Compact implantable RF front-end unit for biomedical applications

2021 ELE Engineering Design Project (MA01)

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Faculty Lab Coordinator

Marco Antoniades

Topic Category

Signal Processing / Communication

Preamble

Achieving highly-efficient yet compact and low-profile RF front-end units for biomedical applications continues to be a major challenge for RF engineers designing implantable devices. Examples of such devices include pacemakers, heart pumps, and cardiac defibrillators. With an increasing trend towards wireless connectivity of such devices, the efficient design of their RF front-ends, which include the indispensable antenna radiating elements and their associated amplifying circuitry, becomes even more important. Recently, metamaterials have been used to create novel antennas and RF/microwave circuits and devices which demonstrate superior performance characteristics compared to their conventional counterparts, and such metamaterial designs will be used in this project.

Objective

The objective of this research project is to design and build a compact RF front-end unit consisting of an antenna and its amplifying circuits (power amplifier & low-noise amplifier), which are specifically intended for placement on an implanted device within a human body. The implanted unit should be able to wirelessly communicate with another unit outside of the body.

Partial Specifications

1. The overall size of the unit will be defined based on a standard device such as a pacemaker, heart pump, or cardiac defibrillator.
2. The frequency of operation will be limited to medical ISM bands.
3. The unit should be able to transmit and receive wireless communication signals up to 30 cm away from a separate unit outside of the body. Thus, the transmitted and received power levels have to be calculated and designed for accordingly.
4. The unit has to conform to standard specific absorption rate (SAR) levels defined for the safe operation of wireless devices.
5. The design should maximize the overall efficiency of the unit by maximizing the radiation efficiency of the antenna and the efficiency of the amplifiers.

Suggested Approach

The students should become familiar with state-of-the-art compact antenna designs, which have been designed specifically for operation within a human body by studying relevant research papers and books. They should also become familiar with standard designs of power amplifiers and low-noise amplifiers and should be able to adapt these for an implantable scenario. The antennas used should employ transmission-line metamaterials in order to reduce their size and improve their performance. Features such as their size, radiation efficiency, transmitted power and matching performance will be evaluated within realistic human body environments, emulated in industry-standard electromagnetic simulation software.

Group Responsibilities

The group should work collaboratively as a team to define the specifications for each component of the unit in order to achieve the overall objective of the project, which is to communicate wirelessly from an implanted device to another unit outside of the body. Each component will be designed separately, which will then be integrated to form a final working prototype of the RF front-end.

Student A Responsibilities

Implantable antenna design and fabrication

Student B Responsibilities

Power amplifier and filter design and fabrication

Student C Responsibilities

Low-noise amplifier and local oscillator design and fabrication

Student D Responsibilities

Mixer design and fabrication, 3D printing of implantable devices and integration of RF front-end components

Course Co-requisites

ELE 861 – Microwave Engineering

To ALL EDP Students

Due to COVID-19 pandemic, in the event University is not open for in-class/in-lab activities during the Winter term, your EDP topic specifications, requirements, implementations, and assessment methods will be adjusted by your FLCs at their discretion.