Patent Description:
Current radio direction-finding (RDF) systems are capable of immediately and precisely finding a location of a transmitting entity that transmits radio signals. However, such RDF systems require extensive hardware and processing resources, and accordingly are very expensive and have a high power consumption.

There is thus a need in the art for a new radio direction-finding system and methods.

References considered to be relevant as background to the presently disclosed subject matter are listed below. Acknowledgement of the references herein is not to be inferred as meaning that these are in any way relevant to the patentability of the presently disclosed subject matter.

<CIT>, relates to a process for locating radio sources by means of a two-channel high resolution radiogoniometer comprising a network of a specified number of sensors. The process comprises at least the following steps: multiplexing the signals supplied by the sensors on the inputs of only two receivers; and estimating with the aid of a calculation device coupled to the outputs of the two receivers the angles of arrival of the waves emitted by the sources on the basis of an estimation of the covariance matrix of the signals supplied by the two receivers.

<CIT>, discloses that in order to compensate for interfering FM or PM modulation of the direction-finding signal of a radio direction finder, the direction-finding signal from the direction-finding antenna is mixed with the reference signal from a reference antenna in accordance with the quadrature principle, and the direction-finding information is determined from the complex quadrature components which are thus directly obtained.

<CIT>, discloses a method of determining the angle of arrival of a signal, the method comprising the steps of: providing a plurality of antennae; sampling, in turn, the output from each of the antennae, to obtain a set of samples, each of the samples relating to different points in time; performing a Fourier transform on the set of samples, thereby producing a sequence of spectral lines; identifying a signal impinging on the antennae from the configuration of the spectral lines; and calculating, from phase and amplitude data gathered from at least a subset of the spectral lines, the direction of arrival of the signal at the antennae.

<NPL>, describes one method of estimating the direction of an electromagnetic source based on phase comparison. The design and fabrication of a prototype antenna to demonstrate a new DF antenna architecture is described. Four antenna elements are grouped into three pairs with element spacing according to a set of symmetrical number system pairwise relatively prime moduli. The phase difference between each pair of elements is a symmetrical folding waveform that is determined using a mixer.

<CIT>, discloses, in an interferometer system, a revolving antenna array to sufficiently resolve all ambiguities in determination of frequency and direction of arrival of a wave-front. The frequency and direction of arrival are determined by matching predicted phase difference codes with an actual code measured at the antenna array, utilizing a cross-correlation technique. The number of parameters that can be simultaneously uniquely determined by the system depends on if the antenna array is rotated in planar or conical surfaces, and if the cross-correlation is uni- or multi-dimensional. The antenna array may include more than one baselines to enhance the system sensitivity and finding capacity.

<CIT>, relates to an apparatus and a method for recognizing a direction of a smart antenna. The apparatus for recognizing a direction of a signal in a smart antenna includes a plurality of antennas arranged in series in a predetermined method and a preconfigured database, a storage unit, a wireless DC converter converting a composite signal of the received signals transmitted to the arranged antenna into a DC signal and receiving the DC signal from the wireless DC converter to obtain a magnitude value of the DC signal, and a controller configured to retrieve a value from the database and determine a phase difference between the received signals corresponding to the magnitude value and a direction in which the received signals are input to the antennas. Accordingly, the phase difference information of the signals received from the smart antenna can be found in the high frequency band.

<CIT>, relates to the field of radiolocation direction-finding systems, and aims to provide a single-channel radiolocation direction-finding system and a direction-finding method thereof. The single-channel radiolocation direction-finding system is characterized by comprising a direction-finding antenna array, a single-channel receiver with the functions of filtration, amplification, frequency conversion and amplitude limitation, and a direction-finding microprocessor for A/D sampling and digital signal processing, wherein the direction-finding antenna array mainly comprises N identical antenna units which are arranged on the circumference of a concentric circle, wherein N is greater than or equal to <NUM>; and each antenna unit is connected with the single-channel receiver through a radio-frequency electronic switch. A single-channel radio direction-finding technology is combined with a phase interference method and a Doppler direction-finding principle, and only needs one single-channel receiver with the functions of filtration, amplification, frequency conversion and amplitude limitation.

<CIT>, receives data via a plurality of antennas, and uses a switching network to couple the antennas to a single receiver and a single analog-to-digital converter to digitize the incoming signal. In the receiver, the incident radiation is mixed with a local oscillator signal and down converted to an intermediate frequency (IF). This IF signal is discretely sampled in the analog-to-digital converter, and further processing is done using digital techniques. The incoming signal has to be phase compared to obtain the angle of arrival. Different delay times are used to receive the digital data from the different antennas at the same sampling times, with the data aligned according to the time axis. The frequency of the incoming signals can then be detected by performing a Fast Fourier Transform (FFT) on the data from one antenna with respect to time. Once the primary frequencies are determined, one can find the related amplitudes of the data from the other antennas. An FFT can then be performed on the amplitude values found. The output of this FFT gives the phase information related to the incoming signals and thus the solution to the Angle of Arrival (AOA) problem.

<CIT>, discloses performing radio-signal direction finding in the following manner. There are a plurality of antennas at different locations. A switchable antenna coupler switches from one antenna being coupled to a radio-signal input, to another antenna being coupled to the radio-signal input. A radio-signal processor processes a radio signal which is present at the radio-signal input so as to obtain a phase-detection input signal. A phase-change detector detects a phase change in the phase-detection input signal due to the switching from the one antenna to the other antenna. A calculator calculates the direction of the radio-signal source on the basis of this phase change. <CIT>, discloses direction findings by radio, and comprises arranging an array of antennas to receive signals from emitters, selecting individual antenna signals using a first multipole switch and determining antenna signal strengths. Individual antenna signals are also selected by multipole switch, which routes a selected signal to a third multipole switch. The third switch switches a phase shifter into and out of an antenna signal path. An adder is employed to add an antenna signal in a first signal path extending via the first multipole switch to a different antenna signal in a second signal path extending via the second and third switches. This determines combined signal strengths between pairs of antenna signals, one of which either has or has not been relatively phase shifted depending on the third switch position. Covariance matrix elements are determined from signal strengths enabling emitter bearings to be derived. <CIT> discloses a direction locating system, <CIT> discloses a method and system for creating micro location zones by defining virtual boundaries using a system of one or more transmitters and receivers with one or more spatially-correlated antennas and <CIT> discloses a digital instantaneous direction finding system.

In accordance with a first aspect of the presently disclosed subject matter, there is provided an antenna and receiver system, the antenna and receiver system comprising: a first antenna array comprising a first plurality of antennas facing a first direction, the first plurality of antennas comprising: at least one main first antenna; and one or more summation first antennas; at least one first radio-frequency (RF) receive path connected to the main first antenna only; a second antenna array comprising a second plurality of antennas facing a second direction that is substantially opposite the first direction, the second antenna array being positioned substantially opposite the first antenna array, and the second plurality of antennas comprising: at least one main second antenna; and one or more summation second antennas; at least one second RF receive path connected to the main second antenna only; and one or more common RF receive paths, each common RF receive path of the common RF receive paths being connected to a distinct pair of substantially oppositely-positioned antennas comprising a given summation first antenna of the summation first antennas and a given summation second antenna of the summation second antennas, so that a first signal received by the given summation first antenna and a second signal received by the given summation second antenna are combined into a respective common signal.

