An electronic circuit is provided. The electronic circuit includes a full-bridge rectifier, a spurious tone detection circuit, and a controller. The rectifier circuit has a plurality of switching elements and first and second radio frequency (RF) terminals. The spurious tone detection circuit has a non-linear circuit element and is coupled between the first RF terminal and a first reference terminal. The spurious tone detection circuit provides a non-zero direct current (DC) voltage in response to detecting harmonic tones at the first RF terminal of the full-bridge rectifier circuit. The controller is coupled to the plurality of switching elements. The controller is for controlling the operation of the plurality of switching elements based at least in part on detecting the harmonic tones. In one embodiment, the electronic circuit may be a wireless charging receiver. In another embodiment, a method for detecting harmonic tones in the electronic device is provided.