Rectangular Cut Research Articles

Dual-frequency microstrip antenna with embedded reactive loading

Novel dual-frequency operation of a single-feed rectangular microstrip antenna with an embedded reactive loading is presented. The reactive loading is provided by a structure of two cascaded microstrip-line sections embedded within a rectangular slot cut in the patch. By selecting suitable dimensions of the microstrip-line sections and the rectangular slot, the proposed antenna can perform dual-frequency operation, with a low frequency ratio of about 1.04–1.15 between the two operating frequencies. ©1999 John Wiley & Sons, Inc. Microwave Opt Technol Lett 23: 186–188, 1999.

Dual‐frequency microstrip antenna with embedded reactive loading

Novel dual-frequency operation of a single-feed rectangular microstrip antenna with an embedded reactive loading is presented. The reactive loading is provided by a structure of two cascaded microstrip-line sections embedded within a rectangular slot cut in the patch. By selecting suitable dimensions of the microstrip-line sections and the rectangular slot, the proposed antenna can perform dual-frequency operation, with a low frequency ratio of about 1.04–1.15 between the two operating frequencies. ©1999 John Wiley & Sons, Inc. Microwave Opt Technol Lett 23: 186–188, 1999.

FDTD Analysis of a Sized-Reduced, Dual-Frequency Patch Antenna - Abstract

A new single probe-fed, compact, dual-frequency antenna is studied, which is a rectangular microstrip patch with a rectangular slot cut in the center. The FDTD method is developed for full-wave analysis of its characteristics. A simple and accurate probe feed model is proposed, together with a simple method of calculating the radiation patterns. It is shown that through loading of the rectangular slot and proper location of the feed point, dual-frequency operations can be realized with an antenna-size reduction of ∼33% and further reductions are also possible by tuning the length and width of the slot and the patch. Electric current distributions on the rectangular patch for both the slot loaded case and the case without slot are given, together with the radiation patterns. Theoretical analysis is verified by experimental results.

Multifrequency operation of microstrip antennas using aperture-coupled parallel resonators

A microstrip antenna composed of parallel dipole resonators of different lengths fed by a rectangular slot cut in the ground plane of a microstrip line is analyzed using an integral equation technique solved in the spectral domain using the Galerkin method of moments. Multifrequency operation of this antenna is demonstrated using two different configurations. Experimental data are shown to be in good agreement with predicted results. The fundamental parameters influencing the realization of multifrequency operation, as well as impedance matching of the different resonances, are studied. Lastly, the radiation patterns of the antenna at different frequencies and the relative contribution of the dipoles to the radiation are investigated.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

