
588 Network Analysis and Synthesis
13.3 CLASSIFICATION OF PASSIVE FILTERS
On the basis of functions they perform, passive filters are classified as follows:
1. Low-Pass Filters (LPF)
2. High-Pass Filters (HPF)
3. Band-Pass Filters (BPF)
4. Band-Stop Filters (BSF)
13.3.1 Low-Pass Filters
These are the filters that pass all the frequen-
cies lower than the selected cut-off frequency f
c
and attenuate/stop/suppress the signals whose
frequency is greater than f
c
. Attenuation char-
acteristic for an ideal LPF is shown in Figure
13.2. From the attenuation characteristic of the
LPF, it is clear that attenuation is zero in pass
band and attenuation ...