In some cases, each of the common RF receive paths, the first RF receive path and the second RF receive path include: a RF front-end, a down-converter, an analog to digital converter and an intermediate-frequency (IF) processing resource.

In some cases, the antenna and receiver system further comprises: a third antenna array comprising a third plurality of antennas facing a third direction, substantially perpendicular to the first direction and to the second direction, the third plurality of antennas comprising: at least one main third antenna; and one or more summation third antennas; at least one third RF receive path connected to the main third antenna only; a fourth antenna array comprising a fourth plurality of antennas facing a fourth direction that is substantially opposite the third direction, the fourth antenna array being positioned substantially opposite the third antenna array, and the fourth plurality of antennas comprising: at least one main fourth antenna; and one or more summation fourth antennas; at least one fourth RF receive path connected to the main fourth antenna only; and one or more second common RF receive paths, each second common RF receive path of the second common RF receive paths being connected to a second distinct pair of substantially oppositely-positioned antennas comprising a given summation third antenna of the summation third antennas and a given summation fourth antenna of the summation fourth antennas, so that a third signal received by the given summation third antenna and a fourth signal received by the given summation fourth antenna are combined into a respective second common signal.

In some cases, each of the common RF receive paths, the second common RF receive paths, the first RF receive path, the second RF receive path, the third receive path and the fourth receive path include: a RF front-end, a down-converter, an analog to digital converter and an intermediate-frequency (IF) processing resource.

In some cases, a combination of the first antenna array, the second antenna array, the third antenna array and the fourth antenna array covers <NUM> degrees.

In accordance with a second aspect of the presently disclosed subject matter, there is provided a radio direction-finding system, comprising: an antenna and receiver system, the antenna and receiver system comprising: a first antenna array comprising a first plurality of antennas facing a first direction, the first plurality of antennas comprising: at least one main first antenna; and one or more summation first antennas; at least one first radio-frequency (RF) receive path connected to the main first antenna only; a second antenna array comprising a second plurality of antennas facing a second direction that is substantially opposite the first direction, the second antenna array being positioned substantially opposite the first antenna array, and the second plurality of antennas comprising: at least one main second antenna; and one or more summation second antennas; at least one second RF receive path connected to the main second antenna only; and one or more common RF receive paths, each common RF receive path of the common RF receive paths being connected to a distinct pair of substantially oppositely-positioned antennas comprising a given summation first antenna of the summation first antennas and a given summation second antenna of the summation second antennas, so that a first signal received by the given summation first antenna and a second signal received by the given summation second antenna are combined into a respective common signal; and a processing circuitry configured to: receive (A) main output signals from (a) the first RF receive path, and (b) the second RF receive path, and (B) common output signals from the common RF receive paths; upon a transmitting entity transmitting radio signals from a given direction, being substantially the first direction or substantially the second direction, analyze the main output signals to provide a coarse determination of the given direction; and upon providing the coarse determination of the given direction, provide a fine determination of the given direction utilizing the common output signals and a selected main output signal, of the main output signals, associated with the coarse determination of the given direction.

In some cases, the coarse determination is provided by performing amplitude-based coarse direction-finding.

In some cases, the fine determination is provided by performing interferometry.

In accordance with a third aspect of the presently disclosed subject matter, there is provided a radio direction-finding system, comprising an antenna and receiver system, the antenna and receiver system comprising: a first antenna array comprising a first plurality of antennas facing a first direction, the first plurality of antennas comprising: at least one main first antenna; and one or more summation first antennas; at least one first radio-frequency (RF) receive path connected to the main first antenna only; a second antenna array comprising a second plurality of antennas facing a second direction that is substantially opposite the first direction, the second antenna array being positioned substantially opposite the first antenna array, and the second plurality of antennas comprising: at least one main second antenna; and one or more summation second antennas; at least one second RF receive path connected to the main second antenna only; one or more common RF receive paths, each common RF receive path of the common RF receive paths being connected to a distinct pair of substantially oppositely-positioned antennas comprising a given summation first antenna of the summation first antennas and a given summation second antenna of the summation second antennas, so that a first signal received by the given summation first antenna and a second signal received by the given summation second antenna are combined into a respective common signal; a third antenna array comprising a third plurality of antennas facing a third direction, substantially perpendicular to the first direction and to the second direction, the third plurality of antennas comprising: at least one main third antenna; and one or more summation third antennas; at least one third RF receive path connected to the main third antenna only; a fourth antenna array comprising a fourth plurality of antennas facing a fourth direction that is substantially opposite the third direction, the fourth antenna array being positioned substantially opposite the third antenna array, and the fourth plurality of antennas comprising: at least one main fourth antenna; and one or more summation fourth antennas; at least one fourth RF receive path connected to the main fourth antenna only; and one or more second common RF receive paths, each second common RF receive path of the second common RF receive paths being connected to a second distinct pair of substantially oppositely-positioned antennas comprising a given summation third antenna of the summation third antennas and a given summation fourth antenna of the summation fourth antennas, so that a third signal received by the given summation third antenna and a fourth signal received by the given summation fourth antenna are combined into a respective second common signal; and a processing circuitry configured to: receive (A) main output signals from (a) the first RF receive path, (b) the second RF receive path, (c) the third RF receive path and (d) the fourth RF receive path, and (B) common output signals from (e) the common RF receive paths and (f) the second common RF receive paths; upon a transmitting entity transmitting radio signals from a given direction, analyze the main output signals to provide a coarse determination of the given direction; and upon providing the coarse determination of the given direction, provide a fine determination of the given direction utilizing the common output signals associated with the coarse determination of the given direction, and a selected main output signal, of the main output signals, associated with the coarse determination of the given direction.

In accordance with a fourth aspect of the presently disclosed subject matter, there is provided a radio direction-finding method, comprising: receiving (A) main output signals from (a) at least one first radio-frequency (RF) receive path, and (b) at least one second RF receive path, and (B) common output signals from one or more common RF receive paths; upon a transmitting entity transmitting radio signals from a given direction, being substantially a first direction or substantially a second direction that is substantially opposite the first direction, analyzing the main output signals to provide a coarse determination of the given direction; and upon providing the coarse determination of the given direction, providing a fine determination of the given direction utilizing the common output signals and a selected main output signal, of the main output signals, associated with the coarse determination of the given direction; wherein the first RF receive path is connected to a main first antenna only, the main first antenna being included in a first antenna array comprising a first plurality of antennas facing the first direction; wherein the second RF receive path is connected to a main second antenna only, the main second antenna being included in a second antenna array comprising a second plurality of antennas facing the second direction, the second antenna array being positioned substantially opposite the first antenna array; and wherein each common RF receive path of the common RF receive paths is connected to a distinct pair of substantially oppositely-positioned antennas comprising a given summation first antenna of one or more summation first antennas of the first plurality of antennas and a given summation second antenna of one or more summation second antennas of the second plurality of antennas, so that a first signal received by the given summation first antenna and a second signal received by the given summation second antenna are combined into a respective common signal.

