When an electromagnetic wave encounters a non-resonant antenna, the wave will induce a current in the conductive material, leading to re-radiation of the signal. This process results in partial reflection, which distorts the local electromagnetic field. Resonant structures can enhance induced currents, creating interference patterns. For a rod or near-resonant structure to effectively act as a mirror, it should be resonant at or slightly below the target frequency, typically requiring a length longer than the resonant length. Shorter rods tend to allow the wave to pass through, behaving more transparently.
