A Composite Dipole Antenna Array with Direct Feed

Design of a composite dipole antenna array with direct feed is presented. In the form of printed-circuit antennas, the structure of the design consists of a doublet antenna and an elliptic loaded monopole antenna with a skirted dipole. As the load of the antenna array, this elliptic monopole provides wider bandwidth. Therefore, with the load possessing a radiation characteristic, it contributes to enhancing efficiency of the antenna array and hence the omni-directional radiation gain. A good agreement between simulated results by CST Microwave Studio and tested results suggests that the reflection coefficient for the frequency range between 4.35 GHz to 5.0 GHz is lower than -10 dB. The out-of-roundness on -plane is lower than 2dB and the maximum gain is higher than 6dB for the frequency range from 4.6 to 5.0 GHz. What's more, the gain per wavelength is about 4 dB, showing the antenna's excellence in miniaturization.