What circuit is used to select one of the sidebands from a balanced modulator?

In a Single Sideband (SSB) transmitter, the balanced modulator produces a double-sideband suppressed-carrier (DSB-SC) signal. Because both the upper and lower sidebands contain identical audio information, transmitting both is redundant and wastes valuable spectrum bandwidth. To create the final SSB signal, a highly selective band-pass filter is placed immediately following the balanced modulator. This filter is designed with a very sharp cutoff to allow only the desired sideband (either upper or lower) to pass through to the next stage, while completely rejecting the other sideband. Other options like the IF amplifier or RF amplifier simply boost signal strength, and the carrier oscillator generates the unmodulated radio frequency. None of these components possess the selective frequency characteristics required to remove a specific sideband.