Search

A new sub-bandgap photonic gated-diode method is proposed to extract the energy-dependent and spatial distributions of traps at the SiO2=Si interface in MOSFETs. For the photonic current-voltage (I-V ) characterisation of MOSFETs, an optical source with a sub-bandgap photon energy less than the silicon bandgap (E[SUPph] = 0.95 eV < E[SUPg] = 1.12 eV) is employed for the characterisation of interface states (D[SUPit]) distributed in the photo-responsive energy band (E[SUBC]-0.95≤E[SUBu]≤E[SUBC]) in MOS systems with a polysilicon gate. [ABSTRACT FROM AUTHOR]

A shared-arm dipole array (SADA) is designed and its radiation pattern analysed. When using a 2D physical array to image a target, arranging the antenna elements in a longitudinal direction becomes problematic owing to the limited element spacing for alias-free sampling. Therefore, the proposed structure is designed such that two dipoles share a single arm, achieving proper space for antenna elements. As a proof-of-concept, a two-port SADA is designed. The initial array shows radiation pattern distortion, which may negatively affect the radar imaging performance. To correct this distortion, antenna arms are resistively loaded. The results show that resistive loading effectively corrects the tilted beam, allowing the proposed structure to be more suitable for imaging radar applications. [ABSTRACT FROM AUTHOR]

A new memristors-based resistive logic computation unit is introduced. By controlling the memristors' conditional set operation adaptively to one of the input polarities, bipolar signal multiplication of an input and a stored reference bit is performed by unipolar memristor devices and control switches. The multiplication result is registered in an output nonvolatile memristor so that the computed output can be accessed anytime later on by reading the output memristor's status. [ABSTRACT FROM AUTHOR]

The focus of this reported research is on the optimisation of input RF power in SCM-based free space optical (FSO) systems to minimise the average BER because higher input RF power does not always provide FSO systems with better performance, due to the effect of the third-order intermodulation (IM3) product. Analysis results demonstrate the optimum input RF power and the minimum average BER. [ABSTRACT FROM AUTHOR]

A differentially-tuned LC-VCO PLL using a transformer-resonator and a loop-phase control scheme is proposed. The phase of a control path between the differential controls is adjusted to suppress spurious tones. The measured results for the proposed PLL, implemented in a CMOS 65 nm process, show operation frequencies of 3.5-5.6 GHz, phase noise of -118.5 dBc/Hz at 1 MHz offset, and spur rejection of 73 dB, while dissipating 3.2 mA at 1 V supply. [ABSTRACT FROM AUTHOR]

A wideband folded monopole antenna coupled with a parasitic inverted-L element for 2.3-10.6 GHz band laptop computer applications is presented. The designed antenna is composed of a printed folded monopole with an asymmetrical line width and a parasitic inverted-L element. The input impedance is matched by widening the line width of the folded monopole and adjusting the space between the parasitic inverted-L element and the folded monopole. The measured -10 dB bandwidth is 4.85:1 (2.27-11 GHz), and the size of the antenna is 13.75 (1λ/10) mm×12 (1λ/11) mm (where λ=2.27 GHz). [ABSTRACT FROM AUTHOR]

With a patterned transparent electrode and compressive-elastic gel material, a multi-input transparent touch screen, which detects touch location and touch force, has been realised. The input device of this touch screen is composed of a flexible upper single wall carbon nanotube electrode (SWCNT), a lower indium tin oxide electrode layer, and a silicone gel layer between two electrodes. When a touch force ranging from 0 N to 5 N was applied to the surface of the upper electrode film, the silicone gel was compressed to change the distance between the two electrodes, which resulted in a capacitance change ranging from 1.92 to 3.42pF. The SWCNT electrode on the polyethylene terephthalate showed sufficient flexibility and robustness for mechanical deformation. [ABSTRACT FROM AUTHOR]

An 18 to 110 GHz two-arm Archimedean spiral antenna directly fed with a Dyson balun is designed, fabricated, and measured. The feed line includes a monolithically integrated rectangular coaxial line impedance transformer designed to reduce the nominal antenna impedance from ∼180 to 80 Ω and to match that impedance to the nominal system's impedance of 50 Ω. Full-wave modelling and impedance measurements are used to assess antenna performance. A VSWR<2.5:1 is obtained throughout the measured band. [ABSTRACT FROM AUTHOR]

