Unbalanced antenna system

摘要

An antenna system (20) provides low radio frequency interference (RFI) using an unbalanced antenna (21) comprised of three eighths wavelength whip antenna element (22) and associated counterpoise (23). Antenna counterpoise (23) may be formed by an EMI shielding conductor which is isolated at the frequency of operation of antenna system (20) from EMI shielding serving as host interface ground conductor (28) using resonant structure (25). Resonant structure (25) isolates antenna counterpoise (23) from host interface ground conductor (28) thereby improving antenna efficiency, and substantially eliminating RFI effects arising from use of antenna system (20).