Dual Polarized Travelling-Wave Array Antenna Formed by Printed Cross Slots

A dual polarized travelling-wave array antenna in Ku-band is presented. The array design uses the two orthogonal modes TE10 and TE01 mode supported by a square waveguide feeding. Each single element of the array contains two orthogonal slots (transversal and longitudinal slots), forming a cross slot. Thus, transversal slots are excited by TE
₁₀
mode while longitudinal slots are excited by TE
₀₁
mode, generating the dual linear polarization. Likewise, a dual polarized array antenna fed by a square waveguide is designed for 98% of radiated power at the design frequency. In order to mitigate the grating lobe appearance as well as to minimize the reflected wave, the distance between elements has been optimized. Due to the proximity between slots, a printed version of the cross slot is proposed to reduce its resonant length. Therefore, mutual coupling effects are reduced, also preventing overlapping between adjacent slots. Finally, the dual polarized array antenna is manufactured and measured. A good agreement between simulated and measured results is achieved, also obtaining high efficiency for both linear orthogonal polarizations.