Microstrip Patch Antennas With Enhanced Gain by Partial Substrate Removal Adviser: Hung-Chi Yang Speaker: Yu-Ming Chen IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 58, NO. 9, SEPTEMBER 2010 Siew Bee Yeap, Member, IEEE, and Zhi Ning Chen, Fellow, IEEE 2010/12/15 1

Outline Introduction Introduction Purpose Purpose Methods ＆ Materials Methods ＆ Materials Conclusion Conclusion Future works Future works References References 2

Introduction 3 Microstrip patch antennas ： 1.Compact 2.Conformal 3.Low cost Three types of losses ： 1.Conductor loss 2.Dielectric loss 3.Surface wave loss Microstrip patch antennas ：微帶貼片天線 Surface wave ：表面波

Introduction 4 Dielectric loss ： 1.The loss tangent of materials 2.The substrate thickness Surface wave loss ： 1.The permittivity of materials 2.The substrate thickness

Introduction 5 The designs that excite very little surface waves ba- sed on the principle that a ring of magnetic current in the substrate has a critical radius. Another easy method is to replace the substrate of patch antennas with air of ε r = 1 or with very low dielectric constant material.

Introduction 6 Electromagnetic band gap structures are also used to improve antenna gain. The periodic structures block the surface waves from propagating in a certain band gap. The alternative is to perforate the substrate i.e. drill holes in the substrate hence synthesizing a lower die- lectric constant substrate.

7 The effects of partial substrate removal on the per- formance of microstrip patch antenna. The basic idea is to improve the gain of a microstrip patch antenna by suppressing surface waves and re- ducing dielectric loss. Purpose

Methods ＆ Materials 8 Microstrip patch with and without substrate removal A. Aperture-Coupled Microstrip Patch B. Microstrip Patch Aperture-Fed With Open Air Cavity C. Comparison of Patch Antennas With Varying Open Air Cavity Configuration Aperture-Coupled ：槽孔耦合