Enhancement of the Gain for Microstrip Antennas Using Negative Permeability Metamaterial on Low Temperature Co-Fired Ceramic (LTCC) Substrate

Abstract

A novel method for enhancement of the gain for microstrip antennas is demonstrated. Compact nested tridimensional split-ring resonators (SRRs) are embedded in low temperature co-fired ceramic (LTCC) substrate integrated with a single patch antenna. The maximum dimension of the SRRs structure is only <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$0.13\lambda_{\rm g}$</tex> </formula> . The SRRs generate an effective magnetic response and give rise to negative effective permeability, which can be designed as a metamaterial insulator to reflect surface waves. A high-gain microstrip antenna is designed for WLAN, operating at 5.2 GHz, surrounded with proposed SRRs in the E-plane. The performance of the antenna shows that the side and backward radiation decreased and the forward radiation increased. Compared to the conventional microstrip antenna, the gain of proposed microstrip antenna is enhanced by 1.5 dB, and the 3-dB beamwidth of the E-plane can be reduced by 14 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$^{\circ}$</tex></formula> .