Patent Description:
The use of wireless terminals is on the rise worldwide, from cell phones, to tablet PCs and personal digital assistants (PDAs), among many other devices that have wireless connectivity capability. This tremendous proliferation of wireless devices with Internet connectivity has posed demands for higher data throughput. In fifth generation (<NUM>) mobile terminals, MIMO (multiple-input-multiple-output) technology is a major enabling technology for such increase in data throughput using multiple antenna elements on the mobile device, as well as at the base-station. One of the key technologies to enable the new generation of mobile communications is mMIMO (massive MIMO) below <NUM>.

Although mMIMO antenna systems will be key in <NUM> standards, the regulations in some countries may be a limiting factor. For instance, some proposed regulations require that for site acquisition and site upgrades, the dimension of the new antennas should be comparable to legacy products. In addition, to be able to maintain the mechanical support structures at the sites, the wind load of the new antennas should be equivalent to the legacy products. These factors lead to a very strict limitation for width of the antenna. As a result, when placing several independent antenna arrays in a small reflector of the antenna, as required for achieving high throughput, coupling is usually high enough to affect the antenna performance. In particular, when a dipole is placed in a side-by-side configuration on a small reflector, the horizontal beam width increases and directivity drops, the signal between adjacent arrays becomes more correlated, and thus the antenna array performance degrades. Such a coupling effect also poses a limitation on the antenna miniaturization.

Current approach to tackle high coupling between antenna arrays relies on placing structures that behave as perfect electric conductors (PEC) in between the antenna arrays. In that way, electromagnetic fields are reflected, and the side-by-side antenna arrays does not receive power from each other, thereby improving the isolation. However, this approach has the limitation that by placing the PECs to isolate the antenna arrays, the available aperture for each antenna array is reduced, and consequently the antenna performance suffers. Other existing solutions rely on narrow band circuits to cancel the coupling.

In an example, "Yagi-Uda" antenna, also known as a Yagi antenna, employs end fire antenna arrays which use reflection arrangement to cause a traverse of at least part of the energy of an end fire slow wave array back along the array to increase the effective length of the array and, therefore, cause an increase in antenna gain. In another example, Electromagnetic band-gap (EBG) structure is used that creates a stopband to block electromagnetic waves of certain frequency bands by forming a fine, periodic pattern of small metal patches on dielectric substrates, and thereby reduce the mutual coupling. In yet another example, metamaterial electromagnetic insulators are formed on the antennas by embedding circuit metamaterials operating in a non-propagating spectral region. In still another example, neutralization lines are provided to compensate for the existing electromagnetic coupling through a direct connection via a conductive link. The conductive link acts as a neutralization device by picking up a certain amount of the signal on one antenna and feeding it back to the other antenna.

There are one or more drawbacks associated with the existing solutions. Therefore, in light of the foregoing discussion, there exists a need to overcome the aforementioned drawbacks associated with conventional antenna devices.

<CIT> relates to dual band antenna. <CIT> relates to phased array antenna and inter-element mutual coupling control method. <CIT> relates to simultaneous transmit and receive antenna system. <CIT> relates to antenna array, antenna transceiver system and radar system.

The present disclosure seeks to provide an antenna device, and a base station that comprises one or more antenna devices. The present disclosure seeks to provide a solution to the existing problem of high coupling associated with conventional antenna devices having a plurality of radiating elements. An aim of the present disclosure is to provide a solution that overcomes at least partially the problems encountered in prior art and provide an improved isolation between the plurality of radiating elements in the antenna device.

In an aspect, an antenna device is provided. The antenna device comprises an antenna array for transmitting a signal. The antenna array comprises a plurality of radiating elements each configured to radiate the signal with a predetermined phase. The antenna device further comprises another radiating element that is not part of the antenna array. Herein, the phase of the signal for each radiating element of the antenna array is controlled such that the signals radiated by the radiating elements of the array interfere destructively at, at least, part of the other radiating element.

The antenna device of the present disclosure provides destructive superposition of the electromagnetic fields from the plurality of radiating elements of the antenna array in the antenna device with more than one collocated source of signal by using multipath environment generated by another radiating element that is not part of the antenna array. This minimizes mutual coupling between the plurality of radiating elements of the antenna array of the antenna device, and thus increases efficiency and performance of the antenna device. This can further be used to miniaturize width of the antenna device with several independent antenna arrays.

In an implementation form, the antenna array is an end fire array.

In the antenna device of the present disclosure, the end fire array arrangement of the antenna array helps to avoid radiation perpendicular to a radiating axis of the radiating elements in the antenna array. Also due to the resulting resonance, the antenna array displays narrower beam and high directivity.

In an implementation form, the other radiating element is located on a broadside of the antenna array.

In the antenna device of the present disclosure, the other radiating element is located on the broadside of the antenna array, i.e. adjacent to the antenna array along a base axis that is perpendicular to a radiating direction of the other radiating element. This allows for destructive superposition of the signals radiated by the radiating elements of the antenna array at the at least part of the other radiating element.

The plurality of radiating elements are each configured to radiate the signal with a different amplitude, and wherein the amplitude of the signal for each radiating element is determined such that a magnitude of a superposition of the signals can be controlled at the at least part of the other radiating element.

In the antenna device of the present disclosure, with the amplitude of the signal radiated by the plurality of radiating elements being different from each other, however being determined helps to configure the other radiating element to generate signal with amplitude difference in order to cause destructive superposition at the at least part thereof, resulting in controllable magnitude of the signal after superposition, and thereby controlling the coupling effect in the antenna array of the antenna device.

The amplitude of the signal for each radiating element includes a variation based on the frequency of the signal.

