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This paper presents a dual-band RF rectifying circuit for wireless power transmission at 1.17 GHz and 2.4 GHz. A dual-band harmonic-tuned inverse-class F/class-F mode power amplifier using a 10 W GaN device has been utilized to implement the proposed rectifier with an on-board coupler and phase shifter. The matching circuit is precisely designed so that the circuit operates in inverse class F and class F mode in the lower and upper frequency bands using dual-band harmonic tuning, respectively. Measurement results show that the rectifier circuit has 78% and 76% efficiencies at 1.17 GHz and 2.4 GHz frequency bands, respectively. To the best of the authors' knowledge, this rectifier is the first demonstration of a dual-band harmonic-tuned synchronous rectifier using a GaN HEMT device with an integrated coupler and phase-shifter for a watt-level RF input power.
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Frequency‐Locked Wireless Multifunctional Surface Acoustic Wave Sensors
Abstract Surface acoustic waves (SAWs) have shown great potential for developing sensors for structural health monitoring (SHM) and lab‐on‐a‐chip (LOC) applications. Existing SAW sensors mainly rely on measuring the frequency shifts of high‐frequency (e.g., >0.1 GHz) resonance peaks. This study presents frequency‐locked wireless multifunctional SAW sensors that enable multiple wireless sensing functions, including strain sensing, temperature measurement, water presence detection, and vibration sensing. These sensors leverage SAW resonators on piezoelectric chips, inductive coupling‐based wireless power transmission, and, particularly, a frequency‐locked wireless sensing mechanism that works at low frequencies (e.g., <0.1 GHz). This mechanism locks the input frequency on the slope of a sensor's reflection spectrum and monitors the reflection signal's amplitude change induced by the changes of sensing parameters. The proof‐of‐concept experiments show that these wireless sensors can operate in a low‐power active mode for on‐demand wireless strain measurement, temperature sensing, and water presence detection. Moreover, these sensors can operate in a power‐free passive mode for vibration sensing, with results that agree well with laser vibrometer measurements. It is anticipated that the designs and mechanisms of the frequency‐locked wireless SAW sensors will inspire researchers to develop future wireless multifunctional sensors for SHM and LOC applications.
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- PAR ID:
- 10641353
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Sensor Research
- Volume:
- 3
- Issue:
- 12
- ISSN:
- 2751-1219
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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