Two-dimensional beam-scanning phase-shifterless technique usinglinear active leaky-wave antenna array

A novel two-dimensional electronic beam scanning technique using a linear leaky-wave antenna array with coupled oscillators is introduced, eliminating the need for phase shifters. The measured H-plane main beam can be continuously scanned from 70 to 40° as the frequency varies from 7.9 to 9.05 GHz. By detuning the free running frequencies of the end elements, the measured E-plane main beam can be continuously scanned from -22 to +26     

Active Frequency-Tune Beam-Scanning Leaky-Wave Antenna Arrays

X-band active beam-scanning leaky-wave antenna arrays, including 1 × 1,1 × 2 and 1 × 4 prototypes, have been demonstrated. These antennas integrated one or several microstrip leaky-wave antenna elements with a single varactor-tuned HEMT VCO as an active source. Measured results on experimental antennas indicate that the beam scanning angle of the 1 × 1 antenna close to 40° can be achieved and the scanning range of 1 × 2 and 1 × 4 antenna arrays are both close to 32°. Furthermore, reflected wave due to the open end of each leaky-wave antenna element has been suppressed by the symmetric configuration of this antenna array and the antenna efficiency increases. When comparing with the measured radiation pattern of the single element antenna, we found that the 1 × 2 and 1 × 4 antenna arrays can effectively suppress the reflected power by more than 5.5 dB and 10.5 dB, respectively, at 10.2GHz. The power gain are more than 2 dB and 3.16 dB higher than the single element antenna with a measured EIRP of 18.67 dBm.     

Design and analysis of digital data recovery circuits using oversampling

A performance evaluation and circuit architecture for all-digital data recovery using an oversampling method is proposed. The architecture is very regular and hence very suitable for standard-cell implementation flow. Due to its feedforward architecture, the required bit-rate can be achieved through proper pipelining. These properties make the proposed architecture very suitable as soft silicon intellectual property. Analysis of BER due to the combined effects of the key design parameters like data jitter, clock jitter and oversampling ratio in the oversampling technique are carried out. Thus different specifications of data recovery can be designed with different design parameters. A module generator that can estimate the design parameters automatically is established. Design implementation shows the proposed all-digital data recovery circuit can achieve 3.07 Gbit/s (post-layout) with 0.25 mum 2.5 V CMOS technology standard-cell design and occupies 380times390 mum² chip area     

Organic light-emitting diode-based plausibly physiologically-friendly low color-temperature night light

Light sources with lower color temperature (CT) show markedly less suppression effect on the secretion of melatonin, an oncostatic hormone. Light sources with higher color rendering index (CRI) provide better visual comfort. In this report, we demonstrate the design and fabrication of low CT, high CRI fluorescent organic light-emitting diode (OLED) with five-band emitting from a single emissive layer. The best performed device exhibits a CT of 1773 K, much lower than that of candles (1800–2000 K) or incandescent bulbs (2000–2500 K), 87 CRI, a beyond theoretical limit external quantum efficiency (EQE) 6.4%, and 11.9 lm/W at 100 cd/m². One major reason for having the ultra-low CT and relative high CRI may be attributed to the significantly intensive deep red emission. The comparatively high efficacy and EQE may be attributed to the employment of a smooth stepwise energy-level structure, enabling low injection barriers and balance carrier injection.     

A novel structure of woven continuous-carbon fiber composites with high electromagnetic shielding

A novel structure employing the woven continuous-carbon fiber (CCF) epoxy composite with high electromagnetic (EM) shielding is presented experimentally and theoretically. The influences of weave type, number, and angle of overlapped plates upon the shielding effectiveness (SE) of the woven CCF-epoxy composite are investigated. The minimum SE of the single, double, and triple-plain or balanced-twill woven CCF-composite plates was measured to be as high as 50 dB, 60 dB, and 70 dB, respectively. More than 100 dB in SE was obtained for the triple-overlapped, plain-weave CCF composite at a frequency of 0.9 GHz. The weight percentage of the single CCF-composite plate required for electronic application is 4.8% only, which is less than one quarter of the CF content, and the performance in SE is 10 dB higher in comparison with long, CF-filled, liquid-crystal polymer (LCP) composites. The SE calculated theoretically is consistent with that measured by the experiment.     

Design of low-voltage cmos low-noise amplifier with image-rejection function

A new design is presented that combines a low-noise amplifier (LNA) with an on-chip filter instead of external filter to eliminate image signal based on TSMC 0.18 mum CMOS technology. The fully integrated 5.9 GHz LNA exhibits 15.2 dB gain, 3.2 dB noise figure, better than -15 dB input and output return loss, and -27 dB image rejection. The circuit operates at a supply voltage of 1 V and consumes only 6.1 mW power.     

ALTO: an iterative area/performance tradeoff algorithm forLUT-based FPGA technology mapping

In this paper, we propose an iterative area/performance tradeoff algorithm for look-up table (LUT)-based field programmable gate array (FPGA) technology mapping. First, it finds an area-optimized, performance-considered initial network by a modified area optimization technique. Then, an iterative algorithm consisting of several resynthesizing techniques is applied to trade the area for the performance in the network gracefully. Experimental results show that this approach can efficiently provide a complete set of mapping solutions from the area-optimized one to the performance-optimized one for the given design. Furthermore, these two extreme solutions produced by our algorithm outperform the results provided by most existing algorithms. Therefore, our algorithm is very useful for the timing-driven, LUT-based FPGA synthesis     

Degradation of pentachlorophenol with zero-valence iron coupled with microwave energy

The objective of this research is to study the degradation of pentachlorophenol with zero-valence iron (Fe(0)) coupled with the use of microwave energy. The sample containing 1000 mg/L PCP solution was dosed with 0.5 g Fe(0) and then subject to 700 W microwave energy for 10s; 85% pentachlorophenol was noted to be removed. If the microwave treatment time was increased to 30s, the pentachlorophenol removal efficiency exceeded 99% with end products including H(2)O, CO(2), HCl, etc. Using Fe(0) as a medium, the microwave treatment is made an efficient method for degrading pentachlorophenol. The time needed to achieve a satisfactory treatment is also reduced leading to significant savings of energy consumption to make this method cost-effective. Since this technology applies Fe(0), which is amenable to natural environment, to speed up the decomposition of an industrial solvent, it is not only cost-effective but also environmental friendly for the industry to pursuit sustainable development.     

An automatic controller extractor for HDL descriptions at the RTL

Extracting controlling finite-state machines can significantly reduce state space and thereby speed functional verification. The controller extraction algorithm uses an approach that frees it from restrictions on HDL code writing style     

Transient response of a peak voltage detector for sinusoidalsignals

A fast peak detector for constant frequency sinusoidal signals is proposed. This detector is based on the concept of the orthogonal function set. The theoretical response time of this detector is less than one-fourth of a cycle. When this detector is used, the transient response of the output voltage is different under different inception angles. The mathematical equations to describe transient phenomena are derived and simulated. Because its transient response performance is superior to the conventional sinusoidal amplitude detector used in an analog controller, it can improve the transient response performance of the controller. For practical applications, the effects of harmonics and frequency variation are also discussed, simulated, and tested