A K-band series-fed microstip array antenna with low sidelobe for anticollision radar application

A k-band microstrip array antenna with low sidelobe is proposed in this letter. The antenna array is designed for anticollision radar application. It is a planar series-fed antenna array which consists of eight identical linear series-fed arrays with low sidelobe. The linear series-fed arrays are fed by a microstrip line with impedance matching stubs. The characteristic of low sidelobe can be realized by changing the width of the antenna units and the impedance matching stubs. The shorted holes at both ends of the linear arrays are used to enhance the performance of the antenna array in both impedance matching and radiation pattern. The antenna array is simulated, manufactured, and measured. The measurement results agree with the simulation results. The experiment results demonstrate that the voltage standing wave ratio (VSWR) of the antenna is less than 2 in the working frequency band (24.3-24.7 GHz). The sidelobe levels in both E-plane and H-plane of the antenna are less than -23 dB and good cross polarization is also obtained in the working frequency band.