Experimental evidence that microstrip patches and flat dipoles on grounded substrates are the same type of element

摘要

Microstrip patches and flat dipoles on grounded substrates are shown to be special cases of a more general type of radiating element whose design may be modeled by a suitable combination of electric and magnetic current sources that themselves are a function of geometrical dimensions, especially the substrate thickness. Extension of the inner conductor of a coaxial line can be used to feed resonant half-wave dipoles one-quarter wavelength in front of a ground plane without the structure becoming effectively a top-loaded monopole. Though novel and unconventional, the feed has mechanical simplicity and warrants more detailed study. No reactive network is needed for wideband impedance matching of elements irrespective of substrate thickness provided the geometry of the patch and the feed point connection are chosen properly.