Simplified Tightly-Coupled Cross-Dipole Arrangement for Base Station Applications

© 2013 IEEE. The electromagnetic fundamentals that govern the performance characteristics of dual-polarized tightly coupled cross-dipoles that are widely used in cellular base station applications are investigated. The mutual coupling effects and their impact on standard performance indices are stressed. A model is developed that considers this type of cross-dipole as an array. Links between the physical dimensions of the components of these model and key radiation characteristics, including directivity, half-power-beam width, and cross polarization discrimination levels, are established. The model guides the introduction and optimization of a simplified cross-dipole structure that exhibits excellent performance. A prototype was fabricated, assembled, and tested. The measured results are in good agreement with their simulated values, validating the model, and its governing principles

A Novel Dual-Polarized Planar Antenna

© 2018 IEEE. A wideband dual-polarized antenna with a novel planar configuration is presented for base station applications. Two groups of simple dipoles are fed by two microstrip feed networks to achieve ±45° polarizations. A novel feeding technique that leads to a planar configuration is described. Measured results show that excellent matching and stable radiation performances are achieved over a wide band

Wideband Planarized Dual-Linearly-Polarized Dipole Antenna and Its Integration for Dual-Circularly-Polarized Radiation

© 2002-2011 IEEE. A planarized dual-linearly-polarized (dual-LP) antenna and an integrated dual-circularly-polarized (dual-CP) antenna are proposed in this letter. For the dual-LP antenna, two groups of dipoles are fed by two balun-included feed networks to achieve ±45° polarizations. The feed networks and the radiators are printed on two sides of a substrate, forming a fully planar structure. Taking advantage of its planar configuration, the dual-LP antenna is further integrated with a wideband coupler to realize dual-CP radiation. The coupler is bent and squeezed into the space between the radiators and the reflector, leading to a compact structure. Both the dual-LP antenna and the dual-CP antenna have very stable radiation performances across a wide operating band >66%

Suppression of Cross-Band Scattering in Multiband Antenna Arrays

© 1963-2012 IEEE. This paper presents a novel method of suppressing cross-band scattering in dual-band dual-polarized antenna arrays. The method involves introducing chokes into low-band (LB) elements to suppress high-band (HB) scattering currents. The experimental results show that by inserting LB-pass HB-stop chokes into LB radiators, suppression of induced HB currents on the LB elements is achieved. This greatly reduces the pattern distortion of the HB array caused by the presence of LB elements. The array considered is configured as two columns of HB antennas operating from 1.71 to 2.28 GHz interleaved with a single column of LB antennas operating from 0.82 to 1.0 GHz. The realized array with choked LB element has stable and symmetrical radiation in both HB and LB

Wideband Dual-Polarized Filtering Antenna for Base Station Applications

A compact wideband dual-polarized filtering antenna based on tightly coupled cross dipoles is presented in this letter. The enhancement of impedance bandwidth is realized by introducing four impedance equalizers to equalize the input resistances of the two inherent resonant modes of tightly coupled cross dipole antenna. The enhancement of the selectivity is realized by introducing two radiation nulls in 5G sub-6 GHz n77 and n79 bands. The radiation null in n77 band is obtained by introducing the cross strips in the center of the antenna. The radiation null in the n79 band is achieved by the introduction of open-end branches. The manipulation of their key parameters allows for independent control over both radiation nulls. The validity of the antenna's design principle was confirmed by carrying out fabrication and measurements. The results obtained showcase the antenna's broad fractional bandwidth of 63.4% and exceptional port isolation of 31 dB. High out-of-band rejection levels in n77 and n79 bands are also obtained. In addition, since the whole radiator of the presented antenna is coplanar, it offers the advantage of a simple structure and convenient manufacturing, making it highly suitable for the use in base stations operating across multiple bands

Wideband Dual-Polarized Filtering Antenna for Base Station Applications

For the purpose of open access, the author has applied a CC BY public copyright licence to any Author Accepted Manuscript version arising from this submission.A compact wideband dual-polarized filtering antenna based on tightly coupled cross dipoles is presented in this letter. The enhancement of impedance bandwidth is realized by introducing four impedance equalizers to equalize the input resistances of the two inherent resonant modes of tightly coupled cross dipole antenna. The enhancement of the selectivity is realized by introducing two radiation nulls in 5G sub-6 GHz n77 and n79 bands. The radiation null in n77 band is obtained by introducing the cross strips in the center of the antenna. The radiation null in the n79 band is achieved by the introduction of open-end branches. The manipulation of their key parameters allows for independent control over both radiation nulls. The validity of the antenna's design principle was confirmed by carrying out fabrication and measurements. The results obtained showcase the antenna's broad fractional bandwidth of 63.4 exceptional port isolation of 31 dB. High out-of-band rejection levels in n77 and n79 bands are also obtained. In addition, since the whole radiator of the presented antenna is coplanar, it offers the advantage of a simple structure and convenient manufacturing, making it highly suitable for the use in base stations operating across multiple bands.Royal Society - International Exchanges 2019 Cost Share (NSFC); Huawei Technologies Ltd, in part by Engineering and Physical Sciences Research Council (EPSRC) (Grant Number: EP/S005625/1 and EP/N032497/1)

Wideband Dual-Polarized Antenna with High Selectivity for 5G Sub-6GHz Base Station Applications

A dual-polarized antenna with wide impedance bandwidth and high selectivity is presented for the use of 5G sub-6GHz base stations. By strategically introducing a novel coupled dual-mode grid structure, two additional resonant modes (One is in-band, another one is out-of-band) as well as two radiation nulls can be obtained to enhance the impedance bandwidth and out-of-band rejection level of the widely used tightly coupled cross-dipole antenna. The two radiation nulls introduced by the grid structure are located at the two edges of the desired frequency band. To further improve the gain suppression level in higher out-of-band, a new radiation null is obtained by symmetrically introducing four T-shaped strips. Apart from these additional radiation nulls, this antenna also exhibits two inherent radiation nulls originating from its feed structure and reflector. The measured results demonstrate that the proposed antenna exhibits a wide impedance bandwidth of 39.5% (ranging from 3.07 GHz to 4.58 GHz), excellent isolation of over 31 dB, and a notable out-of-band rejection level exceeding 17.6 dB and 19.2 dB in the frequency bands of 1.7 GHz-2.7 GHz and 4.8 GHz- 5.0 GHz