A radio transmitter for transmitting signals in a predetermined frequency band has a transmit filter (36) and a compensating filter (48). The transmit filter (36) filters a signal to be transmitted from the transmitter to suppress the transmission of parts of the signal outside the band. The compensating filter (48), e.g., operating in the digital domain, filters the signal upstream from the transmit filter, wherein the compensating filter is arranged to alter the signal to counteract at least one of a phase ripple, an amplitude ripple, and a group delay variation of the transmit filter within the band.