PHASED ARRAY ANTENNA APPARATUS AND METHOD

Abstract

The present invention provides phased array antenna apparatus (200) for operation in frequencies above six gigahertz. The apparatus (200) comprises: a plurality of sub-arrays (208) together configured to form a phased array antenna, each sub-array (208) comprising at least four antenna elements (220), each antenna element (220) for receiving an input signal from the sub-array (220) and comprising: an antenna (230) for transmission of the input signal; and a signal modification component (222) to adjust a phase of the input signal during propagation to the antenna (230); and a plurality of power amplifiers (212), wherein each sub-array (208) is provided with a one of the plurality of power amplifiers (212), wherein each sub-array (208) is arranged to be provided with an amplified input signal, and each antenna element (220) of the sub-array (208) is configured to be provided with the amplified input signal of the respective sub-array (208) as the input signal to the antenna element (220), and wherein the power amplifier (212) for each sub-array (208) is configured to receive a phased array input signal for amplification and to output the respective amplified input signal to the respective sub-array (208). The power amplifier (212) for each sub-array (208) may be physically separate and distinct from each sub-array (208).

Claims

1-25. (canceled)

26. A phased array antenna apparatus for operation in frequencies above six gigahertz, the phased array antenna apparatus comprising: a plurality of sub-arrays together configured to form a phased array antenna, each sub-array comprising at least four antenna elements, an input configured to receive an input signal, and a plurality of respective sub-array circuits between the input and an antenna of the respective antenna element, the antenna for transmission of the input signal, each sub-array circuit comprising: a signal modification component configured to adjust a phase of the input signal during propagation to the antenna; and an attenuator to attenuate the input signal during propagation to the antenna, such that fine tuning of an amplitude tapering of the sub-array is provided; and a plurality of power amplifiers, wherein the sub-array circuits of each sub-array are connected to a one of the plurality of power amplifiers via the input, wherein each sub-array is arranged to be provided with an amplified input signal at the input as the input signal to the input, wherein each power amplifier is configured to receive a phased array input signal for amplification and to output the respective amplified input signal to the plurality of sub-array circuits of the respective sub-array connected to the power amplifier, wherein a first power amplifier of the plurality of power amplifiers, providing the amplified input signal to the input of a central sub-array of the plurality of sub-arrays in the phased array antenna apparatus is configured to amplify the phased array input signal to a greater power than a second power amplifier of the plurality of power amplifiers, providing the amplified input signal to the input of a peripheral sub-array of the plurality of sub-arrays in the phased array antenna apparatus, such that a majority of the amplitude tapering is provided by the power amplifiers providing different amplitudes for the sub-arrays.

27. The phased array antenna apparatus of claim 26, wherein the attenuator of each sub-array circuit is configured to provide fine tuning of the amplification of the amplified input signal to the sub-array circuit to the respective sub-array.

28. The phased array antenna apparatus of claim 26, wherein each power amplifier is provided on a control board of the phased array antenna apparatus, separate from one or more antenna boards of the sub-array, at which the plurality of antenna elements are provided, and wherein the control board is provided away from the sub-array.

29. The phased array antenna apparatus of claim 26, comprising a plurality of test ports for connection of test equipment thereto, each test port provided in the plurality of sub-array circuits of a respective sub-array.

30. The phased array antenna apparatus of claim 26, further comprising at least one controller configured to control the plurality of sub-array circuits, and wherein each sub-array is provided with a separate respective controller for controlling each of the sub-array circuits of the sub-array.

31. The phased array antenna apparatus of claim 26, wherein the attenuator comprises a passive attenuator.

32. The phased array antenna apparatus of claim 31, wherein the attenuator comprises a micro electro-mechanical systems (MEMS) attenuator.

33. The phased array antenna apparatus of claim 31, wherein, of passive attenuation and power amplification of the amplified input signal, only passive attenuation of the amplified input signal is performed in the sub-array circuit.

34. The phased array antenna apparatus of claim 26, wherein in at least one of the plurality of sub-array circuits, of one or more active components and one or more passive components to modify the amplified input signal received at the input, only the one or more passive components are provided, and wherein each of the one or more passive components is configured to receive a control signal having a maximum current of less than 100 milliamps.

