -3db frequency solely for the purpose of achieving a specific phase shift, as this can significantly affect the overall performance and stability of the system.