Antenna apparatus, method of operating and method of manfuacturing thereof

Abstract

An antenna apparatus comprising: a plurality of antenna modules, each of the antenna modules comprising one or more antenna units, each of the one or more antenna units comprising an antenna element and an integrated circuit, the integrated circuit comprising: a first low noise amplifier, LNA, configured to receive a first input signal from the antenna element via a first input and provide a first output signal to a phase shifter; a second LNA configured to receive a second input signal from the antenna element via a second input and provide a second output signal to the phase shifter, wherein the first input signal and the second input signal have different polarisations; and a polarisation control circuit, configured to selectively switch, into an on state or an off state, at least one of: the first LNA and the second LNA with a controlled input and output impedance in each state. A corresponding method of operating an antenna apparatus and a method of manufacturing an antenna apparatus is also disclosed.

Description

[0001] ANTENNA APPARATUS, METHOD OF OPERATING AND METHOD OF

[0002] MANFUACTURING THEREOF

[0003] Field of the invention

[0004] The present invention relates to an antenna apparatus, a method of operating an antenna apparatus and a method of manufacturing an antenna apparatus for radio frequency (RF) signals.

[0005] Background to the invention

[0006] It is known to provide a low noise amplifier (LNA) to amplify a received radio frequency (RF) signal. Existing antenna apparatus typically include a 1 to 1 ratio of LNAs per antenna element. The LNAs are centrally located in the antenna module of which the antenna elements are a part. This means that, on the RF signal path, the antenna RF input and the LNAs are separated by a large distance. As a result, pre-amplification losses of the RF signal are high. It is desired to reduce pre-amplification losses whilst also providing low noise amplification.

[0007] US2020 / 0303833 (Ueda) uses multiple LNAs and provides polarisation switching but requires additional matching components. US5,659,322 (Caille) and US 5,270,719 (Roth) use polarisation switches at LNA outputs. It would be advantageous to not require separate matching components and polarisation switches, which have a power requirement.

[0008] JP2000022440 (Yagi Antenna) discloses a circuit in which the gain of one amplifier is set relative to another to give a desired wave / interference wave ratio downstream of a further amplifier.

[0009] DE29703243U (Chen) discloses a circuit with multiple LNAs which can be switched on and off but without appreciating the implications of not controlling their output impedances.

[0010] It is in this context that the present inventions have been devised.

[0011] Summary of the invention

[0012] In accordance with an aspect of the present invention, there is provided an integrated circuit comprising a first low noise amplifier, LNA, configured to receive a first input signal from an antenna element via a first input and provide a first output signal to a phase shifter. The integrated circuit also comprises a second LNA configured to receive a second input signal from the antenna element via a second input and provide a second output signal to the phase shifter. The first input signal and the second input signal have different polarisations. The integrated circuit also comprises a polarisation control circuit, configured to selectively switch, into an on state or an off state, at least one of: the first LNA and the second LNA.

[0013] In accordance with another aspect of the present invention, there is provided an antenna apparatus comprising: a plurality of antenna modules, each of the antenna modules comprising one or more antenna units, each of the one or more antenna units comprising an antenna element and an integrated circuit. The integrated circuit comprises a first low noise amplifier, LNA, configured to receive a first input signal from the antenna element via a first input and provide a first output signal to a phase shifter. The integrated circuit comprises a second LNA configured to receive a second input signal from the antenna element via a second input and provide a second output signal to the phase shifter. The first input signal and the second input signal have different polarisations. The integrated circuit also comprises a polarisation control circuit, configured to selectively switch, into an on state or an off state, at least one of: the first LNA and the second LNA.

[0014] According to another aspect of the present invention, there is provided a method of operating an integrated circuit comprising a first LNA, a second LNA and a phase shifter. The method comprises the first LNA receiving a first input signal from an antenna element via a first input. The method also comprises the second LNA receiving a second input signal from the antenna element via a second input. The first input signal and the second input signal have different polarisations. The method comprises receiving a polarisation control signal. The method comprises selectively switching, into an on state or an off state in dependence on the polarisation control signal, at least one of: the first LNA and the second LNA. The method comprises the first LNA providing a first output signal to the phase shifter and / or the second LNA providing a second output signal to the phase shifter.

[0015] According to another aspect of the present invention, there is provided a method of operating an antenna apparatus. The antenna apparatus comprises a plurality of antenna modules, each of the antenna modules comprising one or more antenna units, each of the one or more antenna units comprising an antenna element and an integrated circuit. The integrated circuit comprises a first low noise amplifier, LNA, a second LNA and a phase shifter. The method comprising the first LNA receiving a first input signal from the antenna element via a first input. The method comprises the second LNA receiving a second input signal from the antenna element via a second input. The first input signal and the second input signal have different polarisations. The method comprises receiving a polarisation control signal. The method comprising selectively switching, into an on state or an off state in dependence on the polarisation control signal, at least one of: the first LNA and the second LNA. The method comprising the first LNA providing a first output signal to the phase shifter and / or the second LNA providing a second output signal to the phase shifter.

[0016] According to another aspect of the present invention, there is provided a method of manufacturing an integrated circuit comprising a first low noise amplifier (LNA), a second LNA and a phase shifter. The method comprises providing the integrated circuit by providing a first low noise amplifier, LNA, configured to receive a first input signal from an antenna element via a first input and provide a first output signal to a phase shifter. The method of providing the integrated circuit also comprises providing a second LNA configured to receive a second input signal from the antenna element via a second input and provide a second output signal to the phase shifter. The first input signal and the second input signal have different polarisations. The method of providing the integrated circuit comprises providing a polarisation control circuit configured to selectively switch, into an on state or an off state, at least one of: the first LNA and the second LNA.

[0017] According to another aspect of the present invention, there is provided a method of manufacturing an antenna apparatus. The method comprises providing a plurality of antenna modules, each of the antenna modules comprising one or more antenna units. The method comprises providing the one or more antenna units, each of the one or more antenna units comprising an antenna element and an integrated circuit. The method comprises providing the antenna element and the integrated circuit. The method of providing the integrated circuit comprises providing a first low noise amplifier, LNA, configured to receive a first input signal from the antenna element via a first input and provide a first output signal to a phase shifter. The method of providing the integrated circuit comprises providing a second LNA configured to receive a second input signal from the antenna element via a second input and provide a second output signal to the phase shifter. The first input signal and the second input signal have different polarisations. The method of providing the integrated circuit comprises providing a polarisation control circuit configured to selectively switch, into an on state or an off state, at least one of: the first LNA and the second LNA.

