Computer system and method for on-board calibration of direct radiating array antenna

Abstract

To provide a system for calibrating an antenna.SOLUTION: The system includes a processing unit configured to operate an antenna in a transmit calibration mode or a receive calibration mode. In the transmit calibration mode, the processing unit is configured to: cause a test waveform generator to generate a first test waveform signal and provide the first test waveform signal to the antenna and a comparison module; cause the antenna to obtain the first test waveform signal from the test waveform generator and transmit the first test waveform signal; cause a probe, about the antenna, to receive a first received waveform signal and provide the first received waveform signal to the comparison module; and cause the comparison module to obtain the first received waveform signal from the probe and compare the first test waveform signal to the first received waveform signal to determine at least one calibration factor to be applied to the antenna.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The following relates generally to antenna systems, and more particularly to systems and methods for calibrating direct radiating array antennas. [Background technology]

[0002] In terrestrial systems, equipment can be quickly calibrated by personnel who have access to the equipment on-site. In contrast, equipment in satellite systems is expected to be difficult to calibrate because problematic equipment would have to be captured in order to be accessed. Alternatively, the equipment could be left in orbit, functioning incorrectly, until it can be deorbited and replacement initiated.

[0003] In a transmit or receive direct radiating array (DRA) antenna, it is necessary to maintain control of the excitation or weighting coefficients (amplitude and phase) of the active antenna elements. At high frequencies, such as in the Ka band, expected errors in the network over temperature cycling, time, and radiation will result in deviations that will affect the performance of the DRA antenna. Therefore, periodic on-board calibration of the DRA antenna is required to maintain reliable operation.

[0004] The antenna may require a factory calibration, which is performed prior to startup / use, and an in-orbit calibration, which is performed while the antenna is in operation on an orbiting satellite (i.e., during its operational life).

[0005] Existing factory methods for factory calibration of DRA antennas are typically part of the manufacturing process and are typically performed under controlled laboratory conditions, which means that factory calibration is generally not feasible in orbit once the DRA antenna system is deployed.

[0006] Another on-board technique for calibrating the DRA antenna that can be performed while the DRA antenna system is in orbit is the mutual coupling method, however, the mutual coupling method of calibration is not very reliable and adds to the complexity of the system.

[0007] Therefore, there is a need for an improved system and method for calibrating equipment in a DRA antenna system that overcomes at least some of the shortcomings of existing systems and methods. Summary of the Invention [Means for solving the problem]

[0008] A system for calibrating an antenna having multiple antenna elements is provided. The system includes at least one processing unit. The processing unit is configured to operate the antenna in a transmit calibration mode or a receive calibration mode. In the transmit calibration mode, the processing unit is configured to cause a test waveform generator to generate a first test waveform signal and provide the first test waveform signal to the antenna and a comparison module. In the transmit calibration mode, the processing unit is further configured to cause the antenna to obtain the first test waveform signal from the test waveform generator and transmit the first test waveform signal. In the transmit calibration mode, the processing unit is further configured to cause a probe around the antenna to receive a first received waveform signal and provide the first received waveform signal to a comparison module. In the transmit calibration mode, the processing unit is further configured to obtain the first received waveform signal from the probe and cause the comparison module to compare the first test waveform signal with the first received waveform signal to determine at least one calibration factor to be applied to the antenna. In the receive calibration mode, the processing unit is configured to cause the test waveform generator to generate a second test waveform signal and provide the second test waveform signal to the probe and the comparison module. In the receive calibration mode, the processing unit is further configured to cause the probe to transmit the second test waveform signal. In the receive calibration mode, the processing unit is further configured to cause the antenna to receive a second received waveform signal and provide the second received waveform signal to the comparison module. In the receive calibration mode, the processing unit is further configured to cause the comparison module to compare the second received waveform signal with the second test waveform signal to determine at least one calibration factor to be applied to the antenna.

[0009] In one embodiment, the antenna is a direct radiating array (DRA).

