High Q inductor design using modified magnetic substrate structure

Wu, Chang-Mou; Chiu, Hsien‐Tang; Lee, Dasheng; Chang, Meng-Lin; Lu, Chien-Chi; Chang, Chao-Ning

doi:10.1109/wpt.2014.6839564

Cited by 7 publications

(1 citation statement)

References 4 publications

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“…A major factor determining system efficiency is the intercoil coupling coefficient, which depends on the distance between the coils, their geometry, self and mutual inductances, and the quality factor Q of the coils. Much of the recent effort has been diverted to achieve high Q inductor designs to achieve a highly efficient and selected resonant coupling while occupying the same volume …”

Section: Introductionmentioning

confidence: 99%

A wirelessly powered low‐power digital temperature sensor

Amin

Shahbaz

Jawed

et al. 2020

Circuit Theory & Apps

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Summary A wirelessly powered temperature sensor is presented in complementary metal‐oxide‐semiconductor (CMOS) 180‐nm process. The wireless power transfer (WPT) is performed using resonant magnetic coupling, and a diode‐less AC to DC conversion is achieved through a quadrature‐oscillator with native‐MOS. The quadrature‐signals are subsequently used to control the diode‐less rectifier switches. The on‐chip temperature sensor exploits the subthreshold region temperature, and the sensed temperature is converted to frequency using a ring‐oscillator, which is implemented using differential cross coupled oscillator‐based delay cells. The temperature sensor architecture also employs a temperature‐insensitive replica circuit to minimize process dependence and enhance power‐supply rejection ratio (PSRR) of the sensing process. The application‐specific integrated circuit has been designed and fabricated in 180‐nm CMOS process and has dimensions of 2 mm × 2 mm. The measurement results demonstrate that the WPT circuit generates a DC voltage of 1V with a power transfer efficiency of 85% for distances 2 to 8 mm with settling time of microseconds to milliseconds. The temperature sensor demonstrates a resolution of < ±0.6C with a sensitivity of 0.52 mV/C and 126.9 Hz/C along with PSRR of −63dB and Integral Non‐Linraity (INL) of 5% measured across six different dies. The back‐scattering communication demonstrates a −53‐dB signal at a distance of 4 mm without affecting the WPT efficiency. The total power consumption of the temperature sensor along with the integrated biases is 120 nW.

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Section: Introductionmentioning

confidence: 99%

A wirelessly powered low‐power digital temperature sensor

Amin

Shahbaz

Jawed

et al. 2020

Circuit Theory & Apps

View full text Add to dashboard Cite

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Highly Efficient WPT System With Negative Impedance Converter for Q-factor Improvement

et al. 2019

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A negative impedance converter (NIC) has been combined with a wireless power transfer (WPT) system to maximize the system efficiency based on non-foster theory. The NIC is composed of transistor, voltage divider, capacitor, and inductor for impedance matching, and resonant circuit operating at 6.78 MHz. The desired negative impedance can be controlled by tunable impedance in the NIC. In this paper, the loss of the transmitting coil is reduced to 0.1 , yielding a quality factor of 7,050, which is 19.1 times higher than that of the conventional coil. The WPT system with the NIC provides high power transfer efficiency (PTE) at various transmission distances. The experimental results are improved from 64% to 96% and from 5% to 55% at the transmission distances of 50 and 200 mm, respectively. Furthermore, the PTE is enhanced from 38% to 87% and from 2% to 38% at the diagonal misalignment distance of 0 and 150 mm, respectively, at a transmission distance of 100 mm. The proposed technology for increasing the receiving power in the receiving coil with a higher PTE can be utilized for numerous applications in the industrial, scientific, and medical band, with a restricted radio frequency power on the transmitter side.

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