In some cases, the coarse determination is provided by performing amplitude-based coarse direction-finding (DF).

In accordance with a fifth aspect of the presently disclosed subject matter, there is provided a radio direction-finding method, comprising: receiving (A) main output signals from (a) at least one first radio-frequency (RF) receive path, (b) at least one second RF receive path, (c) at least one third RF receive path and (d) at least one fourth RF receive path, and (B) common output signals from (e) one or more common RF receive paths and (f) one or more second common RF receive paths; upon a transmitting entity transmitting radio signals from a given direction, analyzing the main output signals to provide a coarse determination of the given direction; and upon providing the coarse determination of the given direction, providing a fine determination of the given direction utilizing the common output signals associated with the coarse determination of the given direction, and a selected main output signal, of the main output signals, associated with the coarse determination of the given direction; wherein the first RF receive path is connected to a main first antenna only, the main first antenna being included in a first antenna array comprising a first plurality of antennas facing a first direction; wherein the second RF receive path is connected to a main second antenna only, the main second antenna being included in a second antenna array comprising a second plurality of antennas facing a second direction that is substantially opposite the first direction, the second antenna array being positioned substantially opposite the first antenna array; wherein each common RF receive path of the common RF receive paths is connected to a distinct pair of substantially oppositely-positioned antennas comprising a given summation first antenna of one or more summation first antennas of the first plurality of antennas and a given summation second antenna of one or more summation second antennas of the second plurality of antennas, so that a first signal received by the given summation first antenna and a second signal received by the given summation second antenna are combined into a respective common signal; wherein the third RF receive path is connected to a main third antenna only, the main third antenna being included in a third antenna array comprising a third plurality of antennas facing a third direction, substantially perpendicular to the first direction and to the second direction; wherein the fourth RF receive path is connected to a main fourth antenna only, the main fourth antenna being included in a fourth antenna array comprising a fourth plurality of antennas facing a fourth direction that is substantially opposite the third direction, the fourth antenna array being positioned substantially opposite the third antenna array; and wherein each second common RF receive path of the second common RF receive paths is connected to a second distinct pair of substantially oppositely-positioned antennas comprising a given summation third antenna of summation third antennas of the third plurality of antennas and a given summation fourth antenna of summation fourth antennas of the fourth plurality of antennas, so that a third signal received by the given summation third antenna and a fourth signal received by the given summation fourth antenna are combined into a respective second common signal.

In some cases, each of the common RF receive paths, each of the second common RF receive paths, the first RF receive path, the second RF receive path, the third RF receive path and the fourth RF receive path include: a RF front-end, a down-converter, an analog to digital converter and an intermediate-frequency (IF) processing resource.

In accordance with a sixth aspect of the presently disclosed subject matter, there is provided a non-transitory computer readable storage medium having computer readable program code embodied therewith, the computer readable program code, executable by processing circuitry of a computer to perform a radio direction-finding method, comprising: receiving (A) main output signals from (a) at least one first radio-frequency (RF) receive path, and (b) at least one second RF receive path, and (B) common output signals from one or more common RF receive paths; upon a transmitting entity transmitting radio signals from a given direction, being substantially a first direction or substantially a second direction that is substantially opposite the first direction, analyzing the main output signals to provide a coarse determination of the given direction; and upon providing the coarse determination of the given direction, providing a fine determination of the given direction utilizing the common output signals and a selected main output signal, of the main output signals, associated with the coarse determination of the given direction; wherein the first RF receive path is connected to a main first antenna only, the main first antenna being included in a first antenna array comprising a first plurality of antennas facing the first direction; wherein the second RF receive path is connected to a main second antenna only, the main second antenna being included in a second antenna array comprising a second plurality of antennas facing the second direction, the second antenna array being positioned substantially opposite the first antenna array; and wherein each common RF receive path of the common RF receive paths is connected to a distinct pair of substantially oppositely-positioned antennas comprising a given summation first antenna of one or more summation first antennas of the first plurality of antennas and a given summation second antenna of one or more summation second antennas of the second plurality of antennas, so that a first signal received by the given summation first antenna and a second signal received by the given summation second antenna are combined into a respective common signal.

In accordance with a seventh aspect of the presently disclosed subject matter, there is provided a non-transitory computer readable storage medium having computer readable program code embodied therewith, the computer readable program code, executable by processing circuitry of a computer to perform a radio direction-finding method, comprising: receiving (A) main output signals from (a) at least one first radio-frequency (RF) receive path, (b) at least one second RF receive path, (c) at least one third RF receive path and (d) at least one fourth RF receive path, and (B) common output signals from (e) one or more common RF receive paths and (f) one or more second common RF receive paths; upon a transmitting entity transmitting radio signals from a given direction, analyzing the main output signals to provide a coarse determination of the given direction; and upon providing the coarse determination of the given direction, providing a fine determination of the given direction utilizing the common output signals associated with the coarse determination of the given direction, and a selected main output signal, of the main output signals, associated with the coarse determination of the given direction; wherein the first RF receive path is connected to a main first antenna only, the main first antenna being included in a first antenna array comprising a first plurality of antennas facing a first direction; wherein the second RF receive path is connected to a main second antenna only, the main second antenna being included in a second antenna array comprising a second plurality of antennas facing a second direction that is substantially opposite the first direction, the second antenna array being positioned substantially opposite the first antenna array; wherein each common RF receive path of the common RF receive paths is connected to a distinct pair of substantially oppositely-positioned antennas comprising a given summation first antenna of one or more summation first antennas of the first plurality of antennas and a given summation second antenna of one or more summation second antennas of the second plurality of antennas, so that a first signal received by the given summation first antenna and a second signal received by the given summation second antenna are combined into a respective common signal; wherein the third RF receive path is connected to a main third antenna only, the main third antenna being included in a third antenna array comprising a third plurality of antennas facing a third direction, substantially perpendicular to the first direction and to the second direction; wherein the fourth RF receive path is connected to a main fourth antenna only, the main fourth antenna being included in a fourth antenna array comprising a fourth plurality of antennas facing a fourth direction that is substantially opposite the third direction, the fourth antenna array being positioned substantially opposite the third antenna array; and wherein each second common RF receive path of the second common RF receive paths is connected to a second distinct pair of substantially oppositely-positioned antennas comprising a given summation third antenna of summation third antennas of the third plurality of antennas and a given summation fourth antenna of summation fourth antennas of the fourth plurality of antennas, so that a third signal received by the given summation third antenna and a fourth signal received by the given summation fourth antenna are combined into a respective second common signal.

