[天线]40 Antenna Miniaturization and Bandwidth Enhancement Using a Reactive Impedance Substrate

IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 52, NO. 9, SEPTEMBER 2004 2403 +{#Z^y6&  
Antenna Miniaturization and Bandwidth Enhancement Using a Reactive Impedance Substrate +-|}<mq  
Hossein Mosallaei, Senior Member, IEEE, and Kamal Sarabandi, Fellow, IEEE Y=y 0`?K  
Abstract—The concept of a novel reactive impedance surface QP>F *A  
(RIS) as a substrate for planar antennas, that can miniaturize uuL(BUGt-  
the size and significantly enhance both the bandwidth and the U~dqxR"Q  
radiation characteristics of an antenna is introduced. Using the W
C b5  
exact image formulation for the fields of elementary sources ,k(B>O~o  
above impedance surfaces, it is shown that a purely reactive LLbI}:  
impedance plane with a specific surface reactance can minimize c{qTVi5e  
the interaction between the elementary source and its image in the 3sDyB-\&  
RIS substrate. An RIS can be tuned anywhere between perfectly C'S_M@I=  
electric and magnetic conductor (PEC and PMC) surfaces offering ;Zn&Nc7  
a property to achieve the optimal bandwidth and miniaturization }g:'K  
factor. It is demonstrated that RIS can provide performance ?[%.4i;-h  
superior to PMC when used as substrate for antennas. The RIS p\Iy)Y2Lf!  
substrate is designed utilizing two-dimensional periodic printed bfkFk  
metallic patches on a metal-backed high dielectric material. A YdUcO.V  
simplified circuit model describing the physical phenomenon of wNUcL*n  
the periodic surface is developed for simple analysis and design ,wy;7T>ODd  
of the RIS substrate. Also a finite-difference time-domain (FDTD) CIRMAX  
full-wave analysis in conjunction with periodic boundary conditions IoV"t
,  
and perfectly matched layer walls is applied to provide CZ%KC$l.5  
comprehensive study and analysis of complex antennas on such 3K/]{ dkD  
substrates. Examples of different planar antennas including dipole k0TQFx.A  
and patch antennas on RIS are considered, and their characteristics NGZtlNvh  
are compared with those obtained from the same antennas k?/!`  
over PEC and PMC. The simulations compare very well with o,xy'  
measured results obtained from a prototype 10 miniaturized 9NZq k  
patch antenna fabricated on an RIS substrate. This antenna shows /nEK|.j  
measured relative bandwidth, gain, and radiation efficiency of SzFh  
= 67%, = 45 dBi, and = 90%, respectively, 9Vt6);cA-]  
which constitutes the highest bandwidth, gain, and efficien .. ?}EWfs
A  
@]42.oP  

未注册仅能浏览部分内容，查看全部内容及附件请先 登录 或 注册