In the antenna device of the present disclosure, the amplitude of the signal for each radiating element is controlled over corresponding frequency to allow for destructive interference of the signals by each radiating element over different paths at the at least part of the other radiating element. In this way, the coupling effect can be reduced for the entire signal bandwidth or a portion of the bandwidth only.

In an implementation form, a distance between the antenna array and the other radiating element is determined such that the signals radiated by the radiating elements of the array interfere destructively at the at least part of the other radiating element.

In an implementation form, the phase of the signal for each radiating element is controlled such that the signals radiated by the radiating elements of the array interfere destructively at an input port of the other radiating element.

In the antenna device of the present disclosure, the distance between the antenna array and the other radiating element, with the other radiating element, is determined such that the signal radiated by each radiating element of the antenna array has the phase and the amplitude at the at least part of the other radiating element that results in destructive superposition thereat, and thus reduce the coupling effect in the antenna array of the antenna device.

In an implementation form, the plurality of radiating elements are spaced apart along a radiating axis that is parallel to a radiating direction of the antenna array.

In the antenna device of the present disclosure, since maximum power by the antenna array is transmitted in the radiating direction (especially in case of the end fire array antenna), the plurality of radiating elements can achieve high gain as well as sharp directivity in a confined space.

In an implementation form, the antenna device comprises another antenna array. The other antenna array comprises a plurality of radiating elements. The plurality of radiating elements of the other antenna array includes said other radiating element.

In the antenna device of the present disclosure, the said another antenna array with its plurality of radiating elements being the said other radiating elements are positioned/calibrated with respect to the plurality of radiating elements in order to achieve destructive interference of the signals for the plurality of radiating elements of the antenna array at the at least part of the other radiating elements, and thereby helps to reduce the coupling effect in the antenna array of the antenna device.

In an implementation form, the signals radiated by the radiating elements of the antenna array interfere destructively at at least part of each radiating element of the other antenna array.

As discussed above, the said another antenna array with its plurality of radiating elements being the said other radiating elements allows for achieving destructive interference of the signals for the plurality of radiating elements of the antenna array at the at least part of the other radiating elements, and thereby reduces the coupling effect in the antenna array of the antenna device.

In an implementation form, the antenna array and the other antenna array are arranged parallel to each other.

In an implementation form, the other antenna array is configured to radiate in a frequency range that at least partially overlaps with a frequency range of the antenna array.

Since, as discussed, the signals radiated by the radiating elements of the antenna array may have variation in the frequencies of the signals, therefore the other radiating elements in the other antenna array radiate respective signals in the frequency range at least partially overlapping with the frequency range of the antenna array in order to achieve destructive interference for signals with different frequencies by the radiating elements of the antenna array at the at least part of the other radiating elements, and thereby helps to reduce the coupling effect in the antenna array of the antenna device.

In an implementation form, the antenna device further comprises a phase change element arranged between one or more of the radiating elements and the other radiating element, wherein, when the signal radiated by one or more of the radiating elements passes through the phase change element, the phase change element is configured to introduce a phase adjustment into the signal, and wherein the phase adjustment of the phase change element is determined such that the signals radiated by the radiating elements of the array interfere destructively at the at least part of the other radiating element.

The phase change element by introducing the phase adjustment into the signal modifies the phase of the signal radiated by one or more of the radiating elements to ensure that the signals radiated by the radiating elements of the array interfere destructively at the at least part of the other radiating element, and thereby helps to reduce the coupling effect in the antenna array of the antenna device.

In an implementation form, the antenna device further comprises a processor configured to control the phase of the signal for each radiating element.

The processor determines the phase of the signal to be radiated by the radiating elements of the array and controls each radiating element to radiate a signal as per the respective determined phase to ensure destructive interference at the at least part of the other radiating element, and thereby helps to reduce the coupling effect in the antenna array of the antenna device.

In another aspect, a base station comprising one or more antenna devices is provided.

The base station with the one or antenna devices as discussed above provides the advantages and effects achieved thereby. Each of the one or antenna devices of the base station has reduced mutual coupling due to the signals radiated by the radiating elements (of the antenna array therein) interfering destructively at the at least part of the other radiating element thereof.

It will be appreciated that all implementation forms discussed hereinabove can be combined. It has to be noted that all devices, elements, circuitry, units and means described in the present application could be implemented in the software or hardware elements or any kind of combination thereof. Even if, in the following description of specific implementations, a specific functionality or step to be performed by external entities is not reflected in the description of a specific detailed element of that entity which performs that specific step or functionality, it should be clear for a skilled person that these methods and functionalities can be implemented in respective software or hardware elements, or any kind of combination thereof.

The summary above, as well as the following detailed description of illustrative implementations, is better understood when read in conjunction with the appended drawings.

Implementations of the present disclosure will now be described, by way of example only, with reference to the following diagrams wherein:.

<FIG> is a diagrammatic illustration of an antenna device, according to an example implementation of the present disclosure. With reference to <FIG>, there is illustrated an antenna device <NUM>. In the present disclosure, the antenna device <NUM> may also be referred to as an antenna system, or an antenna element of an antenna. The antenna device <NUM> of the present disclosure is used in telecommunication applications. In an example, the antenna device <NUM> may be used in a wireless communication system. Examples of such wireless communication system include, but are not limited to, a base station (such as an Evolved Node B (eNB), a gNB, and the like), a repeater device, a customer premise equipment, and other customized telecommunication hardware.

