In this paper chipless RFID tag, capable of carrying 9-bit data is presented. The tag is optimized for several flexible substrates. With growing information and communication technology, sensor integration with data transmission has gained significant attention. Therefore, the tag with the same dimension is then optimized using paper substrate. For different values of permittivity, the relative humidity is observed. Hence, besides carrying information bits, the tag is capable of monitoring and sensing the humidity. The overall dimension of the tag comprising of 9 ring slot resonators is 7 mm. Due to its optimization on the paper substrate, the tag can be an ideal choice for deploying in various low-cost sensing applications.
In this paper, a novel built-in jitter measurement circuit (BIJM) for Phase-Locked Loops (PLL) based on a variable vernier delay line (VVDL) is proposed. Resolutions of the two-level VDLs can be designed flexibly and their lengths optimally according to the signal under test (SUT). A digitally controlled delay element (DCDE) using varactors acts as the basic delay element in VVDL. Instead of counters, thermometer-to-binary encoders are adopted in the design. An improved phase detector (PD) is also introduced. The circuit has been designed using an all-digital design methodology and verified with the TSMC 130 nm CMOS process. 800 MHz clock frequency is chosen, and the circuit occupies a total silicon area of 0.043 mm2, which is reduced by 60% compared to the traditional VDL. Simulation results indicate coarse timing resolution of 15.4 ps and fine resolution of 2.1 ps, and measurement error is within 2.11%.
This paper presents a 40-Gb/s 3-tap forward feedback equalizer (FFE) incorporating broadband active delay cell, multiplier & summer and a delay-locked loop (DLL). The active delay cell employs capacitive degeneration and negative impedance structures to broaden the bandwidth. The source-degenerated linear transconductor based multiplier & summer circuits are used through appropriate setting of the FFE tap coefficients. The delay time of the delay cells are calibrated by a DLL against process, voltage, and temperature (PVT) variations. For improving calibration accuracy, the phase detector adopting two symmetric XOR gates and the charge pump utilizing current splitting and self-detection compensation techniques are designed. The proposed circuit is fabricated in 130 nm BiCMOS process, which achieves a data rate of 40 Gb/s through 20-inch FR-4 PCB trace and the horizontal and vertical eye openings of 0.55 UI and 150 mV.
This paper formulates the maximum efficiency of multiple-transmitter inductive power transfer system in terms of system kQ-product. We show that the cross-coupling among transmitters does not affect the maximum efficiency. More importantly, the square of system kQ-product is equal to the sum of squares of kQ-products of individual transmitter-receiver links. This result provides an intuitive insight into the characteristics of system efficiency.
We propose a high-voltage switch driven by wavelength-modulated light, which is suitable for remote MEMS (especially electrostatic actuators) device operation. It is fabricated on an SOI wafer and consists of series-connected n-MOSFETs whose substrates are mesa-isolated, allowing the switch to endure a high voltage. The fabrication process requires no modification in a standard CMOS process itself, which is easy for foundries to accept. In addition, by using wavelength-modulated light instead of electric circuits for the control of the switch, it achieves a simple, scalable, small switching circuit regardless of the switching voltage. Fabrication and operation of 50 V switch using 5 V standard CMOS technology is reported in this paper.
A non-contact physiological signal monitoring system was proposed using Doppler radar sensor to detect the movement of human thoracic cavity. The system consists of Doppler radar sensor, signal conditioning, MCU data processing and wireless communication. The system collects human chest movement due to heart and respiration (pleura fretting signals for conditioning). The experimental results show that the Doppler radar that the system used with the zero phase IIR digital filter can achieve real-time monitoring, store the physiological data, separate respiration and heartbeat signals, eliminate the distortion of the signal phase and have advantages of small size, low power consumption, strong penetration.
Digital phase locked-loop (DPLL) is a circuit system for frequency synchronization, and unbiased finite memory DPLL (UFMDPLL) is DPLL using a finite impulse response (FIR) filter for phase detection. This letter proposes a novel method for finding the optimal horizon size, which is a key design parameter of UFMDPLL, based on the minimization of the estimation error variance. The effectiveness and efficiency of the proposed method are demonstrated in comparisons using the conventional Monte Carlo simulation method.
This paper presents a novel PMOS read-port 8T SRAM cell, in which the read circuit is constructed by two cascaded PMOS transistors, and hence the leakage power is significantly optimized compared to the conventional 8T cell. Meanwhile, it also exhibits high area efficiency due to an equalized quantity of NMOS and PMOS transistors per cell. Furthermore, the proposed cell has sufficient potential to enhance performance by employing a Half-Schmitt inverter. The measurements indicate that the proposed cell outmatches conventional 8T cell in terms of leakage suppression and area saving, thus making it a superior choice for ultra low power applications.
