A current steering mechanism is provided in a radio transmitter (e.g., a multiband radio transmitter) to provide compatibility with a variety of baseband parts. Different proportions of an input signal current ("in") are steered to a dummy load, a mixer for a first band, and at least one other mixer for a second band. The mechanism is structured to selectively apportion a current input signal between multiple paths of the same polarity having respective load circuits and concurrently steer different proportions of the current input signal to a dummy load path and at least one mixer path.