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.
The rectangle feeding line of Port 1 and the coupling aperture in the ground plane form an aperture coupled feeding mechanism to excite a directed polarization mode.
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.
It has been shown that the careful choice and modification of coupling apertures
is providing an additional freedom to control asymmetries and the roll-offbut it has not yet been fully evaluated and exploited.
In [7,8], two-layered bandpass filter was designed using open-loop resonators and capacitively loaded square open-loop resonator with different coupling apertures
for electric coupling and magnetic coupling between the resonators to achieve coupling among 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.
This option also is helpful for tuning cavity-resonator filters, making it possible to view the time-domain response, and identify specific resonators and coupling apertures
that need to be tuned.
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