RF Filter calculator | Microstrip filter calculator, Low pass, Bandpass

This RF filter calculator is used for microstrip filter calculations. It covers low pass and bandpass rf filter calculators used in microstrip designs. Both pi filter and T filter section filter topologies are covered.

Microstrip Low pass filter calculator

Following is a simple LC based RF lowpass filter calculator of order N equal to 3.

Cutoff Frequency, MHz (input1) :

Characteristic Impedance, Ohm (input2) :


Inductance(L) in Henries (Output1):

Capacitance (C) in farads (Output2):

Example of RF Filter Calculator of lowpass type:
INPUTS : Fc =1182.5 MHz, Z0 = 50 Ohm
OUTPUTS: L = 1.34e-8 Henries, C = 5.38e-12 farads

Microstrip low pass filter Formula

Following are the equations used in RF lowpass filter calculator of order N equal to 3. Figure-1 depicts lowpass pi filter and T filter section topologies. This simple RF filter calculator made of L and C components is very useful.


RF Filter Calculator formula, low pass filter

Microstrip Bandpass filter calculator

Following is a simple LC based RF bandpass filter calculator of order N equal to 3.

BPF Start frequency, MHz (input1) :

BPF End frequency, MHz (input2) :

Characteristic Impedance, Ohm(input3) :


Inductance(L1) in Henries (Output1):

Inductance(L2) in Henries (Output2):

Capacitance(C1) in Farads (Output3):

Capacitance(C2) in Farads (Output4):

Example of Microstrip Filter Calculator of bandpass type:
INPUTS : f1 = 1024.5 MHz, f2 = 1060.5 MHz, Z01 = 50 Ohm
OUTPUTS: L1 = 4.42e-7 Henries , L2 = 1.319e-10 Henries, C1 = 5.276e-14 farads , C2 = 1.76e-10 Farads

Microstrip Bandpass filter formula

Figure-2 depicts bandpass pi filter and T filter section topologies. Following are the equations for above mentioned RF bandpass filter topologies.


Microstrip Filter Calculator formula, bandpass filter

L1 = [ Z0/ (Pi*(f2-f1)) ] ..... Henries

L2 = [ Z0*(f2-f1) / (4*Pi*f2*f1) ] ..... Henries

C1 = [ (f2-f1) / (4*Pi*f2*f1*Z0) ] ..... Farads

C2 = [ 1 / (Pi*Z0*(f2-f1) ] ..... Farads

In order to understand concepts of Microstrip filter calculator one can also refer step by step RF filter design. This design article covers microstrip based RF/Microwave Low Pass Filter design example along with Kudora's identities, Richard transformation and filter coefficients table for Chebysev LPF. Click to visit RF Filter Design Example➤

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