A Double-Layer Shaped-Beam Traveling-Wave Slot Array Based on SIW

A double-layer shaped-beam traveling-wave slot array based on substrate integrated waveguide (SIW) at X-band is presented. The double-layer SIW longitudinal slot-coupled cavity slot is proposed as the array element, which has an improved bandwidth performance due to the double-resonant feature. By using this kind of slots, a planar nonuniformly spaced shaped-beam traveling-wave array is constructed. To achieve the desired distribution for the shaped-beam pattern, an efficient optimization method, with the mutual coupling effect being considered, is proposed to optimize the array structure parameters. Experimental results show that the array achieves good shaped-beam pattern in a 4.8% frequency band and low-loss characteristic.