A multi-band antenna includes a reflector, and a plurality of first radiating elements on the reflector. The plurality of first radiating elements are configured to radiate a first antenna beam(s) in a first frequency band responsive to at least one feed signal. A passive radiation-filtering element is provided, which extends proximate the first antenna beam(s). The passive radiation-filtering element includes at least one of a low-pass LC circuit, a band-pass LC circuit, and a high-pass LC circuit therein, which is configured to provide a lower frequency-dependent impedance to radiation within the first frequency band relative to radiation at frequencies outside the first frequency band. The passive radiation-filtering element may be configured as a multi-segment fence having capacitive and inductive elements therein, which are electrically coupled in series.