Theoretical Studies of Sub-THz Active Split-Ring Resonators for Near-Field Imaging

TL;DR

This paper presents a theoretical framework for Active Split-Ring Resonators (ASRRs) with tunable properties, enabling high-resolution near-field imaging for non-invasive, real-time applications.

Contribution

It introduces a novel theoretical approach for designing ASRRs with tunable negative resistors, optimizing array performance for near-field imaging.

Findings

Verified through simulations that design guidelines improve SNR and power efficiency.

Analyzed coupling, nonlinear effects, and noise impacts on detection performance.

Provided scalable design strategies for dense pixel arrays in imaging applications.

Abstract

This paper develops a theoretical framework for the design of Active Split-Ring Resonators (ASRRs). An ASRR is a Split-Ring Resonator (SRR) equipped with a tunable negative resistor, enabling both switchability and quality factor boosting and tuning. These properties make ASRRs well-suited for integration into dense arrays on silicon chips, where pixelated near-fields are generated and leveraged for high-resolution 2D imaging of samples. Such imagers pave the way for real-time, non-invasive, and low-cost imaging of human body tissue. The paper investigates ASRR coupling to host transmission lines, nonlinear effects, signal flow, and the influence of various noise sources on detection performance. Verified through simulations, these studies provide design guidelines for optimizing the Signal-to-Noise Ratio (SNR) and power consumption of a single pixel, while adhering to the constraints of a scalable array.