A DSP for DCT-based and wavelet-based video codecs for consumerapplications

We have developed a video digital signal processor (VDSP1) which performs real-time encoding and decoding for discrete cosine transform- (DCT-) based algorithms such as ITU-T H.261, H.263 and wavelet-based subband encoding algorithms. This LSI is suitable for consumer applications, as it was implemented using 0.5 μm CMOS process technology to realize compactness (one million transistors on 65 mm²) and low power (maximum: 560 mW). It features a processing unit which performs wavelet filtering at high speeds, a compact DCT circuit, and a fast, flexible DRAM interface for low-cost systems. At 40 MHz, a single chip is capable of processing quarter common intermediate format (QCIF) (176×144 pixels) size pictures at a rate greater than 15 frames/s     

Multilayer resonators and a bandpass filter fabricated from a novel low-temperature co-fired ceramic

The main objective of this study was to make components from a novel low-loss, low-temperature Co-fired ceramic (LTCC) dielectric, which was also compatible with a high-conductivity silver paste. The multilayer-component fabrication procedure is presented together with a composition for a tape-casting slurry, choice of conductor paste, and LTCC process parameters. A good Q factor, >100 at 2 GHz, using the novel material system has been achieved for λ/2 resonators operating in the frequency range 1.7–3.7 GHz. An excellent frequency response for a 2 GHz bandpass filter has also been achieved; the insertion losses in the passband were less than −2 dB (bandwidth 60 MHz) and the attenuation more than 25 dB in the stopband located 190 MHz higher.     

Contact flexible microstrip applicators (CFMA) in a range from microwaves up to short waves

Contact flexible microstrip applicator (CFMA) is a new light-weight microstrip applicator type for superficial and deep local hyperthermia. Typical specimens are developed for operation at frequencies of 434, 70, 40, and 27 MHz. The main common features of CFMA, namely, their flexibility and light weight, as well as their aperture dimensions slightly depend on the operating frequency. Two antenna types are used in CFMAs: inductive antennas with a radiating plane electrical dipole at microwaves, and coplanar capacitive antennas, providing depression of the normal component of the electrical field in the very high-frequency (VHF) and high-frequency (HF) range. The flexibility of the applicators enables one to conform them with curved surfaces. In a bent state of the applicators there arises a focusing effect of energy deposition in deeper located tissues due to linear polarization of the irradiated electromagnetic (EM) field, inherent in CFMA. All CFMA are integrated with silicon water boluses which serve as a matching element, so as a skin cooling agent. Due to this and to the predominance of the tangential electrical component in the radiated EM field, no fat overheating effects are noticed, as a rule. The aperture of the developed applicators overlap the range 160-630 cm2 providing effective heating field sizes (EFSs) 64-400 cm2, respectively. The most bulky CFMAs with an aperture of (21 x 29) cm2 operating at the frequency of 434 MHz weigh 0.8 kg and 2.5 kg at 27 MHz. Phenomenological analysis of the radiating systems, as well as experimental evaluation of the applicators are presented. CFMAs operating at frequencies of 434 and 40 MHz are used in clinical practice. CFMA at 70 and 27 MHz are subjected to laboratory clinical investigations.     

车载鲨鱼鳍式超宽带多功能天线的研制

设计了一种用于车载应用的新型超宽带鲨鱼鳍天线。该天线工作频域覆盖了应用于车载通信的四个宽频带(824~960 MHz、 1 710~ 2 170 MHz、 2 300~ 2 690 MHz 以及3 300~ 5 000 MHz ),使得该天线系统集卫星导航、移动通信、WiFi、蓝牙、FM收音等多功能性于一体。主集天线尺寸为50 mm ×42 mm ×1.6 mm ,且由1/4椭圆单极子枝节和矩形单极子枝节组成,并将天线垂直放置在鲨鱼鳍式金属板上,从而方便了天线的制作和加工。仿真结果表明,全频段驻波比小于4 dB,全频段天线隔离度小于-15 dB ,且包络相关系数(Envelope Correlation Coefficient,ECC)小于0.1。与最大增益和辐射效率方面的实测值相比,该天线的模拟结果显示出良好的一致性,可广泛应用于车载通信系统中。     

