Carbon nanotube radio

Here we report experimental results for a carbon nanotube (CNT) based amplitude-modulated (AM) demodulator for modulation frequencies up to 100 kHz. Further, the CNT based demodulator was successfully demonstrated in an actual AM radio receiver operating at a carrier frequency of 1 GHz and capable of demodulating high-fidelity audio. The demodulation originates from the nonlinear current-voltage (I-DS vs V-DS) characteristic of the CNT, which induces rectification of a portion of the applied RF signal. By properly biasing the CNT such that the operating point is centered on the maximum nonlinear portion of the V V curve, one can maximize the demodulation effect. This represents a simple application of carbon nanotubes and nanotechnology to the wireless realm.