As illustrated in <FIG>, the antenna device <NUM> comprises an antenna array <NUM>. The antenna device <NUM> further comprises another antenna array <NUM>, also sometimes referred to as another antenna device <NUM> without any limitations. The antenna array <NUM> comprises a plurality of radiating elements, namely a first radiating element 106A and a second radiating element 106B. Similarly, the other antenna array <NUM> comprises another radiating element, or specifically a plurality of other radiating elements, namely a first other radiating element 108A and a second other radiating element 108B. <FIG> illustrates the antenna device <NUM> with the other antenna array <NUM> including one another radiating element, for instance the second other radiating element 108B, according to another example implementation of the present disclosure. In the illustrated example, the antenna device <NUM> also comprises a base <NUM>. The base <NUM> is arranged to support the antenna array <NUM> and the other antenna array <NUM> therein, and is configured to act as an antenna reflector for both the antenna array <NUM> and the other antenna array <NUM>.

<FIG> is a diagrammatic illustration of the antenna array <NUM>, according to an example implementation of the present disclosure. As illustrated, the antenna array <NUM> comprises the first radiating element 106A and the second radiating element 106B. The antenna array <NUM> further comprises a meandered line <NUM>, a power splitter <NUM> and a printed circuit board (PCB) substrate <NUM>. The first radiating element 106A comprises a first polarization top dipole arm 118A, a second polarization top dipole arm 120A, a printed circuit board (PCB) substrate 122A and a top dipole balun 124A. The second radiating element 106B comprises a first polarization bottom dipole arm 118B, a second polarization bottom dipole arm 120B, a printed circuit board (PCB) substrate 122B and a bottom dipole balun 124B. The second radiating element 106B further comprises a ring <NUM>. Herein, the meandered line <NUM> are used to control the phase difference between the dipoles. The power splitter <NUM> is used to control amplitude difference between the dipoles. The printed circuit board (PCB) substrate <NUM> mechanically supports and electrically connects components of the antenna array <NUM> using for example, conductive tracks and pads. Components are generally soldered onto the PCB substrate <NUM> to both electrically connect and mechanically fasten them therewith. Herein, the ring <NUM> is used for impedance matching and beam width improvement.

Further, the first polarization top dipole arm 118A and the second polarization top dipole arm 120A are two identical conductive elements of equal length that radiate a pattern approximating that of an elementary electric dipole when the dipole arm is energized by the current. The printed circuit board (PCB) substrate 122A is similar to the PCB substrate <NUM> and thus has not been explained herein for the brevity of the present disclosure. The top dipole balun 124A is used to balance unbalanced power flow from an unbalanced line to a balanced line. For the first polarization top dipole arm 118A and the second polarization top dipole arm 120A, the currents on both arms of the dipole should be equal in magnitude. However, the currents will not necessarily be equal. The top dipole balun 124A forces choking of the current or a current choke and restores balanced operation.

Similarly, the first polarization bottom dipole arm 118B and the second polarization bottom dipole arm 120B are two identical conductive elements of equal length that radiate a pattern approximating that of an elementary electric dipole when the dipole arm is energized by the current. The printed circuit board (PCB) substrate 122B is similar to the PCB substrate <NUM> and thus has not been explained herein for the brevity of the present disclosure. The bottom dipole balun 124B is used to balance unbalanced power flow from an unbalanced line to a balanced line. For the first polarization bottom dipole arm 118B and the second polarization bottom dipole arm 120B, the currents on both arms of the dipole should be equal in magnitude. However, the currents will not necessarily be equal. The bottom dipole balun 124B forces choking of the current or a current choke and restores balanced operation.

Referring to <FIG> and <FIG> in combination, the antenna device <NUM> comprises the antenna array <NUM> for transmitting a signal. In some examples, the antenna array <NUM> may also be referred to as a radiating device, and the radiating elements 106A, 106B may be referred to as antenna elements. The signal transmitted by the antenna array <NUM> is an electromagnetic wave implemented for wireless telecommunication. Generally, the signal transmitted by the antenna array <NUM> may have a frequency band ranging from <NUM> Megahertz to <NUM> Gigahertz. Alternatively, in some implementations, the signal may be an extremely high frequency signal, e.g., in the millimetre wave range. Each of the radiating elements 106A, 106B of the antenna array <NUM> are collocated to work at the same frequency and are fed independently. Therefore, the antenna array <NUM> may be used in a wireless communication system. Examples of wireless communication system include, but are not limited to, a base station (such as an Evolved Node B (eNB), a gNB, and the like), a repeater device, a customer premise equipment, and other customized telecommunication hardware as known in the art.

The antenna array <NUM> comprises the plurality of radiating elements 106A, 106B each configured to radiate the signal with a predetermined phase. As discussed, the antenna array <NUM> comprises the plurality of radiating elements, namely the first radiating element 106A and the second radiating element 106B. The plurality of radiating elements 106A, 106B radiates high directivity electromagnetic signals for wireless telecommunication. Herein, the first radiating element 106A and the second radiating element 106B are arranged adjacent to each other and are electrically connected with each other, to form the antenna array <NUM>. It may be appreciated that the antenna array <NUM> comprises at least two radiating elements; however, the antenna array <NUM> may include any number of radiating elements, such as three radiating elements like a first radiating element, a second radiating element, a third radiating element and so on, depending on the application and configuration of the antenna array <NUM> without departing from the scope of the present disclosure.

