Contribution adjacent modes for circular microstrip antenna loaded by two annular rings

Abstract

In this paper, theoretical study of circular microstrip antenna loaded by two annular rings (CMSAL2AR) and calculation the contribution of the adjacent modes and studied positively or negatively affected on the antenna's coefficients (Bandwidth and Directive Gain).The proposed antenna using principle equivalence with moment of method formulation of electromagnetic radiation to find unknown electric current density on the conductor surface , and both unknowns electric and magnetic density current on the dielectric surface which are responsible for the generation of far fields radiation in the space for the components (Eθ ,Eφ) . From the radiation pattern can be calculated with contribution of the adjacent mode. The directive gain increased to (G= 19.92 dB) and bandwidth has been better (BW%= 19.9%) when this contribution is affect positively at the ratioRab=5.5 and Rab=6.5respectively.

Keywords

• CMSAL2AR,
• Adjacent modes,
• Radiation pattern
• , Bandwidth,
• Directive gain.