摘要： A printed dual-band dipole filtenna with flexible frequency ratio and improved band-notched performance is proposed. It consists of a driven dipole and three parasitic elements. For the driven dipole with short and long arms, a radiation null is found between two passbands, which achieves a band-notched filtering characteristic. Two parasitic elements are introduced to enhance the passband bandwidth and an additional parasitic element is utilized to improve the band-notched performance. In addition, the characteristics of the proposed design including flexible frequency ratio, independent controllable operating frequency, and controllable band-notched bandwidth have also been demonstrated. A filtenna prototype is fabricated and tested. Measured results show that a fractional bandwidth of 21.1% and 18.1% is obtained in the lower and upper passbands, respectively. The measured efficiency is 84% in the lower band and 74% in the upper band but the efficiency sharply decreases to about 13% within the notched band.