Page 285 - Analog and Digital Filter Design
P. 285
282 Analog and Digital Filter Design
L1 27.849mH C1 77.357nF
L2 320.325mH C2 0.8898pF
L3 111.628mH C3 0.3101yF
LA 1.284H C4 3.5667pF
Where L1, C1, L2, and C2 are components in the P network. The remaining
- -
components are in the N network. Notice that the source impedance is half the
load impedance, this is because the networks are all-pass and the two loads are
effectively in parallel at all frequencies.
L1
L2
Common B Common Pnetwork
-
60Ol-l
d&
I .I
Figure 9.17 tc3 Common t"" N network
Passive Quadrature PO0*
Network (N = 4)
An active quadrature design to achieve the same function is given in Figure 9.18.
The majority of components are set to convenient values, only the shunt resis-
tor values remain to be calculated (to be honest I tried 1 nF capacitors to start
with, but this led to high resistor values so I had to increase the capacitor values
1
to 2.2nF). Using the equation R = -, the following values of shunt resistor
OC
were found:
R1 lO.548kQ R2 101.335kQ
R3 42.283kQ R4 486.358kQ
Where R1 and R2 are in the P network, and R3 and R4 are in the N network.