35. The phased array antenna apparatus of claim 34, wherein the one or more passive components comprises one or more micro electro-mechanical systems (MEMS) components, and wherein the one or more MEMS components are configured to provide at least two of attenuation, phase shift, and RF switching to the amplified input signal in the sub-array circuit.

36. The phased array antenna apparatus of claim 26, wherein each signal modification component comprises one or more phase shifters configured to impart a phase shift to the input signal to thereby adjust the phase of the input signal during propagation to the antenna, and wherein the one or more phase shifters are one or more passive phase shifters.

37. The phased array antenna apparatus of claim 26, wherein at least one sub-array further comprises one or more radio frequency (RF) switches, and wherein the one or more RF switches are each passive components.

38. The phased array antenna apparatus of claim 26, wherein at least one electrical component in the plurality of sub-array circuits is configured to selectively alter the input signal.

39. The phased array antenna apparatus of claim 26, wherein at least one of the plurality of sub-array circuits is controllable independently of at least one other of the plurality of sub-array circuits.

40. The phased array antenna apparatus of claim 26, wherein one or more of the power amplifiers are provided with a power monitor for providing an indication of the power at the respective sub-array or sub-arrays.

41. The phased array antenna apparatus of claim 26, wherein one or more of the power amplifiers are configured to provide harmonic tuning.

42. The phased array antenna apparatus of claim 26, wherein one or more of the power amplifiers are configured to be provided with DC/DC conversion.

43. The phased array antenna apparatus of claim 26, wherein the phased array antenna apparatus further comprises a plurality of test ports for connection of test equipment thereto, each test port provided in the plurality of sub-array circuits of a respective sub-array, wherein one or more of the power amplifiers are configured to be provided with DC/DC conversion, and wherein one or more power amplifiers are provided with a power monitor for providing an indication of the power at the respective sub-array or sub-arrays.

44. A method of operating a phased array antenna apparatus at frequencies above 6 GHz, the method comprising: providing a phased array antenna apparatus comprising: a phased array input configured to receive a phased array input signal; and a plurality of sub-arrays together configured to form a phased array antenna, each sub-array comprising at least four antenna elements, an input configured to receive an input signal, and a plurality of respective sub-array circuits between the input and an antenna of the respective antenna element, the antenna for transmission of the input signal; amplifying the phased array input signal provided to the input of a central sub-array of the plurality of sub-arrays in the phased array antenna apparatus, to a greater power than the phased array input signal provided to the input of a peripheral sub-array of the plurality of sub-arrays, such that a majority of amplitude tapering is provided by the power amplifiers providing different amplitudes for the sub-arrays; adjusting a phase of the input signal during propagation to the antenna in one or more of the sub-array circuits; attenuating the input signal during propagation to the antenna in each of the sub-array circuits, such that fine tuning of the amplitude tapering of the sub-array is provided; and transmitting the input signal from the antenna.

45. The method of claim 44, further comprising switchedly routing the input signal in one or more of the sub-array circuits.

Description

DESCRIPTION OF THE DRAWINGS

[0063] An example embodiment of the present invention will now be illustrated with reference to the following Figures in which:

[0064] FIG. 1 shows a schematic representation of a portion of phased array antenna apparatus as disclosed herein;

[0065] FIG. 2 shows a schematic representation of a portion of the phased array antenna apparatus shown in FIG. 1;

[0066] FIG. 3 shows a further schematic illustration of a phased array antenna apparatus as disclosed herein;

[0067] FIG. 4 shows a schematic representation of an example of a phased array antenna apparatus as disclosed herein;

[0068] FIG. 5 shows a flowchart illustrating a method of relevance to a phased array antenna apparatus as disclosed herein; and

[0069] FIG. 6 shows a further flowchart illustrating a method of relevance to a phased array antenna apparatus as disclosed herein.

