In this paper, we have investigated the electrical characteristics of Silicon Controlled Rectifier (SCR)-based ESD power clamp circuit with high holding voltage for whole-chip ESD protection. The proposed ESD power clamp circuit (HHVSCR: High Holding Voltage SCR) has different well (n/p-well) length (3/7µm - 8/2µm) and p-drift (p+) length (8µm - 16µm). The measurement results indicate that dimension of n/p-well and p-drift has a great effect on holding voltage (2V-5V) and a little effect on the triggering voltage (6.5V∼7V). And the whole-chip ESD protection was designed for 2.5∼3.3V applications, this whole-chip ESD protection design can be discharged in ESD-stress mode (PD, ND, PS, NS) as well as VDD-VSS mode. The robustness of the novel ESD protection cells were measured to 6kV (HBM: Human Body Model), 280V (MM: Machine Model).

View full abstract

A wide band conformal wide slot antenna on circular cylindrical structure with appropriate feed matching circuit is proposed. The slot antenna is in the shape of a hexagon and is fed capacitively by small parasitic patches. These parasitic patches are fed by a microstrip line. The antenna proposed, with an overall substrate thickness of 1.2mm has at least 62 percent bandwidth over the frequency range of 3.38-6.38GHz. The dependence of design parameters on the bandwidth characteristics is investigated. The simulation via a Finite Difference Time domain method in cylindrical coordinates, and measured results on the return loss and the E and H plane radiation patterns of the proposed antennas are presented and shown to be in good agreement.

View full abstract

Reversible circuits have applications in various research areas including signal processing, cryptography and quantum computation. In this paper, a non-search based moving forward synthesis algorithm (MOSAIC) for Boolean reversible circuits is proposed to convert an arbitrary well-formed matrix into an identity matrix using a set of reversible gates. In contrast with the widely used search-based methods, MOSAIC is guaranteed to produce a result and can lead to a solution in much fewer algorithmic steps. To evaluate the proposed algorithms, different circuits and benchmarks were used that show the efficiency of the proposed algorithm to lead a result.

View full abstract

Within the limitations implicit in the magneto-quasi-static approximation, partial inductances are a valuable tool for modeling IC package and interconnect inductances. In the calculation of partial inductances it is not possible to directly apply the image theory due to the absence of charges on the ground plane. In the present paper a correction term is obtained, which allows to calculate partial inductances with the image theory, avoiding in this way the problem of the ground plane segmentation. The formula is valid for conductors parallel to the ground plane. The accuracy of the formula is verified and discussed.

View full abstract

An efficient hybrid distributed video coding (HDVC) scheme combining residual coding, SW-SPIHT coding and intra-mode decision technology is proposed to offer good rate-distortion performance and low-complexity encoding. The scheme adopts the wavelet-domain Wyner-Ziv codec to compress the residual frame between the current frame and its reference frame. An intra-mode decision based on the temporal and spatial correlation is made to determine whether a wavelet block is better coded or not. When the estimated correlation is weak, we use intra-SPIHT coding; otherwise SW-SPIHT(Slepian-Wolf SPIHT) coding is adopted. Experimental results indicate the proposed HDVC achieves evident improvement than the referenced.

View full abstract

In this letter, experimental results of the Chua's circuit designed with unity-gain cells (UGCs) are reported. The UGCs have been implemented with the commercially available integrated circuit (IC) AD844AN from Analog Devices. Parasitic elements of the UGCs are taken in account to design suitable the grounded inductor and the nonlinear resistor (NR) into Chua's circuit. Experimental results are given, showing close agreement with theoretical conclusions.

View full abstract

In this paper an RC time constant digital-tuning method is proposed for multi-bit continuous-time Delta-Sigma modulators. In this approach the effects of the imprecise RC time constant are compensated in digital domain without any requirement to the conventional analog tuning circuitries. In this method, acquiring the response of the loop-filter of the modulator to a known input signal, the actual loop-gain of the modulator is estimated. Comparing the actual loop-gain and the ideal loop-gain, a proper digital IIR (impulse invariant response) filter is inserted in the feedback path of the modulator. Analytic formulas and MATLAB simulations prove that the proposed method compensates the detrimental effects of the imprecise RC time constant appropriately.

View full abstract

A trial for the excitation of a guided wave using a MHz range air-coupled ultrasonic wave in a hollow pipe is attempted. A guided wave is propagated in a 1mm thick aluminum pipe at a critical angle and transmission and reception via air are successfully accomplished. The flexural mode guided wave is detected using wavelet transformation.

View full abstract

In this paper, a new reverse converter for the moduli set {2ⁿ-1, 2ⁿ, 2ⁿ+1, 2ⁿ⁺¹-1} is presented. We improved a previously introduced reverse converter architecture for deriving a high-speed hardware design. Hardware architecture of the proposed converter is based on adders, without the need for ROM or Multiplier. The presented design resulted in a significant reduction in conversion delay in comparison to the last reverse converter for the moduli set {2ⁿ-1, 2ⁿ, 2ⁿ+1, 2ⁿ⁺¹-1}.

View full abstract

We propose a novel estimation of collision response between a virtual and an arbitrary-shaped real objects for virtual realities. Collision is detected by using the overlap ratio between objects. A normal vector of a collided plane is estimated by the collided region, and collision response is calculated by the motion vector of the virtual object and the normal vector. For testing of the method, a sensory game using Web camera was implemented. As the results are successful beyond expectation, this method can be effectively utilized for interactive virtual systems.

View full abstract

A voltage-mode DC-DC converter with a novel oscillator and ramp generator is presented. The proposed oscillator and ramp generator has a simple structure and does not need an external reference signal generator to set the upper and lower levels of the ramp signal. The DC-DC converter was fabricated in a standard 0.5µ m CMOS process. The converter can operate from 465kHz to 556kHz with a supply voltage from 3 to 5.5V, which is appropriate for portable electronic devices that are powered by a single-cell lithium-ion battery. The output ripple voltage is about 10mV with a 10µ F off-chip capacitor and a 10µ H off-chip inductor. The power conversion efficiency is over 80% for load currents from 30 to 400mA.

View full abstract

The goal of this paper is to detect and recover the tampered regions of the digital image. To achieve this goal, the LSB and the second LSB of the spatial domain was selected to embed the watermark. In particular, the watermark consists of three parts: 1) recovery code made by the small sized image of the original, 2) verification code made by the variance value of a block (4 × 4) in the original image (only six MSBs, 1^st ∼ 6^th MSB) and 3) owner code made by a binary logo image. By using this special watermark, we can detect and recover the tampered regions.

View full abstract