Research Article A Compact Wideband Dual-Polarized Antenna with Harmonic Suppression Using Nonuniform Defected Ground Structure Lana Damaj, Anne-Claire Lepage, and Xavier Begaud Comelec Department, Institut Mines-T´ el´ ecom, T´ el´ ecom ParisTech, LTCI CNRS UMR 5141, 46 rue Barrault, 75634 Paris Cedex 13, France Correspondence should be addressed to Xavier Begaud; xavier.begaud@telecom-paristech.fr Received 13 June 2014; Revised 23 August 2014; Accepted 10 September 2014 Academic Editor: Renato Cicchetti Copyright © Lana Damaj et al. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. A wideband dual-polarized coplanar waveguide (CPW) fed antenna integrating a wide stop-band ilter is presented. he designed ilter is based on a nonuniform defected ground structure (DGS) in order to obtain a wide stop-band and a compact size. his ilter is used to reject harmonics and spurious radiation arising from the RF front end. he complete structure (antenna and ilter) has been optimized to have a compact size of 0.6 × 0.6 2 0 ( 0 being the free-space wavelength at the lowest operating frequency). he realized antenna operates in the frequency range between 2.7 GHz and 5.9 GHz (bandwidth of about 74%). he isolation between feeding ports is more than 18 dB. he complete structure has a wide stop-band characteristic (103%) for harmonic rejection. he simulated numerical results have been conirmed with measurements. 1. Introduction An active integrated antenna (AIA) introduces nonlinear devices directly into the radiating element. his concept was used to design antennas including high eiciency power ampliiers. However, these antennas exhibit high levels of har- monic radiation, which may degrade system performances [1]. In conventional systems, additional ilters are used to remove these harmonics. However, these ilters increase the size and the cost of radio frequency (RF) front ends and yield additional losses. hus, it is interesting to perform this iltering function directly within the radiating element. his type of antenna allows the realization of compact RF front ends. Several methods have been used to reject harmonics such as the insertion of slots and short-circuits [2] and the use of photonic band gap (PBG) [3, 4] or defected ground structure (DGS) [5, 6]. Finally, it should be noted that most studies have been carried out for narrowband structures. A wideband antenna supporting a single ield polar- ization has been recently presented in [7, 8]. Using these results, in this paper the design of a wideband dual-polarized antenna, in which the matching circuit and the ilter for harmonic rejection are integrated in the radiating element, is presented. he challenge was to reduce the isolation between the two input ports while maintaining a wide bandwidth and a compact size. Furthermore, a study about the radiation characteristics of the ilter has been performed. he antenna provides wide bandwidth and dual polarization performance, in order to cover many communication standards and to transmit or receive any kind of ield polarization (linear or circular). In [9], it has been shown that the difrac- tion processes arising from the presence of furniture may reduce the communication quality in indoor environments. herefore, antennas that provide dual or circular polarization may be used to improve the service quality. On the other hand, the ilter and the matching network are integrated parts of the radiating element. In this work, the radiating element, the ilter for harmonic rejection, and the impedance matching network, which are traditionally separated circuits, are incorporated into a single unit. he coniguration of the proposed ilter is shown in Section 2. Section 3 describes the design and the simulated and the measured results of the proposed antenna. he Hindawi Publishing Corporation International Journal of Antennas and Propagation Article ID 505123