In this paper, we propose a multi-input R2³SDF-kR architecture for efficient FFT processor in MIMO-OFDM systems with n-antennas at the transmitter and receiver. The proposed architecture is based on R2³SDF for low complexity and it is operated to k times clock rate for multi-stream processing like MDC pipeline method in MIMO-OFDM systems. The proposed multi-input R2³SDF-kR processor reduces the hardware complexity with similar or less computation in comparison of conventional MDC methods. Comparison results show that the proposed R2³SDF-4R and R2³SDF-8R reduce the area about 58% and 76% compared with the most area-efficient methods at 4 × 4 and 8 × 8MIMO channels, respectively.

View full abstract

A new voltage-mode quadrature oscillator employing single differential-input buffered and transconductance amplifier (DBTA), three grounded capacitors, and two grounded resistors is presented. The use of only grounded capacitors and resistors makes the proposed circuit ideal for integrated circuit implementation. Outputs of two sinusoidal signals with 90° phase difference are available in the proposed quadrature oscillator. The oscillation condition and the oscillation frequency are independently adjustable by different grounded passive elements. The passive and active sensitivities of the proposed circuit configuration are low. PSPICE simulation results are given to verify the theoretical analysis.

View full abstract

H.264/AVC High 4:4:4 Intra/Predictive profiles supports RGB 4:4:4 sequences for high fidelity video. RGB color planes rather than YCbCr color planes are preferred by high-fidelity video applications such as digital cinema, medical imaging, and UHDTV. Several RGB coding tools have therefore been developed to improve the coding efficiency of RGB video. In this paper, we propose a new method to extract more accurate correlation parameters for inter-plane prediction. We use a searching method to determine the matched macroblock (MB) that has a similar inter-color relation to the current MB. Using this block, we can infer more accurate correlation parameters to predict chroma MB from luma MB. Our proposed inter-plane prediction mode shows an average bits saving of 15.6% and a PSNR increase of 0.99dB compared with H.264 high4:4:4 intra-profile RGB coding. Furthermore, extensive performance evaluation revealed that our proposed algorithm has better coding efficiency than existing algorithms.

View full abstract

A design method for wide-band CMOS low noise amplifier (LNA) is presented, which is suitable for mobile TV application. The proposed method integrates two kinds of wide-band LNA topologies by different switches, which can achieve better performance and avoid shortcomings when it operates at different modes. It can save the power consumption and improve the linearity at higher input signal power, and it also can reduce the noise at lower input signal power. The proposed wide-band LNA topology for mobile TV application is designed in TSMC 0.18-µm RF CMOS process.

View full abstract

Silicon or glass was a common material for SU8 coating. However, these materials are hard and brittle, make it difficult for drilling and dicing. This paper reported the effect of grayscale and resolution based on the various length of time for Propylene Glycol Methyl Ether Acetate (PGMEA) developing towards SU8-10 coated on polymethylmethacrylate (PMMA). The grayscale results show that the 0% (solid black) produced the highest percentage on the square structure formed to the SU8-10 film coated on PMMA and the highest resolution had been produced for the 30 minutes of PGMEA developing.

View full abstract

The first efficient generic-point parallel scalar multiplication method is presented here. The novelty of the proposed method is that the precomputation overhead can be replaced by postcomputations that can be parallelised. This method will be very attractive for use in high-performance end servers that employ parallel elliptic curve cryptoprocessors.

View full abstract

In this paper, a heuristic mapping algorithm which maps tasks, using priority lists and the crinkle moving pattern is proposed. To evaluate this algorithm, a set of real (i.e. Video Object Plan Decoder) and random applications have been used and the results have been compared. By reducing the number of hops between IP cores, the energy consumption and the completion time of the application (time which all tasks in the task graph execute wholly) have been optimized. Compared to other mapping algorithms, the algorithm execution time (due to its low complexity) is considerably lower.

