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This paper presents a fully integrated passive self-jamming cancellation (SJC) circuit in 0.18 µm Complementary Metal Oxide Semiconductor (CMOS) technology for ultra-high frequency (UHF) radio frequency identification (RFID) applications. Based on the active amplitude and phase control, a novel passive variable capacitor array and signal combiner are adopted instead of a traditional variable amplifier/attenuator and a phase shifter to reduce the circuit complexity and thus achieve higher linearity and low noise. We use an improved cancellation algorithm based on the local search method to quickly and accurately find the cancellation point that minimizes the self-jamming signal power. The simulation and measurement results are constant, and a suppression of 38 dB can be achieved in the working frequency of 860–960 MHz. The cancellation algorithm can be finished within 0.5 ms. These results indicate that the designed SJC circuit can be a promising candidate for UHF RFID applications. more...

This paper proposes a low-power all-digital phase-locked loop (ADPLL) with calibration-free ring oscillator (RO)-based injection-locking time to digital converter (TDC) for BLE applications. The RO is reused as the delay cell of TDC, and the quantization step of TDC is always tracked with the RO period; hence no calibration is needed in this architecture. We adopt RO tuning to lower the injection-locking bandwidth so as to decrease the power consumption of the injection current. Moreover, the fractional part of phase error detection is turned down in the coarse tuning of ADPLL to save power. An LC-based digital-controlled oscillator (LCDCO) with a 6.4 nH inductor and a resistive bias is used to have a low power and better phase noise performance. The ADPLL is fabricated in 40 nm CMOS with a 1 V supply and consumes 1.4 mW when it is locked. The measured phase noise is −114 dBc/Hz at 1 MHz offset. The test results show significant power saving. Thus, it can be a promising candidate for BLE applications. more...

In this article, we proposed an analytical model based on charge distribution for switched-capacitor trans-impedance amplifiers (SCTIAs). The changes in the load state of the amplifier under different operating conditions and the influence of the gain of the operational amplifier (Opamp) on the trans-impedance gain are analyzed to improve the design theory of switched-capacitor trans-impedance amplifiers. According to the conclusion drawn from the analysis, the trans-impedance amplifier (TIA) has been designed by adopting “correlated double sampling technology” and “cross-connection technology” to optimize input-referred noise current, power consumption, and trans-impedance gain. As a result, the trans-impedance gain reaches up to 206 dB, while the bandwidth is 3 kHz. The current readout system achieves an input-referred noise current floor of 2.96 fA/Hz at 1 kHz, and the power consumption of the system is 0.643 mW. The circuit has been simulated with the technology of 0.18 μm, and the layout area is 1000 μm × 500 μm. more...

A simple and sensitive electrochemical cholesterol biosensor was fabricated based on ceramic-coated liposome (cerasome) and graphene quantum dots (GQDs) with good conductivity. The cerasome consists of a lipid-bilayer membrane and a ceramic surface as a soft biomimetic interface, and the mild layer-by-layer self-assembled method as the immobilization strategy on the surface of the modified electrode was used, which can provide good biocompatibility to maintain the biological activity of cholesterol oxidase (ChOx). The GQDs promoted electron transport between the enzyme and the electrode more effectively. The structure of the cerasome-forming lipid was characterized by Fourier transform infrared (FT-IR). The morphology and characteristics of the cerasome and GQDs were characterized by transmission electron microscopy (TEM), zeta potential, photoluminescence spectra (PL), etc. The proposed biosensors revealed excellent catalytic performance to cholesterol with a linear concentration range of 16.0 × 10 more...

