摘要:

AbstractA series transformer‐type loaded‐line phase shifter is proposed in which an impedance transformer is connected in series with a main line. The circuit configuration, a design method, and the test results are described. First, the matching condition and the relationship between the circuit parameters and the required phase shift are shown in the case where the switching semiconductor devices have dissipated. In addition, a design method is presented which determines the loss balance between the two‐phase states and the frequency dependence of the phase shift at the center frequency. The semiconductor loss characteristic to this phase shifter is expressed in terms of the figure of merit (switching cutoff frequency) of the semiconductor device for switching. The peak power handling capability of the phase shifter determined by the breakdown voltage is studied.Based on these investigations, a 90‐degree PIN phase shifter was designed by the present method in the L band. The loss balance at the center frequency was 0.22 dB, and the phase‐shift error was less than 4 degrees at the relative bandwidth of 8 percent. These values are close to those in the design. Hence, the effectiveness of the present phase‐shifter format and the design method wa

ISSN:8756-663X    

DOI:10.1002/ecjb.4420780601

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

年代:1995

数据来源: WILEY

摘要:

AbstractA design method and experimental results of a new‐type fin line diode switch using coupled strip conductors as matching elements are described. A diode and the strip conductor electromagnetically coupled with fin line are connected in shunt. By introducing coupled conductors, the forward biased diode impedance can be made low but the reverse biased diode impedance is high; so the broad band characteristic of the fin line switch with only one diode can be realized. In this switch, in order to get the greatest bandwidth, the parameters of the microstrip line switch consist of the strip conductor, the dielectric substrate, and fin conductors are uniquely determined. The validity of the design method is verified by measuring the experimental single and two‐stage SPST switches at W

ISSN:8756-663X    

DOI:10.1002/ecjb.4420780602

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

年代:1995

数据来源: WILEY

摘要:

AbstractUntil now, the rectangular coordinate system has been used mainly for the analysis of optical beam propagation. Hence, when a tilted waveguide is analyzed, the core shape is expressed by a stepped approximation which causes the quantization error so that the error accumulates as the field propagates.In this paper, with a view to overcome this problem, the finite‐difference beam‐propagation method is proposed in which the oblique coordinate system is employed. To confirm the effectiveness of the method, the propagation error of the fundamental mode is evaluated by the model mismatch loss in a tilted step index slab waveguide. It is found that the mode mismatch loss is kept low as the quantization error in the rectangular coordinate system is now eliminated. Further, as an example of application of this method, an optical waveguide bend is analyzed and the effects of coherent coupling are investigated. It is pointed out that the computational region can be made narrower in this method compared with that required in the rectangular coordinate sys

ISSN:8756-663X    

DOI:10.1002/ecjb.4420780603

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

年代:1995

数据来源: WILEY

摘要:

AbstractOne of the characteristics of the finite difference‐time difference (FD‐TD) method, which is a three‐dimensional time domain analysis technique for the electromagnetic field, is its ability to obtain broadband frequency characteristics by one calculation if the pulse response waveform is Fourier transformed. However, in the system where higher‐order modes may be generated, it is not possible to obtain the frequency characteristics with this procedure. A new method to cope with this problem is proposed here. This method consists of the conventional Fourier transform and Prony's method used in signal processing. The proposed method can be applied to a system containing an arbitrary number of modes. In this paper, as an example, the method is applied to a waveguide discontinuity problem so that the validity and effectiveness of the method are co

ISSN:8756-663X    

DOI:10.1002/ecjb.4420780604

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

年代:1995

数据来源: WILEY

摘要:

AbstractAs a method for eliminating the spurious solution in the finite element analysis of three‐dimensional waveguide discontinuity problems, the use of linear edge elements is most effective. However, the shape of the element has been limited to rectangular blocks and tetrahedral bodies.In this paper, a vector finite element method using triangular‐prism elements is proposed and a formulation for three‐dimensional waveguide discontinuity problems is carried out based on this method. The present triangular‐prism elements can be used with a mixture of different edge elements so that the element division can be made highly efficient. The numerical examples demonstrate that the spurious solutions can be eliminated by using the triangular‐prism elements as other edge element methods and also the hybrid use of edge elements provides a substantial reduction in the number of unknowns compared to the conventional analysis of using only one type of edg