[0018] This invention relates to an electronic package in which each antenna element provides an input to more than one LNA. By providing multiple LNAs with different inputs, it is possible to switch polarisations without using a physical switching element. This reduces the overall losses in the antenna apparatus by reducing the switching losses. In particular, the LNAs can be selectively switched to provide a desired signal to a phase shifter following low noise amplification. Alternatively, both LNAs may be used at the same time to support polarisation diversity in Multiple Input, Multiple Output (Ml MO) systems.

[0019] Advantageously, by using multiple LNAs per antenna element to provide a single channel device, the LNAs are placed close to the antenna feed-point for each antenna element, which eliminates, or at least reduces, RF losses between the feed point of the antenna and the inputs of the LNAs. Moreover, this arrangement significantly reduces the overall size and cost of the array by providing a multi-LNA device in a single package.

[0020] Advantageously, switching the LNA associated with the undesired polarisation into the off state reduces the overall power consumption of the antenna apparatus. The electronic package has been custom designed to maximize the noise performance of each LNA.

[0021] The existing technologies within the field are designed with the aim to reduce the size of the electronic packages by integrating components and functions. In contrast, the claimed invention goes against the accepted teachings within the technical field of wireless communication electronics to integrate components and functions. Instead, the claimed invention was devised with the intention to deliberately disintegrate the components and functions to improve pre-amplification losses due to long signal paths to the LNAs.

[0022] Advantageously, the overall size of the antenna array including the electronic packages of the present invention is reduced as the LNAs being arranged on the electronic component allow for the antenna units to be placed closer together within the array. The claimed invention uses a single channel arrangement instead of a 4 channel arrangement.

[0023] The first and second LNAs amplify the received first and / or second input signal from the antenna element without introducing significant amounts of noise into the signal.

[0024] Typically, it may be that the first and second LNAs are LNAs having suitable characteristics for application in the present invention. In particular, it may be that the first and second LNAs are independently controllable. It may be that the input and output impedances of the first and second LNAs are controlled. It may be that the first and second LNAs have input and output impedances within a given range or of a particular value, as will be described below. It may be that the first and second LNAs are two parallel input LNA blocks. It may be that the first and second LNAs are selected to operate in a target frequency, e.g. RF signals of greater than 10 GHz. In some examples, at least one of the first and second LNAs may comprise Silicon Germanium (SiGe) transistor technology. Advantageously, LNAs using SiGe provide a compromise between performance (gain and noise figure at mm-wave frequencies), power consumption, integration capability, size, and cost. However, it will be appreciated that other LNA technologies could equally be used, depending upon the required parameters for the application, including but not limited to Gallium Arsenide (GaAs), Gallium Nitride (GaN), Complementary metal-oxide semiconductor (CMOS) and Bipolar Complementary metal-oxide semiconductor (BiCMOS).

[0025] Typically, the first and second LNAs are LNAs which are operable in response to control signals which switch the LNAs into (e.g. between) the on state and the off state by switching a power rail of the respective LNA between an operating voltage (on state) and ground (off state).

[0026] Typically, the polarisation control circuit may be configured to (e.g. selectively) switch the first and second LNAs into the on or off state and control the output impedance of the respective LNA. Typically, the method of operating the antenna apparatus may comprise controlling the output impedance of the first and second LNA and (e.g. selectively) simultaneously switching the states of the first and second LNAs in dependence on the polarisation control signal. It may be that when one of the first and second LNAs are switched into the off state, the output impedance of the respective LNA is set to a high impedance. It may be that when one of the first and second LNAs are switched into the on state, the output impedance of the respective LNA is set to a low impedance.

[0027] It may be that the first and second LNA have a noise factor of less than 2.5dB, less than 2.25dB or less than 2dB. Advantageously, use of LNAs having a noise factor as mentioned allows the dual LNA architecture to function whilst reducing losses in the apparatus.

[0028] Another benefit is that by turning the unused LNA off we reduce the overall power consumption in the system. Furthermore, the method of the present invention produces a lower system noise figure than existing technologies because there is no switch loss either before or after the LNAs. It is particularly important to reduce (or prevent) losses before the LNAs so that the strongest and most accurate signal is provided to the LNAs for amplification.

[0029] It may be that the first and second LNAs share some components. It may be that the first and second LNAs are discrete, separate components.

[0030] Typically, the first and second LNAs are connected in parallel.

[0031] Typically, the outputs of the first and second LNAs are connected directly together. Typically, the outputs of the first and second LNAs are connected directly to each other and to the input to the phase shifter. Due to the change in output impedance between the off and on states there is no need for additional matching. Avoiding further components can improve sensitivity and reduce power consumption.

[0032] Typically, there is no polarisation switch connected to the output of the first or second LNAs. By switching the LNAs on and off, and changing their output impedance, polarisation switching is achieved without the need for an additional polarisation switch. Avoiding further components can improve sensitivity and reduce power consumption.

[0033] Typically, at least one of the first and second input signals are (RF) input signals from the antenna element. Typically, the antenna element receives an (RF) input signal from a transmitter (e.g. a satellite) with which it is communicating. It may be that at least one of the first and second input signals have a frequency greater than 10GHz, greater than 15GHz or greater than 20GHz.

[0034] Typically, the first input signal has a first polarisation and the second input signal has a second polarisation. It may be that the first polarisation is linear, circular or elliptical polarisation in a first direction. It may be that the second polarisation is linear, circular or elliptical polarisation in a second direction, different to the first direction. The type of polarisation of the first and second polarisations may typically depend on the type of communication in which the antenna apparatus is partaking. In an example, in satellite communications, the first polarisation may be Left-Hand Circular Polarisation (LHCP) and the second polarisation may be Right-Hand Circular Polarisation (RHCP). In another example, in 5G communication, the two polarisations may be Vertical Linear or Horizontal Linear polarisations. Typically, the first and second inputs are input pins on the IC configured to receive an RF signal having the first and second polarisations, respectively.

[0035] It may be that the first and second output signals are RF output signals from the first and second LNAs, respectively. The first and second output signals have the same polarisation as their respective input signal. The first and second output signals typically have increased power compared to their respective input signal.

[0036] It may be that the first and second LNAs are integrated on the same semiconductor die as the polarisation control circuit and the phase shifter. It may be that the phase shifter is either a passive phase shifter or an active phase shifter. It may be that the first and second LNAs are integrated with a MEMS phase shifter. Advantageously, an active phase shifter provides better control and repeatability than a passive phase shifter.

[0037] Typically, when an LNA is in the on state, it may receive its respective input signal from the antenna element and amplify the signal to provide an output to the phase shifter. Typically, when an LNA is in the off state, it may receive its respective input signal from the antenna element and attenuate the signal. The attenuation of the signal may be sufficiently high that the output signal from the LNA in the off state is small compared to the output signal from the LNA in the on state. Therefore, the output signal from the LNA in the off state may contribute significantly less than the output signal from the LNA in the on state to the input signal to the phase shifter and so the input signal to the phase shifter is dominated by the signal from the output of the LNA in the on state.

