Methods and systems for neurostimulation and/or neurotelemetry of electrically-excitable biological tissue. In one embodiment, a method includes providing a radio frequency output to a diode implanted in biological tissue. The radio frequency output cause current to flow in the diode that is sufficient to provide neurostimulation. Additionally, a radio frequency receiver is configured to receive a second harmonic signal from the diode, which can be used to control the radio frequency output.