Wide Bandwidth Ratio of 10-to-1 CPW-Fed Whip Antenna With Improved Radiation Patterns

In this communication, a novel compact single whip wideband antenna with an improved omnidirectional wideband antenna is proposed. First, a single whip antenna is designed on a thin flexible printed circuit (FPC) with a tapered coplanar waveguide feed line. This proposed antenna shows a wide impedance matching performance in a frequency range from 194 to 2124 MHz with a bandwidth ratio of 10:1, while a measured return loss is better than 10 dB within the desired passband. The single whip antenna has demonstrated an ultrawide bandwidth with satisfactory radiation properties in the lower frequency band. However, the omnidirectional radiation pattern deteriorated in the higher frequency band. Three whipped antennas are codesigned to form an improved omnidirectional radiation pattern. Finally, the measured performance of the fabricated antenna shows a good agreement with that obtained through simulation results.