DETAILED DESCRIPTION OF AN EXAMPLE EMBODIMENT

[0070] As described hereinbefore, the present inventors have realised that phased array antenna apparatus can be formed having a plurality of sub-arrays, each having a plurality of antenna elements, an input configured to receive an input signal and a plurality of respective sub-array circuits between the input and the respective antenna element. The apparatus also comprises a plurality of power amplifiers. The sub-array circuits of each sub-array are connected to a one of the plurality of power amplifiers via the input. The power amplifier is configured to amplify a phased array input signal to provide an amplified input signal as the input signal at the input.

[0071] As a result, fewer power amplifiers are provided compared to phased array antennas of the prior art, which typically include a phased array antenna to amplify the input signal to each antenna element. By reducing the number of power amplifiers required, the cooling requirements of the phased array antenna are also reduced. Furthermore, by locating the power amplifier away from the antenna element, reduced cooling is required at the antenna element, resulting in a less complex and/or more resilient phased array antenna. Yet further, by using fewer power amplifiers, it is more economically and/or technically feasible to use power amplifiers having improved functionality, accuracy and/or reliability whilst still providing a relatively simple (and therefore cost-effective) phased array antenna for manufacture.

[0072] FIG. 1 shows a schematic representation of a portion of phased array antenna apparatus as disclosed herein. The phased array antenna apparatus 100 is configured to receive a phased array input signal 102. The phased array input signal 102 is an input signal for transmission by the phased array antenna apparatus 100. Typically, the phased array input signal comprises a data signal, typically encoded on a carrier signal. Before transmission of the phased array input signal 102 from the phased array antenna apparatus 100, the data signal of the phased array input signal is encoded on a high-frequency carrier signal. The high-frequency carrier signal typically has a frequency from around six gigahertz or more, for example over ten gigahertz or even higher. In some examples, the data signal may be encoded on the high-frequency carrier signal to form the phased array input signal 102. In other examples, the data signal is encoded on the high-frequency carrier signal during subsequent signal processing within the phased array antenna apparatus. It will be understood that data signals can be encoded on carrier signals using substantially any of the techniques known to the skilled person, including amplitude modulation, frequency modulation, phase modulation or substantially any other modulation of the carrier frequency. FIG. 1 shows a simplified schematic representation of phased array antenna apparatus. Therefore, it will be understood that further elements, not shown in FIG. 1, may be provided in at least some implementations of the phased array antenna apparatus.

[0073] The phased array input signal 102 is typically already amplified, at least to an extent. The phased array input signal 102 is input to a splitter 104 to split the phased array input signal 102 into a plurality of (in this case, four) transmission paths 106a, 106b, 106c, 106d. Each transmission path 106a, 106b, 106c, 106d is directed towards a different sub-array 108a, 108b, 108c, 108d of the phased array antenna apparatus 100. Specifically, each transmission path 106a, 106b, 106c, 106d is directed towards an sub-array input 109a, 109b, 109c, 109d of the respective sub-array 108a, 108b, 108c, 108d.

[0074] As used herein, in some examples, the term “sub-array” will be understood to mean a separate physical module in the phased array antenna apparatus 100. In other examples, the term “sub-array” will be understood to mean a separate logical module in the phased array antenna apparatus, even if some components of a first sub-array 108a are co-located on the same board as one or more components of a second sub-array 108b.

[0075] A power amplifier is 112a, 112b, 112c, 112d is arranged in each of the transmission paths 106a, 106b, 106c, 106d, between the splitter 104 and the input 109a, 109b, 109c, 109d. Each power amplifier 112a, 112b, 112c, 112d is configured to receive the phased array input signal 102 for amplification, via the splitter 104, and to output the respective amplified input signal to the respective input 109a, 109b, 109c, 109d of the respective sub-array 108a, 108b, 108c, 108d. Amplification by the power amplifier 112a, 112b, 122c, 112d is necessary for the signal to have sufficient power to propagate a sufficient distance once transmitted from the phased array antenna apparatus 100.

[0076] An amplification level of each of the power amplifiers 112a, 112b, 112c, 112d is independently controllable. Typically, the power levels of the plurality of amplified input signals from the power amplifiers 112a, 112b, 112c, 112d are controlled such that at least one of the power levels is different to at least one other of the power levels. Typically, at least one of the power amplifiers 112a, 112b, 112c, 112d is different to at least one other of the power amplifiers 112a, 112b, 112c, 112d.

