MEANDER LINE-BASED LOW PROFILE RIS WITH DEFECTED GROUND AND ITS USE IN PATCH ANTENNA MINIATURIZATION FOR WIRELESS APPLICATIONS

摘要

A reactive impedance surface (RIS) comprising of 4 x 4 array of grounded unit cells having meander line structure is designed. A detailed impedance analysis of the RIS is presented and validated with simulation results. A triangular patch antenna with metallic ground plane is designed to resonate at 3.78 GHz. The metallic ground is substituted by the RIS which results in shifting of resonant frequency from 3.78 GHz to 2.90 GHz thus exhibiting 23.28 miniaturization. The metallic ground of RIS is made defected by etching a rectangular slotted loop which leads to 50.8 miniaturization as the resonant frequency of the structure shifts to 1.86 GHz which resembles to GSM communication frequency. A tuning parameter has been identified in the slotted loop to control the resonant frequency of the structure. Satisfactory gain, efficiency and stable radiation pattern with low cross polarization level in both E and H planes qualify the proposed structure as a promising candidate for practical wireless applications. A comparison of the proposed structure with previous works in literature is provided to demonstrate the superiority of the proposed technique in terms of the profile of RIS and its miniaturization capability. Experimental verification of the proposed structure is provided. (C) 2017 Wiley Periodicals, Inc.