Summary
International Symposium on Antennas and Propagation
2010
Session Number:3TE3
Session:
Number:3TE3-1
The design of miniature Electromagnetic Band Gap (EBG) ground plane
Wen-Shan Chen, Bau-Yi Lee,
pp.-
Publication Date:2010/11/23
Online ISSN:2188-5079
Summary:
Electromagnetic Band Gap (EBG) is originated from Photonic Band Gap (PBG) structure. They both are periodic structure for forbidding the transmission of certain frequency bands of electromagnetic wave. However, the design of early PBG structures was too large to apply in practical usage. In 1999, Dr. Sievenpiper from UCLA modified corrugated metal stub surface [1-2] and small metal bumps surface [3] to build the mushroom EBG ground plane [4]. Dr. Sievenpiper etched periodic hexagonal patches on top of FR4 substrate and drilled holes to connect the hexagonal patches with the ground plane on the bottom of the substrate. The electric field between the patches creates capacitance effects; the current through the vias of the top and bottom substrate creates inductance effects. The equivalent inductance and capacitance of EBG plane can be represented as LC parallel circuit. The frequency of electromagnetic wave within the resonate frequency of the LC parallel circuit can not propagate through the EBG ground plane. Due to the advantages of small size, low cost and ease fabrication, many research institutes have focused on the applications of EBG ground plane, such as, microstrip antenna [5], band stop filter [6], and RFID [7]. However, the dimensions of EBG ground plane are proportional to the wavelength of electromagnetic wave; therefore, the size of EBG is too large to be used at low frequency bands. This paper proposes two methods to minimize the EBG ground plane. The first method uses meander path to increase the current path for increasing the inductance effects and interdigital structure at the edge of patches to increase the capacitance effects. The second method removes the connecting wire and implements chip inductor within the through hole between top and bottom substrate. From the experimental results, both methods successfully decrease the band gap frequency under the same unit cell size.