Simple, Coil & Capacitor, Low-Pass (Lowpass) & High-Pass (Highpass), T & Pi Filters

Author: R.J.Edwards G4FGQ © 26th December 2002

The majority of L & C filters consist of one or more cascaded basic L-C sections used in applications where pass-band ripple and frequencies of infinite attenuation in the stop-bands are of no interest. E.g., simple power supply smoothing filters and harmonic suppression filters following RF power amplifiers This program assists with design of such simple filters without the operating inconveniences inherent in programs intended for more sophisticated designs.

The four possible basic sections are computed simultaneously: Low-pass Pi, Low pass T, High-pass Pi and High-pass T. (T sections cannot be cascaded with Pi.)

Input data is filter cut-off frequency, terminating impedance Ro, the number of basic sections in cascade and a multiplier which sets the frequency at which the overall filter insertion-loss is to be computed.

Output data is total LuH and CpF per section. As with other networks and lines, Ro = Sqrt(L/C). Actual L and C component values for the required cut-off frequency are shown on the four circuit diagrams. Insertion loss is defined as that when the filter is inserted between generator and load, both of resistance Ro.

Run this Program from the Web or Download and Run it from Your Computer
This program is self-contained and ready to use. It does not require installation. Click this link lpf_hpf then click Open to run from the web or Save to save the program to your hard drive. If you save it to your hard drive, double-click the file name from Windows Explorer (Right-click Start then left-click Explore to start Windows Explorer) and it will run.