Design and fabrication of a waveguide two-dimensional slot array with low sidelobe level of −35dB

A 24-by-27 elements single layer waveguide slot array with Taylor distribution of -35 dB sidelobe are designed and fabricated at 25.3 GHz. The hybrid design by using the combination of a full-wave method of moments (MoM) analysis and an equivalent circuit model is applied for the control of the aperture distribution and the reflection of the array all together; the slot admittance and spacing are designed under the condition of input impedance matching first in the equivalent circuit model while the slot parameters in 2-D array for realizing the active admittance specified above are iteratively determined in the full-wave MoM analysis. The measurement of the test antenna confirms that the overall reflection is suppressed below -18 dB over the frequency range of 24.3~26.3 GHz and that the high antenna efficiencies of 53.9% with very low SLLs below -33 dB are achieved by this hybrid approach.