In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the presently disclosed subject matter. However, it will be understood by those skilled in the art that the presently disclosed subject matter may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the presently disclosed subject matter.

Unless specifically stated otherwise, as apparent from the following discussions, it is appreciated that throughout the specification discussions utilizing terms such as "combining", "receiving", "analyzing", "performing" or the like, include actions and/or processes, including, inter alia, actions and/or processes of a computer, that manipulate and/or transform data into other data, said data represented as physical quantities, e.g. such as electronic quantities, and/or said data representing the physical objects. The terms "computer", "processor", "processing circuitry" and "controller" should be expansively construed to cover any kind of electronic device with data processing capabilities, including, by way of non-limiting example, a personal desktop/laptop computer, a server, a computing system, a communication device, a smartphone, a tablet computer, a smart television, a processor (e.g. digital signal processor (DSP), a microcontroller, a field-programmable gate array (FPGA), an application specific integrated circuit (ASIC), etc.), a group of multiple physical machines sharing performance of various tasks, virtual servers co-residing on a single physical machine, any other electronic computing device, and/or any combination thereof.

As used herein, the phrase "for example," "such as", "for instance" and variants thereof describe non-limiting embodiments of the presently disclosed subject matter. Reference in the specification to "one case", "some cases", "other cases" or variants thereof means that a particular feature, structure or characteristic described in connection with the embodiment(s) is included in at least one embodiment of the presently disclosed subject matter. Thus the appearance of the phrase "one case", "some cases", "other cases" or variants thereof does not necessarily refer to the same embodiment(s).

It is appreciated that, unless specifically stated otherwise, certain features of the presently disclosed subject matter, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the presently disclosed subject matter, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination.

In embodiments of the presently disclosed subject matter, fewer, more and/or different stages than those shown in <FIG> and <FIG> may be executed. In embodiments of the presently disclosed subject matter one or more stages illustrated in <FIG> and <FIG> may be executed in a different order and/or one or more groups of stages may be executed simultaneously. <FIG> illustrate a general schematic of the system architecture in accordance with embodiments of the presently disclosed subject matter. Each module in <FIG> and <FIG> can be made up of any combination of software, hardware and/or firmware that performs the functions as defined and explained herein. The modules in <FIG> and <FIG> may be centralized in one location or dispersed over more than one location. In other embodiments of the presently disclosed subject matter, the system may comprise fewer, more, and/or different modules than those shown in <FIG> and <FIG>.

Attention is now drawn to <FIG>, a schematic illustration of an example of a first antenna system <NUM>, in accordance with the presently disclosed subject matter.

In accordance with the presently disclosed subject matter, first antenna system <NUM> is configured to include a first antenna array (e.g., antenna array <NUM>) and a second antenna array (e.g., antenna array <NUM>). First antenna array (e.g., antenna array <NUM>) is configured to comprise first antennas (e.g., <NUM>-a, <NUM>-b, <NUM>-c) facing a first direction (e.g., direction 'w'), the first antennas (e.g., <NUM>-a, <NUM>-b, <NUM>-c) comprising: at least one main first antenna (e.g., main first antenna <NUM>-a); and one or more summation first antennas (e.g., <NUM>-b, <NUM>-c).

Second antenna array (e.g., antenna array <NUM>) is configured to comprise second antennas (e.g., <NUM>-a, <NUM>-b, <NUM>-c) facing a second direction (e.g., direction 'x') that is substantially opposite the first direction (e.g., direction 'w'), the second antenna array (e.g., antenna array <NUM>) being positioned substantially opposite the first antenna array (e.g., antenna array <NUM>), and the second antennas (e.g., <NUM>-a, <NUM>-b, <NUM>-c) comprising: at least one main second antenna (e.g., main second antenna <NUM>-a); and one or more summation second antennas (e.g., <NUM>-b, <NUM>-c).

Attention is now drawn to <FIG>, a schematic illustration of an example of a second antenna system <NUM>, in accordance with the presently disclosed subject matter.

In accordance with the presently disclosed subject matter, second antenna system <NUM> is configured to include a first antenna array (e.g., antenna array <NUM>) and a second antenna array (e.g., antenna array <NUM>), as detailed earlier herein, inter alia with reference to <FIG>.

Second antenna system <NUM> is further configured to include a third antenna array (e.g., antenna array <NUM>) and a fourth antenna array (e.g., antenna array <NUM>). Third antenna array (e.g., antenna array <NUM>) is configured to comprise third antennas (e.g., <NUM>-a, <NUM>-b, <NUM>-c) facing a third direction (e.g., direction 'y'), substantially perpendicular to the first direction (e.g., direction 'w') and to the second direction (e.g., direction 'x'), the third antennas (e.g., <NUM>-a, <NUM>-b, <NUM>-c) comprising: at least one main third antenna (e.g., main third antenna <NUM>-a); and one or more summation third antennas (e.g., <NUM>-b, <NUM>-c).

Fourth antenna array (e.g., antenna array <NUM>) is configured to comprise fourth antennas (e.g., <NUM>-a, <NUM>-b, <NUM>-c) facing a fourth direction (e.g., direction 'z') that is substantially opposite the third direction (e.g., direction 'y'), the fourth antenna array (e.g., antenna array <NUM>) being positioned substantially opposite the third antenna array (e.g., antenna array <NUM>), and the fourth antennas (e.g., <NUM>-a, <NUM>-b, <NUM>-c) comprising: at least one main fourth antenna (e.g., main fourth antenna <NUM>-a); and one or more summation fourth antennas (e.g., <NUM>-b, <NUM>-c).

In some cases, as illustrated in <FIG>, a combination of the first antenna array (e.g., antenna array <NUM>), the second antenna array (e.g., antenna array <NUM>), the third antenna array (e.g., antenna array <NUM>) and the fourth antenna array (e.g., antenna array <NUM>) covers <NUM> degrees.

Attention is now drawn to <FIG>, a block diagram schematically illustrating an example of an antenna and receiver system <NUM>, in accordance with the presently disclosed subject matter.

In accordance with the presently disclosed subject matter, in some cases, antenna and receiver system <NUM> can be associated with the first antenna system <NUM>. The antenna and receiver system <NUM> that is associated with the first antenna system <NUM> is configured to include at least one first radio-frequency (RF) receive path <NUM> (e.g., first RF receive path <NUM>-a), at least one second RF receive path <NUM> (e.g., second RF receive path <NUM>-a) and one or more common RF receive paths <NUM> (e.g., <NUM>-a and <NUM>-b).

The at least one first RF receive path <NUM> is connected to the at least one main first antenna of the first antenna array (e.g., antenna array <NUM>). In the event that the first antenna array (e.g., antenna array <NUM>) includes a single main first antenna, being, for example, main first antenna <NUM>-a, as in the example of the first antenna system <NUM> that is illustrated in <FIG> and the example of the second antenna system <NUM> that is illustrated in <FIG>, a single first RF receive path (e.g., <NUM>-a) is connected to the main first antenna (e.g., main first antenna <NUM>-a) only, as illustrated in <FIG>. Alternatively, in the event that the first antenna array (e.g., antenna array <NUM>) includes two or more main first antennas, a distinct first RF receive path of the first RF receive paths <NUM> is connected to each main first antenna only.

