I do not understand section 8.6 of my lecture notes (see the attachment).(adsbygoogle = window.adsbygoogle || []).push({});

1. "If two low pass filters are cascaded the output voltage is not simply the product of

two transfer functions." : Why not? Why would we even think of multiplying two transfer functions? Which transfer functions are being referred to? Why?

2. "If you try to analyse such a circuit using phasors and an Argand diagram you will soon realise the shortcomings of that technique. This is because the second filter acts as a load for the first." : Could someone please explain how the second statement leads to the first statement?

3. "However, we shall later that a simple operational amplifier circuit called the unity gain buffer acts as an impedance matcher so that loading of the first filter by the second does not occur. " : What is an impedance matcher? Why does the loading not occur due to an impedance matcher?

Thanks in advance for any help.

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# Cascaded Low pass filters

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