This element is used to provide filtering in the RF path. This system symbol is available on the System toolbar.

Name 
Model 
LPF_ELLIPTIC 
Alternate Models 
LPF_ELLIPTIC_C 
Schematic Symbol 
LPF 
Alternate Schematic Symbols 
None 
NOTE: The alternate model "..._C" is a circuit model created from a synthesis process with real components. The circuit is not visible to the user. Simulation time for the circuit models is generally longer since there are more components.
Parameter 
Description 
Units 
Default Value 
IL 
Insertion Loss 
dB 
0.01 
N 
Filter Order 
none 
3 
Fpass 
Passband Edge Frequency 
MHz 
200 
Apass 
Attenuation at passband 
dB 
3.01 
Amax 
Max Attenuation in stopband 
dB 
100 
Z1 
Reference Impedance Port 1 
Ohm 
50 
Z2 
Reference Impedance Port 2 
Ohm 
50 
TYPE 
Input Stopband Impedance (0 = Short, 1 = Open) 
none 
1 
The Elliptic filter characteristic exhibits ripple in the passband and generated by poles and zeros. This results in a cutoff which is sharper than most other filters. The insertion loss only affects the forward (S_{21}) and backward (S_{12}) transmission, but not the reflection coefficients (S_{11},S_{22}). The input impedance in the stopband only affects the phase of the reflection coefficients. The value for the attenuation at the passband edge (Apass) is the ripple value. For filters of even order, the gain at dc is less than unity to avoid gains greater than unity in the passband. For additional details on filter types see the FILTER Synthesis Manual.
Note: The insertion loss must be greater or equal to zero. The filter order must be an integer greater or equal to 2. The frequency of the passband edge must be positive. The stopband attenuation must be greater than the ripple.
DC Block  DC will only be blocked by the amount of attenuation at 0 Hz.
Maximum Attenuation in stopband  The maximum attenuation in the stopband is modelled with a resistor between the input and output port of the filter. An equation is used to determine the value of the resistor from the given attenuation. This parallel resistor will only be effective when the filter stopband impedance TYPE is set to open. For even filter orders the impedance looking into one port is high and the other low so the maximum attenuation in the stopband has no effect.