Miniaturization of the Biconical Antenna for Ultrawideband Applications

A miniaturized, ultrawideband antenna for the 3.1 to 10.6 GHz frequency band is presented. The antenna is designed to have a low profile to enhance integration onto existing structures and a low directivity pattern for body worn applications. A systematic process to miniaturize the well-known biconical antenna is illustrated by adding several different geometric features that reduce the size of the antenna. After miniaturization, the vertical height of the antenna was reduced by over 60% while maintaining electrical performance. Prototype antennas were manufactured using low cost plastic injection molding and dipping processes to facilitate transition to mass production and to enhance the durability of the antenna. The simulated and measured reflection coefficient of the antenna show good agreement. Measured antenna gain patterns verify that the manufacturing process employed is capable of producing low loss antenna structures. Lastly, time domain short pulse measurements of the antenna verify that it does not appreciably distort radiated signals in the azimuthal plane.