Low cost, low side-lobe array of waveguide-fed microstrip antennas

A low-cost, low side-lobe Ku-band array of microstrip antennas, which is fed by waveguide, is presented in this paper. The 72 corner-fed square patches of the array are arranged in a 6-by-12 configuration. A novel waveguide to microstrip line transition with power divider is employed as a centre fed for the array in order to reduce the loss of the microstrip feed line. The gain of the array was measured to be 24.1 dB. The side-lobe is below -20 dB and the return loss at resonant frequency is less than -25 dB. This array of waveguide-fed microstrip antennas can be used in many modern communication systems, such as a mobile radar sensor, in which the transition can be fixed as a connection between the module with a front-end waveguide and antennas.