Herein, the phase of the signal represents a particular point in time on the cycle of a waveform of the signal, measured as an angle in degrees, with the period of one cycle of the waveform of the signal is divided to <NUM> degrees or 2π radians. The term "phase" is meaningful for waves that repeat themselves over time. Each of the first radiating element 106A and the second radiating element 106B radiates the respective signals. The signal radiated by the first radiating element 106A and the signal radiated by the second radiating element 106B are radiated with the determined phase by exciting each of the plurality of radiating elements 106A, 106B differently. Herein, for example, the predetermined phase of the radiated signals may be anywhere in a range of <NUM> degrees to <NUM> degrees. In such implementation, the predetermined phase may be <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> degrees or <NUM> degrees. In an example, the signal of the first radiating element 106A and the signal of the second radiating element 106B have a difference of phase in between them. For example, the difference of phase between the radiated signals by the first radiating element 106A and the second radiating element 106B is in a range of <NUM> degrees to <NUM> degrees. In such implementation, the difference of phase may vary from <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> or <NUM> degrees up to <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> or <NUM> degrees.

According to an implementation, the antenna array <NUM> is an end fire array. The end fire array (also referred as two collocated radiating structures) is a type of array in which the number of identical radiating elements are placed, generally, at equal spacing and are fed with a current source of, generally, equal magnitude, but the phases of the current source vary progressively to achieve a highly unidirectional radiation pattern. The end fire array may also be defined as an array in which a direction of maximum radiation coincides with a direction of a radiating axis A of the array. That is, the end fire array provides maximum radiation along the radiating axis A thereof. The end fire array arrangement of the antenna array <NUM> helps to avoid radiation perpendicular to the radiating axis A of the radiating elements 106A, 106B in the antenna array <NUM>; and due to the resulting resonance, the antenna array <NUM> displays a narrower beam and high directivity.

According to an implementation, the plurality of radiating elements 106A, 106B are spaced apart along the radiating axis A that is parallel to a radiating direction of the antenna array <NUM>. As discussed, the radiating direction is the direction in which the antenna array <NUM> radiates maximum signal strength and hence, maximum power. Since the antenna array <NUM> is an end fire array, maximum power by the antenna array <NUM> is transmitted along the radiating axis A. Therefore, the plurality of radiating elements 106A, 106B are spaced apart along the radiating axis A. As illustrated in <FIG>, in the present examples, the first radiating element 106A is placed above and spaced apart from the second radiating element 106B along the radiating axis A. This helps to achieve high gain as well as sharp directivity in a confined space for the antenna array <NUM>.

The antenna device <NUM> further comprises another radiating element 108A, 108B that is not part of the antenna array <NUM>. According to an implementation, the antenna device <NUM> comprises another antenna array <NUM>, the other antenna array <NUM> comprising a plurality of radiating elements, the plurality of radiating elements of the other antenna array <NUM> including said other radiating element 108A, 108B. Herein, the other radiating elements 108A, 108B are part of the other antenna array <NUM>. In some examples, the other antenna array <NUM> may also be referred to as a radiating device, and the other radiating elements 108A, 108B may also be referred to as the other antenna element. As discussed, the other antenna array <NUM> comprises the plurality of other radiating elements, namely the first other radiating element 108A and the second other radiating element 108B. The plurality of radiating elements 108A, 108B radiates high directivity electromagnetic signals. Herein, the first other radiating element 108A and the second other radiating element 108B are arranged adjacent to each other and are electrically connected with each other, to form the other antenna array <NUM>. Similar to the antenna array <NUM>, the signal transmitted by the other antenna array <NUM> may have a frequency band ranging from <NUM> Megahertz to <NUM> Gigahertz. Further, similar to the antenna array <NUM>, each of the other radiating elements 108A, 108B of the other antenna array <NUM> are collocated to work at the same frequency and are fed independently. It may be appreciated that the other antenna array <NUM> comprises at least one other radiating element; however, the other antenna array <NUM> may include any number of other radiating elements, such as three radiating elements like a first other radiating element, a second other radiating element, a third other radiating element and so on, depending on the application and configuration of the other antenna array <NUM> and the antenna array <NUM>, without departing from the scope of the present disclosure.

According to an implementation, the signals radiated by the radiating elements 106A, 106B of the antenna array <NUM> interfere destructively at at least part of each radiating element 108A, 108B of the other antenna array <NUM>. Herein, the destructive interference at the at least part of the other radiating elements 108A, 108B of the other antenna array <NUM> results in reduced magnitude of the signals radiated by the radiating elements 106A, 106B of the antenna array <NUM> after superposition, thus reducing the mutual coupling between the radiating elements 106A, 106B of the antenna array <NUM>.

In the antenna device <NUM>, the phase of the signal for each radiating element 106A, 106B of the antenna array <NUM> is controlled such that the signals radiated by the radiating elements 106A, 106B of the array <NUM> interfere destructively at at least part of the other radiating element 108A, 108B. It may be appreciated that the phase of each signal of the first radiating element 106A and of the second radiating element 106B is determined such that the other radiating element 108A, 108B may be positioned/calibrated to cause the signal of the first radiating element 106A and the signal of the second radiating element 106B to interfere destructively at the at least part of the other radiating elements 108A, 108B of the other antenna array <NUM>. Thereby, the magnitude of the signals radiated by the radiating elements 106A, 106B of the antenna array <NUM> after superposition is minimised at the at least part of the other radiating elements 108A, 108B, thus reducing the mutual coupling between the radiating elements 106A, 106B of the antenna array <NUM>.

It is to be noted that the signals radiated by the plurality of other radiating elements 108A, 108B of the other antenna array <NUM> are also radiated with a predetermined phase. It may be contemplated that the predetermined phases of the signals radiated by the other radiating elements 108A, 108B are in a range of <NUM> degrees to <NUM> degrees. In such implementation, the predetermined phase is typically from <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> or <NUM> degrees up to <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> or <NUM> degrees. The phase of the signal radiated by the other radiating elements 108A, 108B is determined such that the radiating element 106A, 106B may be positioned/calibrated to cause the signals of the other radiating elements 108A, 108B to interfere destructively at at least part of the radiating elements 106A, 106B of the antenna array <NUM> after superposition, to reduce the mutual coupling between the radiating elements 106A, 106B of the antenna array <NUM>. In an example, the signals radiated by the plurality of other radiating elements 108A, 108B may have a difference of phase in between them. For instance, the difference of phase in between the signals by the first other radiating element 108A and the second other radiating element 108B of the other antenna array <NUM> is in a range of <NUM> degrees to <NUM> degrees. In such implementation, the difference of phase is typically from <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> or <NUM> degrees up to <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> or <NUM> degrees.

