K-Band Wideband Microstrip Antenna Array With Sidelobe Level Reduction

A single-layer, low-sidelobe, wideband microstrip antenna array is proposed in this paper using PCB technology. In order to overcome the problem of inherent narrow impedance bandwidth of microstrip antennas, two parasitic patches are loaded on both sides of the main radiation patch to expand the impedance bandwidth. In addition, Taylor distribution is introduced in the feeding network to reduce the sidelobe level. CPW-to-microstrip transition is introduced for probe feeding. Simulation results show that: the -10 dB impedance bandwidth is 15.5% from 21.4 to 25 GHz with a peak gain of 18.1 dBi. The simulated radiation patterns agree well with the measured ones which show -25 dB sidelobe level in the H-plane. Impedance matching performance is still under testing.