The WSU-Apontes

the Plaza Mayor of Madrid, directed by Eugenio García Toledano [Primer acto, no. 35]. El villano en su rincón — by the Teatro Escolar of the Padre Suárez Institute of Granada, directed by Prof. Martín Recuerda [Primer acto, no. 32]; by the Teatro de la Tertulia company in the Teatro Principal of Zaragoza, in Jan., 1962 [Primer acto, no. 32]. La viuda valenciana—by the Teatro de Cámara of the Centro Escolar y Mercantil, of Valencia, in the claustro of the Universidad de Valencia, July 19-22. The WSU-Apontes by B. B. Ashcom Wayne State University In the Wayne State University Library comedia collection is, if not the "Sette of Odd Volumes" beloved of bibliographers, at least an odd set of volumes, six in number, uniformly bound in full Spanish pasta, the labels on the spines reading "Calderón de la Barca. Comedias." An examination shows that the set represents some collector's attempt (or what is left of some collector's attempt) to assemble the edition of Calderón published by Juan Fernández de Apontes (11 vols, in 10, Madrid, Viuda de Manuel Fernández, 1760-1763) , or its equivalent. As is well known, Apontes published the plays of the Vera Tassis edition, paying no attention to Vera Tassis' order, and putting vols. X and XI in one binding, with separate pagination, but only one title page. Barrera (53b) is wrong in implying that only the last volume is of 1763. Vol. IX is also of that year. See also Salva, I pp. 373-374. The contents of the WSUL volumes may be of interest to the Comediantes. The WSUL volume 1 consists entirely of sueltas, but it offers the same plays, and in the same order, as does the Primera Parte of Apontes. The sueltas are as follows: (1) Num. 293. /C. F, / CADA VNO PARA SI. / DE DON PEDRO CALDERÓN. 40 unnumbered pp., sigs A-E[4]. The printer has used three type sizes. The second act is headed JORNADA PRIMERA. Colophon: (·.·) FIN (·.·) (2) Num. 38./C F., /LAS ARMAS / DE LA HERMOSURA, / DE DON PEDRO CALDERÓN DE LA BARCA. 44 numbered pp. [Two type sizes, pp. 1-32 and pp. 33-44]. Salamanca , Imprenta de la Santa Cruz, n.d. (3) Num. 314. /CF./ AMADO, Y ABORRECIDO, / DE DON PEDRO CALDERÓN DE LA BARCA. 40 pp., foliated, sigs. A-E[4] [f. 7 misprinted "3"]. N.p., n.d. (4) Num. 58 /C F. /LA SEÑORA, /Y LA CRIADA. /DE DON PEDRO CALDERÓN DE LA BARCA. 32 numbered pp. Salamanca, Imprenta de la Santa Cruz, n.d. (5) Num. 21. /NADIE FIE /SV SECRETO. /DE DON PEDRO CALDERÓN DE LA BARCA. 28 numbered pp. [p. 28 of 3 cols.] Sevilla, Joseph Padrino, n.d. (6) N. 258. Pag. 1/ C F./ LAS TRES JUSTICIAS EN UNA./ DE D. PEDRO CALDERÓN DE LA BARCA. 32 numbered pp. Valencia, Joseph y Thomas de Orga, 1782. (7) Num. 109./ AMAR DESPVES DE LA MVERTE./ C/ F,/ DE DON PEDRO CALDERÓN DE LA BARCA. 32 numbered pp. Sevilla, Viuda de Francisco de Leefdael, n.d. (8) Num. 112./ VN CASTIGO EN TRES/ VENGANZAS./ C/ F,/ DE D. PEDRO CALDERÓN DE LA BARCA. 32 numbered pp. Sevilla, Francisco de Leefdael, n.d. (9) C F. / DVELOS/ DE AMOR,/ Y LEALTAD./ DE DON PEDRO CALDERÓN/ de la Barca. 56 unnumbered pp., sigs. A-G[4] N.p., n.d. Colophon: FIN between two lines of printer's devices and flanked by two other individual devices. Below, a 19 large rectangular cut resembling an ornately decorated initial B, sideways , in frame. Volume 2 reflects what was probably a feeling of frustration on the part of the collector. It starts off confidently enough, with sueltas of the first three plays of Apontes, II. The fourth play is an arrachement from Apontes, II, but the last play, Fineza contra fineza, not the fourth (which was La vida es sueño) . The rest of the volume consists of sueltas of plays the titles of which were apparently selected at random from Apontes IV, VI, VII, and VIII. The sueltas are...

Analysis of a terminated-waveguide slot antenna by an equivalent circuit method

The pattern in a half-space of a slot in the wall of a waveguide is a function of the terminating impedance. The description of the far fields in such a configuration is simplified considerably by the adoption of a network viewpoint, whereby the half-space is represented approximately by two (or more) spherical transmission lines, the feeding waveguide by a single uniform transmission line, and the slot by a coupling network which is directly analogous to that for a hybrid junction. For a given waveguide termination, the spherical mode voltages are computed by a simple network calculation, and the gain pattern is obtained by modal synthesis. The slot equivalent circuit parameters are obtained readily by simple measurements or from available theoretical formulas. Described in detail both theoretically and experimentally is a symmetric rectangular slot cut in either the broad or narrow face of a rectangular waveguide.

Photochemistry of Vitamins A, B, C, D

THE photochemistry of the vitamins has been studied with the help of a large quartz mono-chromator. The solutions to be irradiated were enclosed between quartz windows in a rectangular slot cut in a small brass block. The section of the cell corresponded with the dimensions of the rectangular image formed by the curved slit of the monochromator, so that the whole of the solution was irradiated. The cell was filled and emptied with a hypodermic syringe, and was arranged so that the solutions could be handled in the absence of oxygen. Stirring was effected by two steel shot operated by a magnet.