Compact printed dipole antenna with integrated wideband balun for UWB application

A compact UltrawideBand (UWB) dipole antenna with an integrated wideband balun is presented. The proposed antenna consists of a printed dipole, a wideband slot balun embedded in the ground plane, and an inverted L-shaped microstrip feedline. By using the integrated slot balun, the unbalance-to-balance transformer from the microstrip feedline to the dipole antenna is achieved. This antenna achieves a small size of 16 mm× 28 mm × 0.8 mm based on the substrate having a dielectric constant of 2.55, and operates over the frequency band from 2.9 GHz to 10.7 GHz, with the reflection coefficient <;-10 dB and the relative impedance matching bandwidth of 114.7%. The measured results show the nearly omnidirectional radiation pattern over the UWB band.