Width effects on electromagnetic and mechanical behaviour of Z-slotted waveguide array antennas

Z-shaped slots fit within the narrow wall of a rectangular waveguide, offering a potential mechanical strength advantage compared to conventional inclined narrow wall slotted waveguide antennas for applications where the waveguide tube is a load bearing structure. Squeezing the Z-slots moved the edge of the perforations away from the corners of the WR-90 sized rectangular 6063 aluminum tubing, causing less weakening, giving a structural advantage. For the 10GHz antennas, squeezing the Z-slots to 7mm did not affect the S₁₁ ≤ -10dB bandwidth of 5% and peak gain of 16dBi. For less than 7mm, the return loss exhibited 2 separate narrow resonances, which would impede the use of the antennas for ranging radar onboard a small multi-rotor UAV.