Planar slotted array antennas fed by reduced height wiggly ridge waveguides

Abstract

A reduced height single ridge waveguide is employed to feed an array of centerline longitudinal slots. The ridge has a wiggly shape at the slot position and an indentation is introduced to the ridge at the bending position. It is shown that in absence of the indentation, the propose slot antennas are impractical. The transverse electric field distribution along the slot is studied which indicates that the proposed longitudinal slot antenna can be represented as an equivalent shunt admittance across a fictitious transmission line. Considering this equivalent circuit for the proposed slot antenna and employing the design procedure previously introduced to design the slotted array antenna fed by wiggly ridge waveguide, a planar array is designed, constructed and tested. The effectiveness of the proposed antenna was verified by the simulation and the measurement results of a sample prototype.

Keywords:

• Slot antennas
• centerline longitudinal slots
• wiggly ridge waveguides
• butterfly lobes