[0038] Typically, the phase shifter is configured to (typically individually and selectively) adjust a phase of an electromagnetic (typically RF) signal propagating on the signal conductor to or from the antenna element (e.g. for beam steering).

[0039] It may be that in only either the first output signal or the second output signal, and therefore only one polarisation, is provided to the phase shifter during Multiple Input, Single Output (MISO) communication. It may be that both the first output signal and the second output signal are provided to the phase shifter during Multiple Input, Multiple Output (MIMO) communication. It may be that the LNAs and the antenna element have the same pitch.

[0040] It may be that IC comprises a combiner positioned downstream, or after, the first and second LNAs. Typically, the combiner combines the output signals from the LNAs into a single input signal to the phase shifter.

[0041] It may be that the method of operating the antenna apparatus is a method of operating the antenna apparatus in a receive mode.

[0042] It may be that the antenna element comprises multiple antenna ports (output ports) for providing an RF input signal to the respective LNA. It may be that the antenna element is positioned on an antenna board. It may be that each port of an antenna element corresponds to a different polarity. It may be that the antenna element comprises a first antenna port and a second antenna port. It may be that the first and second antenna elements are isolated from one another. It may be that the antenna element is dualpolarised. It may be that the antenna apparatus is configured to isolate the two antenna ports from each other.

[0043] It may be that the first antenna port, which provides the first input signal to the first LNA, is positioned on a first side of the antenna element. It may be that the second antenna port, which provides the second input signal to the second LNA, is positioned on a second side of the antenna element. It may be that the first and second sides of the antenna element are at right angles to one another. It may be that the first and second sides of the antenna element are adjacent to one another. The antenna element may be rectangular (e.g. square or oblong). For example, it may be that the antenna element is part of a patch antenna. It may be that the antenna element comprises at least a metal layer and a parallel ground layer, usually with a dielectric therebetween.

[0044] Typically, the first RF input signal is conducted from the first antenna port of the antenna element to the first LNA by a first signal conductor. Typically, the second RF input signal is conducted from the second antenna port of the antenna element to the second LNA by a second signal conductor. Each signal conductor may comprise a first portion and a second portion. The first portion may be a linear portion of the signal conductor that extends from the respective antenna port. The first portions of the first and second signal conductors may be orthogonal to one another. The second portion may be a linear portion of the signal conductor that extends from the respective input pin. The second portions of the first and second signal conductors may be orthogonal to one another.

[0045] Advantageously, when the antenna ports are at right angles to one another, the RF signals of those antenna ports are isolated from one another.

[0046] It may be that the antenna apparatus comprises one or more dual-polarised microstrip patch antenna elements. It may be that the antenna apparatus comprise one or more edge fed patch antennae. However, other types of antenna could be used, including aperture fed or probe fed patch antennae.

[0047] It may be that the first input signal to the first LNA is provided by a first antenna element. It may be that the second input signal to the second LNA is provided by a second antenna element. Each of the first and second antenna elements may be configured to receive a single RF signal. It may be that the first antenna element is configured to receive an RF signal having a first polarisation. It may be that the second antenna element is configured to receive an RF signal having a second polarisation, where the first polarisation is different to the second polarisation.

[0048] Typically, the polarisation control circuit is positioned after the first and second LNAs on the integrated circuit. It may be that the method of manufacturing an antenna apparatus comprises providing the polarisation control circuit positioned after the first and second LNAs on the integrated circuit.

[0049] Typically, the polarisation control circuit determines whether both of the first and second output signals are provided to the phase shifter, or either only the first output signal or only the second output signal is provided to the phase shifter. By determining which output signals from the LNAs (i.e. the amplified input signals) are provided to the phase shifter, the polarisation control circuit determines which polarisation is, or polarisations are, provided to the phase shifter. Typically, the polarisation control circuit is a control circuit in which control signals are selectively transmitted to the first and second LNAs. The control signals typically switch the first and second LNAs into the on or off state. The polarisation control circuit may typically not be a physical switch.

[0050] It may be that the polarisation control circuit is distributed across multiple components of the IC. In some examples, the polarisation control circuit may comprise one or more controllers and one or more control lines along which control signals (e.g. to control the LNAs) are transmitted.

[0051] It may be that the polarisation control circuit is positioned after the LNAs in a signal path. It may be that the polarisation control circuit is positioned after the LNAs in a signal path of the first and / or second input signals. It may be that the polarisation control circuit is positioned downstream from the LNAs.

[0052] It may be that beamforming is performed using one phase shifter per antenna element, where a phase shifter is positioned after the first and second LNAs on the integrated circuit.

[0053] Advantageously, placing the polarisation control circuit after (e.g. downstream of) the LNAs reduces the signal losses of the input signals from the antenna element before the input signals are amplified.

[0054] It may be that the first input is directly connected to the first LNA and the second input is directly connected to the second LNA. It may be that the method of manufacturing an antenna apparatus comprises directly connecting the first input to the first LNA and directly connecting the second input to the second LNA.

[0055] Typically, the first and second input signals are provided directly to the first and second LNAs respectively without passing through another component of the IC. Typically, the signal path of the first input signal is from the first input pin directly to the first LNA. Typically, the signal path of the second input signal is from the second input pin directly to the second LNA. That is, the IC may not comprise a switching component positioned before the LNAs. Therefore, polarisation switching is not performed before the LNAs. It may be that, on the signal path of the first input signal from the antenna element to the first LNA, the first switching component is part of the first LNA. It may be that, on the signal path of the second input signal from the antenna element to the second LNA, the first switching component is part of the second LNA. That is, there may be no intervening switching components on the signal path of the first and second input signals from the antenna element to their respective LNAs.

[0056] Advantageously, the direct connection between the LNAs and the first and second input, respectively, from the antenna element reduces losses due to interference. Advantageously, switching of polarisations is provided by control of the LNAs rather than by a switching component of the IC.

[0057] Alternatively, the first and second LNAs may be connected to the respective input from the antenna element through a network of components. Advantageously, these components may be designed to provide a specific phase shift to the input signal in a pre-amplification stage. For example, the first and second LNAs may be connected to the respective input using a 90-degree combiner, which allows multiple RF signals of different polarisations to be received and coupled to the respective LNA inputs.

