Initial assessment of a waveguide with dielectric-filled corrugations as a technology for slot antennas with backward-to-forward scanning capabilities

CRLH waveguide with air-filled double-ridge corrugations

“…The new design is based on using air-filled corrugations instead of the dielectric-filled ones as in [3] in order to avoid any dielectric losses, which is the major disadvantage when the CRLH design is used as a leaky wave antenna as in [4]. The corrugations used in the new design are short-circuited air-filled double ridge waveguides which have a cutoff frequency lower than that of the conventional rectangular waveguides having same width.…”

“…The disadvantage of the first design is that those split-ring resonators, used to provide the series capacitance, are located in the direction of propagation of the wave traveling inside the guide, so a great dielectric loss occurs in the substrate of the split-ring resonators due to the high operating frequency. On the other hand, the disadvantage of the second design is that the high losses occurring in the dielectric medium filling the transverse corrugations when used as a leaky wave antenna [4]. In this paper, a new design supporting CRLH propagation without using any dielectrics other than the air to avoid the dielectric losses.…”

On the Actual Possibilities of Applying the Composite Right/Left-Handed Waveguide Technology to Slot Array Antennas

“…Ref. [9] shows that this impedance accurately predicts the ratio between the electric and magnetic fields in the waveguide broad wall, which is where the slots are to be machined. Like in Fig.…”

Metamaterials for microwave frequencies

“…A new type of antenna uses composite resonant metamaterials to build a highly directive subwavelength cavity antenna with the smallest cavity thickness being of the order of λ/60 [107]. Even the leaky-wave antenna can be improved upon by spreading the main beam pointing angles with metamaterials [108]. An ultra compact directive electronically reconfigurable antenna was created of metamaterials for the telecom industry [109].…”