Reducing the beam squint in scanned leaky-wave antennas using coupled SIW cavities

The systematic design of broadband, directive, scanned planar leaky-wave antennas using coupled-cavity substrate integrated waveguide technology is reported in this work. The design methodology is based on the optimization of the corresponding transverse resonance phase equation, so that a constant scanning angle condition is satisfied for a wide frequency band. This design process is validated with full-wave simulations of a 4th order-cavity optimized design. A 3dB scanned pattern bandwidth of 1.5GHz with 10dBi directivity at a central frequency of 15GHz (10% fractional bandwidth), is reported for 30° elevation scanning angle. This is a much higher bandwidth than conventional 1.7% bandwidth associated to the same type of antenna with a single SIW cavity.