[0010] In one embodiment, transmitting the first test waveform signal includes at least one of transmitting through a single antenna element of a plurality of antenna elements in the antenna and transmitting through a set of a plurality of antenna elements in the antenna.

[0011] In one embodiment, receiving the second received waveform signal includes at least one of receiving by a single antenna element of a plurality of antenna elements in the antenna and receiving by a set of a plurality of antenna elements in the antenna.

[0012] In one embodiment, the probe includes at least one of a calibration antenna, a quasi-far-field (QFF) probe, and a near-field (NF) probe.

[0013] In one embodiment, the system further includes an improvement module communicatively connected to the comparison module and the antenna, the improvement module configured to receive calibration data from the comparison module, generate improvement data based on the calibration data, and provide the improvement data to the antenna.

[0014] In one embodiment, the improvement data includes at least one of a control signal for controlling or adjusting the operation of at least one element of the antenna, an instruction for the antenna to bypass a particular element of the antenna, an instruction for the antenna to disable a particular element of the antenna, and an instruction for the antenna to reconfigure a particular element of the antenna.

[0015] In one embodiment, the comparing includes at least one of comparing the amplitude of the first test waveform signal with the amplitude of the first received waveform signal, comparing the phase of the first test waveform signal with the phase of the first received waveform signal, comparing the amplitude of the second received waveform signal with the amplitude of a reference waveform signal, and comparing the phase of the second received waveform signal with the phase of the reference waveform signal.

[0016] In one embodiment, the system further includes one or more radio frequency (RF) amplifiers communicatively coupled to the antenna.

[0017] In one embodiment, the at least one calibration factor is defined by at least one of a set of mission parameters, a reduction in sidelobe level, or a power attribute.

[0018] In one embodiment, the at least one processing unit is further configured to cause the reporting module to report the at least one calibration factor at the antenna as information in a user interface to enable a user to visualize the system.

[0019] In one embodiment, the processing unit is located in an on-board processing unit of the satellite in which the DRA is or will be disposed.

[0020] In one embodiment, the processing unit is located in a processor of the DRA.

[0021] In one embodiment, the processing unit is located at a ground station.

[0022] A method for factory calibration of a node in a communications network in a processing unit is provided. The method includes generating, by a test waveform generator, a test waveform signal and providing the test waveform signal to an antenna and a comparison module. The method further includes transmitting, by an element of the antenna, the test waveform signal. The method further includes receiving, by a probe, a received waveform signal and providing the received waveform signal to the comparison module. The method further includes comparing, by the comparison module, the test waveform signal and the received waveform signal to calculate a calibration reference factor for the element.

[0023] In one embodiment, the method further comprises performing signal correlation on the received waveform signal.

[0024] In one embodiment, the method further comprises storing the correlation results in a memory.

[0025] A method for on-orbit calibration of a node in a communications network in a processing unit is provided. The method includes generating, by a test waveform generator, a test waveform signal and providing the test waveform signal to an antenna. The method further includes transmitting, by an element of the antenna, the test waveform signal. The method further includes receiving, by each probe of a plurality of probes, a received waveform signal and providing each received waveform signal to a comparison module. The method further includes comparing, by the comparison module, the test waveform signal and each received waveform signal to calculate a calibration correction factor for the element.

[0026] In one embodiment, the method further comprises performing signal correlation on the received waveform signal.

[0027] In one embodiment, the method further comprises storing the correlation results in a memory.

[0028] In one embodiment, the processing unit is located in one of the DRA, the on-board processor, and the ground station.

[0029] A method is provided for on-orbit transmission calibration of a node in a communications network in a processing unit. The method includes generating a test waveform signal by a test waveform generator. The method further includes providing the test waveform signal by the test waveform generator to an antenna and a comparison module. The method further includes transmitting the test waveform signal by an element of the antenna. The method further includes receiving received waveform signals by a plurality of probes. The method further includes providing the received waveform signals by the probes to a comparison module. The method further includes comparing the test waveform signal with the received waveform signals by the comparison module to calculate a calibration correction factor for the element.

