A Wideband Omnidirectional Horizontally Polarized Antenna for 4G LTE Applications

An innovative wideband omnidirectional horizontally polarized (HP) antenna is presented for 4G Long Term Evolution (LTE) wireless communication and networking systems. The proposed planar antenna consists of four pairs of flag-shaped radiators, a balun for balance-unbalance transformation, and four parasitical strips for bandwidth enhancement. Such a design enables in-phase and axially symmetric current flowing along the radiators. The measurements show that the proposed HP antenna exhibits a relative bandwidth of 41% with the return loss greater than or equal to 10 dB; it covers the frequency band of 1.76-2.68 GHz, including PCS, UMTS/LTE, Bluetooth, ISM, and WLAN bands. With an omnidirectional radiation pattern in E-plane, the proposed antenna has a peak gain of 3.6-4.2 dBi across the operational band and a radiation efficiency of 83%. The low profile and compact design, along with the omnidirectional radiation pattern, makes it ideal for ceiling or surface-mounted indoor and automobile 4G applications.