Independent Control over Resonating Modes of Mushroom Resonator loaded Substrate Integrated Waveguide using perturbation slots

This paper presents a method of independent control over the excited modes of a single mushroom resonator loaded SIW cavity. Circular and linear slots are introduced into the mushroom resonator by etching out metal from the patch of the mushroom. Angles of circular slots and length of linear slots are adjusted to change the surface current path of a particular excited mode and attain a desired frequency of resonance without disturbing the other mode. The fundamental mode of resonance, i.e. TE
₁₀₁
is shifted by 12.5% after changing one of the slot angles, θ by 60 , whereas the next mode (TE
₁₀₂
) remains unaffected. Keeping TE
₁₀₁
mode fixed, the 2
^nd
mode of resonance (TE
₁₀₂
) is shifted by nearly 7% after changing the other slot angle, φ by 30 and is also shifted by 4.5% after changing the length of linear slot by 6 mm. This independent control over the excited modes has significant applications in Wi-Fi technology, satellite communications and weather radar systems.