Measuring the Nonlinear and Dynamic Characteristics of Baseband Devices with an Overshoot at the Flat Top of Transient Response

Introduction. Bandwidth broadening and the growing complexity of the signal waveform result in the inadequacy of modern behavioral models used for simulating baseband devices (before and after the demodulator). To measure devices with an overshoot at the flat top of the transient response (TR), a nonlinear dynamic model in the form of a secondorder recursive filter can be used, whose characteristics are currently determined by the variational method. This article presents an alternative approach to measuring the characteristics of baseband devices with an overshoot at the flat top of TR. In this approach, the processing of results does not involve variational algorithms; instead, it qualifies as an indirect measurement of the characteristic functions of a second-order nonlinear recursive filter. Aim. To consider an approach to determining the characteristics of nonlinear dynamical baseband devices with an overshoot at the flat top of the TR using non-iterative calculations based on the results of direct measurements. Materials and methods. A device with an overshoot at the flat top on the TR is simulated by an equivalent electrical circuit, consisting of an in-series connected inductor and resistor with a parallel connected capacitor. The task is to determine the characteristics of each component: the voltage-current characteristic (VCC), the charge-voltage characteristic (CVC), and the magnetic flux-current characteristic (MFCC). The measurement object was a National Instruments PXI-5114 oscilloscope. Results. The developed measurement technique has made it possible to accurately determine VCC, CVC, and MFCC for a device with an overshoot at the flat top without the need for iterative calculations (using indirect measurements). The error in the simulated TR using these measurements in relation to the actual values did not exceed 9 %, which is an acceptable result. Conclusion. The proposed method for calculating characteristic functions without the need for iterations allows for the independent determination of the nonlinear characteristics of devices with an overshoot at the flat top of TR by setting the strobing point at various moments in time. The method is promising for further applications.