摘要:

AbstractPreviously, a model for a microwave oscillator has been proposed which provides the oscillation load characteristics, unilateral injection locking characteristics and mutual locking characteristics that agree better with the experimental results than the van der Pol model often used in analysis.In this paper, the model is simplified and used to study an antiphase coupled system made of two oscillators with identical characteristics coupled by a magic T in terms of its zero input signal characteristics and the response with an external input signal. The results show good agreement with experimental data.It is found that a linear amplification is possible if the frequency of the external signal is equal to the antiphase locking frequency. Moreover, the antiphase locking is shifted to the quasi‐in‐phase or in‐phase locking if the frequency is near the antiphase locking frequency. It is proposed that an application to digitally modulated signal amplification is pos

ISSN:8756-663X    

DOI:10.1002/ecjb.4420731001

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

年代:1990

数据来源: WILEY

摘要:

AbstractUsing monoblock ceramics, we developed a TM110dual mode resonator with a fixed coupling coefficient. In this structure, a wide range of coupling coefficients was obtained, and the unloadedQwas not decreased due to the coupling coefficient. The coupling of the resonator was explained in terms of the principle of even and odd modes and the design procedure was presented. Using this resonator, a 4‐GHz band bandpass filter with a bandwidth of 500 MHz was fabricated. The insertion loss was found to be 0.2 dB and the temperature stability of the frequency was 0.35 MHz. This filter is useful as the input filter for satellite communication relay equipmen

ISSN:8756-663X    

DOI:10.1002/ecjb.4420731002

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

年代:1990

数据来源: WILEY

摘要:

AbstractWe describe the theory and algorithm of the Yasuura methods (a conventional mode‐matching method, the mode‐matching method with a smoothing procedure, the mode‐matching method with a singular‐smoothed procedure) for solving the problems of scattering by perfectly conducting cylindrical obstacles. Both the E‐wave and the H‐wave are considered. Two types of scatterers with either smooth or edged contour are treated. After formulating the problem, we explain the methods of solution with the proof of convergence. All the methods are reduced to a canonical form of the least‐squares problem. Some remarks on actual numerical computations are

ISSN:8756-663X    

DOI:10.1002/ecjb.4420731003

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

年代:1990

数据来源: WILEY

摘要:

AbstractWe describe the discretized forms of the Yasuura methods (the mode‐matching method with a smoothing procedure, the mode‐matching method with a singular‐smoothing procedure) for the numerical solution of scattering by cylindrical obstacles. All the forms are stated in a canonical form of the least‐squares problem in aJ‐dimensional vector space, whereJis the number of sampling points. We show numerically that the choiceJ= 2M, whereMis the number of modal functions, is sufficient and that no rank reductions due to a deficiency of the sampling points occur. A recommended way to solve the discretized problem is to employ the QR decomposition. Some numerical examples are given to show the effectiveness of the Yasuu

ISSN:8756-663X    

DOI:10.1002/ecjb.4420731004

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

年代:1990

数据来源: WILEY

摘要:

AbstractTo analyze optical sources with time‐varying spectra, an optical transient spectrum analyzer (OTSA) with high time resolution is developed. In the spectrum analyzer, the dispersive light is focused on the CCD by a lens and each pixel of the CCD is made to correspond to one spectrum line.It is possible to realize wavelength resolutions between 0.2 and 0.63 nm by changing the optical elements. Variations of extraction pixels of CCD allow time resolutions between 23 μs and 1 ms. Therefore, various applications (such as optical source analyzing systems) are expected.The data from CCD are A‐D transformed and stored in a floppy disk. Therefore, it becomes possible to discuss the characteristics of the optical sources quantitatively. Finally, as an example, the transient mode‐hopping phenomenon of a semiconductor laser is time resolved with high speed and its three‐dimensional (3‐D) observation is

ISSN:8756-663X    

DOI:10.1002/ecjb.4420731005

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

年代:1990

数据来源: WILEY

摘要:

AbstractIn a fundamental investigation of the oxidation of multilayered metal films and accompanying mass transport, Al/Metal/Al model films (in which the metal was Hf, Nb, Mo and Au) were prepared and anodized and were used to investigate oxide growth and mass transport by Auger electron spectros‐copy. Depending on the metal in the middle layer, some specimens exhibited a sequence of oxide layers different from the initial sequence of layers, and in others a layer had been lost by mass transport.Physicochemical properties providing convenient measures of the chemical properties or bonding characteristics of the metals in question were identified and compared. The anodization results and mass‐transport behavior were well explained in terms of these measu

ISSN:8756-663X    

DOI:10.1002/ecjb.4420731006

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

年代:1990

数据来源: WILEY

摘要:

AbstractThis paper presents the peak shift characteristics caused by intersymbol interference and medium defects and their long‐term change and fluctuation in a recording and playback system. Through an analysis of the waveform of the playback differential signal and the effect of the signal amplitude fluctuation on the peak shift under superimposed noise, the intersymbol dependence of the peak shift is obtained.In addition, the signal amplitude fluctuation due to medium defects and the long‐term change of the bit error rate in a high‐temperature and high‐humidity environment are obtained experimentally so that the effect of medium defects and their long‐term change on the peak shift is found. The effect of variations in the external magnetic field and the erasing power on the reduction of the signal‐to‐noise ratio (SNR) is found. Also found is the effect of variation in the recording power on the peak shift shift in RZ and NRZ recording.From this, it is shown that the dependence on the external magnetic field is especially significant in the effect of the variation of the recording and playback system and that the peak shift can be reduced in RZ recording through the use of narrow pulse wi

ISSN:8756-663X    

DOI:10.1002/ecjb.4420731007

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

年代:1990

数据来源: WILEY

摘要:

AbstractTo increase the speed of Hi‐BiCMOS, the process of forming an electrode which simultaneously reduces both parasitic capacitance and parasitic resistance in MOSFET's and bipolar transistors was investigated.Since the etching rate of highly doped polycrystalline silicon is higher than undoped polycrystalline silicon, arsenic‐doped polycrystalline silicon on the gate and emitter electrodes can be etched selectively. Self‐aligned polycrystalline silicon electrode technology (SPEL) using this phenomena was proposed.When the As concentration in polycrystalline Si is higher than 4 × 1020cm−3, the doped polycrystalline Si is etched 10 times faster than undoped polycrystalline Si if plasma etching based on chlorine radicals is carried out.Using this process, the drain capacitance of the MOSFET was reduced one‐half to one‐third that of conventional devices. In bipolar transistors, collector resistance was reduced by a factor of 2 and the external base resistance was reduced by a factor of 3. As a result of simulating the performance of the device formed by the SPEL process, the gate delay time in a dual input NAND BiCMOS was 0.19 ns under no‐load condition while the gate delay time of the conventional device was 0.26 ns; that is, the speed of the SPEL device is 25 percent faster than that of the conve

ISSN:8756-663X    

DOI:10.1002/ecjb.4420731008

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

年代:1990

数据来源: WILEY

摘要:

AbstractAs a pressure sensor to be used at the tip of a catheter, a capacitive relative pressure sensor was fabricated. This paper describes the fabrication process and the characteristics of this pressure sensor.The size of the sensor fabricated is 0.7 × 3.5 × 0.8 mm3and the spacing between the capacitor electrodes is either 1.0 μm or 1.5 μm. The principal features are as follows: (1) In the fabrication of the diaphragm, high‐concentration boron was diffused into an Si wafer. The diaphragm thickness was controlled accurately by etch stop; (2) to reduce the effect of the stray capacitance and to increase the S/N ratio of the sensor, the capacitance detection IC was placed near the diaphragm; (3) since the consumption current flows at the oscillation frequency, it is possible to use two lead wires from the sensor; and (4) this IC has a size of 1.2 × 0.5 mm2and the temperature dependence of the oscillation frequency can be made zero by letting the power supply voltage be 2.24 V. The pressure sensitivity of the obtained sensor is 3.45 × 10−5/mmHg and the temperature coefficient at the zero pressure was 0.17 mmHg/°C. The output of the IC placed by the sensor had a frequency change of about 7 kHz for

ISSN:8756-663X    

DOI:10.1002/ecjb.4420731009

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

年代:1990

数据来源: WILEY

摘要:

AbstractThe space potential for a given boundary condition is obtained, in general, by digital simulation. In the case of an electron‐gun‐type boundary with sharp edges, confirmation of the numerical accuracy is not straightforward as singular electric field points are contained. In this paper, an accurate computation algorithm is proposed for such cases based on the Green's function method.When the computed values were compared with those by the simulation method, it was found that the present method can arrive at a high‐precision solution in a shorter period of time. In general, the analytical solution of a three‐dimensional boundary value problem containing sharp edges contain function series terms with poor convergence. Hence, the conventional acceleration method is not very effective.This paper obtains a convergence criterion suitable for the nature of the analytical solution and a significant reduction in computational time. From the nature of the basic computation equation, accuracy can be improved easily by an appropriate discretization of the numerical integral. The present method is effective for high‐precision computation of the weak electric field near the cathode. In the aberration analysis of a cathode lens, this method can be used as an effective comparison when the accuracy of the solution by the simulation is

ISSN:8756-663X    

DOI:10.1002/ecjb.4420731010

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

年代:1990

数据来源: WILEY