A low-jitter 110 MHz-to-620 MHz phase-locked loop (PLL) that includes a low-noise wide-frequency-range ring oscillator with a dual-mode operation is presented. The measurement results using a 65 nm low-power CMOS process show that the proposed PLL achieves as low as a 2.5 ps RMS jitter at 600 MHz of output frequency while consuming 2.7 mW at a 1.2 V supply. The die area is only 0.09 mm2. [ABSTRACT FROM AUTHOR]

The recessed channel fin field-effect transistor (RC-FinFET) has been developed as a future DRAM cell transistor. A recess-channel structure is applied to the FinFET to form a RC-FinFET. A three series-connected transistor model is proposed to understand the electrical characteristics. The RC-FinFET is considered to be a serial connection of three transistors consisting of one bottom transistor and two vertical transistors. The electrical characteristics of the RC-FinFET are compared with the normal FinFET and recessed-channel-array transistor (RCAT). The short channel immunity of the RC-FinFET is better than the normal FinFET and RCAT. [ABSTRACT FROM AUTHOR]

Background noise robustness is one of the major concerns in speaker identification systems. Extended missing feature theory (EMFT) has been applied for this application by ignoring the unreliable parts of the input feature. Proposed is the advanced missing feature theory (AMFT) to improve the identification rate of EMFT by considering the cross-terms in a feature vector. To reduce the computational complexity of AMFT, also proposed is the fast-AMFT (F-AMFT) by applying the recursive score-calculation algorithm. Compared with EMFT, F-AMFT requires around 400 times lower complexity and gives significantly better identification rate even for non-stationary background noise environments. [ABSTRACT FROM AUTHOR]

A new dual-mode oscillation scheme that adopts a transformer resonator is proposed. Switch-controlled common- and differential-mode operations enable the proposed oscillator to generate low and high frequency band, respectively. Simulated results for the proposed oscillator designed in CMOS 0.13 µmm process show dual-band frequencies of 2–2.87 and 5.75–9.36 GHz at the mode switch-on and switch-off, respectively, while dissipating 2.5 mA at 1.2 V supply. [ABSTRACT FROM AUTHOR]

A RF tunable dual-mode filter employing a BST (BaxSr1-xTiO3)-based ring resonator and a capacitor is proposed. BST thin film was deposited on TiO2/Si substrate and a TiO2 buffer layer grown by ALD (atomic layer deposition). The device with a BST varactor capacitance of 0.5 pF and 40% of tunability applied voltage of 40 V, and a tunable ring resonator frequency of 1.53–2.02 GHz with a bias of up to 40 V, has been realised. The fabricated bandpass filter has a centre frequency of 1.53 GHz and shows a tunability of approximately 20% with an applied voltage of 40 V. It also has a bandwidth of 74 MHz and shows a tunability of approximately 27% with an applied voltage of 40 V. [ABSTRACT FROM AUTHOR]

A new topology in PLL architecture dual-mode KVCO (DMK) to reduce in-band noise and reference spurs is presented. The DMK PLL also adopts the technique to shrink the spurs by modulating the control voltage. The prototype DMK PLL is implemented in a 65 nm CMOS and shows about 3 ps RMS jitter, phase noise of -107 and -109 dBc/Hz at 100 kHz, 1 MHz offset frequency and reference spur of 68.5 dBc. [ABSTRACT FROM AUTHOR]

Described is a 14 bit 50 MS/s CMOS four-stage pipeline A/D converter (ADC)-based on a digital code-error calibration. The proposed calibration technique measures the capacitor mismatch errors of the front-end multiplying DAC (MDAC) with the back-end pipeline stages while the measured code errors are stored in memory and corrected in the digital domain during normal conversion. The calibration needs the increased power dissipation and chip area of 1.4% and 10.7%, respectively, compared to a 14 bit uncalibrated conventional pipeline ADC. The prototype ADC fabricated in a 0.18um CMOS process occupies an active die area of 4.2 mm2 and consumes 140 mW at 1.8 V and 50 MS/s. After calibration, the measured DNL and INL of the ADC are improved from 0.69 to 0.39 LSB and from 33.60 to 2.76 LSB, respectively. [ABSTRACT FROM AUTHOR]

