A multiband SSr diode RF rectifier with an improved frequency ratio for biomedical wireless applications

Area of Science:

• Electrical Engineering
• Biomedical Engineering
• Radio Frequency Engineering

Background:

• Biomedical implantable devices (BIDs) require efficient power sources.
• Existing RF energy harvesting solutions often face limitations in bandwidth and efficiency.
• There is a need for compact, multi-band rectifiers for BIDs.

Purpose of the Study:

• To develop a simplified, four-band implantable RF rectifier.
• To enhance RF energy harvesting capabilities for low-power biomedical applications.
• To investigate the performance of a multi-band rectenna for powering BIDs.

Main Methods:

• Sequential matching of RF-rectifier cells to four operational frequencies.
• Design and fabrication of a compact RF-rectifier on an FR-4 PCB.
• Testing of the rectenna's performance at various RF frequencies and power levels.

Main Results:

• The RF rectifier operates across multiple bands, including 1.830 GHz, 2.100 GHz, and Wi-Fi bands (2.38–2.68 GHz).
• Achieved a maximum RF-to-DC power conversion efficiency (PCE) of 73.00% at 2.100 GHz with 2 dBm input power.
• Demonstrated outdoor performance with an output voltage of 0.440 V, capable of driving a low-power evaluation module.

Conclusions:

• The proposed four-band RF rectifier offers simplified circuit complexity and effective frequency domain utilization.
• The design exhibits potential for powering various low-power biomedical implantable devices through efficient ambient RF energy harvesting.
• The multi-band operation and good impedance bandwidth contribute to the rectenna's practical applicability.