Low-Cost Series-Fed Microstrip Antenna Arrays With Extremely Low Sidelobe Levels

This paper presents a new method of designing and implementing low-cost series-fed microstrip antenna arrays with low sidelobe levels by applying standard single-layer PCB technology. The method is based on the Z-parameter characteristics obtained from the electromagnetic full-wave simulation of the array elements by using a two-port network model. Two types of antenna arrays are designed and presented with the use of the proposed method. The first type is a uniform linear array with sidelobe level of 24.2 dB at the 24.125 GHz frequency band. The second type is a nonuniform linear array that provides at least 50% more physical space between the central patches to be used in 2-D arrays; this antenna has sidelobe level of 25 dB at 24.125 GHz. Both antennas achieve an excellent performance in the entire bandwidth of 250 MHz.