RF

RF MEMS fractal capacitors with high self-resonant frequencies

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RF

Amro Elshurafa, et al., "RF MEMS fractal capacitors with high self-resonant frequencies." Journal of microelectromechanical systems 21, (1), 2011, 10. This letter demonstrates RF microelectromechanical systems (MEMS) fractal capacitors possessing the highest reported self-resonant frequencies (SRFs) in PolyMUMPS to date. Explicitly, measurement results show SRFs beyond 20 GHz. Furthermore, quality factors higher than 4 throughout a band of 1-15 GHz and reaching as high as 28 were achieved. Additional benefits that are readily attainable from implementing fractal capacitors in MEMS are

Low voltage RF MEMS variable capacitor with linear CV response

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Amro Elshurafa, et al., "Low voltage RF MEMS variable capacitor with linear CV response." Electronics letters 48 (7), 2012, 392.. An RF MEMS variable capacitor, fabricated in the PolyMUMPS process and tuned electrostatically, possessing a linear capacitance-voltage response is reported. The measured quality factor of the device was 17 at 1 GHz, while the tuning range was 1.2:1 and was achieved at an actuation DC voltage of 8 V only. Further, the linear regression coefficient was 0.98. The variable capacitor was created such that it has both vertical and horizontal capacitances present. As the

Wide-range adaptive RF-to-DC power converter for UHF RFIDs

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Mahmoud H. Ouda, et al., "Wide-range adaptive RF-to-DC power converter for UHF RFIDs." IEEE Microwave and Wireless Components Letters 26 (8), 2016, 634. A wide-range, differential, cross-coupled rectifier is proposed with an extended dynamic range of input RF power that enables wireless powering from varying distances. The proposed architecture mitigates the reverse-leakage problem in conventional, cross-coupled rectifiers without degrading sensitivity. A prototype is designed for UHF RFID applications, and is implemented using 0.18 μm CMOS technology. On-chip measurements demonstrate a

Fully printed 3D cube-shaped multiband fractal rectenna for ambient RF energy harvesting

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Azamat Bakytbekov, A, et al., "Fully printed 3D cube-shaped multiband fractal rectenna for ambient RF energy harvesting". Nano energy, 53, 2018, 587. The Internet of Things (IoT) is an emerging paradigm that requires billions of wirelessly connected devices in a complex radio-frequency (RF) environment. With such a huge number of devices in this scenario, recharging or replacing batteries becomes impractical. Therefore, powering IoT devices by harvesting energy from ambient sources, such as that available in the RF spectrum, is an attractive solution. The antenna for the RF energy harvester