A miniaturized broadband four-port antenna located on a cylindrical conductor

A novel miniaturized broadband four-port antenna is developed in this paper, which is realized on the top of a cylindrical conductor. Due to its planar multi-layer geometry, this antenna is easy to be manufactured, with a size of 0.7^¿ × 0.7^¿ × 0.2^¿ and a -10 dB bandwidth of 54% achieved. Its S-parameters is measured, and its return loss can be adjusted effectively by changing the vertical height of main radiation patch. The radiation pattern of our designed antenna is also shown, with good agreement obtained between the measured and simulated ones.