[0058] It may be that the antenna apparatus comprises a first port and a second port. It may be that the first port has a first polarisation to receive a signal having a first linear polarisation (e.g. vertically polarised). It may be that the second port has a second polarisation to receive a signal having a second linear polarisation (e.g. horizontally polarised). It may be that the first and second linear polarised signals are combined using the network of components (e.g. combiner / coupler, such as a 90 degree hybrid) to provide the first and / or second input signals to the first and second LNAs respectively. It may be that the network of components is configured to provide the first input signal to the first LNA. It may be that the network of components is configured to provide the second input signal to the second LNA. It may be that the network of components provides either the first or second input to the respective LNA depending on which output of the network of components is connected to the signal path. It may be that the first input signal to the first LNA generated by the network of components has a first circular polarisation (e.g. Right hand circular polarisation, RHCP). It may be that the second input signal to the second LNA generated by the network of components has a second circular polarisation (e.g. Left hand circular polarisation, LHCP).

[0059] It will be appreciated that there are other methods in which the ways of generating an RHCP or LHCP signal.

[0060] It may be that an input impedance of the first LNA (e.g in either the on state of the off state) is equal to an input impedance of the second LNA (e.g. in either the on state or the off state). It may be that the method of manufacturing an antenna apparatus comprises providing the first and second LNAs having equal input impedances irrespective of the state of each LNA.

[0061] It may be that the input impedance of the first and second LNAs is equal when the LNAs are in both the on state and the off state.

[0062] Advantageously, the first and second LNAs having the same input impedance provides impedance matching for the input impedance of the LNAs when in both the on state and the off state.

[0063] It may be that an input impedance of the first LNA is less than 650 and an input impedance of the second LNA is less than 65Q. It may be that the method of manufacturing an antenna apparatus comprises providing the first and second LNAs each having an input impedance less than 65Q.

[0064] It may be that the input impedance of the first LNA is less than 55Q and the input impedance of the second LNA is less than 55Q. It may be that the input impedance of the first LNA is equal to 50Q and the input impedance of the second LNA is equal to 500.

[0065] It may be that the input impedance of the first LNA and the second LNA is selected to provide RF impedance matching with the phase shifter on the IC. Advantageously, this reduces losses of the RF signal as it is transmitted to the phase shifter.

[0066] It may be that the polarisation control circuit is configured to switch one of the first and second LNAs into the on state and the other LNA into the off state to provide either the first output signal or the second output signal to the phase shifter at any one time. It may be that the method of operating an antenna apparatus comprises switching one of the first and second LNAs into the on state and the other LNA into the off state to provide either the first output signal or the second output signal to the phase shifter at any one time.

[0067] Typically, switching of the first and second LNAs comprises a control signal applied to an LNA to switch the LNA into the on state. An LNA in the on state typically amplifies the respective input signal and provides an output signal to the phase shifter. Typically, switching of the first and second LNAs comprises a control signal applied to an LNA to switch the LNA into the off state. An LNA in the off state typically attenuates the respective input and does not provide an output signal to the phase shifter. Typically, when either the first output signal or the second output signal is provided to the phase shifter at any one time, this is MISO communication.

[0068] Advantageously, the antenna apparatus to switch between polarisations quickly and effectively whilst minimising losses due to interference caused by the signal path to the LNA.

[0069] Advantageously, having an LNA corresponding to the polarisation that is not used in the off state reduces interference with the signal that corresponds to the polarisation that is used and reduces power consumption.

[0070] It may be that the polarisation control circuit is configured to switch both of the first and second LNAs into the on state to provide both the first output signal and the second output signal to the phase shifter at any one time. It may be that the method of operating an antenna apparatus comprises switching both of the first and second LNAs into the on state to provide both of the first output signal and the second output signal to the phase shifter at any one time.

[0071] Typically, when both the first output signal and the second output signal are provided to the phase shifter at any one time, this is MIMO communication.

[0072] It may be that the ratio of an output impedance of the LNA in the off state to an output impedance of the LNA in the on state is 10:1. It may be that the output impedance of the LNA in the off state is 500Q and the output impedance of the LNA in the on state is 50Q. It may be that method of operating an antenna apparatus comprises providing a ratio of an output impedance of the LNA in the off state to an output impedance of the LNA in the on state of 10:1. It may be that the method of operating the antenna apparatus comprises providing the output impedance of the LNA in the off state of 500Q and the output impedance of the LNA in the on state of 50Q.

[0073] Advantageously, the high ratio of the output impedance of the LNA in the off state to an output impedance of the LNA in the on state sufficiently isolates the off LNA from the circuit.

[0074] It may be that the ratio of an output impedance of the LNA in the off state to an output impedance of the LNA in the on state is greater than 10:1.

[0075] It may be that the first LNA is connected to a first power rail and the second LNA is connected to a second power rail. It may be that the polarisation control circuit is configured to control the connection to the first and second power rails to selectively switch at least one of the first LNA and the second LNA into the on or off state. It may be that the method of operating an antenna apparatus comprises controlling the connection to the first and second power rails to selectively switch at least one of the first LNA and the second LNA into the on or off state. It may be that the method of manufacturing an antenna apparatus comprises connecting the first LNA to a first power rail and connecting the second LNA to a second power rail.

[0076] Typically, the polarisation control circuit transmits a control signal to the LNAs to control the connection of the LNA to the respective power rail. Transmitting a control signal may comprise providing an operating voltage to a power rail of the LNA (to switch the LNA to the on state) or ground voltage to a power rail of the LNA (to switch the LNA to the off state). It may be that for each power rail, either an operating voltage or ground voltage is applied. It may be that the polarisation control circuit is configured to apply either and operating voltage or a ground voltage to the first and second power rails to selectively switch at least one of the first LNA and the second LNA into the on or off state. Typically, when the control signal causes an LNA to connect to its respective power rail having an operating voltage applied, the respective LNA is in the on state. Typically, when the control signal causes an LNA to connect to its respective power rail having a ground voltage applied, the LNA is in the off state. In some examples, the polarisation control circuit may transmit control signals to both the first and second LNAs to connect to their respective power rails, meaning that both the first and second LNAs are in on state.

[0077] As described above, the output impedance of the LNAs is different (for example by a factor of10:1) in the on and off states. Typically, the output impedance is higher in the off state than the on state. Thus, providing an operating voltage to a power rail of an LNA and / or transmitting the control signal may have the effect of both switching an LNA between the on and off state and switching the output impedance of the LNA.

[0078] It may be that the total number of individually switchable LNAs per antenna unit is greater than the total number of antenna elements per antenna unit. It may be that the first and second inputs from the antenna element are parts (typically opposite ends) of a continuous conductor. It may be that the method of manufacturing an antenna apparatus comprises providing a greater total number of LNAs per antenna unit than the total number of antenna elements per antenna unit. It may be that the method of manufacturing an antenna apparatus comprises providing the first and second inputs from the antenna element on a continuous conductor.

