The recent advancement of oxide-based electric-double-layer transistors (EDLTs) is exciting in many aspects, but further development requires a better understanding of their physical nature. Since the electrolytic capacitance dominates the unique properties of EDLTs, its understanding has become a critical issue in this area. This study simulated electrolytic capacitance using the ion drift-diffusion model and compared it with actual measured data. Ion concentration was identified as the most significant factor affecting the quasi-static EDL capacitance. And in addition to that, ion diffusion coefficient and electrolyte thickness also impact the frequency dependence of the EDL capacitance and, consequently, the transient response of EDLTs.
The modified Zener diode-triggered silicon controlled rectifier (MZDTSCR) is proposed in this paper. The MZDTSCR has low trigger voltage, suitable holding voltage, low leakage current and good electrostatic discharge (ESD) robustness. The physical mechanism and results analysis of the MZDTSCR are discussed. In addition, how do the trigger and holding voltages vary with the width increasing of the N+ bridge inside the MZDTSCR, are also analyzed. Test and simulation data show that MZDTSCR can be applied to the circuit with 5V operating voltage.
A novel D-shaped micro-structured optical fiber (MOF) based surface plasmon resonance (SPR) sensor is designed and numerically investigated, to solve the problem of low sensitivity at the RI range below 1.33 of fiber SPR sensors. By depositing a gold layer on a semicircular ring-shaped channel at the top of the fiber to excite SPR, the RI sensitivity of the sensor can reach 13300 nm/RIU at 1.25, with the resolution of $7.52\times 10^{-6}$ RIU. The RI sensing range can be extended to as low as 1.17 with high sensitivity, which can be used for some low RI analytes detection such as the anesthetic sevoflurane, medical oxygen, and liquid carbon dioxide.
In this paper, we propose a compact, broadband balanced filter based on integrated passive process (IPD), which can realize the balanced-unbalanced conversion of microwave signal. The proposed balanced filter is composed of a band-pass filter and a balun, the former selects the working frequency band for the balanced filter, and the latter realizes the conversion of the signal. Simulation results show that the specific operation frequency band of the balanced filter is 2.8 GHz to 4.8 GHz, the insertion loss of the two output ports at the center frequency of 4.37 GHz is −1.514dB and −1.541dB respectively, the phase difference is 180.9°, and the center frequency is within the range of 500 MHz. The insertion loss of the two output ports does not exceed −2.5dB, the maximum difference between the insertion loss of the two ports is about 1 dB, the phase difference fluctuates up and down by ±5°, and the overall size is approximately 1250 $\mu {\mathrm {m}} \times 1250 \mu$m. It has the advantages of compact structure, low loss, frequency bandwidth, low phase deviation, it can be suitable for applications in communication, RF front-end, Bluetooth, WiFi, GPS navigation and other fields.
Electrostatic discharge (ESD) protection is an important issue for the modern integrated circuits (ICs). As for the input/output (I/O) pins having a varying operating voltage in the positive and negative ranges, the traditional diode or GGNMOS architecture is not applicable, making the corresponding ESD design more difficult. Among the several widely used ESD protection devices, the silicon-controlled rectifier (SCR) has a high ESD robustness. However, it should be further optimized to decrease its trigger voltage and meet the requirement for the bidirectional applications. In this paper, a new modified diode triggered bidirectional SCR is proposed, the layout area is reduced by commonly using the trigger diode. The clamp voltage is also reduced by changing the locations of the active regions. The proposed device was fabricated in a 28 nm CMOS technology. The experimental results show that the new proposed device has a symmetry I-V characteristic and a good ESD robustness.
