Time derivatives via interconnected waveguides

TL;DR

This paper introduces a novel waveguide-based method for computing derivatives of temporal signals, enabling high-speed, low-power analog processing by controlling transmission line parameters to perform differentiation directly on signal envelopes.

Contribution

It presents a new technique using interconnected waveguides with adjustable stubs to perform direct temporal differentiation, including higher order and fractional derivatives, in wave-based analog computing.

Findings

The proposed structure accurately computes derivatives of modulated signals.

Theoretical analysis confirms the ability to perform higher order and fractional derivatives.

Potential for scalable, wave-based analog processing systems is demonstrated.

Abstract

Electromagnetic wave-based analogue computing has become an interesting computing paradigm demonstrating the potential for high-throughput, low power, and parallel operations. In this work, we propose a technique for the calculation of derivatives of temporal signals by exploiting transmission line techniques. We consider multiple interconnected waveguides (with some of them being closed-ended stubs) forming junctions. The transmission coefficient of the proposed structure is then tailored by controlling the length and number of stubs at the junction, such that the differentiation operation is applied directly onto the envelope of an incident signal sinusoidally modulated in the time domain. The physics behind the proposed structure is explained in detail and a full theoretical description of this operation is presented, demonstrating how this technique can be used to calculate higher order or even fractional temporal derivatives. We envision that these results may enable the development of further time domain wave-based analogue processors by exploiting waveguide junctions, opening new opportunities for wave-based single operators and systems.