A frequency-reconfigurable antenna for a mobile phone with small volume is proposed. The proposed antenna consists of a planar inverted F-antenna (PIFA) with volume of 4×36×5 mm3 and a monopole antenna embedded in the same space. The two antennas are excited by two separate feeds with a common ground plane. A switch is used in the PIFA for frequency-reconfigurable operation. The PIFA can cover either LTE (698–806 MHz) or GSM900 (880–960 MHz) depending on the state of the switch. The monopole antenna can cover either PCS1900 (1.85–1.99 GHz) and m-WiMAX (3.4–3.8 GHz) or WLAN 802.11a (5.15–5.35 GHz) depending on the state of the switch. The antenna gain is in the range of -1.99–0.61 dBi over 700 MHz–2 GHz bands and 2.39–4.62 dBi over the bands higher than 3 GHz. The proposed antenna is shown to have good radiation characteristics. [ABSTRACT FROM AUTHOR]

Noble micromachined integrated spiral inductors on anodised aluminium substrate are presented. The RF characteristics of the fabricated inductors have been measured. A high peak Q-factor of 82.36 at 4.2 GHz has been achieved with inductance of 2.59 nH (at 2 GHz) and a self-resonant frequency of around 10 GHz. This work demonstrates that an integrated passive device on anodised aluminium substrate has a competitive RF performance compared to that of LTCC technology. [ABSTRACT FROM AUTHOR]

The low resistive band-to-band tunnelling (BTBT) model has been developed for radio-frequency (RF) silicon negative differential resistance (NDR) device simulation on the TCAD platform. The BTBT mechanism in a forward-biased tunnel junction is modelled based on a generation–recombination term in a continuity equation by considering a spatially varying electric field through the tunnelling distance. Using this model, DC/AC characteristics of silicon NDR devices have been successfully described on a numerical device simulation platform. The calculated speed index from the junction capacitance and peak tunnelling current of the tunnel diode shows good agreement with experiments. [ABSTRACT FROM AUTHOR]

A multi-phase digital delay-locked loop (DLL) capable of a low-jitter feature for DDR memory interface is reported. The DLL repeatedly selects the output clock edge which is closest to the reference clock edge to reduce the total jitter. A test chip was fabricated in a 0.18 µm CMOS process to verify its functionality. The measured RMS and peak-to-peak jitter of the DLL are 6.2 and 20.4 ps, respectively. The power consumption of the DLL is 12 mW from a 1.8 V supply voltage. [ABSTRACT FROM AUTHOR]

A low-cost novel antenna for radio frequency identification (RFID) tags mountable on metallic surfaces is presented. It is designed to work on a substrate FR4 that has a thickness of 3.2 mm and relative permittivity of 4.6, and to operate from 902 to 928 MHz. For easy impedance matching with various microchip impedances without major modification of the radiating element, the proposed antenna has the structure of the folded dipole type with two parasitism-patches. The proposed design is verified by simulation and measurement, which show good agreement. [ABSTRACT FROM AUTHOR]

The efficiency of the resistive vee dipole antenna, the arms of which are loaded with surface-mount chip resistors according to the modified Wu-King profile, is obtained numerically. The numerical model is based on the method of moments and validated by a set of reflection measurements. The numerical model is used to obtain the radiation efficiency and the power dissipated in each chip resistor. Results show that the antenna has low radiation efficiency because the chip resistors dissipate a significant portion of input power. The results may be used to determine the amount of input power that can be handled by the antenna or the resistor types that can handle the power required for a desired application. [ABSTRACT FROM AUTHOR]

A BST ferroelectric thin-film microwave phase shifter with interdigital capacitors on TiO2/Si substrate is presented. The interdigital capacitors have 230 µm signal width, 100 µm signal to ground gap, and 10 µm finger gap. The device, with phase shifts of 142° and FoM of 107.3°/dB applied voltage of 50 V at 16 GHz, has been realised. The TiO2 buffer layer grown by ALD enables successful integration of BST-based microwave tunable devices with Si wafer. [ABSTRACT FROM AUTHOR]