[0077] In the sub-array 108a, 108b, 108c, 108d, the amplified input signal received at the input 109a, 109b, 109c, 109d is directed through a plurality of sub-array circuits (not labelled in FIG. 1). The sub-array 108a, 108b, 108c, 108d comprises a further splitter 118a, 118b, 118c, 118d, arranged in each of the plurality of sub-array circuits of the sub-array 108a, 108b, 108c, 108d to split the amplified input signal received at the input 109a, 109b, 109c, 109d into four sub-array circuits for onward propagation to four antenna elements (shown grouped as 120a, 120b, 120c, 120d in FIG. 1).

[0078] It will be understood that each of the splitters described with reference to FIG. 1 can be implemented directly as a 1 to i splitter, where i is greater than 2. Whilst this particular embodiment has been described, it will be understood that substantially any splitter arrangement that splits the signal into the required number of signal paths can be used.

[0079] Control circuitry 170 is also shown. For simplicity, control circuitry 170 is only shown connected to first power amplifier 112a on the first transmission path 106a and to associated first group of antenna elements 120a in the first sub-array 108a. Nevertheless, it will be understood that control circuitry is typically provided for each of the other power amplifiers 112b, 112c, 112d and the other groups of antenna elements 120b, 120c, 120d. Control circuitry 170 carries one or more control signals from a controller 172 to control operation of the power amplifier 112a, and the antenna elements 120a.

[0080] The portion of the phased array antenna apparatus 100 connecting the power amplifiers 112a, 112b, 112c, 112d to the inputs 109a, 109b, 109c, 109d can each function as a test port for testing the operation of a portion of the phased array antenna apparatus including the power amplifiers 112a, 112b, 112c, 112d during assembly of the phased array antenna apparatus 100.

[0081] The components of the sub-arrays 108a, 108b, 108c, 108d, specifically the antenna elements 120a, 120b, 120c, 120d, will be described further with reference to FIGS. 2 and 3.

[0082] FIG. 2 shows a further example of a portion of phased array antenna apparatus. The phased array antenna apparatus 200 is substantially similar to the phased array antenna apparatus 100 described hereinbefore with reference to FIG. 1, apart from the hereinafter described distinctions. Like numerals are used to refer to like features, with the first digit of the numeral representative of the figure. Furthermore, FIG. 2 also provides further detail regarding the structure and functions of the antenna elements 120a, 120b, 120c, 120d described with reference to FIG. 1.

[0083] The splitter 204 is configured to split the phased array input signal 202 into N transmission paths 206a to 206n. FIG. 2 shows the signal processing operations performed in a first transmission path 206a, though it will be understood that similar signal processing operations can also be performed in the other signal paths.

[0084] After the phased array input signal 202 has been split by the splitter 204, the first transmission path 206a passes through an upconverter 210 to change the frequency of the phased array input signal 202 from a first frequency to a second frequency, higher than the first frequency, and to be transmitted from the phased array antenna apparatus 200.

[0085] The upconverted signal is next amplified by a power amplifier 212. An amplification level of the power amplifier 212 is set based on a signal from an amplitude controller 214. The amplification level of the upconverter 210 is also controlled by the amplitude controller 214. The amplitude controller 214 is controlled by a further control circuit (not shown). In this example, the signal from the amplitude controller 214 is further passed through a DC/DC voltage converter 216 before providing the control input to the power amplifier 212 to provide a particularly efficient implementation.

[0086] Following a further splitting of the signal in the further splitter 218, each of the signals passes to the antenna element 220. In FIG. 2, it will be understood that the input to the sub-array 208 is provided between the power amplifier 212 and the further splitter 218, such that the further splitter 218 is part of the sub-array 208. The antenna element 220 comprises a plurality of further components 222, 224, 226, 228 to further modify the signal input to the antenna element 220 from the further splitter 218.

[0087] Finally, the modified signal is transmitted from the phased array antenna apparatus 200 via an antenna 230.

[0088] A signal modification component 222 in the form of a phase shifter 222 alters a phase of the signal in the sub-array circuit from the further splitter 218 to the antenna 230. The phase shifter 222 is controllable to impart a phase shift different to one or more phase shifts imparted by other antenna elements having the signal propagated thereto from the further splitter 218. In this way, the phase of the signal can be modified to electronically steer the transmission beam of the phased array antenna apparatus 200.

