Experimental Study on Coexistence of a Spiking Neural Network and 77 GHz VCO on a Single Chip

The third generation of artificial neural networks, the Spiking Neural Networks (SNN), becomes popular for numerous applications. However, a physical circuit-level SNN implementation and feasibility of its integration with millimeter-wave circuit blocks towards a system on chip (SoC) has not been reported yet A voltage-controlled oscillator (VCO) is the core element of FMCW radar transceivers and one of the most sensitive blocks in the system. This work evaluates empirically for the first time the potential interferences during concurrent operation of an SNN and a 77 GHz VCO integrated on the same chip. The coupling effects are investigated experimentally in time- and frequency-domain, particularly by phase noise measurements. The VCO exhibits a low phase noise of -100.25 dBc/Hz at an offset frequency of 1MHz from 77 GHz carrier, while the SNN activity is turned off. By an intentional triggering of the SNN, a significant impact on VCO is observed and the phase noise is deteriorated up to as much as -89.75 dBc/Hz at the same offset frequency. The circuit blocks are implemented on a testchip in a 130 nm BiCMOS technology.