CCD摄像头的无线转发器

目前各种监控用微型 CCD 摄像头,价格较低,体积小巧,而且有的产品还内附有小型电容式话筒,直接输出模拟的音、视频信号,只要将其音、视频输出接入录像机或电视机 AV 输入插口,即可对需要监视的目标进行实时监视监听,或用录像机录下有价值的内容。该系列产品无论对工业生产、安全保护、防盗都有极为广泛的用途。即使用于家庭,也会给生活带来方便,如用于来客识别、婴儿睡眠的监视,有价值的即兴集会记录等,虽然其分辨率没有摄像机那么高,但是较低价格却仍有吸引力。使用中唯一感到不便的是其音、视频输出用电缆连接,因为其信号输出较弱,也不允许电缆过长,否则信号衰减过大,清晰度更低,此外电缆连接在使用中也颇感不便。为此可自制一台音、视频调制器,将音、视频信号变为 RF 载波信号,

A Wavelength Tunable DBR Laser Integrated with an Electro-Absorption Modulator by a Combined Method of SAG and QWI

We report a wavelength tunable electro-absorption modulated DBR laser based on a combined method of SAG and QWI. The threshold current is 37mA and the output power at 100mA gain current is 3.5mW. When coupled to a single-mode fiber with a coupling efficiency of 15% ,more than a 20dB extinction ratio is observed over the change of EAM bias from 0 to -2V. The 4.4nm continuous wavelength tuning range covers 6 channels on a 100GHz grid for WDM telecommunications.

A CMOS Power Amplifier with 100% and 18% Modulation Depth for Mobile RFID Readers

Aiming at the specific protocol of RFID technology,a 915MHz CMOS transmitter front-end for OOK modulation is implemented in a 0.18μm CMOS process. The transmitter incorporates a class-E power amplifier （PA）, a modulator, and a control logic unit. The direct-conversion architecture minimizes the required on-and-off-chip components and provides a low-cost and efficient solution. A novel structure is proposed to provide the modulation depth of 100% and 18% ,respectively. The PA presents an output ldB power of 17.6dBm while maintaining a maximum PAE of 35.4%.

Widely Tunable Sampled-Grating DBR Laser

The 3-section SG-DBR tunable laser is fabricate d using an ion implantation quantum-well intermixing process.The over 30nm discontinuous tuning range is achieved with the SMRS greater than 30dB.

Tunable Distributed Bragg Reflector Laser Fabricated by Bundle Integrated Guide

The tunable BIG RW distributed Bragg reflector lasers with two different coupling coefficient gratings are proposed and fabricated.The threshold current of the laser is 38mA and the output power is more than 8mW.The tunable range of the laser is 3 2nm and the side mode suppression ratio is more than 30dB.The variation of the output power within the tunable wavelength range is less than 0 3dB.

An Integratable Distributed Bragg Reflector Laser by Low-Energy Ion Implantation Induced Quantum Well Intermixing

An integratable distributed Bragg reflector laser is fabricated by low energy ion implantation induced quantum well intermixing.A 4 6nm quasi continuous wavelength tuning range is achieved by controlling phase current and grating current simultaneously,and side mode suppression ratio maintains over 30dB throughout the tuning range except a few mode jump points.

Enabling electrically tunable radio frequency components with advanced microfabrication and thin film techniques

Multi-function,multiband,cost-effective,miniaturized reconfigurable radio frequency(RF)components are highly demanded in modern and future wireless communication systems.This paper discusses the needs and implementation of multiband reconfigurable RF components with microfabrication techniques and advanced materials.RF applications of fabrication methods such as surface and bulk micromachining techniques are reviewed,especially on the development of RF microelectromechanical systems(MEMS)and other tunable components.Works on the application of ferroelectric and ferromagnetic materials are investigated,which enables RF components with continuous tunability,reduced size,and enhanced performance.Methods and strategies with nano-patterning to improve high frequency characteristics of ferromagnetic thin film(e.g.,ferromagnetic resonance frequency and losses)and their applications on the development of fully electrically tunable RF components are fully demonstrated.

Performance and Optimization of 10 Gb/s Electroabsorption Modulator in Short Transmission

Transmission performance of electroabsorption modulator in 10 Gb/s transmission systems has been simulated and analyzed under the condition of taking into account the chirp,extinction ratio, transmissivity and rise/fall time.Results show that short transmission distance without EDFA after EAM can be used in future metropolitan area network,but the transmissivity must be carefully considered. The sampling time range and decision level can be optimized to reduce the bit error ratio.