[0089] An attenuator 224 provides attenuation of the signal in the transmission path from the further splitter 218 to the antenna 230. It will be understood that attenuating the signal allows a tapered amplitude profile of the transmitted signal from the plurality of antennas 230 of the sub-array 208 to be provided, even though the signals all originated from the same signal, amplified by the power amplifier 212.

[0090] An RF switch 226, in this example in the form of a single pole double throw (SPDT) switch 226 is provided to selectively route the signal through a polarisation-specific route 228 present for only one of the two transmission lines of the sub-array circuit between the SPDT switch 226 and the antenna 230. Thus, the polarisation of the signal transmitted by the antenna 230 can be controlled by operation of the SPDT switch 226. In other words, the RF switch 226 is used to select one of two feed ports for the antenna 230. Each feed port can be configured to excite a different polarisation in the antenna.

[0091] Each of the components of the sub-array 208 between the power amplifier 212 and the antenna element 230 are passive components. That is, each of the components of the sub-array 208 between the power amplifier 212 and the antenna element 230 are configured not to increase the power of the signal. Furthermore, each of the components of the sub-array 208 between the power amplifier 212 and the antenna element 230 are low-power components in that a power requirement for operation of the components is relatively low, in particular, less than the power requirement of the power amplifier 212. Furthermore, each of the components of the sub-array 208 between the power amplifier 212 and the antenna element 230 are low-loss components in that an inherent signal loss caused by the components during propagation from the further splitter 218 to the antenna 230 is low, for example less than 2.5 dB.

[0092] The phase shifter 222, the attenuator 224, and the RF switch 226 are each implemented as micro electro-mechanical systems (MEMS) components, in the form of MEMS switches, suitable implementations for which are known to the skilled person. Thus, the arrangement of the components 222, 224, 226, and therefore the antenna element itself 220 is compact.

[0093] Control of the phase shifter 222, the attenuator 224 and the RF switch 226 is provided by control signals received from control circuitry (not shown). It will be understood that the control circuitry can be provided at the sub-array 208, for example at the antenna elements 220, or away from the antenna elements 220. In some examples, the control circuitry may be distributed between several portions of the phased array antenna apparatus 200.

[0094] The power amplifier 212 may comprise additional functionality in some examples. For example, the power amplifier 212 can provide harmonic tuning to improve efficiency of the phased array antenna apparatus 200.

[0095] Typically, the power amplifiers 212 in each of a plurality of sub-arrays 208 of the phased array antenna apparatus 200 are each different, such that in a first sub-array of the phased array antenna apparatus 200, a first amplified input signal is provided to the antenna elements from a first power amplifier, and in a second sub-array of the phased array antenna apparatus 200, a second amplified input signal is provided to the antenna elements from a second power amplifier. The first amplified input signal is amplified more than the second amplified input signal. The first sub-array may be mounted closer to a centre of the phased array antenna apparatus than the second sub-array. In this way, it can be seen that amplitude tapering can be provided for sub-arrays of the phased array antenna apparatus. By choosing each amplifier to be capable of efficiently providing the required amplification to achieve the desired amplitude tapering, a particularly efficient implementation of the phased array antenna apparatus can be provided.

[0096] In some embodiments, a test port can be provided in the transmission path from the power amplifier 212 towards the antennas 230 (not shown in FIG. 1). In this way, it will be understood that it will be possible to test performance of the phased array antenna apparatus 200, including the power amplifier 212, without use of an over-the-air (OTA) antenna test, which can often be time-consuming and expensive to undertake. The phased array antenna apparatus 200 can be tested during manufacture, even before connection of the antenna elements 220 of the sub-arrays thereto. Of course, it will also be understood that the testing may be of only certain components in the phased array antenna apparatus 200, typically including the power amplifier 212.

