Properties Of Slot Research Articles

Multifrequency Seashell Slot Antenna With Cold-Electron Bolometers for Cosmology Space Missions

A novel type of the “seashell” multichroic polarized antenna is proposed for cosmology space missions. The polarized slot antennas are arranged in the compact form of a seashell with individual slots for each frequency and each polarization. Such an arrangement gives a unique opportunity for independent adjusting individual parameters of slots with microstrip lines (MSLs) and bolometers. For each frequency band, the seashell antenna contains two pairs of orthogonal slots for each polarization connected by MSLs with a bolometer in the middle for in-phase operation. To fit slots in the $\lambda/2$ area for the best beam shape, lumped capacitances in the form of the H-slot were introduced. Ellipticity of a beam was improved to the level of better than 1%. The seashell antenna gives a unique opportunity to select the needed bandwidth using two options. The first option is the frequency selection by resonance properties of slots with MSLs and resistive cold-electron bolometer (CEB). The second option is the frequency selection by resonant CEB with an internal nanofilter organized by a kinetic inductance of the NbN superconducting nanostrip and a capacitance of the nanoscale superconductor–insulator–normal tunnel junction.

The retreat from overgeneralization in child language acquisition: word learning, morphology, and verb argument structure.

This review investigates empirical evidence for different theoretical proposals regarding the retreat from overgeneralization errors in three domains: word learning (e.g., *doggie to refer to all animals), morphology [e.g., *spyer, *cooker (one who spies/cooks), *unhate, *unsqueeze, *sitted; *drawed], and verb argument structure [e.g., *Don't giggle me (c.f. Don't make me giggle); *Don't say me that (c.f. Don't say that to me)]. The evidence reviewed provides support for three proposals. First, in support of the pre-emption hypothesis, the acquisition of competing forms that express the desired meaning (e.g., spy for *spyer, sat for *sitted, and Don't make me giggle for *Don't giggle me) appears to block errors. Second, in support of the entrenchment hypothesis, repeated occurrence of particular items in particular constructions (e.g., giggle in the intransitive construction) appears to contribute to an ever strengthening probabilistic inference that non-attested uses (e.g., *Don't giggle me) are ungrammatical for adult speakers. That is, both the rated acceptability and production probability of particular errors decline with increasing frequency of pre-empting and entrenching forms in the input. Third, learners appear to acquire semantic and morphophonological constraints on particular constructions, conceptualized as properties of slots in constructions [e.g., the (VERB) slot in the morphological un-(VERB) construction or the transitive-causative (SUBJECT) (VERB) (OBJECT) argument-structure construction]. Errors occur as children acquire the fine-grained semantic and morphophonological properties of particular items and construction slots, and so become increasingly reluctant to use items in slots with which they are incompatible. Findings also suggest some role for adult feedback and conventionality; the principle that, for many given meanings, there is a conventional form that is used by all members of the speech community. WIREs Cogn Sci 2013, 4:47-62. doi: 10.1002/wcs.1207 For further resources related to this article, please visit the WIREs website. The authors declare no conflict of interest.

Radiation properties of a long slot in the broad wall of a waveguide

The radiation properties of long slots cut into the broad wall of a rectangular metal waveguide are described. It is shown that an approximate method for calculating the impedance properties of the slot yields acceptable values of attenuation and phase for the travelling wave in the waveguide.

Coupling properties of the slot in a waveguide junction

The coupling properties of a transverse slot in the common wall between two butting rectangular waveguides are discussed. By means of Galerkin’s method which takes into account the wall thickness, equivalent magnetic currents on the aperture surface of the slot are obtained, and then the general formulae of scattering fields and of equivalent parameters are derived. The dimensions as well as seats of those two waveguides and the slot, and the thickness of the wall are arbitrary. For example, the transforming coefficients and the VSWRs of numerical calculation and experimental results are given. They are in good agreement.

Radiation properties of slot and dipole elements on layered substrates

This paper presents calculations of the radiation properties of slot and dipole antennas on electrically thick, grounded, dielectric substrates. These structures offer the possibility of simplifying the fabrication of imaging array antenna structures which operate at millimeter wave and far infrared freqeuncies. They also offer the possiblility of good beam patterns which can be tailored to suit a specific need. We present an analysis of practical layered structures which have beam patterns that are suitable for millimeter wave and far-infrared imaging array applications. We discuss considerations of the choice of dielectric layers with regard to beam patterns, surface wave losses, and the type of element used. The effects of dielectric and ground plane losses in high-gain structures are also considered. Efficiencies and beam patterns for three and five layer structures are presented, although the analysis techniques are extendable to an arbitrary number of layers. It is found that in combination with the use of a twin element configuration, both slot and dipole antennas can overcome the problems of losses to surface waves in the substrate. Consequently, they can be made to efficiently radiate to air on these layered dielectric structures.

Slot and microstrip guiding structures using magnetoplasmons for nonreciprocal millimeter-wave propagation

A full-wave spectral-domain approach for general anisotropy is used to determine the nonreciprocal phase and attenuation properties of slot and microstrip line structures. Dominant-mode dispersive behavior is controlled by the semiconductor substrate characteristics, geometric dimensions, and magnetic field bias magnitude and angle in the Voigt configuration. Numerical results to establish the nonreciprocal properties up to 85 GHz are presented. >