Antenna assembly, and associated method, having an active antenna element and counter antenna element

The present invention relates generally to antenna apparatus used to transduce radio frequency signals, such as the radio frequency signals generated by, or received at, a mobile terminal operable in a cellular, or other radio, communication system. More particularly, the present invention relates to an antenna assembly, and an associated method, which utilizes a counter antenna element together with an active antenna element. The counter antenna element operates to reduce the frequency about which the active antenna element is resonant without necessitating a corresponding increase in the length of the active antenna element. The antenna assembly is thereby able to be of reduced lengthwise dimensions relative to conventional antennas operable about a resonant frequency. An antenna assembly, and an associated method, for a radio device, such as a mobile terminal operable in a cellular communication system. The antenna assembly includes an active antenna element and at least a parasitic element. The active antenna element is of a selected lengthwise dimension and is resonant, in isolation, at a first resonant frequency. The parasitic antenna element is positioned proximate to the active antenna element and separated therefrom by a selected separation distance. The selected separation distance is determinative of a reduction in frequency at which the active antenna element is resonant. Thereby, for a given length, the resonant frequency of the active antenna element is reduced, permitting the lengthwise dimensional requirements of the antenna transducer of which the active antenna element is formed to be reduced relative to conventional antenna transducers.