The at least one second RF receive path <NUM> is connected to the at least one main second antenna of the second antenna array (e.g., antenna array <NUM>). In the event that the second antenna array (e.g., antenna array <NUM>) includes a single main second antenna, being, for example, main second antenna <NUM>-a, as in the example of the first antenna system <NUM> that is illustrated in <FIG> and the example of the second antenna system <NUM> that is illustrated in <FIG>, a single second RF receive path (e.g., <NUM>-a) is connected to the main second antenna (e.g., main second antenna <NUM>-a) only, as illustrated in <FIG>. Alternatively, in the event that the second antenna array (e.g., antenna array <NUM>) includes two or more main second antennas, a distinct second RF receive path of the second RF receive paths <NUM> is connected to each main second antenna only.

Each common RF receive path (e.g., <NUM>-a, <NUM>-b) of the common RF receive paths <NUM> is connected to a distinct pair of substantially oppositely-positioned antennas comprising a given summation first antenna of the summation first antennas (e.g., <NUM>-b, <NUM>-c) in first antenna array (e.g., antenna array <NUM>) and a given summation second antenna of the summation second antennas (e.g., <NUM>-b, <NUM>-c) in second antenna array (e.g., antenna array <NUM>). For example, in the antenna and receiver system <NUM> that is illustrated in <FIG>, one common RF receive path <NUM>-a of the common RF receive paths <NUM> is connected to summation first antenna <NUM>-b and summation second antenna <NUM>-b, and the other common RF receive path <NUM>-b of the common RF receive paths <NUM> is connected to summation first antenna <NUM>-c and summation second antenna <NUM>-c. By connecting each common RF receive path (e.g., <NUM>-a, <NUM>-b) to a distinct pair of substantially oppositely-positioned antennas, the number of RF receive paths in the antenna and receiver system <NUM> can be reduced, thereby reducing the hardware requirements, size, cost and power requirements of the antenna and receiver system <NUM>.

In some cases, antenna and receiver system <NUM> can be associated with the second antenna system <NUM>. The antenna and receiver system <NUM> that is associated with the second antenna system <NUM> is configured to include the at least one first RF receive path <NUM> (e.g., first RF receive path <NUM>-a), the at least one second RF receive path <NUM> (e.g., second RF receive path <NUM>-a), the one or more common RF receive paths <NUM> (e.g., <NUM>-a and <NUM>-b), at least one third RF receive path <NUM> (e.g., third RF receive path <NUM>-a), at least one fourth RF receive path <NUM> (e.g., fourth RF receive path <NUM>-a), and one or more second common RF receive paths <NUM> (e.g., <NUM>-a and <NUM>-b).

The at least one first RF receive path <NUM> (e.g., first RF receive path <NUM>-a) is connected to the at least one main first antenna (e.g., main first antenna <NUM>-a) of the first antenna array (e.g., antenna array <NUM>), as described earlier herein.

The at least one second RF receive path <NUM> (e.g., second RF receive path <NUM>-a) is connected to the at least one main second antenna (e.g., main second antenna <NUM>-a) of the second antenna array (e.g., antenna array <NUM>), as described earlier herein.

Each common RF receive path (e.g., <NUM>-a, <NUM>-b) of the common RF receive paths <NUM> is connected to a distinct pair of substantially oppositely-positioned antennas comprising a given summation first antenna of the summation first antennas (e.g., <NUM>-b, <NUM>-c) in first antenna array (e.g., antenna array <NUM>) and a given summation second antenna of the summation second antennas (e.g., <NUM>-b, <NUM>-c) in second antenna array (e.g., antenna array <NUM>), as described earlier herein.

The at least one third RF receive path <NUM> is connected to the at least one main third antenna of the third antenna array (e.g., antenna array <NUM>). In the event that the third antenna array (e.g., antenna array <NUM>) includes a single main third antenna, being, for example, main third antenna <NUM>-a, as in the example of the second antenna system <NUM> that is illustrated in <FIG>, a single third RF receive path (e.g., <NUM>-a) is connected to the main third antenna (e.g., main third antenna <NUM>-a) only, as illustrated in <FIG>. Alternatively, in the event that the third antenna array (e.g., antenna array <NUM>) includes two or more main third antennas, a distinct third RF receive path of the third RF receive paths <NUM> is connected to each main third antenna only.

The at least one fourth RF receive path <NUM> is connected to the at least one main fourth antenna of the fourth antenna array (e.g., antenna array <NUM>). In the event that the fourth antenna array (e.g., antenna array <NUM>) includes a single main fourth antenna, being, for example, main fourth antenna <NUM>-a, as in the example of the second antenna system <NUM> that is illustrated in <FIG>, a single fourth RF receive path (e.g., <NUM>-a) is connected to the main fourth antenna (e.g., main fourth antenna <NUM>-a) only, as illustrated in <FIG>. Alternatively, in the event that the fourth antenna array (e.g., antenna array <NUM>) includes two or more main fourth antennas, a distinct fourth RF receive path of the fourth RF receive paths <NUM> is connected to each main fourth antenna only.

Each second common RF receive path (e.g., <NUM>-a, <NUM>-b) of the second common RF receive paths <NUM> is connected to a distinct pair of substantially oppositely-positioned antennas comprising a given summation third antenna of the summation third antennas (e.g., <NUM>-b, <NUM>-c) in third antenna array (e.g., antenna array <NUM>) and a given summation fourth antenna of the summation fourth antennas (e.g., <NUM>-b, <NUM>-c) in fourth antenna array (e.g., antenna array <NUM>). For example, in the antenna and receiver system <NUM> that is illustrated in <FIG>, one second common RF receive path <NUM>-a of the second common RF receive paths <NUM> is connected to summation third antenna <NUM>-b and summation fourth antenna <NUM>-b, and the other second common RF receive path <NUM>-b of the second common RF receive paths <NUM> is connected to summation third antenna <NUM>-c and summation fourth antenna <NUM>-c. By connecting each second common RF receive path (e.g., <NUM>-a, <NUM>-b) to a distinct pair of substantially oppositely-positioned antennas, the number of RF receive paths in the antenna and receiver system <NUM> can be reduced, thereby reducing the hardware requirements, size, cost and power requirements of the antenna and receiver system <NUM>.

