LCLowpassST (Singly Terminated Lowpass Filter)

Symbol

Parameters

Name	Description	Unit	Default
Fp	Passband corner frequency	GHz	1
Fs	Stopband frequency	GHz	2
Ap	Passband attenuation	dB	3
As	Stopband attenuation	dB	20
N	Order of filter	None	0
ResponseType	Type of filter response	None	Maximally Flat
Termination	Open or short load termination	None	Short Termination
Rg	Source impedance	Ohm	50
MaxRealizations	Maximum number of realizations during synthesis	None	25

Notes

1. A singly terminated lowpass filter provides a lowpass frequency response between the input (pin 1) and output (pin 2) ports. This component has a real, non-zero source termination and either an open or short at the load termination.
2. The type of frequency response (i.e. Chebyshev, Elliptical, etc.) depends on the parameter ResponseType. The transition bands of the frequency response depend on the filter order.
3. The filter order is either set manually or is calculated by the passband and stopband frequencies and attenuations.

Example

A maximally flat lowpass filter (Maximally Flat Lowpass Filter) was designed for 3 dB attenuation at 1 GHz and 20 dB attenuation at 2 GHz with matched 50 ohm terminations. This resulted in a filter order of N=4.

Maximally Flat Lowpass Filter