摘要:

AbstractA phase‐locked loop is combined with a highly selective bandpass filter in such a way that a steady‐state single‐frequency signal is extracted from a spectrum. The system goal is to maintain the phase of the wave irrespective of the actual signal frequency. © 1995 John Wiley&Son

ISSN:0895-2477    

DOI:10.1002/mop.4650080602

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

年代:1995

数据来源: WILEY

摘要:

AbstractA quasioptical resonator for the frequency range between 170 and 260 GHz and a Q factor of more than 50,000 has been built. We use a semiconfocal resonator that is tunable in resonance and has a passive temperature stabilization. The coupling in of electromagnetic energy is realized using metallic meshes with quadratic apertures and polarizing wire grids as well. The resonator is tuned by moving the spherical mirror with a piezo driver. © 1995 John Wiley&Sons. Inc

ISSN:0895-2477    

DOI:10.1002/mop.4650080603

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

年代:1995

数据来源: WILEY

摘要:

AbstractUsing the weak guidance approximation and Goell's point‐matching method, a numerical analysis has been made of a guide with a pentagonal cross section, which may find wide applications in integrated optic technology. Two cases have been dealt with, namely, (i) a pentagonal guide cladded with a conducting substance, and (ii) a pentagonal guide loaded with conducting substance on alternate surfaces, the remaining surfaces being made of a dielectric substance. © 1995 John Wiley&Sons. I

ISSN:0895-2477    

DOI:10.1002/mop.4650080604

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

年代:1995

数据来源: WILEY

摘要:

AbstractThe finite‐element or finite‐difference techniques are well known for the solution of Maxwell's equation in differential form. But terminating the mesh accurately at a finite distance from the body in the case of an open problem is a major challenge. Though there have been several techniques presented [1, 2], this new approach allows for the terminating surface to encapsulate the body very tightly. In this proposed method, the finite‐element technique is used for open‐region problems, whereas an integral equation solution approach using the Green's function is applied to enforce the radiation condition. At each iteration cycle, field sources within the domain are evaluated and their potential at the terminating surface is calculated. The proposed method leads to increased computational efficiency of the finite‐element method. It can be generalized for the case of inhomogeneous and nonlinear media, for static and dynamic fields. Typical numerical results are presented for the solution of the Laplace equation to illustrate the accuracy of the technique. © 1995 John Wiley

ISSN:0895-2477    

DOI:10.1002/mop.4650080605

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

年代:1995

数据来源: WILEY

摘要:

AbstractThis article presents a rigorous analysis of microstrip Yagi array antennas using a full‐wave method and a moment‐method calculation. The input impedance of a microstrip Yagi array antenna is formulated and calculated. The obtained input impedance is found to be significantly altered as compared to that of a single driven microstrip patch, due to strong coupling between the driven and parasitic patches. Radiation patterns of the microstrip Yagi array antenna are also calculated and discussed. Both the E‐ and H‐plane coupling cases are considered. © 1995 John Wiley&S

ISSN:0895-2477    

DOI:10.1002/mop.4650080606

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

年代:1995

数据来源: WILEY

摘要:

AbstractA wave‐front splitting interferometer has been constructed and analyzed for measuring the phase modulating properties of popular spatial light modulators (SLM). A modified liquid crystal television (LCTV) was then used in the experiment to verify the technique. It was determined that for this interferometric architecture, one full fringe shift corresponds to a 2π phase modulation. © 1995 John Wiley&Sons.

ISSN:0895-2477    

DOI:10.1002/mop.4650080607

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

年代:1995

数据来源: WILEY

摘要:

AbstractA frequency‐selective surface consisting of three arrays of ring elements is analyzed. It is shown that broad transmission and reflection bands can be generated with separation ratios of less than 1.03:1. Measurements confirm that the diplexer performance is relatively insensitive to the angle and plane of incidence. © 1995 John Wiley&Sons. I

ISSN:0895-2477    

DOI:10.1002/mop.4650080608

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

年代:1995

数据来源: WILEY

摘要:

AbstractThe effects of optical illumination on the microwave characteristics of a conventional MESFET have been studied theoretically. The effect of the changes in the intrinsic parameters of the device under illumination has been utilized to calculate the Y parameters of the device at microwave frequencies. The small‐signal equivalent circuit of the device in the illuminated condition has been obtained with the various components determined from the Y parameters. The attractive feature of the present model is that it is fully compatible with commonly used circuit simulation packages like SPICE. © 1995 John Wiley&Sons. I

ISSN:0895-2477    

DOI:10.1002/mop.4650080609

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

年代:1995

数据来源: WILEY

摘要:

AbstractThe resonant frequencies of the modes in a cabineted microwave package are investigated by the mode‐matching method. The upper region of the package is partitioned into several cabinets using vertical diaphragms of a same depth and of negligible thickness. Numerical results are shown to agree with those of the measurement. The change of the resonant frequencies with the diaphragm depth is presented and explained. It is found that the resonance‐free frequency bands can be broadened by suitably designing the positions and the depth of the diaphragms. © 1995 John Wiley&Sons.

ISSN:0895-2477    

DOI:10.1002/mop.4650080610

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

年代:1995

数据来源: WILEY

摘要:

AbstractA new integral‐equation‐based numerical approach to microwave imaging is presented. It can be applied to focused imaging in the sense that only one part of an inhomogeneous body is viewed as an unknown scatterer to be reconstructed. This approach is of great usefulness in many applications, as it results in a notable computational saving and in high flexibility. Moreover, it allows the range of applicability of the Born approximation to be considerably expanded. © 1995 John Wiley&Sons.

ISSN:0895-2477    

DOI:10.1002/mop.4650080611

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

年代:1995

数据来源: WILEY