Methods and apparatus for reducing radiated field feedback in radio frequency (RF) transmitters. An exemplary RF transmitter includes a power amplifier (PA) and a low-field oscillator (LFO) that are co-located, either on a common module or integrated in the same integrated circuit chip. By using an LFO for the transmitter's local oscillator, radiated field feedback from the PA to the LFO is substantially reduced. In addition to, or instead of using an LFO to reduce radiated field feedback, the LFO or a voltage controlled oscillator (VCO) may be configured to operate at either a harmonic or a non-integer multiple of the transmitter's output signal frequency. Using an LFO or VCO and/or operating the oscillator at a harmonic or a non-integer multiple of the radio system output signal frequency reduces the degree by which electromagnetic fields generated by the radio system's PA and antenna interfere with electromagnetic fields generated by the LFO or VCO, thereby allowing the LFO or VCO to be co-located with or integrated in the same integrated circuit chip as the radio system's PA.