In some cases, as illustrated in <FIG>, each of the at least one first RF receive path <NUM> (e.g., first RF receive path <NUM>-a), the at least one second RF receive path <NUM> (e.g., second RF receive path <NUM>-a) and the common RF receive paths <NUM> (e.g., <NUM>-a and <NUM>-b) can be configured to include: a respective RF front-end (RFFE) (e.g., <NUM>-a, <NUM>-b, <NUM>-c, <NUM>-d), a respective down-converter (DCU) (e.g., <NUM>-a, <NUM>-b, <NUM>-c, <NUM>-d), a respective analog-to-digital converter (ADC) (e.g., <NUM>-a, <NUM>-b, <NUM>-c, <NUM>-d), and a respective intermediate-frequency (IF) processing resource (e.g., <NUM>-a, <NUM>-b, <NUM>-c, <NUM>-d). Moreover, in some cases in which the antenna and receiver system <NUM> is associated with the second antenna system <NUM>, and as illustrated in <FIG>, each of the at least one third RF receive path <NUM> (e.g., third RF receive path <NUM>-a), the at least one fourth RF receive path <NUM> (e.g., fourth RF receive path <NUM>-a) and the second common RF receive paths <NUM> (e.g., <NUM>-a and <NUM>-b) can be configured to include: a respective RF front-end (RFFE) (e.g., <NUM>-e, <NUM>-f, <NUM>-g, <NUM>-h), a respective down-converter (DCU) (e.g., <NUM>-e, <NUM>-f, <NUM>-g, <NUM>-h), a respective analog-to-digital converter (ADC) (e.g., <NUM>-e, <NUM>-f, <NUM>-g, <NUM>-h), and a respective intermediate-frequency (IF) processing resource (e.g., <NUM>-e, <NUM>-f, <NUM>-g, <NUM>-h).

Each respective RFFE of the at least one first RF receive path <NUM> (e.g., first RF receive path <NUM>-a), the at least one second RF receive path <NUM> (e.g., second RF receive path <NUM>-a), the at least one third RF receive path <NUM> (e.g., third RF receive path <NUM>-a) and the at least one fourth RF receive path <NUM> (e.g., fourth RF receive path <NUM>-a), for example RFFEs <NUM>-a, <NUM>-b, <NUM>-e and <NUM>-f, is configured to process the radio signal(s) that it receives from its respective main antenna, being the main antenna to which it is connected or coupled, at the original incoming radio frequencies of the radio signal(s). In the antenna and receiver system <NUM> that is illustrated in <FIG>, RFFE <NUM>-a of the first RF receive path <NUM>-a is configured to process the radio signal(s) that it receives from main first antenna <NUM>-a, and RFFE <NUM>-b of the second RF receive path <NUM>-a is configured to process the radio signal(s) that it receives from main second antenna <NUM>-a. Moreover, in the antenna and receiver system <NUM> that is illustrated in <FIG>, RFFE <NUM>-e of the third RF receive path <NUM>-a is configured to process the radio signal(s) that it receives from main third antenna <NUM>-a, and RFFE <NUM>-f of the fourth RF receive path <NUM>-a is configured to process the radio signal(s) that it receives from main fourth antenna <NUM>-a.

In addition, each respective RFFE of the common RF receive paths <NUM>, for example RFFEs <NUM>-c and <NUM>-d, is configured to process the radio signals that it receives from its respective summation antennas, being the summation first antenna and the summation second antenna to which it is connected or coupled, at the original incoming radio frequencies of the radio signals. The processing of the radio signals by each respective RFFE of the common RF receive paths <NUM> includes combining respective first radio signal(s) that are received by the respective RFFE from its respective summation first antenna and respective second radio signal(s) that are received by the respective RFFE from its respective summation second antenna into respective common signal(s). In the antenna and receiver system <NUM> that is illustrated in <FIG>, RFFE <NUM>-c of the common RF receive path <NUM>-a is configured to process the radio signals that it receives from summation first antenna <NUM>-b and summation second antenna <NUM>-b, including combining respective first radio signal(s) that are received by RFFE <NUM>-c from summation first antenna <NUM>-b and respective second radio signal(s) that are received by RFFE <NUM>-c from summation second antenna <NUM>-b into respective common signal(s). Furthermore, RFFE <NUM>-d of the common RF receive path <NUM>-b is configured to process the radio signals that it receives from summation first antenna <NUM>-c and summation second antenna <NUM>-c, including combining respective first radio signal(s) that are received by RFFE <NUM>-d from summation first antenna <NUM>-c and respective second radio signal(s) that are received by RFFE <NUM>-d from summation second antenna <NUM>-c into respective common signal(s).

Each respective RFFE of the second common RF receive paths <NUM>, for example RFFEs <NUM>-g and <NUM>-h, is configured to process the radio signals that it receives from its respective summation antennas, being the summation third antenna and the summation fourth antenna to which it is connected or coupled, at the original incoming radio frequencies of the radio signals. The processing of the radio signals by each respective RFFE of the second common RF receive paths <NUM> includes combining respective third radio signal(s) that are received by the respective RFFE from its respective summation third antenna and respective fourth radio signal(s) that are received by the respective RFFE from its respective summation fourth antenna into respective second common signal(s). In the antenna and receiver system <NUM> that is illustrated in <FIG>, RFFE <NUM>-g of the second common RF receive path <NUM>-a is configured to process the radio signals that it receives from summation third antenna <NUM>-b and summation fourth antenna <NUM>-b, including combining respective third radio signal(s) that are received by RFFE <NUM>-g from summation third antenna <NUM>-b and respective fourth radio signal(s) that are received by RFFE <NUM>-g from summation fourth antenna <NUM>-b into respective second common signal(s). Furthermore, RFFE <NUM>-h of the second common RF receive path <NUM>-b is configured to process the radio signals that it receives from summation third antenna <NUM>-c and summation fourth antenna <NUM>-c, including combining respective third radio signal(s) that are received by RFFE <NUM>-h from summation third antenna <NUM>-c and respective fourth radio signal(s) that are received by RFFE <NUM>-h from summation fourth antenna <NUM>-c into respective second common signal(s).

Each respective down-converter (DCU) of the at least one first RF receive path <NUM> (e.g., first RF receive path <NUM>-a), the at least one second RF receive path <NUM> (e.g., second RF receive path <NUM>-a) and the common RF receive paths <NUM> (e.g., <NUM>-a and <NUM>-b), for example DCUs <NUM>-a, <NUM>-b, <NUM>-c and <NUM>-d, is configured to down-convert, to an intermediate frequency (IF), the RF signal(s) that are output by the respective RFFE (e.g., <NUM>-a, <NUM>-b, <NUM>-c, <NUM>-d) that is connected or coupled to the respective down-converter (DCU) (e.g., <NUM>-a, <NUM>-b, <NUM>-c, <NUM>-d), thereby generating respective IF signal(s). Moreover, each respective down-converter (DCU) of the at least one third RF receive path <NUM> (e.g., third RF receive path <NUM>-a), the at least one fourth RF receive path <NUM> (e.g., fourth RF receive path <NUM>-a) and the second common RF receive paths <NUM> (e.g., <NUM>-a and <NUM>-b), for example DCUs <NUM>-e, <NUM>-f, <NUM>-g and <NUM>-h, is configured to down-convert, to the intermediate frequency (IF), the RF signal(s) that are output by the respective RFFE (e.g., <NUM>-e, <NUM>-f, <NUM>-g, <NUM>-h) that is connected or coupled to the respective down-converter (DCU) (e.g., <NUM>-e, <NUM>-f, <NUM>-g, <NUM>-h), thereby generating respective IF signal(s).

