The present disclosure relates in general to communication systems and components, and is particularly directed to multi column antenna array architecture, containing a plurality of driven radiating elements that are spatially arranged having a quadrature of higher frequency radiating elements positioned within confines of the lower frequency radiating elements while providing an independent operation there between.
A base station antenna for mobile communication is designed by means of a space diversity scheme or a polarization diversity scheme so as to reduce a fading phenomenon. A space diversity scheme means to install a transmitting antenna and a receiving antenna while being spaced a predetermined distance from each other, and has a large limit in space and a disadvantage in cost. Accordingly, a mobile communication system has typically used a dual-band dual-polarized antenna to which a polarized diversity scheme is applied.
Modern wireless antenna array implementation generally includes a plurality of radiating elements that may be arranged over a common reflector plane defining a radiated signal beam-width and elevation plane angle. Multi band antennas are antennas providing wireless signals in multiple radio frequency bands, i.e. two or more frequency bands. They are commonly used and are well known in wireless communication systems, such as GSM, GPRS, EDGE, UMTS, LTE, and WiMax systems. In this respect, the antenna arrays often comprises a plurality of antenna elements adapted for transmitting and/or receiving in different frequency bands. Most often dual band antenna elements are adapted for transmitting and/or receiving in a lower frequency band and in a higher frequency band while the single band antenna elements are adapted for transmitting and/or receiving in the higher frequency band only. The dual band and single band antenna elements are arranged such that the distance between the centers of two adjacent elements transmitting/receiving in the same frequency are often 0.5-1.0 times the wavelength λ for the center frequency for the given operating frequency band, and typically around 0.8λ of that wavelength. That is, the distance between two adjacent single band antenna elements Sx is often 0.8 times the wavelength for the centers frequency for the higher frequency band while the distance between two adjacent dual band antenna elements Qx is often 0.8 times the wavelength for the centers frequency for the lower frequency band.
A prior antenna system antenna assembly has been disclosed in US publication 2013/0002505 by Teillet al. In the published application an antenna assembly comprises a reflector, an array of first frequency band radiating elements configured above the reflector, the elements arranged in one or more columns extending in a first direction, and a plurality of second frequency band radiating elements configured above the reflector including first and second sub groups, each of the first sub group of radiating elements essentially co-located with a corresponding first frequency band radiating element, and wherein the second sub group of radiating elements are configured outside of the first frequency band radiating elements, the second sub group offset with respect to the first sub group of radiating elements in the first direction. Although this type of antenna element array arrangement was adapted and yielded acceptable performance some of the antenna parameters resulted in a limited deployment due to its larger size and weight, which was mandated by spacing between the antenna elements depending on the operating frequency. In prior art arrangement dual band antenna elements required spacing=Vs1+Vs2+Vs1>2λ (where Vs1 and Vs2 dimensions are related to spacing between HAx axis) at a lower frequency band, which limited number of dual frequency band antenna elements that could be placed onto a reflector resulting in a lower forward gain in low frequency band than otherwise is possible. Therefore there is a need to improve compactness of multiband antennas which result in greater forward gain (in both frequency bands), while providing greater number of independent RF terminals per unit volume weight allotted to such multi band antenna array.
This disclosure provides an antenna array arrangement which fully or in part mitigates and/or solves the drawbacks of prior art antenna array arrangements. More specifically, the present disclosure provides an antenna array arrangement which makes it possible to support dual band elements where the operating frequency range between lower (FL) and higher (FH) frequency bands is between 1.8 to 3.4 times higher than the lower frequency band.
This disclosure also provides an antenna array arrangement which has a smaller, lighter, and smaller wind load than prior art solutions. This disclosure also provides an alternative antenna array arrangement compared to prior art, by providing higher forward gain in multiple bands while maintaining the same overall volume and weight allotted to antenna array.