According to an implementation, the antenna device <NUM> comprises a processor (not shown) configured to control the phase of the signal for each radiating element 106A, 106B. As discussed, the phase of the signal for each radiating element 106A, 106B of the antenna array <NUM> is controlled such that the signals radiated by the radiating elements 106A, 106B of the array <NUM> interfere destructively at at least part of the other radiating element 108A, 108B. The processor may determine a suitable phase of the signal for each radiating element 106A, 106B of the antenna array <NUM> to cause the signal for each radiating element 106A, 106B to interfere destructively with other signals radiated by the radiating elements 106A, 106B of the antenna array <NUM> at the at least part of the other radiating elements 108A, 108B of the other antenna array <NUM>. The processor may achieve this by manipulating or exciting the radiating elements 106A, 106B of the antenna array <NUM> with a different phase and amplitude.

It may be appreciated that the processor may be any analog device or digital device capable of controlling the radiating elements 106A, 106B in the antenna array <NUM>. In the present examples, the processor relates to a computational element that is operable to respond to and processes instructions that determines the phase of the signal. Optionally, the processor includes, but is not limited to, a microprocessor, a microcontroller, a complex instruction set computing (CISC) microprocessor, a reduced instruction set (RISC) microprocessor, a very long instruction word (VLIW) microprocessor, or any other type of processing circuit. Furthermore, the term "processor" may refer to one or more individual processors, processing devices and various elements associated with a processing device that may be shared by other processing devices. Additionally, the one or more individual processors, processing devices and processing elements are arranged in various architectures for responding to and for processing received instructions related to signal manipulation.

According to an implementation, the other radiating element 108A, 108B is located on a broadside of the antenna array <NUM>. As illustrated in <FIG>, the other radiating elements 108A, 108B of the other antenna array <NUM> are located adjacent to the radiating elements 106A, 106B of the antenna array <NUM> along a base axis B. Herein, the base axis B is perpendicular to the radiating direction A of the radiating elements 106A, 106B of the antenna array <NUM>. Further, as discussed, the other radiating elements 108A, 108B are part of the other antenna array <NUM>.

According to an implementation, the antenna array <NUM> and the other antenna array <NUM> are arranged parallel to each other. As may be contemplated, such arrangement with the antenna array <NUM> and the other antenna array <NUM> being arranged parallel to each other, and the other radiating element 108A, 108B of the other antenna array <NUM> being located on the broadside of the antenna array <NUM> allows for destructive superposition of the signals radiated by the radiating elements 106A, 106B of the antenna array <NUM> at the at least part of the other radiating elements 108A, 108B.

According to an implementation, a distance between the antenna array <NUM> and the other radiating element 108A, 108B is determined such that the signals radiated by the radiating elements 106A, 106B of the array <NUM> interfere destructively at the at least part of the other radiating element 108A, 108B. As illustrated in <FIG>, the antenna array <NUM> and the other antenna array <NUM> are spaced apart along the base axis B. The base axis B is a horizontal axis that is perpendicular to the radiating axis A of the antenna array <NUM> along which the antenna array <NUM> and the other antenna array <NUM> are arranged. As may be contemplated, the phase of the signal radiated by each of the plurality of radiating elements 106A, 106B of the antenna array <NUM> depends on the distance by which the waveform of the signal has travelled. The distance between the antenna array <NUM> and the other antenna array <NUM> is such determined that the signal radiated by each of the plurality of radiating elements 106A, 106B of the antenna array <NUM> is out of phase with each other to interfere destructively at the other radiating elements 108A, 108B. This ensures that the magnitude of the superposition of the signal radiated by each of the plurality of radiating elements 106A, 106B of the antenna array <NUM> is reduced to minimize mutual coupling between the radiating elements 106A, 106B.

In accordance with an implementation, the other antenna array <NUM> is configured to radiate in a frequency range that at least partially overlaps with a frequency range of the antenna array <NUM>. As discussed, the signal radiated by the other antenna array <NUM> is a radio frequency wave that is transmitted by the other radiating elements 108A, 108B therein. It may be desired that the signal radiated by each of the plurality of radiating elements 106A, 106B of the antenna array <NUM> may interfere destructively at the other radiating elements 108A, 108B of the other antenna array <NUM>. This ensures that the magnitude of the superposition of the signal radiated by each of the plurality of radiating elements 106A, 106B of the antenna array <NUM> is reduced to minimize mutual coupling between the radiating elements 106A, 106B. For this purpose, it may be required that at least a part of the frequency range of the signal radiated by the other radiating element 108A, 108B of the other antenna array <NUM> overlaps with the signal radiated by each of the plurality of radiating elements 106A, 106B of the antenna array <NUM> to allow for destructive interference at the at least part of the other radiating element 108A, 108B of the other antenna array <NUM>.

In one or more examples, the plurality of other radiating elements 108A, 108B of the other antenna array <NUM> are directly fed from the same source as the radiating elements 106A, 106B of the antenna array <NUM> so that the signals radiated by the other radiating elements 108A, 108B of the other antenna array <NUM> have an overlapped frequency band with the signals radiated by the other radiating elements 108A, 108B of the antenna array <NUM>. In an example, the frequency range of the antenna array <NUM> is <NUM> Megahertz to <NUM> Megahertz and the frequency range of the other antenna array <NUM> is <NUM> Megahertz to <NUM> Megahertz, resulting in an overlap of <NUM> Megahertz between <NUM> Megahertz to <NUM> Megahertz.