In some cases, one or more of the down-converters (DCUs) in the at least one first RF receive path <NUM>, the at least one second RF receive path <NUM>, the common RF receive paths <NUM>, the at least one third RF receive path <NUM>, the at least one fourth RF receive path <NUM>, or the second common RF receive paths <NUM> can be configured as an analog down-converter (DCU). For example, in the antenna and receiver system <NUM> that is illustrated in <FIG>, the down-converters (DCUs) <NUM>-a, <NUM>-b, <NUM>-c, <NUM>-d, <NUM>-e, <NUM>-f, <NUM>-g and <NUM>-h in the first RF receive path <NUM>-a, the second RF receive path <NUM>-a, the common RF receive path <NUM>-a, the common RF receive path <NUM>-b, the third RF receive path <NUM>-a, the fourth RF receive path <NUM>-a, the second common RF receive path <NUM>-a and the second common RF receive path <NUM>-b, respectively, are configured as analog DCUs.

For each of the RF receive paths that includes an analog down-converter (DCU) from among the at least one first RF receive path <NUM>, the at least one second RF receive path <NUM>, the common RF receive paths <NUM>, the at least one third RF receive path <NUM>, the at least one fourth RF receive path <NUM> and the second common RF receive paths <NUM>, an ADC of the respective RF receive path can be connected or coupled to an output of the analog DCU of the respective RF receive path, and configured to convert the respective IF signal(s) that are generated by such analog DCU to respective digital IF signal(s). Turning again to the antenna and receiver system <NUM> that is illustrated in <FIG>, the analog-to-digital converters (ADCs) <NUM>-a, <NUM>-b, <NUM>-c, <NUM>-d, <NUM>-e, <NUM>-f, <NUM>-g and <NUM>-h in the first RF receive path <NUM>-a, the second RF receive path <NUM>-a, the common RF receive path <NUM>-a, the common RF receive path <NUM>-b, the third RF receive path <NUM>-a, the fourth RF receive path <NUM>-a, the second common RF receive path <NUM>-a and the second common RF receive path <NUM>-b, respectively, are configured to convert the respective IF signal(s) that are generated by analog DCUs <NUM>-a, <NUM>-b, <NUM>-c, <NUM>-d, <NUM>-e, <NUM>-f, <NUM>-g and <NUM>-h, respectively, to respective digital IF signal(s).

In some cases, one or more of the down-converters (DCUs) in the at least one first RF receive path <NUM>, the at least one second RF receive path <NUM>, the common RF receive paths <NUM>, the at least one third RF receive path <NUM>, the at least one fourth RF receive path <NUM>, or the second common RF receive paths <NUM> can be configured as a digital down-converter (DCU). For each of the RF receive paths from among the at least one first RF receive path <NUM>, the at least one second RF receive path <NUM>, the common RF receive paths <NUM>, the at least one third RF receive path <NUM>, the at least one fourth RF receive path <NUM> or the second common RF receive paths <NUM> that includes a digital DCU, an ADC of the respective RF receive path can be connected or coupled to an output of the RFFE of the respective RF receive path, and configured to convert the respective RF signal(s) that are output by such RFFE to respective digital RF signal(s). The respective digital DCU of the respective RF receive path can be configured to down-convert the respective digital RF signal(s) to respective digital IF signal(s).

Each IF processing resource of the at least one first RF receive path <NUM> (e.g., first RF receive path <NUM>-a), the at least one second RF receive path <NUM> (e.g., second RF receive path <NUM>-a), the common RF receive paths <NUM> (e.g., <NUM>-a and <NUM>-b), the at least one third RF receive path <NUM> (e.g., third RF receive path <NUM>-a), the at least one fourth RF receive path <NUM> (e.g., fourth RF receive path <NUM>-a), and the second common RF receive paths <NUM> (e.g., <NUM>-a and <NUM>-b), for example IF processing resources <NUM>-a, <NUM>-b, <NUM>-c, <NUM>-d, <NUM>-e, <NUM>-f, <NUM>-g and <NUM>-h, can be configured to process the respective digital IF signal(s) that it receives at the intermediate frequency (IF).

Each IF processing resource of the at least one first RF receive path <NUM> (e.g., first RF receive path <NUM>-a) and the at least one second RF receive path <NUM> (e.g., second RF receive path <NUM>-a), for example IF processing resources <NUM>-a and <NUM>-b, can be configured to process the respective digital IF signal(s) that it receives at the IF to provide respective main output signal(s). The respective main output signal(s) that are provided by the IF processing resources of the at least one first RF receive path <NUM> and the at least one second RF receive path <NUM> can be analyzed for determining a coarse location of one or more transmitting entities that transmit radio signals that are received by the first antenna system <NUM>, as detailed further herein, inter alia with reference to <FIG>.

Each IF processing resource of the common RF receive paths <NUM> (e.g., common RF receive paths <NUM>-a and <NUM>-b), for example IF processing resources <NUM>-c and <NUM>-d, can be configured to process the respective digital IF signal(s) that it receives at the IF to provide respective common output signal(s). The respective common output signal(s) that are provided by the IF processing resources of the common RF receive paths <NUM> can be analyzed for determining a fine location of one or more transmitting entities that transmit radio signals that are received by the first antenna system <NUM>, as detailed further herein, inter alia with reference to <FIG>.

Each IF processing resource of the at least one third RF receive path <NUM> (e.g., third RF receive path <NUM>-a) and the at least one fourth RF receive path <NUM> (e.g., fourth RF receive path <NUM>-a), for example IF processing resources <NUM>-e and <NUM>-f, can be configured to process the respective digital IF signal(s) that it receives at the IF to provide respective main output signal(s). The respective main output signal(s) that are provided by the IF processing resources of the at least one first RF receive path <NUM>, the at least one second RF receive path <NUM>, the at least one third RF receive path <NUM> and the at least one fourth RF receive path <NUM>, for example IF processing resources <NUM>-a, <NUM>-b, <NUM>-e and <NUM>-f, can be analyzed for determining a coarse location of one or more transmitting entities that transmit radio signals that are received by the second antenna system <NUM>, as detailed further herein, inter alia with reference to <FIG>.

Each IF processing resource of the second common RF receive paths <NUM> (e.g., second common RF receive paths <NUM>-a and <NUM>-b), for example IF processing resources <NUM>-g and <NUM>-h, can be configured to process the respective digital IF signal(s) that it receives at the IF to provide respective common output signal(s). The respective common output signal(s) that are provided by the IF processing resources of the common RF receive paths <NUM> and the second common RF receive paths <NUM>, for example IF processing resources <NUM>-c, <NUM>-d, <NUM>-g and <NUM>-h, can be analyzed for determining a fine location of one or more transmitting entities that transmit radio signals that are received by the second antenna system <NUM>, as detailed further herein, inter alia with reference to <FIG>.