The effect of the birefringence of an intracavity diamond heat spreader on the lasing performance of a vertical external cavity surface emitting laser is investigated. The birefringence in the intra-cavity diamond caused considerable additional round-trip loss when a birefringent filter was inserted into the cavity. The effect of the birefringence of intra-cavity diamond can be reduced by rotation of the sample. By aligning the axes of the diamond birefringence and those of the Brewster surfaces, a pump-power limited green output power of 5.2 W was achieved – a pump to green conversion efficiency of 24%. [ABSTRACT FROM AUTHOR]

A Littrow-configured grating-coupled external cavity wavelength tunable laser monolithically integrated with a semiconductor optical amplifier, an etched grating, and a beam steering controller (BSC) is demonstrated. Using incidence angle variation induced by current injection into the BSC region, 7 nm of wavelength tuning range and over 35 dB side-mode suppression ratio is obtained. [ABSTRACT FROM AUTHOR]

A wide wavelength tunable filter based on a side-polished polarization-maintaining fibre in contact with a polymer planar waveguide overlay is proposed and demonstrated. The good thermo-optic effect of the polymer waveguide induced by a micro-strip heater leads to a wide tunable wavelength range of 230 nm with an applied electrical power of 0.76 W. [ABSTRACT FROM AUTHOR]

An antenna for a wireless sensor network for an indoor environment is proposed. The proposed antenna is composed of an artificial magnetic conductor reflector, two branched radiators, and a power divider including a switched-line phase shifter. Two branched radiators act as four bent monopoles or two crossed dipoles by the switched-line phase shifter. The power divider provides two branched radiators in-phase or out of phase power which makes a side directional pattern or a normal directional pattern, respectively. The proposed antenna has less than 10 mm height with 100 × 100 mm area and more than 100 MHz bandwidth at 2.4 GHz. [ABSTRACT FROM AUTHOR]

Sphere-shaped-recess cell-array transistors (S-RCATs) have been playing a major role in DRAMs on the 70 nm design-rule. The S-RCAT has a recessed-channel structure that produces small drain-induced barrier lowering (DIBL) and large body-bias effect. The temperature and body-bias dependence of DIBL is studied for a S-RCAT. Negative DIBL is peculiarly observed under certain conditions. It is assumed that the negative DIBL originates from the increase of body-bias effect with increasing drain bias and temperature. [ABSTRACT FROM AUTHOR]

A 60 GHz power amplifier (PA) using standard 90 nm CMOS technology is presented. This PA has power gain greater than 30 dB and 18.3% peak power added efficiency (PAE) under 2 V supply voltage. The parallel arrayed cascode power cells, which have a small number of fingers, are combined by the delay line to produce high gain and high PAE. Common gate inductors are inserted as gain booster circuits. A diode lineariser (DL) is adopted for increasing PAE and output P1dB (OP1dB). The measured saturation power is 13.2 dBm with its 11.5 dBm OP1dB. The measure power gain is above 25 dB over the whole frequency range (56-65 GHz). Due to the DL, the measured PAE exceeds 14% at the OP1dB power. This is believed to be the first CMOS PA having such high power gain and PAE. [ABSTRACT FROM AUTHOR]

A simple on-line compensation scheme of nonlinearity in an inverter-fed PMSM drive using an MRAC-based disturbance estimation and co-ordinate transformation is presented. The disturbance voltage caused by the nonlinearity can be effectively estimated using the proposed scheme without any additional circuits or the disadvantages existing in the conventional methods. The asymptotic stability is proved and the effectiveness is verified through simulations. [ABSTRACT FROM AUTHOR]

Considering video conferencing applications, presented is the first utility accrual (or UA) real-time scheduling algorithm for multiple (m, k)-firm deadline-constrained streams running on multiprocessors, called the global multiprocessor utility accrual scheduling algorithm for (m, k)-firm deadline-constraint multimedia streams (or gMUA-MK). Analytical and experimental studies show that gMUA-MK achieves timeliness performance and relatively high quality of multimedia services compared to existing schemes including gMUA. [ABSTRACT FROM AUTHOR]

A radiation pattern-reconfigurable antenna is designed to operate over DCS 1800 and PCS 1900 bands. The proposed antenna is symmetric with respect to the vertical centre line and has a pair of pin diodes for switching. The electrical shape of the antenna consists of a monopole-loaded loop and an open wire, which serves as a director. Depending on the switching state, the antenna can select between two beam directions with essentially no input impedance variation. The return losses and radiation patterns for two bias conditions are measured and compared with simulated results. The measured results indicate that the antenna has high front-to-back ratios for both bias conditions, representing clear pattern reconfigurability. [ABSTRACT FROM AUTHOR]

