A compact biconical antenna for ultrawideband applications

A compact ultrawideband antenna with the asymmetric biconical and upside-down discone is proposed. The asymmetric biconical antenna has wire structure like octopus legs for covering at lower operating frequency, and the upside-down discone antenna has conical shape playing a role as covering at higher operating frequency. By introducing several different geometric features, the impedance bandwidth of the antenna is improved while maintaining good electrical performance. Finally, the antenna can achieve an impedance bandwidth of 200:1 for VSWR≤2.5 ranging from 40 MHz to 8 GHz. These features make such antennas highly suitable for application to ultrawideband system.