According to an implementation, the plurality of radiating elements 106A, 106B are each configured to radiate the signal with a different amplitude, and wherein the amplitude of the signal for each radiating element 106A, 106B is determined such that a magnitude of a superposition of the signals is minimised at the at least part of the other radiating element 108A, 108B. Herein, with the amplitude of the signal radiated by the plurality of radiating elements 106A, 106B being different from each other, however being determined (i.e. known) helps to position/calibrate the other radiating elements 108A, 108B to cause destructive superposition of the signal for each radiating element 106A, 106B at the at least part of the other radiating elements 108A, 108B, resulting in minimised magnitude of the signal for each radiating element 106A, 106B after superposition (i.e. destructive interference), and thereby reducing coupling effect in the antenna array <NUM> of the antenna device <NUM>.

According to an implementation, the amplitude of the signal for each radiating element 106A, 106B includes a variation based on the frequency of the signal. That is, the amplitude of the signal radiated by the first radiating element 106A and the amplitude of the signal radiated by the second radiating element 106B varies based on the frequency variation in order to control the amplitude of the signals over frequency range so that there is a spectrum of signals with varying frequencies and amplitude, and thus there is an increased probability of destructive superposition at the at least part of the other radiating elements 108A, 108B, resulting in minimised magnitude of the signals after superposition (i.e. destructive interference), and thereby reducing the coupling effect in the antenna array <NUM> of the antenna device <NUM>.

<FIG> is a schematic illustration of an antenna device 200A, according to an example implementation of the present disclosure. With reference to <FIG>, as shown, the antenna device 200A comprises the plurality of radiating elements 106A, 106B of the antenna array <NUM> and the other radiating elements 108A, 108B of the other antenna array <NUM>. Herein, the signals radiated by the radiating elements 106A, 106B are referred to as "first signals" and the signals radiated by the other radiating elements 108A, 108B are referred to as "second signals". The amplitude and the phase of the first signal radiated by the first radiating element 106A with respect to the first other radiating element 108A are represented as a<NUM> and α<NUM>, respectively; and the amplitude and the phase of the signal radiated by the first radiating element 106A with respect to the second other radiating element 108B are represented as a<NUM> and α<NUM>, respectively. Further, the amplitude and the phase of the signal radiated by the second radiating element 106B with respect to the first other radiating element 108A are represented as a<NUM> and α<NUM>, respectively; and the amplitude and the phase of the signal radiated by the second radiating element 106B with respect to the second other radiating element 108B are represented as a<NUM> and α<NUM> , respectively. Furthermore, the amplitude and the phase of the second signal radiated by the first other radiating element 108A with respect to the first radiating element 106A are represented as b<NUM> and β<NUM>, respectively; and the amplitude and the phase of the second signal radiated by the first other radiating element 108A with respect to the second radiating element 106B are represented as b<NUM> and β<NUM>, respectively. Also, the amplitude and the phase of the second signal radiated by the second other radiating element 108B with respect to the first radiating element 106A are represented as b<NUM> and β<NUM>, respectively; and the amplitude and the phase of the signal radiated by the second other radiating element 108B with respect to the second radiating element 106B are represented as b<NUM> and β<NUM>, respectively.

According to implementations of the present disclosure, the amplitude and the phase of the first signal for each radiating element 106A, 106B of the antenna array <NUM> is determined to position/calibrate the other radiating elements 108A, 108B of the other antenna array <NUM> such that the amplitude of the first signal radiated by the radiating elements 106A, 106B is minimized in superposition at the at least part of the other radiating elements 108A, 108B, and thereby reduce coupling effect between the radiating elements 106A, 106B in the antenna array <NUM> of the antenna device 200A. Cancellation of the signals in superposition at the location of the one other radiating elements 108A, 108B of the other antenna array <NUM> is represented as the following equations, <MAT> <MAT>.

Similarly, the amplitude and the phase of the second signal for each other radiating element 108A, 108B of the other antenna array <NUM> is determined to position/calibrate the radiating elements 106A, 106B of the antenna array <NUM> such that the amplitude of the second signal radiated by the other radiating elements 108A, 108B is minimized in superposition at the at least part of the radiating elements 106A, 106B. Cancellation of the signals in superposition at the location of the one other radiating elements 108A, 108B of the other antenna array <NUM> is represented as the following equations, <MAT> <MAT>.

The above approach as described in reference to <FIG> provides for direct cancellation of mutual coupling between the radiating elements 106A, 106B in the antenna array <NUM> of the antenna device 200A over air. Herein, the cancellation is achieved due to the superposition of electromagnetic fields of the signals in the antenna device 200A.

