US Patent 10073812 Digital discrete-time non-foster circuits and elements

A method to implement circuits and circuit elements having one or more ports may include digitizing, using analog-to-digital converters, continuous-time input signals received from one or more ports of a circuit to form discrete-time input signals. At a digital signal processor, the discrete-time input signals are received and the discrete-time input signals are processed to calculate a desired discrete-time output signals. Using digital-to-analog converters, the calculated desired discrete-time output signal are calculated to form outputs of continuous-time output signals at the one or more ports of the circuit. The continuous-time output signals are output to the same one or more ports that receive the continuous-time input signals; and producing, thereby, a desired relationship between the continuous-time output signals and the continuous-time input signals at the one or more ports.