A small UWB antenna with slotted ground plane

Abstract

There is always an increasing dem and for sm aller antenna size, greater capa cities and transm ission speeds, which will ce rtain ly require m ore operating bandwidth in the near future. Research works on UW B antennas have been repor ted in m any litera tures . Many techniques to broaden the impedance bandwidth of s mall antennas an d to optim ize the char acteristics of broadband antennas have been widely investigated. Som e exa mple s of the techniques used to im prove the im pedance ba ndwidth of the planar m onopole antenna include the use of bevelin g technique, cutting notches at bottom , and a dual feed. The radiat ors m ay be slotted to improve the im pedance m atching, especially at higher frequency. In th is chap ter, a sm all UWB anten na is p resen ted. The effect of two not ches cut at the botto m edges of patch antenna to im pedance bandwidth is discussed. Slotted or notched ground plane is also taken into consid eration. This modified truncated ground plane acts as an impedance matching elem ent to cont rol the im pedance bandwidth of a rectangula r patch. T his is be cau se th e truncation creates a capacitive load that neutralizes the ind uctiv e nature of the patch to produc e nearly-pure resistive input im pedance.