[0097] Although the above disclosure has described phased array antenna apparatus 100, for use as a transmitter, it will be understood that the phased array antenna apparatus 100, 200 described herein can further be used instead or additionally as a receiver. In examples where the phased array antenna apparatus is to be used as a receiver, it will be understood that a low noise amplifier (LNA) will typically be provided instead of, or in a further transmission path in parallel with the power amplifier. The low noise amplifier is configured to amplify the signals received by the antennas of the phased array apparatus 100, 200.

[0098] FIG. 3 shows a further schematic illustration of a phased array antenna apparatus as disclosed herein. The phased array antenna apparatus 300 comprises a plurality of antenna elements 320a, 320b, 320c, 320d forming a sub-array 308. The plurality of antenna elements are each configured to receive an amplified input signal from a power amplifier 312 via a splitter network 318. In a receive configuration, a low noise amplifier 332 is arranged to receive a received signal from each of the plurality of antenna elements 320a, 320b, 320c, 320d. As in FIGS. 1 and 2, each transmission path, sometimes referred to as each sub-array circuit, between each respective antenna 330 and the power amplifier 312 (or the low noise amplifier 332) comprises a respective signal modification component 322 in the form of a phase shifter 322. Although not shown in FIG. 3, it will also be understood that additional components such as an RF switch and an attenuator can also be included in some or all of the transmission paths between each respective antenna 330 and the power amplifier 312 (or the low noise amplifier 332) as required.

[0099] Depending on the operational mode of the phased array antenna apparatus 300, mixer 334 may function as an upconverter or a downconverter. When the phased array antenna apparatus 300 is operating in the transmit operational mode, the mixer 334 functions as an upconverter. When the phased array antenna apparatus 300 is operating in the receive operational mode, the mixer 334 functions as a downconverter. The operation of an upconverter and a downconverter will be understood by the person skilled in the art.

[0100] For clarity, not every single element has been labelled in FIG. 3. Nevertheless, it will be understood that FIG. 3 illustrates a phased array antenna system 300 in which the sub-array 308 comprises 16 antenna elements 320a, 320b, 320c, 320d, each having a phase shifter 322 and an antenna 330.

[0101] FIG. 4 shows a schematic representation of a phased array antenna apparatus as disclosed herein. The phased array antenna apparatus 400 comprises a first sub-array board 402 and a second sub-array board 404. Although only two sub-array boards 402, 404 are shown, it will be understood that more may be present, for example at least four, at least 16, or even more. The sub-array boards 402, 404 are each provided with MEMS components of the antenna elements 406 fabricated thereon, and also further comprise the antennas provided thereon (not shown). A motherboard 408 is mounted at an underside of the sub-array boards 402, 404. The motherboard comprises a plurality of amplifiers, including a plurality of power amplifiers 410, each for supplying an amplified input signal to the plurality of antenna elements 406 forming a respective sub-array on the sub-array boards 402, 404, as described hereinbefore.

[0102] Heat transfer away from the motherboard 408 is facilitated via heat-conductive standoffs 412, in this example formed from brass, to conduct heat away from the motherboard 308 to a back plane 414. The back plane 414 is formed from aluminium.

[0103] FIG. 5 shows a flowchart illustrating a method of testing a phased array antenna during assembly. In brief, the method 500 comprises testing the power amplifiers of the phased array antenna apparatus 100, 200, 300, 400 during assembly, without requiring an over the air (OTA) test.

[0104] The method 500 comprises providing 510 a first portion of phased array antenna apparatus, substantially as described hereinbefore. The first portion of the phased array antenna apparatus comprises a phased array input port, a plurality of power amplifiers and a plurality of intermediate connection ports. The phased array input port is for receiving a phased array input signal, including for example a test input signal. The phased array input port is in signal communication with an input of each of the plurality of power amplifiers. The plurality of power amplifiers each have the input and an output. The output of each power amplifiers is in signal communication with a respective one of the plurality of intermediate connection ports. Thus, the amplified signals, output from the power amplifiers, are each provided to the respective intermediate connection ports.

[0105] The method 500 further comprises connecting 520 test equipment to one or more of the intermediate connection ports. The test equipment can be substantially any suitable equipment for detecting and measuring an output at each of the plurality of intermediate connection ports to a test input signal provided as a phased array input signal.