Attention is now drawn to <FIG>, a block diagram schematically illustrating an example of a radio direction-finding system <NUM>, in accordance with the presently disclosed subject matter.

In accordance with the presently disclosed subject matter, radio direction-finding system <NUM> can be configured to include an antenna and receiver system <NUM>, as detailed earlier herein, inter alia with reference to <FIG>.

Radio direction-finding system <NUM> can also be configured to include processing circuitry <NUM>. Processing circuitry <NUM> can be one or more processing units (e.g. central processing units), microprocessors, microcontrollers (e.g. microcontroller units (MCUs)) or any other computing devices or modules, including multiple and/or parallel and/or distributed processing units, which are adapted to independently or cooperatively process data, including data for finding the direction(s) from which radio signal(s) are received by the antenna and receiver system <NUM>.

Processing circuitry <NUM> can be configured to include a coarse direction determination module <NUM> and a fine direction determination module <NUM>.

Coarse direction determination module <NUM> can be configured, for each of the radio signals that are received by the antenna and receiver system <NUM>, to provide a coarse determination of the given direction from which the respective radio signal was transmitted (e.g., a coarse determination of a location of the transmitting entity that transmitted the respective radio signal), as detailed further herein, inter alia with reference to <FIG> and <FIG>.

Fine direction determination module <NUM> can be configured, for each of the radio signals that are received by the antenna and receiver system <NUM>, to provide a fine determination of the given direction from which the respective radio signal was transmitted (e.g., a fine determination of a location of the transmitting entity that transmitted the respective radio signal), as detailed further herein, inter alia with reference to <FIG> and <FIG>.

Attention is now drawn to <FIG>, a flowchart illustrating an example of a first radio direction-finding method <NUM>, in accordance with the presently disclosed subject matter.

In accordance with the presently disclosed subject matter, first radio direction-finding method <NUM> is associated with the first antenna system <NUM> and an antenna and receiver system <NUM> that only includes the RF receive paths that are connected to the antennas that are included in the first antenna system <NUM>.

To perform the first radio direction-finding method <NUM>, processing circuitry <NUM> can be configured to receive (A) main output signals, being the respective main output signal(s) that are provided by the at least one first RF receive path <NUM> and the at least one second RF receive path <NUM>, and (B) common output signals, being the respective common output signal(s) that are provided by the common RF receive paths <NUM> (block <NUM>).

Processing circuitry <NUM> can be further configured, e.g. using coarse direction determination module <NUM>, to analyze the main output signals to immediately provide, for a respective radio signal that is received by the first antenna system <NUM>, a coarse determination of a location of a transmitting entity that transmitted the respective radio signal (block <NUM>).

In some cases, the coarse determination can be provided by performing amplitude-based (power-based) coarse direction-finding (DF).

Processing circuitry <NUM> can also be configured, upon providing the coarse determination, to analyze the common output signals and selected main output signal(s), of the main output signals, that are associated with the coarse determination, e.g. using fine direction determination module <NUM>, to provide a fine determination of the location of the transmitting entity that transmitted the respective radio signal (block <NUM>).

In some cases, the fine determination can be provided by performing interferometry (e.g., phase interferometry).

Attention is now drawn to <FIG>, a flowchart illustrating an example of a second radio direction-finding method <NUM>, in accordance with the presently disclosed subject matter.

In accordance with the presently disclosed subject matter, second radio direction-finding method <NUM> is associated with the second antenna system <NUM> and the antenna and receiver system <NUM> that is associated with the second antenna system <NUM>.

To perform the second radio direction-finding method <NUM>, processing circuitry <NUM> can be configured to receive (A) main output signals, being the respective main output signal(s) that are provided by the at least one first RF receive path <NUM>, the at least one second RF receive path <NUM>, the at least one third RF receive path <NUM>, and the at least one fourth RF receive path <NUM>, and (B) common output signals, being the respective common output signal(s) that are provided by the common RF receive paths <NUM> and the second common RF receive paths <NUM> (block <NUM>).

Processing circuitry <NUM> can be further configured, e.g. using coarse direction determination module <NUM>, to analyze the main output signals to immediately provide, for a respective radio signal that is received by the second antenna system <NUM>, a coarse determination of a location of a transmitting entity that transmitted the respective radio signal (block <NUM>).

Processing circuitry <NUM> can also be configured, upon providing the coarse determination, to analyze the common output signals that are associated with the coarse determination, and selected main output signal(s), of the main output signals, that are associated with the coarse determination, e.g. using fine direction determination module <NUM>, to provide a fine determination of the location of the transmitting entity that transmitted the respective radio signal (block <NUM>).

It is to be noted that, with reference to <FIG> and <FIG>, some of the blocks can be integrated into a consolidated block or can be broken down to a few blocks and/or other blocks may be added. It should be also noted that whilst the flow diagrams are described also with reference to the system elements that realizes them, this is by no means binding, and the blocks can be performed by elements other than those described herein.

It is to be understood that the presently disclosed subject matter is not limited in its application to the details set forth in the description contained herein or illustrated in the drawings. The presently disclosed subject matter is capable of other embodiments and of being practiced and carried out in various ways. Hence, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for designing other structures, methods, and systems for carrying out the several purposes of the present presently disclosed subject matter.

Claim 1:
An antenna and receiver system (<NUM>), the antenna and receiver system (<NUM>) comprising:
a first antenna array (<NUM>) comprising a first plurality of antennas (<NUM>-a, <NUM>-b, <NUM>-c) facing a first direction, the first plurality of antennas (<NUM>-a, <NUM>-b, <NUM>-c) comprising:
at least one main first antenna (<NUM>-a); and
one or more summation first antennas (<NUM>-b, <NUM>-c);
at least one first radio-frequency (RF) receive path (<NUM>) connected to the main first antenna (<NUM>-a) only;
a second antenna array (<NUM>) comprising a second plurality of antennas (<NUM>-a, <NUM>-b, <NUM>-c) facing a second direction that is substantially opposite the first direction, the second antenna array (<NUM>) being positioned substantially opposite the first antenna array (<NUM>), and the second plurality of antennas (<NUM>-a, <NUM>-b, <NUM>-c) comprising:
at least one main second antenna (<NUM>-a); and
one or more summation second antennas (<NUM>-b, <NUM>-c) ;
at least one second RF receive path (<NUM>) connected to the main second antenna (<NUM>-a) only; and
one or more common RF receive paths (<NUM>), each common RF receive path of the common RF receive paths (<NUM>) being connected to a distinct pair of substantially oppositely-positioned antennas comprising a given summation first antenna of the summation first antennas (<NUM>-b, <NUM>-c) and a given summation second antenna of the summation second antennas (<NUM>-b, <NUM>-c), so that a first signal received by the given summation first antenna and a second signal received by the given summation second antenna are combined into a respective common signal.