A radio frequency (RF) transmitter includes a transmitter processing module that generates a processed signal and a modulating signal based on outbound data. A programmable delay module generates a first plurality of delayed signals from the processed signal, wherein a delayed signal of the first plurality of delayed signals is scaled based on one of a first plurality of coefficients, wherein the first plurality of coefficients are selected based on a control signal. An up-conversion module up-converts the processed signal and the first plurality of delayed signals to generate a plurality of up-converted signals. A combining module combines the plurality of up-converted signals to generate a shaped-spectrum signal. A polar amplifier amplifies and amplitude modulates the shaped-spectrum signal based on the modulating signal to generate a transmit signal. A processing module generates the control signal to control a spectrum parameter of the transmit signal.