The coupling aperture
could be small, known as a nonresonant aperture or comparable to a half wavelength, known as a resonant aperture.
It is shown that the coupling coefficient is determined by the width of the coupling aperture with the given height.
Input and output transmission lines for external coupling are shorted above the coupling apertures for the maximum magnetic coupling.
The dual-orthogonal linear polarizations are generated by an L-shaped coupling probe and an H-shaped coupling aperture
. As the L-shaped coupling probe provides additional capacitance between the probe and circular patch to compensate the large inductance associated with the probe feed .
The positions of coupling aperture
and slot relative to the major axis of the SIEC can be adjusted to generate two modes.
In this paper, a multilayer filter with dual mode characteristic has been realized by the coupling aperture
located in input/output port and the arc-shaped coupling slot etched between layers.
In [5-9], using the ground-plane aperture technique conventional coupled resonators are used to realize different filter configurations based on the position of the coupling apertures
. The apertures in the ground plane are used to achieve coupling between the resonators.
In the realization stage of a narrow bandpass filter design, a given set of coupling values (coupling matrix) must be translated into the physical domain in the form of coupling apertures
, loop- or probe-coupling dimensions.
For these oversized H-plane cavities we need to look into the phase relation of the magnetic field at the input and output coupling apertures
of the cavity to determine the sign of the coupling coefficient [13,14].
Transfering power between two adjacent layers in a multilayer structure can be done using either a pin, which makes an electrical contact, or via coupling apertures
in the ground plane separating the layers.
Similar results have been found for other coupling apertures
. The narrow bandwidth is due to the high-Q factor of the cavity.