Suppose you have two RC-filters as shown below. Ignore the #'s, they are for spacing purposes.(adsbygoogle = window.adsbygoogle || []).push({});

o---R1--------o

# # # # # | #

Ui(1) # # C1 # Uo(1)

# # # # # | #

o--------------o

o---R2--------o

# # # # # | #

Ui(2) # # C2 # Uo(2)

# # # # # | #

o--------------o

Calculating the transfer functions [itex]H_1(\omega), H_2(\omega)[/itex] ([itex]H(\omega)=u_o/u_i[/itex]) using the impedance model is simple.

But what if you couple the two? By coupling the output Uo(1) of the first at the input Ui(2) of the second. Is there an easy way to calculate the resulting transfer function? It's not just the product of the two and my calculation is big and ugly. I know there is a trick or method to do it easily, by using some sort of substitution or something? Can anyone enlighten me?

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# Transfer function of RC-filter

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