摘要:

AbstractA 12‐GHz band, two‐stage monolithic HEMT (high‐electron mobility transistor) low‐noise amplifier and a broadband monolithic HEMT distributed amplifier have been developed. The HEMTs used in the amplifiers have a gate length of 0.5 μm and show a typical noise figure of 1.0 dB at 12 GHz. A noise figure of the two‐stage amplifier is less than 1.7 dB with a gain over 15.0 dB in the frequency range from 11.7 to 12.7 GHz. A noise figure of the distributed amplifier is less than 6.2 dB and gain of 7 ± 0.9 dB in the frequency range from

ISSN:8756-663X    

DOI:10.1002/ecjb.4420740501

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractThis paper assumes a simple model for the DRAW (direct‐read/after‐write) optical disk using a Te‐alloy recording medium. The scattering of the light‐beam by the pit or boss of arbitrary shape on the boundary of three‐layered dielectrics is analyzed by the boundary‐element method. The sum and the differential signal output characteristics of the two‐split‐type optical detector also is discussed. The results of simulation are shown for the effect of the adjacent pit in the square and V‐shaped pregrooved models, the dependencies of the sum and the differential signals on the tracking error, and the dependencies of the sum and the differential signals on the pit depth, when the signal recording pit is provided in the two types of

ISSN:8756-663X    

DOI:10.1002/ecjb.4420740502

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractThis paper considers the measurement of the residual birefringence distribution in a glass laser disk by means of birefringent measurement equipment with a frequency‐stabilized transverse Zeeman laser as a light source.The birefringence by the residual distortion of a glass laser amplifying medium is an important factor in determining its optical performance. A method of accurate measurement of the birefringence phase difference and the principal axis direction has been conceived based on an optical heterodyne method using a frequency‐stabilized transverse Zeeman laser which is a two‐frequency orthogonally polarized light source. This measurement system consists of a rotating half‐wave plate, a rotating linear polarizer, a detector and electric phase meter and a personal computer.In this paper, the measurement principle and the error analysis are clarified with the use of Stokes parameters. The data processing method for the measured results and the experimentally observed minimum detection limit are described. With the present measurement system, birefringent measurement of an elliptic glass laser disk is carried out and its residual birefringence distribution is cl

ISSN:8756-663X    

DOI:10.1002/ecjb.4420740503

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractThe results of the authors' previous experiment on multiembossed holograms using a stamper whose master model is an echelette grating revealed a requirement for signals (molded grating grooves with different orientation angles and constant spatial frequency) with relatively uniform diffraction efficiency and weakened unwanted diffraction. The requirement can be written asd'/d>>1 whered' is the groove width anddis the grating constant [1].In this paper, the molding of grating grooves using stampers (d'/d= 0.12) of square cross section which satisfy the condition and the recording of the multi‐embocsed hologram have been tested.The uniformity of diffraction efficiency within one decade and the noise ratio (the ratio of the first‐order diffraction efficiencies of the unwanted diffraction and the signal) below 0.6 have been obtained with a multi‐embossed hologram (eight times). These characteristics are obtained by varying the value of the pressure when the temperature of the stamper is constant and are suited to the typewriter input type of recording. In addition, a suggestion for a stamper which is applicable to holographic memory for information retrieval is given (d'/dless than about

ISSN:8756-663X    

DOI:10.1002/ecjb.4420740504

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractThis paper describes the theoretical and experimental characteristics of the band reject filter made of a waveguide loaded with yttrium‐iron‐garnet (YIG) films. First, the problem of reflection and transmission of the plane electromagnetic wave from a semiinfinite YIG film is described. Next, it is noted that the electromagnetic wave of the TE10mode in a waveguide loaded with an isotropic medium can be expressed as a superposition of these plane waves. Their treatment is applied in an approximate approach to the waveguide loaded with a YIG film. The band rejection characteristics are investigated in which the center frequency varies depending on the dc magnetic field applied. Further, it is shown that a good characteristic is obtained as a band reject filter if YIG films are stacked as a multilayer.Finally, an experiment is carried out at the × band so that the forementioned characteristics are confirmed experimentally. When a dc magnetic field of 2.818 kOe is applied, the observed filter characteristics are such that the center frequency is 10.0 GHz, the insertion loss is 1.0 dB, the bandwidth is 144.7 MHz and the maximum attenuation within the stopband exceeds 6