视频DSP中运动估计的快速实现

运动估计是运动补偿技术的核心部分。本文在比较了VDSP中几种运动估计算法（光流分析法、块匹配法和象素递归法）的基础上,详细介绍了硬件复杂度较低、易于实现的块匹配法的典型电路。结合这种设计思路,设计出了具有良好前景的VDSP专用芯片。     

An integrated optic RE spectrum analyzer in a ZnO-GaAs-AlGaAswaveguides

A report is presented on the realization of an integrated optic RF spectrum analyzer (IOSA) that combines a wideband acoustooptic Bragg cell and a pair of waveguide lenses in ZnO/GaAs/Al_0.15Ga_0.85As composite waveguide 7×23 mm² in size. A total of 10 and 40 channels at the center frequencies of 167 MHz and 500 MHz, respectively, and a frequency resolution of 5.5 MHz were realized. The diffraction efficiencies of 11.5%/W and 4.0%/W of RF drive power at the center frequencies of 167 MHz and 500 MHz, respectively, and a dynamic range larger than 16 dB were measured. Further integration of this IOSA (integrated optic spectrum analyzer) with a laser source, a photodetector array, and electronic driving circuits could produce a monolithically integrated optic RF spectrum analyzer     

A spread spectrum clock generator with a wide frequency and attenuation tuning range based on a third-order error-feedback delta-sigma modulator

In this paper, a novel design of spread-spectrum clock generator (SSCG) with a third-order error-feedback delta-sigma modulator is presented. The proposed SSCG with triangular modulation can generate clocks with center spread ratios of 0.25, 1, 1.75, 2.5, 3.5, 5% and down spread ratios of 0.5, 2, 3.5, 5, 7, 10% over a wide frequency range from 20 to 700 MHz. The SSCG is implemented on a chip using SMIC 0.13 um CMOS process. Our tests show that 11.31 dB attenuation of the EMI at 80 MHz with down spread ratio of 10% and 12.98 dB attenuation at 133.3 MHz with center spread ratio of 5% can be achieved which is in agreement with the theoretic calculation.     

Injection seeding for single-mode operation in an optically pumped high-power D2O laser

Spectrally narrow, pulsed outputs consisting of almost a single mode have been obtained from an optically-pumped high-power (200kW) D₂O laser by adopting the injection seeding method, where single-mode radiation (seed pulse) from a low-power, compact D₂O laser has been injected into the main D₂O laser. Spectrally narrow outputs with high power having spectral widths as narrow as 5 MHz have been obtained, when the seed pulses with frequency tuned to one longitudinal mode of the main D₂O laser have been injected at a time sufficiently before the lasing of the main laser took place. The experimental results have been compared with those of numerical simulation modified to include the injection field with varying injection times.     

A supply-noise-insensitive CMOS PLL with a voltage regulator usingDC-DC capacitive converter

A 500-MHz supply-noise-insensitive CMOS phase-locked loop (PLL) with a voltage regulator using a capacitive dc-dc converter (VRCC) achieves a jitter level of 30-ps RMS for quiet supply, and 42-ps RMS for 600-mV supply noise, with a locking range of 110 to 850 MHz. The worst-case power supply noise rejection (PSNR) using the VRCC shows -45 dB in the mid-frequency band. The circuit is fabricated in a 0.35-μm 3.3-V standard digital CMOS process and occupies 2.3 mm². The power consumption at 3.3 V including buffer is 42 mW at 500 MHz     

Correlation functions of complete AltBOC signals with a constant envelope

The structure of the modulating function (MF) of a complete alternative binary offset carrier modulated signal (AltBOC signal) with a constant envelope (eight-component complete AltBOC signal) is considered. Analytical expressions for the correlation functions (CFs) of single elements of the MFs of complete AltBOC signals with a constant envelope are derived at typical values of multiplicity coefficient N _m of meander pulses (N _m = 2 and 3). Plots of the CFs of single elements of the MFs of complete AltBOC signals with a constant envelope are obtained for N _m = 2 and 3. The properties of these CFs are discussed. With the help of the Fourier transform applied to the CFs, the energy spectra (spectral power densities) of single elements of the MFs of complete AltBOC signals with a constant envelope are calculated at N _m = 2 and 3. In illustrating examples, most attention is focused on complete AltBOC signals with a constant envelope at the carrier frequency f _car = 1191.795 MHz for the AltBOC (15, 10) modulation and the repetition rate of the elements of ranging-code pseudorandom sequences f _s = 10f _ref = 10.23 MHz, where the reference (base) frequency is f _ref = 1.023 MHz. These signals are applied in the Galileo European satellite radio navigation system (SRNS) and, as is supposed, in the Chinese BeiDou-2/Compass SRNS.     