[0079] Advantageously, provision of a greater number of LNAs per antenna unit than antenna elements per antenna units allows the LNAs to be located closer on the signal path to the antenna element to reduce loss whilst also providing polarisation switching functionality before the phase shifter.

[0080] Typically, there is an integer number, which is greater than 1 , of individual switchable LNAs per antenna element. The integer may be 2. The integer may be greater than 2. The integer may be 3. The integer may be 4.

[0081] Typically, the ratio of LNAs to antenna elements is greater than 1 to 1. The ratio may be 2 to 1 . The ratio may be greater than 2 to 1 . The ratio may be 4 to 1.

[0082] It may be that the first and second output signals are provided to the phase shifter via a combiner circuit. That is, both the first and second LNA may amplify the respective first and second input signals, each input signal having a different polarisation. The output signal of both the first and second LNAs may be combined such that a single RF signal is provided to the phase shifter. It may be that the combiner circuit is, for example, a Wilkinson Power Combiner.

[0083] Alternatively, it may be that the first and second output signals are provided directly to the phase shifter. Typically, the output of each LNA is directly connected to the phase shifter. In this way there are no electronic components between the output of each LNA and the phase shifter.

[0084] It may be that the first and second inputs from the antenna element are formed on a continuous conductor. Advantageously, this reduces signal losses within the antenna apparatus.

[0085] It may be that the polarisation control circuit is configured to alternately switch the first and second LNAs into the on state while switching the other LNA into the off state. It may be that the first LNA and the second LNA are alternately switched on every switching period. It may be that the maximum switching period is 100 microseconds. It may be that the method of operating an antenna apparatus comprises alternately switching the first and second LNAs into the on state while switching the other LNA into the off state. It may be that the method of operating an antenna apparatus comprises alternately switching on the first LNA and the second LNA every switching period. It may be that the maximum switching period is 100 microseconds.

[0086] Typically, the polarisation control circuit cause alternate switching of the first and second LNAs into the on state. When one LNA is switched into the on state, the other LNA is off. This may herein be referred to as “polarisation switching”. It may be that polarisation switching comprises alternately applying the operating voltage and a ground voltage to each power rail. It may be that each LNA is switched into the on state for a switching period. When the switching period expires, the polarisation control circuit typically provides a control signal to the other LNA that was previously in the off state, to thereby switch that LNA into the on state. This provides switching between the first and second polarisations. It may be that the polarisation control circuit causes polarisation when scanning for incoming RF signals. It may be that the maximum switching period is 80 microseconds, 60 microseconds or 50 microseconds. It may be that the maximum switching period is 120 microseconds, 150 microseconds or 175 microseconds.

[0087] It may be that the at least one of the first LNA and the second LNA are selectively switched in dependence on formation of a communication link between the antenna apparatus and a transmitter and / or receiver. It may be that the at least one of the first LNA and the second LNA are selectively switched in dependence on transmission of an RF signal through the antenna apparatus. It may be that the method of operating an antenna apparatus comprises selectively switching at least one of the first LNA and the second LNA in dependence on formation of a communication link between the antenna apparatus and a transmitter and / or receiver. It may be that the method of operating an antenna apparatus comprises selectively switching at least one of the first LNA and the second LNA in dependence on transmission of an RF signal through the antenna apparatus.

[0088] Advantageously, the IC switches polarisations, on demand, when establishing a new communication link between the antenna apparatus to which it is a part and the transmitter and / or receiver.

[0089] Typically, the formation of a communication link refers to a new wireless communication connection between the antenna apparatus and the transmitter and / or receiver.

[0090] Advantageously, the IC switches polarisations, on demand, when receiving an RF signal and transmitting the received RF signal through the antenna apparatus.

[0091] That is, at least one of the first and second LNAs may be switching into the on state when a new communication link is to be established and / or an RF signal is received by the antenna apparatus.

[0092] It may be that a track of the first input on the integrated circuit is orthogonal to a track of the second input on the integrated circuit. It may be that each of the first input and the second input are each located between a first ground and a second ground on the integrated circuit. It may be that the method of manufacturing an antenna apparatus comprises providing a track of the first input on the integrated circuit orthogonal to a track of the second input on the integrated circuit. It may be that the method of manufacturing an antenna apparatus comprises providing each of the first input and the second input between a first ground and a second ground on the integrated circuit.

[0093] Typically, the first input pin and the second input pin are orthogonal to one another.

[0094] Advantageously, by providing the tracks of the first and second inputs at a right angle to one another, the isolation of the input pins is increased, thereby reducing interference and losses.

[0095] Synergistically, it may be that the integrated circuit and the antenna element are each rectangular (e.g. square or oblong) and the first and second antenna ports of the antenna element are located on adjacent, orthogonal sides of the antenna element, and are connected to the first and second inputs to the integrated circuit, and the first and second inputs to the integrated circuit are located on adjacent, orthogonal sides of the integrated circuit. The conductors extending between the antenna ports and the inputs to the integrated circuit may each comprise a single right-angle bend. The antenna element may be aligned with but offset diagonally from the integrated circuit. Thus, the RF signals of different polarisations of the antenna element can be conducted to the inputs of the antenna element and to the LNAs while remaining isolated.

[0096] Advantageously, by providing the first and second inputs between ground pins, the isolation between the input pins is increased, thereby reducing interference and losses.

[0097] Typically, the first and second grounds are pins on the IC that are connected to ground.

[0098] Typically, the IC is a combination of electronic circuits formed on a semiconductor material.

[0099] Typically, the antenna apparatus is intended for use in RF communications. It may be that the antenna apparatus is a phased array antenna apparatus. It may be that the antenna apparatus is MEMS based in that it includes one or more microelectromechanical structures, MEMS, for example the one or more MEMS switches. Typically, the antenna apparatus comprises one or more antenna elements arranged on a flat two-dimensional plane, (i.e. all antenna elements are at the same height).

[0100] It may be that the antenna module comprises a substrate configured to support the one or more antenna units. It may be that the one or more antenna units comprise a substrate configured to support components of the antenna unit (e.g. the antenna element and the integrated circuit).

[0101] Typically, the antenna element is a radiating element of the antenna apparatus. It may be that the antenna element is formed (e.g. on the substrate) by depositing and / or patterning metal (e.g. by photolithography).

[0102] Typically, the one or more antenna units each comprise a signal conductor configured to propagate a signal (e.g. an RF signal). It may be that the signal conductor is conductively connected to the antenna element.

[0103] According to another aspect of the present invention, there is provided a phased array comprising at least one of the antenna apparatus as described above.