<FIG> is a schematic illustration of an antenna device 200B, according to another example implementation of the present disclosure. With reference to <FIG>, as shown, the antenna device 200B comprises the plurality of radiating elements 106A, 106B of the antenna array <NUM> and the other radiating elements 108A, 108B of the other antenna array <NUM>. Herein, the signals radiated by the radiating elements 106A, 106B are referred to as "first signals" and the signals radiated by the other radiating elements 108A, 108B are referred to as "second signals". The amplitude and the phase of the first signal radiated by the first radiating element 106A with respect to the first other radiating element 108A are represented as a<NUM> and α<NUM>, respectively; and the amplitude and the phase of the signal radiated by the first radiating element 106A with respect to the second other radiating element 108B are represented as a<NUM> and α<NUM>, respectively. Further, the amplitude and the phase of the signal radiated by the second radiating element 106B with respect to the first other radiating element 108A are represented as a<NUM> and α<NUM>, respectively; and the amplitude and the phase of the signal radiated by the second radiating element 106B with respect to the second other radiating element 108B are represented as a<NUM> and α<NUM> , respectively. Furthermore, the amplitude and the phase of the second signal radiated by the first other radiating element 108A with respect to the first radiating element 106A are represented as b<NUM> and β<NUM>, respectively; and the amplitude and the phase of the second signal radiated by the first other radiating element 108A with respect to the second radiating element 106B are represented as b<NUM> and β<NUM>, respectively. Also, the amplitude and the phase of the second signal radiated by the second other radiating element 108B with respect to the first radiating element 106A are represented as b<NUM> and β<NUM>, respectively; and the amplitude and the phase of the signal radiated by the second other radiating element 108B with respect to the second radiating element 106B are represented as b<NUM> and β<NUM> , respectively. Further, the amplitude and the phase of signal radiated between the plurality of radiating elements 106A, 106B of the antenna array <NUM> are represented as c<NUM> and Ω<NUM>, respectively; and the amplitude and the phase of signal radiated between the other radiating elements 108A, 108B of the other antenna array <NUM> are represented as c<NUM> and Ω<NUM>, respectively.

According to an implementation, the phase of the signal for each radiating element 106A, 106B is controlled such that the signals radiated by the radiating elements 106A, 106B of the array <NUM> interfere destructively at an input port of the other radiating element 108A, 108B. Cancellation of the signals in superposition at the input port of the other antenna array <NUM> is represented by the following equation, <MAT>.

Furthermore, in an example, the phase of the signal for each other radiating element 108A, 108B is controlled such that the signals radiated by the other radiating element 108A, 108B. interfere destructively at an input port of the radiating elements 106A, 106B of the array <NUM>. Cancellation of the signals in superposition at the input port of the antenna array <NUM> is represented by the following equation, <MAT>.

The above approach as described in reference to <FIG> provides for cancelling of coupling between the radiating elements 106A, 106B of the antenna array <NUM> at the input port of the other radiating elements 108A, 108B, i.e. the other antenna array <NUM>. This approach also accounts for structure of the radiating elements 106A, 106B and the other radiating elements 108A, 108B.

<FIG> is a schematic illustration of an antenna device 200C, according to an example implementation of the present disclosure. With reference to <FIG>, as shown, the antenna device 200C comprises the plurality of radiating elements 106A, 106B of the antenna array <NUM> and the other radiating elements 108A, 108B of the other antenna array <NUM>. Herein, the signals radiated by the radiating elements 106A, 106B are referred to as "first signals" and the signals radiated by the other radiating elements 108A, 108B are referred to as "second signals". The amplitude and the phase of the first signal radiated by the first radiating element 106A with respect to the first other radiating element 108A are represented as a<NUM> and α<NUM>, respectively; and the amplitude and the phase of the signal radiated by the first radiating element 106A with respect to the second other radiating element 108B are represented as a<NUM> and α<NUM>, respectively. Further, the amplitude and the phase of the signal radiated by the second radiating element 106B with respect to the first other radiating element 108A are represented as a<NUM> and α<NUM>, respectively; and the amplitude and the phase of the signal radiated by the second radiating element 106B with respect to the second other radiating element 108B are represented as a<NUM> and α<NUM> , respectively. Furthermore, the amplitude and the phase of the second signal radiated by the first other radiating element 108A with respect to the first radiating element 106A are represented as b<NUM> and β<NUM>, respectively; and the amplitude and the phase of the second signal radiated by the first other radiating element 108A with respect to the second radiating element 106B are represented as b<NUM> and β<NUM>, respectively. Also, the amplitude and the phase of the second signal radiated by the second other radiating element 108B with respect to the first radiating element 106A are represented as b<NUM> and β<NUM>, respectively; and the amplitude and the phase of the signal radiated by the second other radiating element 108B with respect to the second radiating element 106B are represented as b<NUM> and β<NUM>, respectively.

As illustrated in <FIG>, the antenna device 200C further comprises a phase change element <NUM>. According to an implementation, a phase change element <NUM> is arranged between one or more of the radiating elements 106A, 106B and the other radiating element 108A, 108B, wherein, when the signal radiated by one or more of the radiating elements 106A, 106B passes through the phase change element <NUM>, the phase change element <NUM> is configured to introduce a phase adjustment into the signal, and wherein the phase adjustment of the phase change element <NUM> is determined such that the signals radiated by the radiating elements 106A, 106B of the array <NUM> interfere destructively at the at least part of the other radiating element <NUM>. The phase change element <NUM> is a media placed in the path of propagation of the signal between the antenna array <NUM> and the other antenna array <NUM> to change the phase of the signal when the signal passes through the phase change element <NUM> without causing distortion and loss of the signal. For example, the phase change element <NUM> is placed between the antenna array <NUM> and the other antenna array <NUM> to alter the phase α<NUM> of the first signal radiated by the first radiating element 106A. In the present examples, the phase change element <NUM> may be formed from any suitable material, for example, a dielectric material or metamaterial. The phase adjustment of the phase change element <NUM> is determined such that the signal radiated by the at least one of the radiating elements 106A, 106B undergoes destructive interference with the signal radiated by the other of the radiating elements 106A, 106B that results in minimized amplitude of the signal at the other radiating elements 108A, 108B of the other antenna array <NUM>. In the illustration of <FIG>, the phase adjustment provided by the phase change element <NUM> is represented as τ <NUM>. Cancellation of the signals using the phase change element <NUM> at the other antenna array <NUM> is represented by the following equation, <MAT>.