ISSN:8756-663X    

DOI:10.1002/ecjb.4420780605

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

年代:1995

数据来源: WILEY

摘要:

AbstractBy inserting a strain into the active layer of quantum‐well lasers, the functionality of the laser can be improved. Regarding the valence band structure of the strained quantum‐well laser with an external electric field applied, a multiband‐effective‐mass theory is developed in which the band‐mixing effect of the valence band including the spin‐split off interaction is taken into account herein. Further, the present method is applied to the gain calculation of the TE and TM modes in a strained quantum well laser. As a result, it is found that the switching operation from the TE mode to the TM mode of the induced emission is possible with an external ele

ISSN:8756-663X    

DOI:10.1002/ecjb.4420780606

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

年代:1995

数据来源: WILEY

摘要:

AbstractFor the two‐dimensional discontinuity problems in an electron waveguide with arbitrary potential distributions and arbitrary effective mass distributions, an analysis method based on the finite‐element method is proposed and formulated. Specifically, the method is applied to a rectangular bend in an electron waveguide so that its validity and effectiveness are presented. Also, a formulation is carried out for a more practical electron wave circuit in which the potential outside the waveguide is finite. The formulation is applied to a rib‐type discontinuity in an electron waveguide and the transmission characteristics are analyzed. The results are compared with those for the case in which the potential outside the waveguide is inf

ISSN:8756-663X    

DOI:10.1002/ecjb.4420780607

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

年代:1995

数据来源: WILEY

摘要:

AbstractA new method has been proposed to evaluate bulk (crystal) and facet degradation in semiconductor lasers separately by cleaving the degraded laser diodes into three regions along a resonator direction. By applying the method to AlGalnP visible light laser diodes, it has been demonstrated that it is possible to evaluate the changes in facet reflectivity and the effects of bulk and facet degradation on performance characteristics of as‐cleaved laser diodes as well as laser diodes with antirefiection and high‐reflection (AR‐HR) facet co

ISSN:8756-663X    

DOI:10.1002/ecjb.4420780608

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

年代:1995

数据来源: WILEY

摘要:

AbstractWith a view to increasing the efficiency of the scalar finite element for nonlinear optical channel waveguides, triangular isoparametric elements are introduced. In addition, the numerical integration formula by Hammer et al. is used for the integration needed for deriving the element matrix. The numerical analysis is carried out for the nonlinear optical fibers. It is confirmed that accurate solutions can be obtained by the present method with a small‐size calculation. Also, the analysis of a nonlinear graded channel optical waveguide is carried out for the first time. The effect of the refractive index profile of the substrate on the optical power dependence of the effective index of the guided mode is investigate

ISSN:8756-663X    

DOI:10.1002/ecjb.4420780609

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

年代:1995

数据来源: WILEY

摘要:

AbstractThe error‐correcting decoder is designed assuming that the input data have a constant data length. In the case of digital video technology recorders (VTR), however, there is a possibility that the length of the playback data sequence changes by desynchronization.This paper proposes an independent reset‐type error‐correcting decoder that can cope with the playback data sequence with varying data length. In the independent reset method, the signal indicating the end of processing in the operational block composing the pipeline is used as the reset signal for the operational block in the next stage. By this mechanism, a sufficient time for the operation is secured for each operational block, even if the data length of the input data varies.By applying the proposed method to the D2 digital VTR system, the miscorrection probability is examined. It is then shown that the miscorrection probability can be decreased compared to the conventional method, both in the normal and the special playback.Using the proposed independent reset method, the error‐correcting LSI decoder based on the Reed‐Solomon code is constructed. LSI is shared by the decoding processes of the inner and the outer codes of D2 system. LSI is designed so that up to 4 Bytes can be corrected for both random error and erasure corrections. The additional circuit complexity due to the independent reset mechanism is several percent of the

ISSN:8756-663X    

DOI:10.1002/ecjb.4420780610

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

年代:1995

数据来源: WILEY