fractional bandwidth (antenna) (FBW)

For the determination of a relative bandwidth, there is the dimensionless characteristic value Fractional Bandwidth (FBW). This is the bandwidth of a filter, antenna or electronic circuit, relative to its center frequency.

The fractional bandwidth can only assume values between 0 and 2, in percentages this corresponds to 0 % to 200 %. For example, if a bandpass has a bandwidth of 1 MHz and a center frequency of 10 MHz, then the ratio results in a Fractional Bandwidth of 0.1 or 10 %. The larger the FBW value, the wider the bandwidth of the corresponding electronic component.