A Compact Dipole Antenna for DTV Applications by Utilizing L-Shaped Stub and Coupling Strip

In this study, a small dipole antenna for digital television (DTV) reception band (470-862 MHz) is developed. The antenna is composed of a pair of bent dipoles, which are coupling fed by a coaxial cable. The resultant antenna has compact size of 20×200×0.8 mm
³
. Two parasitically coupling strips are added to excite one additional resonance mode. Bent dipole antennas and feeding structures are fabricated on the different planes of the substrate to embed two L-shaped stubs, thus resulting in improvement of the impedance matching condition. After careful optimization of the geometrical parameters of the antenna, the resonances are merged and thus, a wide impedance bandwidth is obtained. The measured -6-dB bandwidth of the antenna in free space is 615 MHz (80.4%).