Some new microwave antenna designs based on the trough waveguide

Several new antenna designs use the trough waveguide as a transmission line. Among the most recent are linear arrays made of resonant or non-resonant monopoles, slow-wave structures, a hybrid type of TEM-to-trough-guide mode isolator, and a trirod variable coupler. The trough guide invented by the personnel of Airborne Instruments Laboratory, Inc. is admirably suited to such applications because of its geometry, simple mechanical construction, and broadband characteristics. Typical examples that demonstrate its superior properties as compared with a rectangular waveguide having conventional slots or dipoles are the fixed-beam linear array and the mode isolators in trough guide whose designs are discussed in this paper.