[0104] It may be that the antenna modules are arranged in a grid formation. It may be that the antenna units are arranged in a grid formation.

[0105] The invention extends to a (e.g. cellular mobile) wireless telecommunications base station or a small, micro or femto cell infrastructure, or (typically wireless) backhaul, transmitter, receiver or transceiver comprising said antenna apparatus (or one or more antenna modules) or said phased antenna array.

[0106] The invention extends to a portable personal mobile wireless telecommunications device comprising one or more said antenna modules or a said phased antenna array.

[0107] Description of the Drawings

[0108] An example embodiment of the present invention will now be illustrated with reference to the following Figures in which: Figure 1 illustrates a schematic of an antenna apparatus according to an aspect of the invention,

[0109] Figure 2 illustrates a schematic of an integrated circuit according to an aspect of the invention,

[0110] Figure 3 illustrates a schematic of an antenna apparatus according to an aspect of the invention,

[0111] Figure 4 illustrates schematic of an antenna apparatus according to an aspect of the invention,

[0112] Figure 5 illustrates a flowchart of a method according to an aspect of the invention,

[0113] Figure 6 illustrates a flowchart of a method according to an aspect of the invention, and

[0114] Figure 7 illustrates a schematic of a controller according to an aspect of the invention.

[0115] Detailed Description of an Example Embodiment

[0116] Figure 1 illustrates a schematic of an antenna apparatus 100 according to an aspect of the invention. The antenna apparatus 100 comprises an integrated circuit (IC) 110 and an antenna element 150. The antenna element 150 receives an RF signal from a transmitter, such as a satellite (not illustrated).

[0117] The IC 110 comprises a first low noise amplifier (LNA) 120 and a second LNA 130. The first LNA 120 is controlled by control signals transmitted on a first LNA control line 125 and the second LNA 130 is controlled by control signals transmitted on a second LNA control line 135. The first and second LNA control lines 125, 135 transmit control signals which determined whether the respective LNA 120, 130 is on or off. The control of the first and second LNAs 120, 130 controls which polarisation is transmitted through the antenna array 100. The LNA 120, 130 corresponding to the desired polarisation is switched into the on state and the LNA corresponding to the other polarisation is switched into the off state.

[0118] The input impedance of the first and second LNAs 120, 130 is 50Q when the LNAs are both on and off. The output impedance of the on LNA is also 50 Q. The output impedance of the off LNA is 5000 as a minimum. The off LNA attenuates the undesired signal so that it is not transmitted through the antenna array 100.

[0119] The antenna element 150 provides a first RF input signal 150a to the first LNA 120 and a second RF input signal 150b to the second LNA 150b. The first and second RF input signals 150a, 150b are amplified by the respective first and second LNAs 120, 130 when the LNAs are in the on state. The first LNA 120 provides a first LNA output 120a and the second LNA 130 provides a second LNA output 130a. The first input signal 150a has a first polarisation and the second input signal 150b has a second polarisation. In an example, the first polarisation is vertical polarisation and the second polarisation is horizontal polarisation. In another example the first polarisation is right handed circular polarisation and the second polarisation is left handed circular polarisation.

[0120] The IC 110 also comprises a phase shifter 140, which is controlled by a phase shifter controller 145. The phase shifter controller 145 controls the phase shift applied to the RF signals received by the phase shifter 140. The first LNA 120 outputs an amplified first output signal 120a to the phase shifter 140 and the second LNA 130 outputs an amplified second output signal 130a to the phase shifter 140. The phase shifter 140 outputs a phase shifted output signal 140a.

[0121] Figure 2 illustrates an IC 110 according to an aspect of the present invention. The IC comprises the first and second LNAs, 120, 130 and the phase shifter 140. The first LNA control line 125 and the second LNA control line 135 are connected to and controller by the IC controller 180. The phase shifter controller 145 (which is not illustrated in Figure 2 for simplicity) is controlled by IC controller 180. The control lines 125, 135 and the IC controller 180 function as the polarisation control circuit. As is shown in Figure 2, the polarisation control circuit is positioned after the inputs to the first and second LNAs 120, 130.

[0122] The IC 110 comprises a first RF input pin 155a for transmitting the first RF input signal 150a from the antenna element 150 to the first LNA 120. Similarly, the IC 110 comprises a second RF input pin 155b for transmitting the second RF input signal 150b from the antenna element 150 to the second LNA 130. The IC 110 also comprises an output pin 160 to transmit the amplified RF output signal 140a from the phase shifter 140 to other components within the antenna array 100.

[0123] The first input pin 155a, the second input pin 155b and the output pin 160 are each positioned between a first ground connection pin and a second ground connection pin, which are represented by reference numerals 170a - 170f, to isolate the respective pins. The first input pin 155a is located on a first side 112 of the IC 110. The second input pin 115b is located on a second side 114 of the IC 110. The first side 112 and the second side 114 of the IC 110 are orthogonal to one another, meaning that the first 155a and second 155b input pins are orthogonal to one another.

[0124] The first LNA 120 is connected to a first power rail and the second LNA 130 is connected to a second power rail.

[0125] The output signals from the first LNA 120 and the second LNA 130 are combined in the combiner 138. The output provided by the combiner 138 is transmitted to the phase shifter 140 as the phase shifter input signal.

[0126] The IC 110 also comprises a control input pin 185. The IC controller 180 receives inputs through the control input pin 185. The IC 110 also comprises a various other pins 190a - 190j for other components of the IC 110, such as power and communication with other components of the antenna array. Other properties of the received RF signal are also controlled, such as the attenuation of the received signal.

[0127] Figure 3 illustrates a schematic of an antenna array apparatus 200. Some features of the IC 110 are not shown in Figure 3 for simplicity. The antenna array 200 includes ‘n’ antenna elements 150-1 to 150-n, which include are arranged on an antenna board. The antenna elements 150-1 to 150-n (which are patch antennas) comprise two antenna ports 156, 158 which output the signal that is the first RF input signal to the first LNA and the signal that is the second RF input signal to the second LNA, respectively. The first antenna port 156 is provided on a first side 152 of the antenna element (i.e. antenna board) and the second antenna port 158 is provided on a second side 154 of the antenna element (i.e antenna board). The first RF input signal is transmitted by a first signal conductor which is formed of first portion 162a and second portion 164a. The second RF input signal is transmitted by a second signal conductor which is formed of first portion 162b and second portion 164b. The first portions 162a, 162b are connected to respective antenna ports 156, 158. The second portions 164a, 164b are connected to respective input pins 155a, 155b. The first portions 162a, 162b of the signal conductors are at a right angle to one another so that the RF signal output by the respective antenna port are isolated from one another from the beginning of the signal path. The second portions 164a, 164b of the signal conductors are at a right angle to one another so that the respective RF input signals 150a, 150b are isolated from one another when they are inputted to the IC 110.

