Search

Abstract A probe‐fed dipole antenna with parasitic patches is proposed in this study as the element for wideband and wide‐scanning planar‐phased arrays. Parasitic patches are used to realize wideband performance by significantly reducing the active input impendence. The printed dipole antenna with parasitic patches is directly matched with the subminiature version A (SMA) connector through the modified probe structure. The cell size is 0.5 × 0.5 × 0.145 λhigh3. The planar and low‐profile characteristics make it suitable for modular phased array applications. It is shown that the infinite array simulation results achieve 45.2% bandwidth (7.86–12.45 GHz) with active voltage standing wave ratio (VSWR) < 2 at broadside, 60° scans in E‐, D‐planes and 50° scan in H‐plane. An 8 × 8 prototype array has been manufactured and measured to validate the proposed design and the active element patterns agree well with simulation results.

In recent years, the screen-to-body ratio of mobile handsets has been increasing. Today, the screen nearly fills up the entire front side. Conventionally, the screen is mainly seen as a metallic object that adversely affects antenna performance. In this paper, the large screen is used for the first time to facilitate an additional uncorrelated MIMO port in a tri-port design, for several LTE bands below 1 GHz. To this end, the screen and the terminal chassis are modeled as two metal plates and their characteristic modes are analyzed. Four modes are then tuned to resonance and selectively excited to yield three uncorrelated MIMO ports. Simulation and measurement results are in good agreement. The measured bandwidths are 23%, 17% and 21%. Within the operating band, the measured isolation is above 13 dB, envelope correlation coefficient below 0.16 and average total efficiency above 72%.

A planar multifunctional four-port antenna system integrated on one substrate applied in the suburban mobile tablet is presented in this paper. The types of these antennas are selected based on different functions and the interactions between them are analyzed and reduced. Two identical T-shaped printed monopole antennas are designed for the MIMO mobile ad-hoc networks (MANET) application. The mutual coupling between the ports of these two MANET antennas is decreased by introducing a decoupling metal strip loaded with an inductor. Two horizontal printed dipoles with parasitic strips are developed to operate in the satellite navigation and communication frequency bands. Through the analysis of the interaction between the MANET antenna and satellite antennas, the satellite antennas with improved broadside radiation patterns are obtained. The performance stability of the proposed antenna system is verified by the investigation of the performances in different gestures. A prototype of the antenna system is fabricated and the measured results show that the proposed antenna system can cover the frequency bands of MANET communication, satellite navigation, and satellite communication with good performances. This proposed multifunctional antenna system is a good choice for the sub-urban mobile terminal systems.

A differentially fed dual-polarization slotted antenna with an ultra-wide bandwidth and low cross polarization is presented in this paper. The antenna is composed of a radiation patch and a ground plane, both of which are printed on the top of the dielectric substrate. The ground is extended toward the radiation patch to form a slotted coplanar structure. In order to expand the bandwidth, a cross-shape symmetrical slotted structure is loaded into the radiation patch. Differential feed is adopted to realize 0°C/90°C linear polarizations and suppress the cross polarization. Simulation and measurement results show that the proposed antenna with dimensions of 0.53λC0 × 0.53λ0 × 0.0135λ0 (λ0 is the wavelength at 4 GHz) has a differential mode impedance bandwidth of 82.25% (2.27-5.56 GHz), a differential feed port isolation of higher than 28 dB, and a cross polarization level of less than -30 dB, which achieves the characteristics of ultra-wideband, high isolation, and low cross polarization level. [ABSTRACT FROM AUTHOR]

The authors propose the design of a compact mechanically frequency and pattern reconfigurable patch antenna. The frequency tuning is achieved by changing the positions of two adjustable shorting screws which are used to modify the length of the antenna radiating patch. Simulated and measured results are carried out to validate the proposed approach. When the screws are symmetrically positioned, the measured operating frequency can be tuned from 2.95 to 5.16 GHz without degrading the radiation characteristics over the entire comparatively wide measured tuning range of 54.5%. The antenna main radiating beam can be tilted from θ = 0° to θ = 30° when the screws are asymmetrically positioned. The measured gains and efficiencies range from 3.01 to 5.53 dBi and 68 to 74%, respectively. The overall antenna size is only 0.39λ0 x 0.39λ0 x 0.02λ0. [ABSTRACT FROM AUTHOR]

A wideband dual-polarization patch antenna array is proposed in this letter. The array is fed by a parallel strip line balun, which is adopted to generate 180° phase shift in a wide frequency range. In addition, this balun has simple structure, very small phase shift error, and good ports isolation. The working band of the antenna array is from 1.88 to 2.9 GHz with a relative bandwidth of 41.7%. The height of the antenna array is only 0.144λ, and the cross polarization is below -20 dB. Two feeding ports are presented, which correspond to two orthogonal linear polarization. The isolation between the ports is higher than 30 dB. The simulation and measurement turns out to be similar. This antenna array can be used in TD-LTE base stations, and the design methods are also useful to other wideband microstrip antennas. [ABSTRACT FROM PUBLISHER]