Appendix D Useful tables and formulae

The deciBel (dB) represents a logarithmic ratio between two quantities. Of itself it is unitless. If the ratio is referred to a specific quantity (P_{2}, V_{2} or I_{2} below) this is indicated by a suffix, e.g. dBμV is referred to 1μV, dBm is referred to 1mW.

Originally the dB was conceived as a power ratio, hence it is given by:

Power is proportional to voltage squared, hence the ratio of voltages or currents across a constant impedance is given by:

Conversion between voltage in ...

Start Free Trial

No credit card required