ISSN:
1572-9559
Keywords:
Filters
;
Inductive grids
;
Modal expansion methods
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract We compare rigorous modal expansion methods with transmission-line models for the spectral properties of inductive grids. We compare the predictions of the former with measurements of grid transmittance, reflectance and phase angles as a function of wavelength. We show that the rigorous theory can accurately reproduce measured grid properties, both for normal and oblique incidence, and for both fundamental polarizations of incident radiation. We pay particular attention to the so-called “thickness dip”, an abrupt drop in transmittance which occurs for one polarization at off-normal incidence. We study the variation of $$\lambda _a$$ , the wavelength of the thickness dip, with grid parameters. We also study the variation of $$\lambda _m$$ , the wavelength of maximum transmittance, with grid parameters. We give four design rules which enable the optimization of grid parameters for use in multi-element filter stacks not relying on interference properties. We present a comprehensive set of curves showing the variation of spectral transmittance with grid aperture and thickness, for both fundamental polarizations and for a range of angles of incidence.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01009671
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