[0106] The method 500 further comprises performing 530 a test procedure on the first portion of the phased array antenna apparatus using the test equipment. Thus, the functionality of any of the components of the phased array antenna apparatus between the phased array input port and the output of the power amplifier can be evaluated in the test procedure.

[0107] The method further comprises connecting 540 each intermediate connection port of the first portion of the phased array antenna apparatus to a second portion of the phased array antenna apparatus. The second portion of the phased array antenna apparatus comprises a plurality of sub-arrays together configured to form a phased array antenna. Each sub-array comprises a sub-array connection port, a plurality (e.g., at least four) antenna elements and a plurality of respective sub-array circuits between the sub-array connection port and an antenna of the respective antenna element. Each sub-array circuit is arranged to be provided with an amplified input signal via the respective sub-array connection port as an input signal to the sub-array circuit. The antenna is configured to transmit the input signal. Each sub-array circuit comprises a signal delay component. The signal delay component is configured to adjust the phase of the input signal to the antenna. In this way, when assembled, the phased array input signal applied at the phased array input port is provided to the plurality of antennas for onward transmission, via the intermediate connection ports, the sub-array connection ports and the sub-array circuits.

[0108] The steps of the method 500 are typically performed in the order described. In other words, performing 530 the test procedure usually occurs prior to connecting 540 each intermediate connection port to the second portion of the phased array antenna apparatus.

[0109] FIG. 6 shows a flowchart illustrating a method of operating a phased array antenna. In brief, the method 600 comprises amplifying a phased array input signal to at least two respective, different power levels and providing a one of the amplified signals as the input to the sub-arrays of the phased array antenna apparatus. In this way, the amplification is performed before the signal is split up to be sent to individual antenna elements in the sub-arrays.

[0110] The method 600 comprises providing 610 phased array antenna apparatus, for example as described hereinbefore. The phased array antenna apparatus comprises a phased array input and a plurality of sub-arrays. The phased array input is configured to receive a phased array input signal. The plurality of sub-arrays are together configured to form a phased array antenna. Each sub-array comprises a plurality of (e.g., at least four) antenna elements, an input and a plurality of respective sub-array circuits between the input and an antenna of the respective antenna element. The input is configured to receive an input signal. The antenna is for transmission of the input signal.

[0111] The method 600 further comprises amplifying 620 the phased array input signal to at least two different respective power levels for providing as the input to each of the plurality of sub-arrays.

[0112] The method 600 further comprises adjusting 630 a phase of the input signal to the antenna in one or more sub-array circuits. In some examples, the method 600 may further comprise performing other operations in relation to the input signal before the input signal is received at the antenna, for example attenuation and or switched routing.

[0113] The method 600 further comprises transmitting the input signal from the antenna.

[0114] Although the present disclosure has been described with reference to carrier frequencies over six gigahertz, it will be understood that in other examples, the carrier frequency may be substantially any carrier frequency for which phased array antennas may be used, even frequencies below six gigahertz.

[0115] In summary, there is provided phased array antenna apparatus (200) for operation in frequencies above six gigahertz. The apparatus (200) comprises: a plurality of sub-arrays (208) together configured to form a phased array antenna, each sub-array (208) comprising at least four antenna elements (220), each antenna element (220) for receiving an input signal from the sub-array (220) and comprising: an antenna (230) for transmission of the input signal; and a phase shift component (222) to adjust the phase of the input signal to the antenna (230); and a plurality of power amplifiers (212), wherein each sub-array (208) is provided with a one of the plurality of power amplifiers (212), wherein each sub-array (208) is arranged to be provided with an amplified input signal, and each antenna element (220) of the sub-array (208) is configured to be provided with the amplified input signal of the respective sub-array (208) as the input signal to the antenna element (220), and wherein the power amplifier (212) for each sub-array (208) is configured to receive a phased array input signal for amplification and to output the respective amplified input signal to the respective sub-array (208).

[0116] Features and characteristics described herein in relation to particular embodiments and examples will be understood to be applicable to any other embodiments and examples described herein, or otherwise falling within the scope of the disclosure, in any suitable combination, unless explicitly excluded. The scope of the disclosure is not intended to be limited to the particular examples and embodiments described herein.