According to one aspect of the disclosure, these features are achieved with an antenna array arrangement for a multi band antenna, comprising a plurality of first dual band antenna elements adapted for transmitting/receiving in a lower antenna frequency band and in a higher antenna frequency band, a plurality of first single band antenna elements adapted for transmitting/receiving in the higher antenna frequency band, the first dual band antenna elements and the first single band antenna elements being arranged in a row, wherein at least two first single band antenna elements are arranged adjacent to each other.
Further features and advantages of the present disclosure will be appreciated from the following detailed description of the disclosure. It is an object of the present disclosure to provide a dual band, multicolumn antenna employing interdigitated antenna element technology to achieve broad frequency coverage. In carrying out these and other objectives, features, and advantages of the present disclosure, interdigitated antenna module based antenna array is provided for a wireless network system.
Reference is made to the accompanying drawings, which assist in illustrating the various pertinent features of the present disclosure. Due to multi positioning and use of identical elements in the parallel paths these may be referred to without the suffix a or b, and etc. since suffix indicates either of the relevant pair or grouping of elements is being referred to without distinction. The present disclosure will now be described primarily in solving aforementioned problems relating to use of interposed dual band capable antenna elements, and it should be expressly understood that the present disclosure may be applicable in other applications wherein multiband operation of an antenna array is required or desired. In this regard, the following description of a multi band, dual column, cross-polarized antenna array is presented for purposes of illustration and description. Furthermore, the description is not intended to limit the disclosure to the form disclosed herein. Accordingly, variants and modifications consistent with the following teachings, and skill and knowledge of the relevant art, are within the scope of the present disclosure. The embodiments described herein are further intended to explain modes known for practicing the disclosure disclosed herewith and to enable others skilled in the art to utilize the disclosure in equivalent, or alternative embodiments and with various modifications considered necessary by the particular application(s) or use(s) of the present disclosure. Present antenna is suitable for receiving and transmission of Radio Frequency (RF) signals as it shall be understood that signal flow is complementary and bidirectional unless pointed out otherwise.
The present disclosure advantageously provides interdigitated antenna elements to achieve multi band operation in an antenna array for receiving and transmitting. With reference to
In a second preferred embodiment of an antenna array (2) is equipped with only column 12 axis, each column having five composite antenna modules (20A to 20E, 30A to 30E) positioned longitudinally along respective column (12, 14) axis on the outwardly facing surface (10a) of the common antenna reflector (10) will now be described.
RF interface (90) is provided at the bottom gable (101) of the antenna array (2), but its location may be altered to a suitable location as needed. In first preferred embodiment six sets (91 to 96) antenna ports are provided. Each set of RF antenna ports consists of RF port dedicated to +45 degree and −45 degree polarization—in total 12 RF interfaces are provided (91a, b to 96a, b).
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A J-Feed network is used to couple to planar dipole elements used for Low frequency band (FL). High band feeds a coupled to aperture coupled patch antenna elements which are used for High frequency band operation (FH). Upper edges (64a, b) protrude through corresponding slots in the dipole arms (70a, b; 71a, b). A composite capacitvely coupled ground connection is provided via top side ground patch (65a-d) in combination with via holes between main feed network (60) first and second planar structures (61a, b) ground planes and interdigitated planar dipoles (70, 71) arms to provide ground reference to the four (80a-d) aperture coupled patch (ACP) antenna elements.
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In the first preferred embodiment antenna is configured for 4×4 MIMO for the high band and 2×2 MIMO for the low band. A total of 12 RF interface ports (91-96a,b) at the lower gable (90) of the antenna are provided. Internally the interface ports (91-96a,b) are coupled to corresponding low band (PL1, PL2) and high band (PH1 to 4) phase shifter—power dividing networks. It is a common practice to utilize fixed phase shifter—power dividing networks (PL1, 2; PH1 to 4) for a fixed beam down tilt or alternatively variable phase shifter networks can provide adjustable beam tilt. Interconnect details are provided in a table below for a left side of antenna, right side is similarly constructed.
Alternative configurations are also possible. For example, a 2×2 higher gain MIMO.