High-speed FSK Modulator Using Switched-capacitor Resonators

TL;DR

This paper introduces an ultra-fast FSK modulation method using switched-capacitor resonators, enabling high-speed binary FSK with minimal energy loss and independent of resonator bandwidth, validated through experiments.

Contribution

The paper presents a novel switched-capacitor resonator technique for high-speed FSK modulation, achieving rapid switching without energy dissipation and independent of resonator bandwidth.

Findings

Achieved FSK modulation rates as high as the carrier frequency.

Demonstrated energy-efficient switching with zero crossing synchronization.

Validated through experimental results matching simulations.

Abstract

In this paper, an ultra-fast frequency shift-keying (FSK) modulation technique based on switched capacitor resonators is presented. It is demonstrated that switching a reactive component such as a capacitor, in a high-Q resonator with proper switching signal can preserve the stored energy and shift it to a different frequency. Switching boundaries are found by continuity of electric charge and magnetic flux. It is shown that if switching time is synchronous with zero crossing of the voltage signal across the switched capacitor, impulsive components can be avoided and continuity of electric charge is satisfied without energy dissipation. We use this property to realize a fast binary frequency-shift keying (FSK) modulator with only a single RF source. In this technique, the modulation rate is independent of the resonator bandwidth and can be as high as the lower carrier frequency. Experimental results are presented to validate the simulations.