Super regenerative receiver design for medical implant devices

Abstract

Implant devices are one kind of the state-of-art medical equipment, which have been started to be used widely in diagnosis and treatment. Implanted devices require wireless data transfer for the comfort of patients and ease of the operation. Since these devices are powered remotely or by a battery, low power operation is crucial to eliminate the need for any surgical intervention to maintain the functionality. The most power hungry block in these devices is mostly the RF front-end. Super-regenerative receiver architecture overcomes high power consumption requirement by means of quenching the local oscillator that consumes most of the front-end power. Quenching the oscillator makes it possible to use almost-infinity gain at the start-up to regenerate the received weak signal. The super-regenerative reception theory is explained in detail and two super-regenerative receivers are proposed in this thesis work. The first receiver employs passive inductors; hence, an on-chip inductor was designed to be used in MedRadio band. On the other hand, the second receiver uses only inductorless architectures. For the second receiver, an active inductor was designed to emulate the inductance needed for the frequency selective circuitry. All designs were laid out, fabricated, and characterized. Comparison of the schematic and the post-layout simulation results are provided along with the performance comparison of silicon measurements with the previous work. Finally, a brief conclusion is drawn and perspective for future work is presented.