This calculator allows you to determine the form factor and the quality factor of a microwave bandpass filter from its central frequency and its bandwidths at 3 dB and 60 dB. It helps evaluate filter performance and design RF systems with optimal selectivity.
Formulas
Form factor (SF) = BW 60dB / BW 3dB
Quality factor (Q) = f c / BW 3dB
Or :
- f c = central frequency of the bandpass filter
- BW 3dB = bandwidth at 3 dB
- BW 60dB = bandwidth at 60 dB
Explanation of formulas
The form factor (SF) measures the selectivity of the filter, that is, its ability to attenuate out-of-band signals. A lower SF indicates a more selective filter. The quality factor (Q) expresses the purity of the bandwidth: the higher Q, the narrower and more precise the filter. Frequencies are converted to hertz to ensure consistency of calculations.
Uses of the calculator
- Analysis and design of RF and microwave bandpass filters.
- Optimization of selectivity and signal quality.
- Useful for radio engineers and communications system designers.
- Allows you to compare different filters for receive and transmit applications.