In some demonstrative embodiments, a simultaneous transmit and receive (STR) transceiver may include a receiver; a transmitter; a Radio Frequency (RF) echo cancellation module to generate an analog echo cancellation signal to be applied to a received RF signal via the receiver based on a transmitted RF signal via the transmitter; and a digital baseband module. The RF echo cancellation module may include a plurality of tap modulators to modulate a plurality of delayed taps of the transmitted RF signal. A tap modulator may include a plurality of phase shifters to generate a plurality of phase-shifted signals by applying a plurality of phase shifts to a delayed tap; and a plurality of multipliers to multiply the plurality of phase-shifted signals with a respective plurality of weights. The digital baseband module may determine the plurality of weights based on a plurality of subcarriers of a digital frequency-domain signal corresponding to the transmitted RF signal.