Wideband microstrip-fed slot loop antenna with the conducting via

Compact wideband slot loop antenna fed by microstrip line is presented. In the proposed antenna, the microstrip feed line is connected to the center conductor of the slot loop by the conducting via. The operating bandwidth of the proposed antenna is more than octave band (2.48 to 5.7 GHz) for a VSWR<;2. And the radiation pattern of the antenna is omnidirectional and similar to the (half wavelength) dipole antenna over the whole operating frequency band.