ISSN:8756-663X    

DOI:10.1002/ecjb.4420740505

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractAnodization of single‐crystalline silicon was carried out under microwave plasma created by electron cyclotron resonance (ECR), and the anodization characteristic and oxide film property were evaluated. The growth rate of the oxide film depended strongly on the oxygen pressure and the growth rate reached the maximum under relatively high oxygen pressure.Since the plasma parameters and substrate temperature were dependent on the oxygen pressure, the oxidation was thought to be dependent on the supply of oxygen atoms from plasma and the generation of silicon atoms and dangling bonds at the Si‐oxide interface.The X‐ray photoelectron spectra revealed the formation of stoichiometric SiO2. This result provided insight into the oxide growth process. In addition, the electric conduction in an MOS device formed using this oxide was investigated. As a result, it was found that the dc high field conduction prior to the self‐healing breakdown was based on the tunneling of electrons injected by Schottky emission through the oxide. Also, the negative resistance observed after the self‐healing breakdown was caused by the formation of space charges caused by the impu

ISSN:8756-663X    

DOI:10.1002/ecjb.4420740506

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractLow‐temperature microwave plasma CVD deposition of an SiN film on a polycarbonate substrate for a photomagnetic disc was attempted. To enhance the adhesion between the SiN film and polycarbonate substrate, an Si intermediate film was deposited by plasma CVD.As a result, it was found that a peel‐free and crack‐free substrate could be fabricated by depositing an Si intermediate layer by (microwave + RF) superimposed CVD.To investigate the high adhesion of the Si film to the substrate, the concentration of elements at the interface was analyzed by RBS (Rutherford backscaering spectrometry). As a result, it was confirmed that not only an Si intermediate layer but also a complex film consisting of polycarbonate and Si is present near the surface of the polycarbonate substrate. It was concluded that the improvement of the film adhesion was due to the chemical bond between polycarbonate a

ISSN:8756-663X    

DOI:10.1002/ecjb.4420740507

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractNbN nanobridge dc SQUIDs were fabricated by the field evaporation method and their noise characteristics were evaluated. The fabricated device has a magnetic flux‐voltage conversion efficiency Φ of about 2.5 mV/Φ0and hence the device has a higher gain than that of the tunneling‐type device with a resistive shunt. The energy resolution is as small as 40 h. When the fabricated SQUID was installed in an FLL circuit and the dynamic range was measured, it is found that an output is proportional to the input for the input magnetic flux of ±32Φ0without removing the lock. The magnetic flux resolution of the FLL circuit used is 9 × 10−10Φ02/Hz in the white noise region (at 3 kHz). In the low‐frequency region less than 100 Hz, the 1/fnoise described by 5.8 × 10−8(1/f)Φ02/Hz was observed. This value of the magnetic flux resolution is large by one order of magnitude than that inherent to the device and the noise of the electroni

ISSN:8756-663X    

DOI:10.1002/ecjb.4420740508

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractThe following results have been obtained by evaluating the circuit delay times of submicron BiCMOS, CMOS, and ECL gates by the same criterion: (1) analytical relationships to represent the delay time of each circuit by device parameters have been developed; (2) these relationships have been verified by the circuit simulator using BiCMOS device parameters with minimum dimension of 0.5 μm; (3) using submicron devices for each circuit, the delay time ratio of CMOS, BiCMOS and ECL is 4:2:1; (4) reduction of the device parasitic capacitance is more effective in improving BiCMOS gate delay than that of CMOS gate; and (5) reduction of the parasitic capacitance can make the BiCMOS gate operate as fast as the ECL gate

ISSN:8756-663X    

DOI:10.1002/ecjb.4420740509

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY

摘要:

AbstractA simulator has been developed which can calculate optical characteristics of TFT addressed liquid crystal displays (LCDs) such as optical threshold voltage and contrast ratio. Then the performance of LCDs addressed by amorphous silicon TFTs are analyzed. This simulator has advantages of obtaining accurate solution of optical characteristics, which previously had been obtained only by measurements, by giving TFTs dimensions and their characteristics, and LCD's driving conditions as the input data.Furthermore, the simulator has also taken into consideration the effects of voltage distortion due to line resistance and capacitance, and voltage dependence of gate source parasitic capacitance in addition to temperature dependencies of threshold voltage and mobility of TFTs, and liquid crystal characteristics on LCD performance to obtain more accurate solution. It was found that calculated characteristics agreed well under a practical temperature range from 0 to 60°C with the measurements obtained for large‐area 10‐inch diagonal TFT‐LCDs. This agreement verified the simulation va

ISSN:8756-663X    

DOI:10.1002/ecjb.4420740510

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1991

数据来源: WILEY