[0030] In one embodiment, the method further comprises performing signal correlation on the received waveform signal.

[0031] In one embodiment, the method further comprises storing the correlation results in a memory.

[0032] In one embodiment, the processing unit is located in one of the DRA, the on-board processor, and the ground station.

[0033] A method is provided for on-orbit receive calibration of a node in a communications network in a processing unit. The method further includes generating a test waveform signal by a test waveform generator. The method further includes simultaneously providing the test waveform signal to a comparison module and a plurality of calibrated probes by the test waveform generator. The method further includes transmitting the test waveform signal by the probes. The method further includes receiving a received waveform signal by an element of an antenna. The method further includes providing the received waveform signal to a comparison module by the antenna. The method further includes comparing the received waveform signal with the test waveform signal by the comparison module to calculate a calibration correction factor for the element.

[0034] In one embodiment, the method further comprises performing signal correlation on the received waveform signal.

[0035] In one embodiment, the method further comprises storing the correlation results in a memory.

[0036] In one embodiment, the processing unit is located in one of the DRA, the on-board processor, and the ground station.

[0037] Other aspects and features will become apparent to those skilled in the art upon review of the following description of several exemplary embodiments.

[0038] The drawings included herein are for the purpose of illustrating various examples of the articles, methods, and apparatus herein, and in the drawings: [Brief explanation of the drawings]

[0039] [Figure 1] FIG. 1 is a block diagram of an exemplary system for calibrating a direct radiating array (DRA) antenna, according to one embodiment. [Figure 2] 1 is a flowchart of an exemplary method for factory calibration of a node in a communication network, according to one embodiment. [Figure 3A] 1 is a flowchart of an exemplary method for transmit on-orbit calibration of nodes in a communication network, according to one embodiment. [Figure 3B] 1 is a flowchart of an exemplary method for receive on-orbit calibration of nodes in a communication network, according to one embodiment. [Figure 4] FIG. 1 is a block diagram of an exemplary calibration system for a transmitting DRA antenna, according to one embodiment. [Figure 5] FIG. 1 is a block diagram of an exemplary calibration system for a receive DRA antenna, according to one embodiment. [Figure 6] FIG. 1 is a block diagram of an exemplary electronic device, according to one embodiment. [Figure 7]FIG. 5 is a diagram of an exemplary arrangement of the system shown in FIG. 4, according to one embodiment. [Figure 8] FIG. 6 is a diagram of an exemplary arrangement of the system shown in FIG. 5, according to one embodiment. [Figure 9] FIG. 1 is a flow diagram of a method for on-board calibration of a DRA antenna, according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0040] Various devices or processes are described below to provide examples of each claimed embodiment. The embodiments described below do not limit any claimed embodiment, and any claimed embodiment may encompass processes or devices different from those described below. Claimed embodiments are not limited to devices or processes having all of the features of any one device or process described below, or to features common to multiple or all of the devices described below.

[0041] One or more systems described herein may be implemented in a computer program executing on a programmable computer, each comprising at least one processor, a data storage system (including volatile and non-volatile memory and / or storage elements), at least one input device, and at least one output device. For example, but not limited to, a programmable computer may be a programmable logic unit, a mainframe computer, a server, a personal computer, a cloud-based program or system, a laptop, a personal data assistant, a cellular telephone, a smartphone, or a tablet device.

[0042] Each program is preferably implemented in a high-level procedural or object-oriented programming language and / or scripting language to communicate with a computer system. However, the programs can be implemented in assembly or machine language, if desired. In either case, the language can be a compiled or interpreted language. Each such computer program is preferably stored on a storage medium or device readable by a general-purpose or special-purpose programmable computer for configuring and operating the computer when the storage medium or device is read by the computer to perform the procedures described herein.

[0043] A description of an embodiment with several components in communication with each other does not imply that all such components are required. On the contrary, various optional components are described to illustrate the wide variety of possible embodiments of the present invention.