[0128] The antenna element 150-2 and the IC 110-2 are shown having these features and it will be appreciated that the other antenna elements and ICs also have these features, but they have not been labelled in Figure 3 for simplicity.

[0129] The antenna array 200 includes ‘n’ ICs 110-1 to 110-n which are the same as IC 110. Each IC 110, in particular the IC controller 180, communicates with a master controller 280 using the control input pin 185. The master controller 280 controls the switching of the LNAs 120, 130 and the phase shift and attenuation of each individual IC 110. Each IC 110 provides an output signal 160a through the output pin 160. The output signal 160a of the IC 110 is transmitted to a combining network, followed by a downconverter and Intermediate Frequency (IF) signal processing (not shown).

[0130] In this example, which is an antenna array apparatus 200 in a phased array application, each IC 110 is controlled such that the same polarisation is provided to the phase shifter 140 by turning the same LNAs 120, 120 on each IC 110 on and off. The phase shift and attenuation of each IC 110 will be determined to enable a beam steering function, meaning they are typically different across the array, and are implemented by each individual IC 110.

[0131] Figure 4 illustrates a schematic of an antenna array apparatus 300 comprising an antenna module 330-1. The antenna module 330-1 comprises four antenna units, of which one is labelled in Figure 4 as 320-1. Each antenna unit 320-1 comprises an IC, e.g. IC 110-1 , and an antenna element 150-1. The antenna array apparatus 300 is described as an example and antenna apparatus having more antenna modules, antenna modules having more antenna units, and antenna units having more ICs and antenna elements, than those shown in Figure 4 will be envisaged.

[0132] Figure 5 illustrates a flowchart of a method 500 of operating the antenna apparatus 100, 200 or 300 according to an aspect of the present invention. The method 500 could also be a method of operating the IC 110. The method 500 includes the first and second LNAS 120, 130 receiving 510 the first and second RF input signals, respectively, from the antenna element 150 via the respective input pins 155a, 155b.

[0133] The method 500 also comprises receiving 520 a polarisation control signal from the polarisation control circuit. The polarisation control signal determines which signal is provided to the phase shifter 140. The polarisation control signal is used to determine which LNA 120, 130 to switch into the on state and which LNA 120, 130 should be in the off state. In some examples, the polarisation control circuit may cause both polarisations to be provided to the phase shifter 140.

[0134] The first and second LN As 120, 130 are then selectively switched 530 in dependence on the polarisation control signal to provide one of the first or second output signal 120a, 130a to the phase shifter 140. This may be implemented by connecting the first or second power rail to the respective LNA 120, 130. The LNA 120, 130 that provides an output signal to phase shifter 140 is the “on” LNA. The LNA that is not connected to the phase shifter 140 is the “off” LNA.

[0135] The “on” LNA performs low noise amplification of the RF input signal it receives. The amplified output signal of the “on” LNAs 120, 130 is provided 540 to the phase shifter 140. The “off’ LNA attenuates the RF input signal it receives. In some examples, it may be that both polarisations, and so both the first and second RF input signals 150a, 150b are amplified and provided to the phase shifter 140, if both LNAs are on.

[0136] The selective switching of the first and second LNAs 120, 130 are triggered by the formation of a new communication link and / or the transmission of a RF signal by the antenna apparatus 100, 200, 300. The first and second LNAs 120, 130 are switched every 100 microseconds to perform a polarisation scan. As part of the method 530 of selectively switching the LNAs, the method 500 comprises providing a ratio of an output impedance of the LNA in the off state to an output impedance of the LNA in the on state of 10:1 to sufficiently isolate the off LNA.

[0137] Figure 6 illustrates a flowchart of a method 600 of manufacturing the antenna apparatus 100, 200 or 300 according to an aspect of the present invention. The method 600 comprises providing 610 a plurality of antenna modules, such as antenna module 330-1 , providing 620 one or more antenna units, such as antenna unit 320-1 , in each antenna module and providing 630 an antenna element 150 and an IC 110 in each antenna unit. The method 600 also comprises, on each IC 110, providing 640 the first LNA 120 and providing 650 the second LNA 130. The method 400 further comprises, on each IC 100, providing 660 the polarisation control circuit 160.

[0138] When providing 640, 650 the first and second LNAs 120, 130 on the IC 110, the LNAs are directly connected to the first and second input pins 155a, 155b from the antenna element 150, respectively.

[0139] Providing 660 the polarisation control circuit includes positioning the polarisation control circuit after the LNAs 120, 130 on the IC 110.

[0140] During manufacturing, the first and second LNAs 120, 130 are provided 640, 650 by selecting LNAs having equal impedances which are below 65 Q, namely 50 Q. In addition, the method of providing 640, 650 the first and second LNAs includes connecting the LNAs to respective power rails.

[0141] As shown Figures 1 to 3, there are two LNAs per IC 110. The method 600 comprises providing a greater total number of LNAs per antenna unit than the total number of antenna elements per antenna unit.

[0142] In addition, the method 600 includes providing each of the first input pin 115a and the second input 155b between ground pins 170a, 170b, 170c, 170d. As shown Figures 1 to 3, the IC 110 is manufactured by providing a track of the first input on the integrated circuit orthogonal to a track of the second input on the integrated circuit. The method 600 also includes forming the first and second inputs from the antenna element on a continuous conductor. Figure 5 illustrates a schematic of a controller 710 according to an aspect of the present invention. The controller 710 comprises one or more processors 720 and a non- transitory computer readable memory 730. The non-transitory computer readable memory 730 stores instructions which, when executed by the one or more processors 720, causes operation of the methods described herein. The controller 710 exchanges data and / or control signals 725 with other components of the IC 110. The controller 710 is part of the antenna apparatus 100, 200 or 300. The controller 710 may be the master controller 280, the IC controller 180 and / or the phase shifter controller 145.

[0143] Throughout the description and claims of this specification, the words “comprise” and “contain” and variations of them mean “including but not limited to”, and they are not intended to and do not exclude other components, integers, or steps. Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

[0144] Features, integers, characteristics, or groups described in conjunction with a particular aspect, embodiment, or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and / or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive. The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

Claims1. An antenna apparatus comprising: a plurality of antenna modules, each of the antenna modules comprising one or more antenna units, each of the one or more antenna units comprising an antenna element and an integrated circuit, the integrated circuit comprising: a first low noise amplifier, LNA, configured to receive a first input signal from the antenna element via a first input and provide a first output signal to a phase shifter; a second LNA configured to receive a second input signal from the antenna element via a second input and provide a second output signal to the phase shifter, wherein the first input signal and the second input signal have different polarisations; and a polarisation control circuit, configured to selectively switch, into an on state or an off state, at least one of: the first LNA and the second LNA.

