No abstract

The design and measured results of a single-substrate transceiver module suitable for 76-77-GHz pulsed-Doppler radar applications are presented. Emphasis on ease of manufacture and cost reduction of commercial millimeter-wave systems is employed throughout as a design parameter. The importance of using predictive modeling techniques in understanding the robustness of the circuit design is stressed. Manufacturing techniques that conform to standard high-volume assembly constraints have been used. The packaged transceiver module, including three waveguide ports and intermediate-frequency output, measures 20 mm 22 mm 8 mm. The circuit is implemented using discrete GaAs/AlGaAs pseudomorphic high electron mobility transistors (pHEMTs), GaAs Schottky diodes, and varactor diodes, as well as GaAs p-i-n and pHEMT monolithic microwave integrated circuits mounted on a low-cost 127-m-thick glass substrate. A novel microstrip-to-waveguide transition is described to transform the planar microstrip signal into the waveguide launch. The module is integrated with a quasi-optical antenna. The measured performance of both the component parts and the complete radar transceiver module is described.

An efficient and rigorous method for the analysis of planarly layered geometries with vertical metallizations is presented. The method is based on the use of the closed-form spatial-domain Green's functions in conjunction with the method of moments (MoM). It has already been demonstrated that the introduction of the closed-form Green's functions into the MoM formulation results in significant computational improvement for the analysis of planar geometries. However, in cases of vertical metallizations, such as shorting pin's, via holes, etc., there are some difficulties in incorporating the closed-form Green's functions into the MoM formulation. In this paper, these difficulties are discussed and their remedies are proposed. The proposed approach is compared to traditional approaches from a theoretical point of view, and the numerical implementation is demonstrated through some examples. The results are also compared to those obtained from the commercial software em by SONNET. Index Terms-Closed-form Green's functions, generalized pencil of function method, method of moments, planarly layered media.

Most electromagnetic problems can be reduced to either integrating oscillatory integrals or summing up complex series. However, limits of the integrals and the series usually extend to infinity, and, in addition, they may be slowly convergent. Therefore numerically efficient techniques for evaluating the integrals or for calculating the sum of an infinite series have to be used to make the numerical solution feasible and attractive. In the literature there are a wide range of applications of such methods to various EM problems. In this paper our main aim is to critically examine the popular series transformation (acceleration) methods which are used in electromagnetic problems and to introduce a new acceleration technique for integrals involving Bessel functions and sinusoidal functions. IntroductionNumerical techniques used in the solution of electromagnetic problems require, in general, either evaluating oscillatory integrals over infinite domain or calculating the sums of infinite complex series. For example, the method of moments (MoM) in the spectral domain for two-dimensional geometry requires double-infinite integration of complex highly oscillatory functions; the MoM in the spatial domain employs the spatial domain Green's functions, which are defined as the Hankel transform of the spectral domain Green's function; in the analysis of a periodic structure one needs to employ a periodic Green's function which has double infinite summations; or, in the analysis of a microstrip patch antenna via cavity model, the input impedance or field distribution are written in terms of an infinite sum of modes in the cavity.If the summations and integrals given in the examples above are evaluated by "brute force" as they appear in the problems, the corresponding methods could be computationally very inefficient, rendering these problems impractical. To overcome this computational burden, special acceleration techniques, also called transformation techniques, for both integrals and summations have been proposed and successfully employed. Since these techniques have been studied for specific problems and compared to only a few other techniques, the potentials of these Copyright 1995 by the American Geophysical Union. Paper number 95RS02060. 0048-6604/95/95RS-02060508.00 techniques with their advantages and disadvantages have not been examined entirely for electromagnetic problems. Hence the contributions of this paper are in (1) providing the complete set of acceleration techniques used in the electromagnetic problems, (2) comparatively studying the acceleration techniques for integrals and series, and (3) introducing a new acceleration technique for integrals involving Bessel functions and sinusoidal functions. The transformations given and compared in this paper are the Euler transformation [Hildebrand, 1974], Shanks' Transformation [Shanks, 1955; Singh and Singh, 1991a], Wynn's • algorithm, the method of averages [Mosig and Gardiol, 1979], the Chebyshev-Toeplitz algorithm [Wimp, 1974; Singh and Singh, 1992b], the O algo...

Most electromagnetic problems can be reduced to either integrating oscillatory integrals or summing up complex series. However, limits of the integrals and the series usually extend to infinity, and, in addition, they may be slowly convergent. Therefore numerically efficient techniques for evaluating the integrals or for calculating the sum of an infinite series have to be used to make the numerical solution feasible and attractive. In the literature there are a wide range of applications of such methods to various EM problems. In this paper our main aim is to critically examine the popular series transformation (acceleration) methods which are used in electromagnetic problems and to introduce a new acceleration technique for integrals involving Bessel functions and sinusoidal functions