[0044] Additionally, although process steps, method steps, algorithms, etc. may be described (in this disclosure and / or in the claims) sequentially, such processes, methods, and algorithms may be configured to work in alternative orders. In other words, any sequence or order of steps that may be described does not necessarily indicate a requirement that the steps be performed in that order. Steps of processes described herein may be performed in any order that is practical. Additionally, some steps may be performed simultaneously.

[0045] When a single device or article is described herein, it will be readily apparent that two or more devices / articles (whether they cooperate or not) may be used in place of the single device / article. Similarly, when two or more devices or articles (whether they cooperate or not) are described herein, it will be readily apparent that a single device / article may be used in place of the two or more devices or articles.

[0046] The following relates generally to antenna systems, and more particularly to on-board calibration of direct radiating array (DRA) antennas.

[0047] The calibration methods of the present disclosure are performed using at least one processing unit. In variations, the processing unit may be implemented as part of the antenna system being calibrated (e.g., as part of a DRA), as part of an on-board processor (i.e., on-board the satellite), or at a ground station. Thus, although references to "on-board calibration" are made throughout this disclosure, it should be understood that aspects of the processing performed as part of the calibration may be performed on-board the satellite or on the ground (e.g., at a ground station).

[0048] A system and method are provided for onboard calibration of DRA antennas. The system can be used to perform factory or on-orbit calibration of DRA antennas. Factory or on-orbit calibration can be performed remotely. Calibration involves generating test wave signals, transmitting and receiving signals, and comparing the original generated and received signals according to a calibration algorithm. The calibration algorithm is coded as computer-executable instructions and executed by a processing unit (e.g., an on-board processor) to calibrate or correct the excitation or weighting coefficients (amplitude and phase) of the DRA's active antenna elements. The techniques disclosed herein can be applied to receive or transmit DRA antennas. The system uses one or more on-board probes located outside the array of radiating elements (depending on the antenna type) to transmit or receive test wave signals. In one embodiment, four probes are used, arranged in a quadrature arrangement around the array. Each probe can include its own dedicated RF chain, which can improve signal quality.

[0049] The techniques disclosed herein can be used not only to calibrate DRA antennas, but also in calibrating MIMO-type antennas, 5G antennas, or collections of multiple single antennas, for example, on the ground or in space. Thus, the disclosed techniques can be applied whenever there is a need to calibrate the amplitude and phase of different transmitters or receivers that will be used in a coherent signal sum.

[0050] As used herein, a "transmitting device" refers to an electronic device that generates radio waves using an antenna. As used herein, a "receiving device" refers to an electronic device that receives the radio waves in order to interpret the information carried in the waves into a usable form.

[0051] As used herein, a "processing unit" refers to a component or system designed to execute instructions and process data. A processing unit may be capable of executing algorithms, managing data flow, performing calculations, or controlling other components in the system. Furthermore, a processing unit may include specific hardware (e.g., a CPU) and / or software components for performing data processing tasks. A processing unit may be integrated with other components of a system, such as memory, I / O interfaces, or network interfaces. A processing unit may be located, for example, in a DRA antenna, in an on-board processor, or even in a ground station. A processing unit may also include, for example, one or more field programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs) to rapidly perform processing operations. Thus, and by way of example, when an on-board processor is referred to as processing data, it may be interpreted to mean that a processing unit located in the on-board processor is used to process the data.

[0052] The systems and methods of the present disclosure may provide certain advantages. Elements of a DRA antenna may be calibrated individually, or the DRA antenna as a whole may be calibrated. Malfunctioning radiating elements in a DRA antenna may be identified so that they can be repaired or bypassed during transmission and reception. Techniques for transmitting and receiving DRA antennas are not significantly different, nor are techniques for factory and on-orbit calibration significantly different.

[0053] The on-board calibration system disclosed herein offers several advantages over remote calibration techniques, despite a slight increase in size, weight, power, and cost (SWAP-C) per DRA antenna.