Airline electromechanical actuators (EMAs), on the task of controlling flight surfaces, hold a great promise with the development of more- and all-electric aircraft. Notwithstanding, the deficiencies in both robustness and adaptability of control algorithms prevent EMAs from extensive use. However, the state-of-the-art control schemes fail to precisely compensate the system nonlinear uncertainties of servo control. In this paper, from the innovation point of view, we tend to put forward the foundation of devising an active disturbance rejection robust adaptive control (ADRRAC) strategy, whose main purpose is to deal with the position servo control of EMA. Specifically, an adaptive control law is designed and deployed for resolving not only the nonlinear disturbance, but also the parameter uncertainties. In addition, an extended disturbance estimator is employed to estimate the external disturbance and thus eliminate its impact. The proposed controlling algorithm is deemed best able to address the external disturbance based on the nonlinear uncertainty compensation. With the input parameters and control commands, the ADRRAC strategy maintains servo system stability while approaching the controlling target. Following the algorithm description, a proof of the controlling stability of ADRRAC strategy is presented in detail as well. Experiments on a variety of tracking tasks are conducted on a prototype of an EMA to investigate the working performance of the proposed control strategy. The experimental outcomes are reported, which verify the effectiveness of the ADRRAC strategy, compared to widely applied control strategies. According to the data analysis results, our controller is capable of obtaining an even faster system response, a higher tracking accuracy and a more stable system state. more...

Tourette syndrome (TS) is a childhood-onset neuropsychiatric disorder characterized by repetitive motor movements and vocal tics. The clinical manifestations of TS are complex and often overlap with other neuropsychiatric disorders. TS is highly heritable; however, the underlying genetic basis and molecular and neuronal mechanisms of TS remain largely unknown. We performed whole-exome sequencing of a hundred trios (probands and their parents) with detailed records of their clinical presentations and identified a risk gene, ASH1L, that was both de novo mutated and associated with TS based on a transmission disequilibrium test. As a replication, we performed follow-up targeted sequencing of ASH1L in additional 524 unrelated TS samples and replicated the association (P value = 0.001). The point mutations in ASH1L cause defects in its enzymatic activity. Therefore, we established a transgenic mouse line and performed an array of anatomical, behavioral, and functional assays to investigate ASH1L function. The Ash1l+/− mice manifested tic-like behaviors and compulsive behaviors that could be rescued by the tic-relieving drug haloperidol. We also found that Ash1l disruption leads to hyper-activation and elevated dopamine-releasing events in the dorsal striatum, all of which could explain the neural mechanisms for the behavioral abnormalities in mice. Taken together, our results provide compelling evidence that ASH1L is a TS risk gene. more...

ASD-associated genes are enriched for synaptic proteins and epigenetic regulators. How those chromatin modulators establish ASD traits have remained unknown. We find haploinsufficiency of Ash1l causally induces anxiety and autistic-like behavior, including repetitive behavior, and alters social behavior. Specific depletion of Ash1l in forebrain induces similar ASD-associated behavioral defects. While the learning ability remains intact, the discrimination ability of Ash1l mutant mice is reduced. Mechanistically, deletion of Ash1l in neurons induces excessive synapses due to the synapse pruning deficits, especially during the post-learning period. Dysregulation of synaptic genes is detected in Ash1l mutant brain. Specifically, Eph receptor A7 is downregulated in Ash1l more...

Tourette syndrome (TS) is a childhood-onset neuropsychiatric disorder characterized by repetitive motor movements and vocal tics. The clinical manifestations of TS are complex and often overlap with other neuropsychiatric disorders. TS is highly heritable; however, the underlying genetic basis and molecular and neuronal mechanisms of TS remain largely unknown. We performed whole-exome sequencing of a hundred trios (probands and their parents) with detailed records of their clinical presentations and identified a risk gene, ASH1L, that was both de novo mutated and associated with TS based on a transmission disequilibrium test. As a replication, we performed follow-up targeted sequencing of ASH1L in additional 524 unrelated TS samples and replicated the association (P value = 0.001). The point mutations in ASH1L cause defects in its enzymatic activity. Therefore, we established a transgenic mouse line and performed an array of anatomical, behavioral, and functional assays to investigate ASH1L function. The Ash1l more...