Topics in automotive networking - A Measurement Study of Time-Scaled 802.11a Waveforms Over The Mobile-to-Mobile Vehicular Channel at 5.9 GHz

We have studied the effects of the mobile vehicle-to-vehicle (V2V) channel on scaled versions of the current IEEE 802.11 a standard to investigate how readily they can be applied to vehicular networks. In particular, measured parameters for the V2V channel at 5.9 GHz in suburban, highway, and rural environments are studied in the context of critical parameters for OFDM. Actual performance of scaled OFDM waveforms with bandwidths of 20 MHz (bandwidth of IEEE 802.11 a), 10 MHz (bandwidth of the draft IEEE 802.11 p), and 5 MHz (halved bandwidth of IEEE 802.11 p) are described and interpreted in light of the channel parameters. At 20 MHz the guard interval is not long enough, while at 5 MHz errors increase from lack of channel stationarity over the packet duration. For these choices of the scaled 802.11 a OFDM waveform, 10 MHz appears to be the best choice.     

一种新型三频PIFA天线设计

针对天线的多频问题,提出一种新型的三频段平面倒F天线(PIFA天线),该结构采用在辐射贴片上开U形槽和∏形槽来实现。通过HFSS13.0对天线模型进行仿真分析,使得天线最终工作于GSM(890～960 MHz)、DCS(1 710～1 880 MHz)和ISM2 400 MHz(2 400～2 484 MHz)3个频段。仿真结果表明,3个频段的相对带宽分别为10%、6%和11%,能满足通信要求。此外,天线整体辐射性能良好,且结构简单。     

Radiometric observations of the 752.033-GHz rotational absorption line of H2O from a laboratory jet

The intensity and lineshape of the Doppler-broadened 752.033-GHz (2₁₁ ← 2₀₂) rotational transition of H₂O has been studied passively using a high-resolution two-stage heterodyne radiometer with single-sideband system noise temperature of 45,000 K. The purpose of the experiments was to demonstrate the observability at submillimeter wavelengths of a high-altitude rocket plume simulated by a laboratory H₂O jet in a vacuum chamber. First-stage mixing was accomplished by means of a GaAs Schottky diode with first local-oscillator power supplied by a CO₂-laser pumped formic-acid laser (761.61 GHz), generating and X-band IF signal. Second localoscillator power was provided by a tunable C-band source. One-MHz resolution capability was obtained by means of a 3-GHz waveguide cavity filter with only 9-dB insertion loss. In the H₂O jet experiments, the center frequency of the line was determined to within 1 MHz of the previously reported value. A rotational temperature ～ 75 K, a linewidth ～5 MHz, and a Doppler shift ～ 3 MHz (from a 45-degree rotation of the flow direction) were measured with the line-of-sight intersecting the jet axis at a distance downstream of 30 nozzle diameters. These absorption data were ogtained against continuum background radiation sources at temperatures of 1175 and 300 K.     

Continuous-Time 4th Order Butterworth Low-Pass Filter for Video Frequency Applications

In this paper, a continuous-time 4th order Butterworth low-pass filter based on current-mode processing is presented for applications over the video frequency range. A new type of integrator in which both voltage and currents may be integrated is presented and used as the main active block. The filter has been implemented using a very low-cost 2.4 m CMOS process (Mietec). The whole circuit occupies 2.8 mm² and consumes 19 mW from a ±1.5 V supply. Experimental results are given for a 4.5 MHz to 12 MHz tunable low-pass filter with 58 dB of dynamic range at 10 MHz.     