[0054] First, the disclosed on-board calibration allows for low system infrastructure costs. On-board calibration provides continuous monitoring, higher accuracy, is channel independent, self-contained, simpler, and more reliable. On-board calibration may reduce the overall cost and complexity of the system compared to other proposed remote calibration systems.

[0055] The disclosed on-orbit on-board calibration approach eliminates the need for access to or use of any ground station. In this way, calibration can be performed autonomously and onboard the platform (i.e., the satellite) hosting the DRA antenna system. The techniques disclosed herein also provide greater flexibility around when calibration can be performed. When relying on a ground station, calibration can only be performed when the ground station is within line of sight. With on-board calibration, this constraint is removed. With increased calibration flexibility, the accuracy of the DRA antenna system increases because there are more opportunities to perform calibration (and therefore, it can be accurately calibrated more frequently).

[0056] Additionally, the systems and methods of the present disclosure may implement a single element calibration (SEC) method (i.e., element-by-element calibration), allowing individual radiating elements of a DRA antenna to be calibrated. This advantage allows for detection of failed elements of a DRA antenna. Calibration may also be performed without traffic and in a time-efficient manner.

[0057] The calibration techniques of the present disclosure may also be performed using the entire DRA antenna frequency band, along with several reference frequencies, allowing calibration across different reference frequencies.

[0058] In addition, the method disclosed herein can be used to measure delay. There are two types of compensation in a digital beamformer: delay and phase. The method captures on-orbit phase changes. Nevertheless, by evaluating the phase gradient across frequency, it is possible to obtain delay information, which is useful in factory calibrations that require that information.

[0059] In a variant, the calibration method of the present disclosure may be used to calibrate transmitting and receiving DRA antennas, as well as any product in a low Earth orbit (LEO), medium Earth orbit (MEO), or geostationary orbit (GEO) satellite system.

[0060] Referring now to FIG. 1, shown therein is a system 100 for calibrating a direct radiating array (DRA) antenna, according to one embodiment.

[0061] System 100 includes a waveform generator 102, a DRA antenna 104, a probe 112, a calibration probe RF path 114, and a comparison module 116. The DRA antenna 104 includes multiple DRA radio frequency (RF) paths 106 and a radiating array 108. The array 108 includes multiple radiating elements 110 (also referred to as antenna elements). Each radiating element 110 has its own dedicated RF path 106. While only three DRA RF paths 106 are shown, it will be understood by those skilled in the art that each radiating element 110 will have its own DRA RF path 106, and therefore, the illustration of three DRA RF paths 106 should not be construed as limiting.

[0062] In the exemplary system 100, the DRA antenna 104 is a transmitting DRA antenna; however, the system 100 can be modified so that the DRA antenna 104 is a receiving DRA antenna.

[0063] System 100 may be implemented as part of a ground-based or space-based antenna system. In a space-based antenna system, system 100 may be located in or on a satellite, for example. Performing calibration onboard a satellite while in orbit is sometimes referred to as on-orbit calibration.

[0064] The waveform generator 102 is implemented in a processing unit, which may be an on-board processor. The comparison module 116 is implemented in the processing unit, which may be an on-board processor. The on-board processor may be implemented as a processor located on the DRA antenna 104 and non-transitory computer-readable memory that stores instructions that, when executed by the processor, configure the system 100 to perform the operations disclosed herein.

[0065] In some embodiments, the system 100 further includes an improvement module 120. The improvement module 120 is implemented in a processing unit. The processing unit may be an on-board processor. In some embodiments, the improvement module 120 may also be implemented in an on-board processor that is the same as or similar to the on-board processor in which the waveform generator 102 and the comparison module 116 are implemented.

[0066] The comparison module 116 is configured to execute a calibration algorithm 118 to calibrate the DRA antenna 104 .

[0067] The calibration algorithm 118 may be encoded as computer-executable instructions that, when executed by a processor, cause a computer to perform the steps of the calibration algorithm 118 .

[0068] In some embodiments, the calibration algorithm 118 is used to calculate DRA antenna phase and amplitude compensation.