RELAY ASSISTED TRANSMISSSION WITH BIT-INTERLEAVED CODED MODULATION

We investigate an adaptive cooperative protocol in a Two-Hop-Relay (THR) wireless system that combines the following: (1) adaptive relaying based on repetition coding; (2) single or two transmit antennas and one receive antenna configurations for all nodes, each using high order constellation; (3) Bit-Interleaved Coded Modulation (BICM). We focus on a simple decoded relaying (i.e. no error correcting at a relay node) and simple signal quality thresholds for relaying. Then the impact of the two simple thresholds on the system performance is studied. Our results suggest that compared with the traditional scheme for direct transmission, the proposed scheme can increase average throughput in high spectral efficiency region with low implementa-tion-cost at the relay.

Strip Waveguide Directional Coupling Modulator with Equivalent Refractive Index

The equivalent refractive index（ERI） method is employed to analyze the function of the strip waveguide directional coupling modulator（SWM）. Through deducing the diagnostic equation of the Exmn mode of the four-layer media film waveguide equivalent to the SWM,the transmission constant of the symmetrical mode of the positive phase and negative one and the coupling length of powerful transference are obtained. The veracity of ERI is validated with the example of Ex11 basal mode under conditions of comparing the three results of ERI,EIM and Marcatili.

Transition Stage Control of Tail Sitter Aircraft Based on Guardian Maps

To deal with the high nonlinearities and strong couplings in the transition stage of tailsitter aircraft,an adaptive gainscheduling controller is proposed by combining the guardian maps theory and H∞control theory.This method is applied to track the flightpath angle of the transition stage of tailsitter aircraft,and compared with the linear quadratic regulator(LQR)method based on traditional gain scheduling.Simulation results show that the controller based on the guardian maps theory can autonomously schedule the appropriate control parameters and accomplish the stable transition.Besides,the proposed method shows better tracking performance than the LQR method based on traditional gain scheduling.

Novel transmitter of dark RZ signal based on external modulator

A novel transmitter to generate a dark RZ signal with tunable duty cycle and extinction ratio is proposed, by modifying the process of preceding, modulating and coding, A dark RZ signal is generated simply by using one dual-arm Mach-Zehnder LiNbO3 modulator. We demonstrate experimentally that this optical dark RZ signal can be directly measured by a conventional binary intensity modulation direct detection （IM-DD） receiver. When different values of duty cycles at 2.5 Gbit/s are adjusted, the experimental results show different BER curves and eye diagrams of the optical dark RZ signal.

Research on Application of Stereoscopic Warehouse in Logistics Equipment

This paper first introduces the basic concepts of the automated warehouse, on the basis of it, this paper introduces in detail the basic conditions of the studied system, and designs the overall structure of the form of the system for the modem warehousing industry. This paper introduced related technology of a bar code and radio frequency identification （RFID） in the system. Automatic recognition of shape code is one of the most widely used ways in modem warehousing industry, and RFID is development direction of the automatic identification in warehousing industry, that has greatly enhanced the management level applied in the system. System testing show that： this system is reliable, stable, convenient operation, information processing, convenient and quick, has achieved the anticipated target, meet the actual demand of logistics laboratory.

Performance of R141b Ejector with Thermal Storage for Solar Air Conditioning

This paper was designed to determine the performance of the R 141 b ejector includes analysis in economics. The first step is to determine the operating condition and ejector geometry through computer calculation program. That found at the generator temperature 84 ℃ and evaporator temperature 8 ℃, diameter of nozzle throat is 2 mm, diameter of nozzle exit is 8 mm, diameter of mixing chamber inlet is 25 mm, diameter of constant area section is 8 mm. Area of evacuated solar collector is 10 m2, thermal storage tank size is 0.33 m3, cold thermal storage size is 2.3 m3. The entrainment ratio and COP （coefficient of performance） of computer calculation program are 0.295 and 0.235, respectively. The second step ejector is fabricated and equipped to solar ejector refrigeration system, it is found that, average COP is 0.265. The economics analysis of solar ejector cooling system are invested in the investment cost was 158,158 baht. When calculating payback period was 7.73 years, the return value on a NPV （net present value） was 60,872.63 baht of lifetime of the system throughout a period of 15 years, and IRR （internal rate of return） is 13.57%.

