Electromagnetic energy transport along Yagi arrays

Yagi arrays consisting of closely spaced metal rods (spacing=2 mm, height=14 mm) were investigated as guiding structures for electromagnetic energy in the microwave regime at 8 GHz (λ=37 mm) both by experiment and simulation. Information transport is possible at a group velocity of 0.6c. Ninety percent of the electromagnetic energy is confined within a distance of 0.05λ from the guiding structures. The propagation loss in a straight array is 3 dB/8 cm. Routing of energy around 90° corners is possible with a power loss of 3–4 dB. Signals can be split via a tee structure which can also serve as a three-terminal modulator. Analogies to plasmon wires consisting of arrays of nanometer-sized metal clusters are discussed.