An nth-order multi-bit delta-sigma (ΣΔ) analogue-to-digital converter (ADC) using a synthetic aperture radar (SAR) quantiser is proposed. By exploiting the residue voltage of a multi-bit SAR ADC, the proposed ADC performs as an nth-order noise shaping converter with only one opamp and removes the need for a feedback multi-bit DAC. In addition, the proposed architecture is very reconfigurable and can be implemented as a bandpass ADC. [ABSTRACT FROM AUTHOR]

Proposed is an antenna design for achieving wide bandwidth using an extended ground. The poor radiation performance of a planar inverted-F antenna with branch structures was significantly improved using the proposed feeding method, in which the ground is extended under a feed line. The antenna design achieved 27% relative impedance bandwidth at 1.9 GHz. [ABSTRACT FROM AUTHOR]

A novel on-chip process-variation monitoring circuit for nanoscale CMOS designs is proposed. The proposed circuit can monitor both global and local variations associated with transistors on an integrated circuit. The process variation is monitored by gate-tunnelling-leakage sensing with weak temperature dependence, which solves the problem of the strong temperature dependence of the conventional subthreshold leakage sensing. The proposed circuit with low power dissipation (1.92 µW at 85°C) is implemented using 45 nm technology, and the results show that it monitors only the process variation with weak dependence (within 5%) on VDD and temperature variations. [ABSTRACT FROM AUTHOR]

A ten-bit (10b) 100 MS/s 0.18 µm CMOS three-step pipeline ADC with various circuit sharing techniques is described. Two MDACs share a single two-stage low-power switched amplifier without MOS series switches and memory effects as observed in conventional shared op-amps. All three flash ADCs use only one resistor ladder rather than three for reference voltages while the second and third flash ADCs share pre-amps for area and power reduction. The prototype ADC with an active die area of 0.80 mm2 shows a maximum SNDR and SFDR of 54.2 and 68.8 dB, respectively, and consumes 24.2 mW at 1.8 V and 100 MS/s. [ABSTRACT FROM AUTHOR]

An X-band linear power amplifier with an on-chip lineariser is developed using a 0.25 µm SiGe HBT BiCMOS process. The proposed on-chip lineariser improves the 1 dB compression to as much as 3.4 dB with no additional DC power consumption. Under a 3.3 V DC power supply, the single-stage cascode amplifier shows a measured small-signal gain of 12.2 dB and output P1 dB of 20.8 dBm, with power added efficiency of 27.4% at the operating frequency range 8.5–10.5 GHz. [ABSTRACT FROM AUTHOR]

To improve power efficiency in a transmitter, a novel method is proposed, this being an uneven multi-level linear amplifier with a nonlinear component (UMLINC). Compared to a normal multi-level LINC (MLINC), the UMLINC employs a new uneven multi-level signal component separator (UMSCS) that significantly improves transmitter efficiency. [ABSTRACT FROM AUTHOR]

A reconfigurable antenna based on a folded dipole structure has been designed to operate at 2.45 GHz. The antenna consists of a folded dipole and a reflector. Depending on the states of the switches, the antenna symmetrically changes its shape and thus steers the beam pattern. The measured reflection coefficient and radiation pattern are presented. Also, the antenna is shown to have a larger gain with the reflector than without. [ABSTRACT FROM AUTHOR]

The new structure of electrically erasable programmable read-only memory (EEPROM), using a capacitor of stacked metal-insulator-metal (MIM) and n-well, is proposed. The oxide capacitance in the n-well region is effectively applied without sacrificing the cell area and the control gate coupling ratio. Therefore, for the same program-voltage rating, the proposed cell allows the EEPROM to have a higher speed handling capability even with a quite small cell size. Measured results show that the programming speed of the proposed cell is almost the same as that of the conventional MIM control gate cell. In an endurance test of 10 000 program/erase cycles, the shift of program threshold voltage is found to be 1.4 V without degradation of read currents. [ABSTRACT FROM AUTHOR]