View full abstract

This paper presents a low voltage 2.8-11.2GHz CMOS broadband low noise amplifier (LNA) using folded common-gate (CG) topology. The broadband input matching is achieved by adopting CG topology. Bandwidth extension is proposed by inserting an inductor to create a broadband band-pass characteristic with a choke inductor. A folded topology is employed to reduce the supply voltage and thus power consumption. A source follower jointly acts as the buffer stage for broadband output impedance matching and feed-forward path for gain enhancement. Maximum power gain is 11.2dB and the NF ranges from 2.58 to 4dB over the full band. The LNA achieves an average IIP3 of -6.5dBm while consumes only 4.6mW.The proposed broadband LNA is designed in 0.18-µm CMOS process from 1V supply.

View full abstract

This letter presents a wideband antenna of the modified planar inverted-F antenna (PIFA), which covers GPS, DCS, PCS, UMTS, and WLAN band. The proposed antenna mainly comprises four resonance frequencies of rectangular patch, two strips and U-shaped slot, which fed by a 50Ω coaxial line, occupies a volume of 21 × 27 × 4mm³. The mobile phone considered in this study has a system ground plane of size 32 × 60 × 0.2mm³. Measured results show that the proposed antenna provides enough bandwidth to cover five bands for return loss less than -6dB (VSWR < 3). The simulated return loss is compared with measured return loss, which shows a good agreement between them.

View full abstract

A simple single-switch single-stage AC/DC converter based on the flyback topology with the high power factor correction, high efficiency and small size is proposed and implemented. It complies with IEC 61000-3-2 for low frequency harmonics under a power range (20-50W) at 110VAC input. The proposed converter introduces the auxiliary winding of the transformer to replace the bulk inductor of the conventional converter topologies. The voltage of the bulk capacitor is (1) clamped under the rectified line voltage and (2) not influenced by the output load. The efficiency reaches 89∼90% and the power factor is between 0.94 and 0.95.

View full abstract

A millimeter-wave power amplifier module achieves 140mW maximum output power and 80mW output 1-dB gain compression point at 125GHz. The 0.08µm gate length InGaAs/InP composite-channel HEMTs were applied to single-chip coplanar-design amplifier MMIC. The module's output power in this frequency band is a record to the best of our knowledge.

View full abstract

Recently, various types of silica-based planar lightwave circuits (PLCs) have been used for optical networks. However, silica exhibits large temperature dependence, so the temperature of silica-based PLCs needs to be controlled. We can reduce the cost and the energy budget of optical equipment by using athermal waveguides. We propose an athermal optical waveguide comprised of trenches filled with low-refractive index material. The propagation constant of the waveguide is determined by the refractive indices of the core and the low-refractive index material; their thermo-optic coefficients have opposite signs, and therefore the temperature dependence of the waveguide can be suppressed. A 1-bit delay circuit was designed for a 12.5Gbit/s differential phase shift keying receiver using the athermal waveguide, and it displayed a wide operating temperature range.

View full abstract

In this paper, we propose a modified RLS algorithm with Adaptive Forgetting Factor using a low-complexity forgetting factor update equation. The conventional AFF-RLS method has a high-complexity update equation to update forgetting factor. In order to reduce complexity, an approximated version of the AFF-RLS method had been derived by Song. But this modified AFF-RLS method shows degraded performance because it suffers from `gradient error amplification' problem. In order to obtain the same performance as AFF-RLS with relatively low computational cost, we noted that AFF-RLS had been derived by `method of steepest descent', and we use normalization technique which is used in NLMS. The Experiment result shows that the proposed method has almost same performance as the conventional AFF-RLS method with relatively low-complexity.

View full abstract

Orientation field plays the most important role in fingerprint recognition. Proposed in this paper is a novel approach of pixel-wise orientation field estimation using multi-scale Gaussian filter. A three-stage averaging framework in pixel-scale, block-scale, and orientation-scale is developed for handling gradient vectors, coherence data, and orientation vectors, respectively. Experimental results on various FVC datasets show the proposed algorithm achieves accurate orientation field estimation which is robust to local defects, such as scar, low contrast, ridge discontinuity, smudged area, etc. with a low computational cost.

View full abstract