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Antonio_Magma
Joined: 21 Jun 2005
Posts: 138
Helped: 1
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 11 Apr 2006 9:40 Frequency response and amplitude response |
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| Are they the same? Since in frequency response the y axis is also in dB magnitude
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mshareef
Joined: 18 Feb 2006
Posts: 203
Helped: 45
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| 11 Apr 2006 10:32 Re: Frequency response and amplitude response |
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Yes they are same. Frequency response is the gain and phase response of a circuit or other unit under test at all frequencies of interest. Although the formal definition of frequency response includes both the gain and phase, in common usage, the frequency response often only implies the magnitude (gain). The plot is dB or V & rad (or degrees) vs. Hz
And amplitude response is a synonym for the frequency response function (magnitude). It is defined as magnitude (or complex modulus) of the frequency response. It is also often called the magnitude frequency response.
The plot is V vs. Hz.
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SkyHigh
Joined: 13 Jan 2005
Posts: 376
Helped: 51
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| 11 Apr 2006 18:11 Re: Frequency response and amplitude response |
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Amplitude response and frequency response are in fact different, but inter-related in principles.
As explained earlier by other forumers, frequency response of a system is described by its the Phase (rad) and Gain (dB).
Amplitude response refers to the peak voltage (Volt) with respect to the average power of a signal at a particular operating frequency of interest is in fact the amplitude of the signal actually perceived in time domain.
As said earlier, amplitude response and frequency response are inter-related by average power through a common variable, i.e. peak voltage.
Average Power = RMS Voltage x RMS Current
To simply this, we normlised to 1Ω, thus Average Power = RMS Voltage˛/1Ω
Since RMS Voltage = Peak Voltage x 0.707, we get Average Power = (Peak Voltage x 0.707)˛
Gain = Output Power/ Input Power. Both Output Power and Input Power are respresented in average power measured.
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