An enhanced time-frequency analysis of vibroarthrographic (VAG) signals is devised using segmentation by the dynamic time warping and denoising algorithm by the singular value decomposition, and the normal and abnormal VAG signals are classified by a back-propagation neural network. A total of 1408 VAG segments (normal 1031, abnormal 377) were used for evaluating the performance of the devised method and, consequently, the average accuracy was 92.0 ±1.6% (ranging from 89.4 to 95.4). This method could be used as a complementary tool for the non-invasive diagnosis of joint disorders. [ABSTRACT FROM AUTHOR]

Two frequency-reconfigurable antennas have been designed and combined in a space with limited volume, i.e. 40 ×20 ×6 mm. Each antenna can be reconfigured to operate at different frequency bands depending on the state of an embedded switch, which is implemented using a pin diode. The first antenna can be switched between the 0.82–0.96 GHz band (GSM/CDMA) and the 1.7–2.17 GHz band (DCS/PCS/WCDMA), which are cellular bands. The second antenna can be switched between the 3.4–3.6 GHz band (mWiMax) and the 2.3–2.5 GHz, 5.15–5.35 GHz bands (WiBro/WLAN 11a/b/g/n), which are connectivity bands. The proposed combined antenna operates over both cellular bands and connectivity bands concurrently. [ABSTRACT FROM AUTHOR]

An RF tunable active bandpass filter employing a BaxSr1-xTiO3 (BST) based capacitor is proposed. This filter consists of an active capacitance circuit together with a BST tunable varactor. The active capacitor is made of a field effect transistor that exhibits negative resistance as well as capacitance. BST thin film was deposited by Sol-Gel solution and using the metal-insulator-metal capacitor process. The fabricated capacitor showed capacitance of 2.7–1.5 pF at 1.8 GHz for a maximum applied electric field of 34 V/µm. The measured second-order active bandpass filter showed bandwidth of 100 MHz, insertion loss of+0.48 dB at 1.8 GHz centre frequency and tuning frequency of 220 MHz with the application of 34 V/µm. [ABSTRACT FROM AUTHOR]

An aluminium-based packaging platform with microreflector and electrical via for an interconnection electrode is first proposed for a package component of a light-emitting diode (LED). The electrode-guided interconnection with 180 µm thickness has been successfully fabricated by using the selectively anodising process, and not by either the plating or the solder paste technique. The reflector was formed during the isotropic etching process. By mainly a two-step chemical process, the LED packaging platform integrated microreflector and electrical via in one body was developed in a low-cost process. [ABSTRACT FROM AUTHOR]

An active-matrix organic light emitting diode (OLED) display employing a hydrogenated amorphous silicon thin-film transistor prefers a cathode-contact structure to an anode-contact structure. A new normal top-emitting OLED employing cathode-contact structure is proposed. To implement normal OLED structure, the cathode layer on top is separated as sub-pixels by a negative photoresist separator. The current of the cathode-contact structure is maintained 20% higher after 20 h than that of the anode-contact structure during the accelerated life test. [ABSTRACT FROM AUTHOR]

An efficient image alignment algorithm for panorama modelling on a mobile platform is presented. The full degree-of-freedom (DOF) of camera roll, pitch and yaw can be estimated based on 3D rotational matrix decomposition. The time cost for four photos is only ∼3 s on a typical mobile platform (SPH-M4300). This is believed to be the first mobile solution for 3-DOF image alignment. [ABSTRACT FROM AUTHOR]

A simple procedure to calibrate numerical data in a manner which allows for accurate comparison to experimental data is presented. A simple dipole is used to demonstrate the procedure. The numerical calibration procedure is essentially the same as the experimental calibration procedure which makes it possible to make good comparisons. The antenna, along with three calibration standards, are numerically modelled and experimentally measured. Standard S-parameter calibration procedures are used for both. The calibrated numerical data and the measured data are compared in terms of reflected voltage in the feed line. Agreement is shown to be improved significantly with the calibration technique. [ABSTRACT FROM AUTHOR]

A novel optical access network with Manchester coded downstream and remodulated NRZ coded upstream is proposed and experimentally implemented in a 20 km standard singlemode fibre network. When the downstream light source is reused for the upstream signal, acceptably small penalty was observed compared to the unmodulated light source case. [ABSTRACT FROM AUTHOR]