Further, cancellation of the second signal using the phase change element <NUM> at the at least part of the plurality of radiating elements 106A, 106B of the antenna array <NUM> is represented by the following equation, <MAT>.

<FIG> is a diagrammatic illustration of an antenna device 300A, according to an example implementation of the present disclosure. As illustrated in <FIG>, the antenna device 300A comprises a first antenna structure <NUM>, a second antenna structure <NUM> and a third antenna structure <NUM>. Each of the first antenna structure <NUM>, the second antenna structure <NUM> and the third antenna structure <NUM> comprises multiple ports.

<FIG> is a graphical representation that depicts an exemplary scattering parameter 300B of the antenna device 300A of <FIG>, according to an example implementation of the present disclosure. The scattering parameter 300B provides the input-output relationship between ports in the antenna device 300A. The scattering parameter 300B shows reflection and transmission characteristics of amplitude and optionally phase of the signal in the frequency domain. Herein, the power (dB) of the scattering parameter 300B is shown on Y-axis <NUM> at each frequency (in Megahertz) on the X-axis <NUM>.

In the scattering parameter 300B, it may be seen that a first line <NUM> represents the return loss (Sii) of a first port which operates best at about <NUM> Megahertz with power at about -<NUM> dB. Further, a second line <NUM> represents the return loss (Sii) of a port which operates best at about <NUM> Megahertz with power at about -<NUM> dB. Also, as may be seen, a third line <NUM> represents the coupling (Sij) of a port which operates best at about <NUM> Megahertz with power at about -<NUM> dB. Similarly, a fourth line <NUM> represents the coupling (Sij) of a port which operates best at about <NUM> Megahertz with power at about -<NUM> dB. Also, a fifth line <NUM> represents the coupling (Sij) of a port which operates best at about <NUM> Megahertz with power at about -<NUM> dB. The graphical representation shows how it is possible to have each element tuned and isolated from adjacent elements even with a very small distance between them.

<FIG> is a block diagram of a base station with one or more antenna devices, according to an example implementation of the present disclosure. <FIG> is described in conjunction with elements from <FIG> and <FIG>, <FIG>, and <FIG>. With reference to <FIG>, there is shown a base station <NUM> that comprises one or more antenna devices <NUM>, such as the antenna device <NUM>, 200A, 200B, 200C, or <NUM>. The base station <NUM> include suitable logic, circuitry, and/or interfaces that may be configured to communicate with a plurality of wireless communication devices over a cellular network (e.g. <NUM>, <NUM>, <NUM>, or <NUM>) via the one or more antenna devices <NUM>, such as the antenna device <NUM>, 200A, 200B, 200C, or <NUM>. Examples of the base station <NUM> may include, but are not limited to, an evolved Node B (eNB), a Next Generation Node B (gNB), and the like. In an example, the base station <NUM> may include an array of antenna devices that function as an antenna system to communicate with the plurality of wireless communication devices in an uplink and a downlink communication. Examples of the plurality of wireless communication devices include, but are not limited to, a user equipment (e.g. a smartphone), a customer premise equipment, a repeater device, a fixed wireless access node, or other communication devices or telecommunications hardware.

The antenna device of the present disclosure has a plurality of radiating elements that radiate signals with predetermined different phases and amplitudes that result in destructive interference, which in turn results in reduced coupling between adjacent antenna arrays without degrading the individual performance of each antenna array. The phase and amplitude may be determined directly based on propagation of the signal, distances between the antenna array and the other antenna array and source excitations of the plurality of radiating elements. Thus, the proposed antenna device reduces coupling without increasing the size of the antenna device, which facilitates certain activities related to telecommunication services, such as site acquisition, local regulations regarding site upgrades and/or reuse of current mechanical support structures at the installation sites.

The antenna device of the present disclosure ensures decoupling of two closely spaced end fire antenna elements. This is achieved by having two sources of the same signal with a phase difference, such that the fields can be added destructively on the adjacent antenna array, therefore, reducing the coupling between them. Each of the collocated antennas work at the same frequency and are fed independently, which allows a phase selection that would cancel the coupling on an adjacent equivalent element. In the antenna systems, as electromagnetic (EM) fields propagate, constructive and destructive superposition can be generated. The present antenna device provides a novel approach to increase the isolation between closely spaced antenna arrays. The antenna device generates destructive superposition of the EM fields on the side by side elements of the array by profiting from the multipath environment generated when using a radiating element with more than one collocated source of signal and another radiating element. The achieved isolation improvement can be used to miniaturize the width of an antenna device with several independent antenna arrays. Since the changes in design of antenna device are based on propagation rather than circuitry, the resulting design is broadband enough to support current bands in base stations.

Claim 1:
An antenna device (<NUM>, 200A, 200B, 200C, <NUM>, <NUM>) comprising an antenna array (<NUM>) for transmitting a signal, the antenna array comprising: a plurality of radiating elements (106A, 106B) each configured to radiate the signal with a predetermined phase;
the antenna device further comprising another radiating element (108A, 108B) that is not part of the antenna array,
wherein the phase of the signal for each radiating element of the antenna array is controlled such that the signals radiated by the radiating elements of the array are configured to interfere destructively at at least part of the other radiating element;
wherein the plurality of radiating elements (106A, 106B) are each configured to radiate the signal with a different amplitude, and
wherein the amplitude of the signal for each radiating element is determined such that a magnitude of a superposition of the signals is minimised at the at least part of the other radiating element (108A, 108B);
wherein the amplitude of the signal for each radiating element (106A, 106B) includes a variation based on the frequency of the signal.