2. The antenna apparatus of claim 1 , wherein the polarisation control circuit is positioned after the first and second LNAs on the integrated circuit.

3. The antenna apparatus of claim 1 or claim 2, wherein the first input is directly connected to the first LNA and the second input is directly connected to the second LNA.

4. The antenna apparatus of any preceding claim, wherein an input impedance of the first LNA in either the on state or the off state is equal to an input impedance of the second LNA in either the on state or the off state.

5. The antenna apparatus of any preceding claim, wherein an input impedance of the first LNA is less than 650 and an input impedance of the second LNA is less than 650.

6. The antenna apparatus of any preceding claim, wherein the polarisation control circuit is configured to switch one of the first and second LNAs into the on stateand the other LNA into the off state to provide either the first output signal or the second output signal to the phase shifter at any one time.

7. The antenna apparatus of claim 6, wherein the ratio of an output impedance of the LNA in the off state to an output impedance of the LNA in the on state is 10: 1 , optionally, wherein the output impedance of the LNA in the off state is 5000 and the output impedance of the LNA in the on state is 500.

8. The antenna apparatus of any preceding claim, wherein the first LNA is connected to a first power rail and the second LNA is connected to a second power rail, and the polarisation control circuit is configured to control the connection to the first and second power rails to selectively switch at least one of the first LNA and the second LNA into the on or off state.

9. The antenna apparatus of any preceding claim, wherein at least one of: the total number of individually switchable LNAs per antenna unit is greater than the total number of antenna elements per antenna unit, and the first and second inputs from the antenna element are parts (typically opposite ends) of a continuous conductor.

10. The antenna apparatus of any preceding claim, wherein the polarisation control circuit is configured to alternately switch the first and second LNAs into the on state while switching the other LNA into the off state, optionally wherein the first LNA and the second LNA are alternately switched on every switching period, optionally wherein the maximum switching period is 100 microseconds.

11. The antenna apparatus of any preceding claim, wherein at least one of the first LNA and the second LNA are selectively switched in dependence on: formation of a communication link between the antenna apparatus and a transmitter and / or receiver, and / or. transmission of an RF signal through the antenna apparatus.

12. The antenna apparatus of any preceding claim, wherein at least one of: a track of the first input on the integrated circuit is orthogonal to a track of the second input on the integrated circuit; andeach of the first input and the second input are each located between a first ground and a second ground on the integrated circuit.

13. A phased array comprising at least one of the antenna apparatus as claimed in any preceding claim.

14. A method of operating an antenna apparatus, the antenna apparatus comprising a plurality of antenna modules, each of the antenna modules comprising one or more antenna units, each of the one or more antenna units comprising an antenna element and an integrated circuit comprising a first low noise amplifier, LNA, a second LNA and a phase shifter, the method comprising: the first LNA receiving a first input signal from the antenna element via a first input; the second LNA receiving a second input signal from the antenna element via a second input, wherein the first input signal and the second input signal have different polarisations; receiving a polarisation control signal; selectively switching, into an on state or an off state in dependence on the polarisation control signal, at least one of: the first LNA and the second LNA; and the first LNA providing a first output signal to the phase shifter and / or the second LNA providing a second output signal to the phase shifter.

15. The method of operating an antenna apparatus of claim 14, comprising switching one of the first and second LNAs into the on state and the other LNA into the off state to provide either the first output signal or the second output signal to the phase shifter at any one time.

16. The method of operating an antenna apparatus according to claim 15, comprising providing a ratio of an output impedance of the LNA in the off state to an output impedance of the LNA in the on state of 10:1 , optionally comprising providing the output impedance of the LNA in the off state of 5000 and the output impedance of the LNA in the on state of 500.

17. The method of operating an antenna apparatus of any of claims 14 to 16, wherein the first LNA is connected to a first power rail and the second LNA is connected to a second power rail, and the method comprises controlling the connection to the first and second power rails to selectively switch at least one of the first LNA and the second LNA into the on or off state.

18. The method of operating an antenna apparatus of any of claims 14 to 17, comprising alternately switching the first and second LNAs into the on state while switching the other LNA into the off state, optionally comprising alternately switching on the first LNA and the second LNA every switching period, optionally wherein the maximum switching period is 100 microseconds.

19. The method of operating an antenna apparatus of any of claims 14 to 18, comprising selectively switching at least one of the first LNA and the second LNA in dependence on: formation of a communication link between the antenna apparatus and a transmitter and / or receiver; and / or transmission of an RF signal through the antenna apparatus.

20. A method of manufacturing an antenna apparatus comprising: providing a plurality of antenna modules, each of the antenna modules comprising one or more antenna units; providing the one or more antenna units, each of the one or more antenna units comprising an antenna element and an integrated circuit; providing the antenna element and the integrated circuit, wherein providing the integrated circuit comprises: providing a first low noise amplifier, LNA, configured to receive a first input signal from the antenna element via a first input and provide a first output signal to a phase shifter; providing a second LNA configured to receive a second input signal from the antenna element via a second input and provide a second output signal to the phase shifter, wherein the first input signal and the second input signal have different polarisations; and providing a polarisation control circuit configured to selectively switch, into an on state or an off state, at least one of: the first LNA and the second LNA.

21. The method of manufacturing an antenna apparatus according to claim 20, comprising providing the polarisation control circuit positioned after the first and second LNAs on the integrated circuit.

22. The method of manufacturing an antenna apparatus according to claim 20 or claim 21 , comprising directly connecting the first input to the first LNA and directly connecting the second input to the second LNA.

23. The method of manufacturing an antenna apparatus according to any of claims 20 to 22, comprising providing the first and second LNAs having equal input impedances irrespective of the state of each LNA.

24. The method of manufacturing an antenna apparatus according to any of claims 20 to 23, providing the first and second LNAs each having an input impedance less than 650.

25. The method of manufacturing an antenna apparatus according to any of claims 20 to 24, comprising connecting the first LNA to a first power rail and connecting the second LNA to a second power rail.

26. The method of manufacturing an antenna apparatus according to any of claims 20 to 25, comprising providing at least one of: a greater total number of LNAs per antenna unit than the total number of antenna elements per antenna unit; and the first and second inputs from the antenna element on a continuous conductor.

27. The method of manufacturing an antenna apparatus according to any of claims 20 to 26, comprising at least one of: providing a track of the first input on the integrated circuit orthogonal to a track of the second input on the integrated circuit; and providing each of the first input and the second input between a first ground and a second ground on the integrated circuit.

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