In this paper, a wideband magneto-electric (ME) dipole antenna with wide beam-width both in the E-plane and Hplane is investigated. The proposed antenna, which is a differential one, has a simple structure and can realize wide beam-width in the E-plane and H-plane in whole operating bandwidth. This antenna is easy to manufacture and low cost. The antenna consists of a pair of Г-shaped metal plates, a Г-shaped fed line, and six metal columns. The Г-shaped metal plates and metal columns change the current distribution which changes the radiation performance of the proposed antenna. Some parameters which effect on the performances of the antenna are studied. The proposed antenna achieves the impedance bandwidth (≤ -10 dB) of about 81.1% (3.3 – 7.8 GHz). The half-power beam-width (HPBW) of the proposed antenna is obviously broadened. The HPBW is 215° in the E-plane and 186° in the H-plane at 5.5 GHz. Besides, the cross polarization of the antenna is very low. The antenna is fabricated and measured to verify the design. The measured results are in good agreements with the simulated one. Good radiation characteristics of the new ME dipole antenna have been obtained in the whole frequency band.

A technique for the synthesis of shaped beam radiation patterns is proposed. The new synthesis method is based on superposition principle and Taylor method. The method may control the sidelobe level of the shaped beam. The approach includes four steps: 1) get the distribution of pencil beam array with low sidelobe by Taylor method; 2) let the beams scan as a phased array to the specific angles according to the requirement of the shaped beam, The sum pattern is close to the shaping beam; 3) determine the value of angles and weights; and 4) count the distribution of the shaped beam array according to the new array factor function. Numerical results are provided to assess the capabilities of the proposed design method. The method develops an effective approach for the synthesis of shaped beams via uniform linear arrays. Both the ripple and sidelobe level of shaped beam may be controlled by the new synthesis method.

A wideband and dual-polarization antenna array with high efficiency and high isolation is proposed. In order to achieve the desired performance, a wideband radiating element and a full-corporate waveguide feed network are employed in the design. In particular, E-plane waveguides are utilized for the feed-network configuration so as to suppress wave leakage between adjacent layers when the antenna is fabricated via conventional machining techniques. The operational mechanism is presented and a 16 × 16 antenna array is tested for verification. Experimental results show that the bandwidths of VSWR <; 2.0 for both of the polarizations are about 17.1% (12.45-14.78 GHz) and the isolation between the two polarization ports is better than 39.5 dB. In addition, more than 70% antenna efficiency with higher than 29.4 dBi gain is achieved over the operational bandwidth.

A wideband antenna with ±45° dual polarization is proposed. The antenna is mainly comprised of four printed trapezoidal metal walls standing on a ground plane that forms a 3-D open square aperture cavity structure with tapered cut on the four wall edges. The metal walls are fed by two orthogonally positioned (±45°) feeding networks, forming two pairs of dipole arms. Because of the excited magnetic-electric resonances, wide bandwidth can be achieved. The proposed antenna is fabricated, and the measured results show that it has an impedance bandwidth of 56% (1.62-2.87 GHz) for VSWR <; 1.5. In addition, isolation of larger than 30 dB is also exhibited across the bandwidth between the two feeding ports. Because the proposed antenna has a hollow inside structure, it is a good candidate for multiband sharing aperture antenna element. Furthermore, it has a simplified fabrication process and is suitable for outdoor base station antennas that require VSWR <; 1.5.

A lightweight, wideband, and dual Circular Polarized (CP) waveguide cavity array operating at Ku-band is proposed. To obtain dual orthogonal Linear Polarizations (LP), the basic radiating element is a square cavity fed by two waveguides. By properly tuning the feed-networks, equal amplitude and phase of radiated electric field for two orthogonal polarizations can be obtained, culminating in a 16 ×16 dual-LP array. A wideband waveguide-based hybrid coupler is integrated with a dual-LP array to achieve the final dual-CP array. The proposed dual-CP array is fabricated by applying the Direct Metal Laser Sintering (DMLS) method. Its overall size is 288 mm ×288 mm ×52 mm3, and it has weighted slightly less than 1.3 kg. The measured results show that for both the CP ports, the array has exhibited desirable bandwidth of 12.25-14.5 GHz (at VSWR< 2), and its isolation is better than 15 dB. The measured gain ranges from 29.5–32.4 dBic while the Axial Ratio (AR) is better than 4.5 dB over the entire band. A total efficiency of over 60% can be obtained for both the LHCP and RHCP radiations.