A digitally controlled phase-locked loop with a digitalphase-frequency detector for fast acquisition

A digitally controlled phase-locked loop (DCPLL) that achieves fast acquisition by employing a digital phase-frequency detector (DPFD) and a variable loop gain scheme was developed for an advanced clock synthesizer and was fabricated in a 3.3-V 0.6-μm CMOS process. The DPFD was developed to measure the frequency difference and to generate digital outputs corresponding to the difference. Using these features, the DCPLL achieves ideally one-cycle frequency acquisition when programmed with an appropriate gain. The experimental results show that the fabricated DCPLL exhibits three-cycle and one-cycle frequency acquisitions, when locking to 400 MHz (VCO at 800 MHz) and 200 MHz (VCO at 400 MHz), respectively     

Triple-frequency planar monopole antenna for side-feed communication device on GSM/DCS/PCS operation

A novel side-feed planar monopole antenna capable of triple-frequency operation at about 900, 1800 and 1900 MHz is presented. The planar monopole antenna occupies a small area of 6/spl times/31 mm, and is easily made using thin copper. The planar monopole antenna can be side-fed and mounted perpendicularly to the main circuit board of a communication device so that it offers a novel design with a free degree of feed point so as to save device space, resulting in a low profile to the system ground plane. In addition, the obtained impedance bandwidths of the proposed antenna at about 900, 1800 and 1900 MHz can cover the GSM (890-960 MHz), DCS (1710-1880 MHz) and PCS (1850-1990 MHz) bands.     

Reconfigurable Circularly Polarized Microstrip Antenna on a Slotted Ground

A compact square patch antenna with reconfigurable circular polarization (CP) at 2.4 GHz is proposed. Circular polarization is generated by an arc‐shaped slot on the ground plane. In order to switch the CP orientation, the current flow direction of the patch is reconfigured via the PIN diodes mounted on the slot. As the slot and bias circuit are not placed on the patch side, the proposed antenna radiates a CP wave without alteration in the main beam direction. From the experimental results, the impedance and CP bandwidths of the proposed antenna have been demonstrated for up to 80 MHz and 25 MHz, respectively.     

Design of a 270 MHz/340 mW processing element for high performance motion estimation systems application

Emerging architectures, technologies and strategies applied to the development of systems for video processing will alleviate the restrictions imposed by limited bandwidth in present communication channels. In this article, the use of GaAs technology together with the application of different techniques applied to existing architectures for motion estimation developed in the literature, are presented. Among the several possible searching methods to compute the block-matching algorithm (BMA), the full-search BMA (FBMA) has obtained great interest from the scientific community due to its regularity, optimal solution and low control overhead which simplifies its VLSI realization. On the other hand, its main drawback is the demand of an enormous amount of computation. There are different ways of overcoming this factor, being the use of advanced technologies, such as gallium arsenide (GaAs), the one adopted in this article together with different techniques to reduce area overhead. The implementation of a 270 MHz processing element (PE) for a FBMA scheme is presented in this paper. From the results obtained for this basic module, an implementation for MPEG applications is proposed, leading to an architecture running at 145 MHz with a power dissipation of 3.48 W and an area of 11.5 mm².     

应用于RFID 的小型化双频微带天线的设计与分析

提出了一种适用于射频识别手持读写器的双频单层微带天线新颖设计,适用于超高频频段(920～925MHz)和ISM频段(2.4 ～2.5GHz)的射频识别系统.切四角和中心方形结合缝隙结构,实现了天线的小型化设计,满足了天线设计要求,选用廉价FR4板材尺寸为75mm×75mm×3mm.给出了天线设计思路,并利用电磁仿真软件分析了天线性能,仿真与测试结果吻合良好.天线测试结果表明:在917.1 ～936.5MHz频带范围内回波损耗小于15dB,在2.43～2.47GHz频段内小于-15dB;在UHF频段与ISM频段内,读写器天线的最大增益为0.02dBi和1.66dBi,所以本天线能满足我国射频识别读写器的应用要求,具有良好的应用前景.     

Dual Band Planar Spiral Feed Backed by a Stepped Ground Plane Cavity for Satellite Boresight Reference Antenna Applications

This paper presents development of a new planar spiral feed for a satellite boresight reference antenna, operating at two widely separated frequency bands (2200–2300 MHz and 8000–8400 MHz). A stepped ground plane cavity with different quarter wavelength distances is proposed to provide unidirectional patterns at these frequency bands. A back lobe suppression of around 12 dB in 2 GHz band and better than 15 dB in 8 GHz band with a measured on-axis axial ratio of less than 3 dB is achieved for the dual band planar spiral feed with stepped ground plane cavity configuration. A boresight reflector antenna employing this feed has measured beamwidths of 7 degrees and 1.8 degrees respectively and gain of 26 dBi and 36 dBi at 2250 MHz and 8200 MHz.