A planar nanodevice, known as the self-switching diode (SSD) which can be exploited as a high-speed rectifier in a wide range of applications. The non-linearity in the I-V characteristic of the SSD structure has been aimed for rectification application at GHz frequencies is reported. In this work simulation has been conducted on Si-based SSD structure with 230 nm L-shaped channels using ATLAS device simulator under the channel length range of 0.5 μm to 1.3 μm. Furthermore, the validity of the cut-off frequency has also been described using a theoretical value of f t at zero bias. The results showed that the optimization in the channel length of the SSD can assist the high cut-off frequency of SSD rectifying behavior to efficiently operate as microwave rectifier.