Jet Screech Reduction with Perforated Flat Reflector

In the present experimental study, investigations have been carded out to evaluate the performance of the new control technique of jet screech with different perforated flat reflectors. Mainly two types of porous flat reflectors had been used in the experiment. One reflector （reflector-V） designed for placing the reflector surface vertical to the jet axis, when, another type of reflector （reflector-H） designed for placing the reflecting surface horizontal to the jet axis. In both cases the reflectors had been placed at the nozzle （base tube with uniform cross-sectional area） exit. The diameter of the reflector-V was 15D when the diameter of the reflector-H was 10D. The porous area of the reflector-V was 6D and 4.5D for reflector-H where D indicated the diameter of the nozzle exit. The placement of the reflector at the exit of the nozzle reduces the sound pressure at the nozzle exit. Thus the muted sound can not excite the unstable disturbance at the nozzle exit and the loop of the feedback mechanism disappeared, finally, the generation of jet screech be cancelled. The suction space located at the back side of the porous surface of the reflector-V improves the efficiency of the screech control technique. However, in the case of reflector-H, the receptivity process of feedback loop had been controlled by reducing the disturbances at the effective shock fronts as well as at the nozzle exit. The performance of the proposed method was verified with a flat reflector concept and good performance in jet screech suppression has been confirmed in the case of porous reflector.

Dual-band bandpass tunable microwave photonic filter based on stimulated Brillouin scattering

A dual-band bandpass microwave photonic filter(MPF) based on stimulated Brillouin scattering(SBS) is theoretically analyzed and experimentally demonstrated. Two separated tunable laser sources(TLSs) are employed to generate two passbands by implementing phase modulation to amplitude modulation conversion by using SBS induced sideband amplification. The center frequencies of both passbands can be independently tuned ranging from 1 GHz to 19 GHz. High resolution with 3 d B bandwidth less than 30 MHz and large out-of-band rejection about 40 d B under 25 m W optical pump power are achieved.

Blue top-emitting organic light-emitting devices using Alq_3 as phase shift adjustment layer

Blue top-emitting organic light-emitting devices （TEOLEDs） are demonstrated by employing Alq3 as phase shift adjustment layer （PSAL） to increase the phase shift on reflection of the top electrode within a range, which also improves the light out-coupling. By adjusting the thickness of P SAL, the CIEx,y of devices, which utilize 2, 7-Di-pyrenyl-9, 9-spiro-bifluorene （DPSF） as emitting layer, changes from （0.16, 0.50） to （0.18, 0.37）. The maximnum current efficiency of 7.1 cd/A is acquired under 4.5 V with an increasing luminance of 139 cd/m^2. Compared with adjusting the total thickness of organic layer, it is more beneficial for achieving blue TEOLEDs with high efficiency.

A tunable microwave photonic filter with complex coefficient based on slicing spectrum and stimulated Brillouin scattering

In this paper,we propose a method to realize microwave photonic filter(MPF) with complex coefficient,whose central frequency f 0 and 3 dB bandwidth are tunable.The complex coefficient is realized by multi-wavelength optical source and stimulated Brillouin scattering(SBS).The central frequency of the filter is tuned by adjusting the phase shift caused by SBS without changing its frequency response.The frequency selectivity of filter can be improved through increasing the bandwidth of broadband optical source(BOS) or decreasing wavelength separation to increase the taps of MPF.The mainlobeto-sidelobe suppression ratio(MSSR) of the filter is affected by the weight of each tap.When the length of fiber is 0.5544 m in birefringence fiber loop mirror(FLM),the MSSR is improved by 18.55 dB compared with that without the weight controlling.

Transient emission wavelength estimation for DFB laser with temperature tuning

The prediction method of dynamic wavelength is proposed for temperature tuning process. The temperature of the thermistor integrated in laser diode(LD) module is recorded to predict the LD chip temperature. Then according to the injection current and priori tuning characteristics of the LDs, the emission wavelength is estimated in real time. The method is validated by using a 1.58 μm distributed feedback(DFB) LD. The absorption spectra of mixture gas of CO_2 and CO are measured by means of the thermal tuning gas sensing system. The center wavelength of each absorption line is compared with the data in HITRAN2012 database. The results show that the deviations are less than 5 pm. This method fully meets the needs of spectroscopic measurement, and can be applied to spectroscopy, optical communications and other fields.

Reflective terahertz tunable polarization controller

This paper proposes an optical device which can continuously change the polarization state of terahertz （THz） waves. The device consists of metal gate, anU-refleetlon coatings, liquid crystal and mirror. By changing the refractive index of liquid crystal in the interface between the metal gate and the mirror, the phase difference between two beams with orthogonal polarization is varied and a continuous phase sliift is achieved. The phase shift of the device is calculated by using the finite difference time domain （FDTD） method, and the transmittance and reflectance are calculated by using the rigorous coupled wave analysis （RCWA） method. The results reveal that the structure can realize continuously tunable phase shift for THz wave at 1 THz.