Compact planar super-wideband monopole antenna with four notched bands

Abstract

A compact-sized planar super-wideband (SWB) monopole antenna with four notched bands is presented in this paper. The antenna consists of a rectangular ground plane and a circular radiator that is fed by a tapered microstrip feed line. The overall size of the antenna is 18 mm × 12 mm × 0.5 mm, and its impedance bandwidth (S11 ≤ −10 dB) ranges from 2.5 GHz to 40 GHz (bandwidth ratio of 16:1). Four notched bands are obtained using two inverted U-shaped slots, a split-ring resonator (SRR), and a meandered slot. The notched frequency bands can be adjustable by changing the parameters of parasitic slot elements, and the realized notched bands in this paper are Wi-MAX band (3.5 GHz), WLAN band (5.5 GHz), satellite communication X-band (7.5 GHz), and amateur radio band (10.5 GHz). The simulated and experimental results show good agreement with each other. The antenna possesses a high gain, super-wide impedance bandwidth, and omni-directional radiation patterns.