A Wideband Series Fed Patch Array with Side Lobe Level Control

In this paper a novel series fed patch array for healthcare radar monitoring applications has been proposed. The antenna is composed of six patches and works in the 5.8GHz Industrial, Scientific and Medical (ISM) band. The shape of the single patch has been designed to overcome two important limitations of this antenna topology: narrow bandwidth and high Side Lobe Level (SLL). To enhance the bandwidth, a dual band structure, obtained by the superposition of two tapered patches with different lengths has been used. For the SLL an innovative technique has been proposed. The amount of power radiated by each patch of the array and one transferred to the following radiating elements are controlled by the curvature degree of the upper hedge of the patch. The designed antenna has a fractional bandwidth of 5.92% (more than twice the available one at 5.8GHz) and a SLL of -21.6 dB at the central frequency. Both the reflection coefficient and the radiation pattern at 5.8GHz have been measured showing a really good agreement with simulation results.