This letter presents a compact bandpass filter using a hybrid structure of quarter-mode substrate integrated waveguide (QMSIW) and coplanar waveguide (CPW). The hybrid structure is realized by inserting a CPW resonator into the two side-coupled QMSIW resonators. The CPW structure not only works as a resonator but also introduces extra electric coupling between the two magnetically coupled QMSIW that generates additional transmission zero. Also, the CPW does not occupy additional circuit size which further reduces the whole circuit size of the filter. To validate the proposed concept, a prototype filter is fabricated and measured. Good agreement is achieved between simulation and measurement.
This paper proposes a new switching power circuit topology combining a boost converter and a forward one by integrating the inductor. The target application of the proposed scheme is a photovoltaic (PV) power conditioning system which operates according to the differential power processing architecture. The boost converter delivers the main PV string power to the DC-link, and the forward converter handles a portion of the boost inductor’s energy to compensate the power difference among the PV panels. Not only the compensation, but also operates the forward converter the distributed maximum power point tracking (DMPPT) control for each PV panel. Since the input of the forward comes through the transformer coupled with the boost converter’s inductor instead of the high voltage DC-link, this converter requires no extremely step-down voltage conversion ratios, which give several benefits such as low device stresses and high conversion efficiency. In the paper, analysis and design procedures are presented and a 200-W hardware is implemented to validate the performance of the proposed topology such as the efficiency and DMPPT control.
A five-pole ultra-wideband (UWB) bandpass filter (BPF) with broad stopband for FCC UWB indoor communication application is developed. It employs a step-impedance stub-loaded tri-mode resonator, by properly selecting the impedance ratio of the stub, the proposed resonator is able to be downsized without changing significantly its tri-mode characteristics. The advantages of such resonator are easy control of its frequency response and highly compact in structure compared with other resonators. Moreover, a lowpass filter (LPF) is utilized to suppress the unwanted high-frequency harmonics of the proposed UWB BPF. Design and synthesis procedures with details are provided, and good agreement between simulated and measured results is also observed. Due to the fact that the introduced filter structure is simple and all the geometrical parameters are larger than 0.1 mm, the UWB BPF is feasible for low-cost fabrication using conventional printed circuit fabricating techniques.
This paper describes the detection of tissue coagulation for a microwave surgical device. This method uses variations in the electrical properties of biological tissue before and after heating. To evaluate the proposed method, we made coagulated tissue and measured the impedance of the tissue using the microwave surgical device. The results of the measurements show that the impedance of the heated tissue changed significantly due to tissue coagulation. This results implies that coagulation of tissue can be detected by variation of electrical impedance.
This paper presents an envelope detector that can be used in an ultra-wide operation frequency range (1 GHz∼10 GHz) and the transient response time of the detector is less than several nanoseconds. The detector comprises an operational trans-conductance amplifier (OTA), a mirror and a buffer. An extra discharging path is added specially to accelerate the falling-down transient process. The value of the discharging current and the choice of the charging/discharging capacitor are the key factors in the transient process. The circuit is implemented using HuaHong 0.18 µm standard CMOS technology. Simulation and measured results are offered showing both better frequency (up to 10 GHz) and transient (several nanoseconds of delay) performance.
An ultra-miniature modified quarter mode substrate Integrated waveguide (QMSIW) resonator is proposed. The dominant resonant mode of the proposed resonator is TE101 mode. The area of the modified QMSIW resonator is reduced by nearly 97.3% compared with the conventional full-mode SIW resonator. With the new coupling structures, the miniaturized resonator can be properly arranged in the filter design to minimize the footprint of the circuit. A novel filter using compact modified QMSIW cavity is designed, the proposed compact filter is fabricated to prove the predicted results in experiment, and good agreement is obtained.
In this letter a compact tri-band bandpass filter (BPF) based on a modified tri-section stepped impedance resonator (SIR) and a stub-loaded SIR is proposed. By properly adjusting the resonant modes of the two resonators independently, a tri-band BPF centred at 1.8/3.5/5.2 GHz is designed, corresponding to the GSM, WiMAX, WLAN applications, respectively. Moreover, several transmission zeros (TZs) are generated on each side of the passbands to improve the selectivity. Measured results show good agreement with the simulated results.
We develop a single-end-access strain/temperature sensor configuration based on multimodal interference in a polymer optical fiber (POF) with an extremely high sensitivity. The light Fresnel-reflected at the distal open end of the POF is exploited. We obtain high strain and temperature sensitivities of –122.2 pm/µε and 10.1 nm/°C, respectively, which are shown to be comparable to those in two-end-access configurations.
Scheduling algorithm is crucial to the performance of the Network-on-chip router. Different from traditional scheduling algorithms that concentrate on local fairness, we propose a congestion-aware scheduling algorithm based on input buffer of downstream router. The scheduling algorithm keeps a match dynamically between input and output by detecting the flits number to be transferred in the same packet. It can reduce network congestion especially under heavy traffic loads. Compared to RRM and iSLIP algorithm, the new scheduling algorithm can increase the saturation throughput by 8.2% and reduce the average communication latency by 7.8% under non-uniform traffic.