[0069] Waveform generator 102 is configured to generate a single test waveform signal for each radiating element, provide test waveform signal 122 to DRA antenna 104, and provide test waveform signal 123 to comparison module 116. Test waveform signal 123 provided to comparison module 116 is considered and sometimes referred to as a "non-transmitted" test waveform signal.

[0070] These test waveform signals are listed differently in the figures for clarity, but it will be understood that test waveform signal 122 and test waveform signal 123 are the same test waveform signal.

[0071] The DRA antenna 104 receives a test waveform signal 122 from the waveform generator 102 and transmits a test waveform signal (referred to as a transmitted waveform signal 124).

[0072] In some embodiments, the DRA antenna 104 may receive the test waveform signal 122 via one or more of the DRA RF paths 106, which may then provide the test waveform signal to the array 108. In some embodiments, the DRA antenna 104 may transmit the test waveform signal (as a transmitted waveform signal 124) via the array 108 of radiating elements 110. In some embodiments, transmission may be performed using the entire DRA antenna 104 (i.e., using all of the radiating elements 110). In other embodiments, transmission may be performed by selecting individual radiating elements 110. Transmission by individual elements 110 may provide greater granularity in the system 100.

[0073] The probe 112 receives the transmitted waveform signal 124 from the DRA 104 and provides a received waveform signal 130 to the comparison module 116 via the calibration probe RF path 114 .

[0074] In some embodiments, multiple probes 112 are used.

[0075] In a particular embodiment, four probes 112 may be used. The four probes may be arranged in a quadrature configuration around the transmit DRA antenna 104. In other embodiments, other numbers or configurations of probes may be used.

[0076] It will be reasonably understood that the probe 112 may be used in transmit or receive mode for receive or transmit DRA antenna calibration, respectively.

[0077] The comparison module 116 obtains the received waveform signal 130 from the receiving device, compares the test waveform signal 123 (the "non-transmitted test waveform signal") with the received waveform signal 130, and outputs calibration information (also referred to as calibration data 126).

[0078] In particular, the comparison module 116 executes the calibration algorithm 118 to compare the test waveform signal 123 with the received waveform signal 130 and to generate the calibration data 126 .

[0079] In some embodiments, the comparison module 116 may further provide the results of the comparison (eg, calibration data 126) to the refinement module 120.

[0080] The refinement module 120 provides refinement output (data) 128 to the DRA antenna 104 for calibration of the array 108 and the DRA RF path 106.

[0081] For example, the refinement module 120 may receive the calibration data 126 and generate the refinement data 128 based on the calibration data 126 .

[0082] The refinement data 128 may include, for example, control signals for controlling or adjusting the operation of one or more of the elements 110 of the array 108 .

[0083] In some embodiments, the refinement data may include, but is not limited to, the DRA calibration reference factor (CRF) performed at the factory calibration. d ) and / or Probe Calibration Reference Factor (CRF p ), as well as calibration factors such as calibration correction factors (CCFs). Such refinement data may be used to refine or calibrate the DRA antenna 104.

[0084] Improvements to the DRA antenna may include, for example, turning off particular elements 110 in the DRA antenna, bypassing or ignoring elements 110, or mathematically adjusting the calibration or improvement data to reflect the desired results.

[0085] For a transmit DRA antenna, the code and signal generation can be in the transmit analog or digital beamformer.

[0086] Similarly, for a receive DRA antenna, the code and signal collection can be in the receive analog or digital beamformer.

[0087] Additionally, signal generation and capture for the receive and transmit DRA antennas utilize calibration subsystem hardware and processing units. Signal generation can be pseudorandom noise (PRN) code, continuous wave, or any other signal that is resistant to noise and interference. Due to the large dynamic range of the captured signal of each element, significant processing gain is required to extract the signal information with sufficient signal-to-noise ratio. Typically, signal generation and capture is performed in the beamformer via memory playback, capture, or via a correlator.

[0088] The calibration subsystem hardware includes four external low-profile probes placed symmetrically (e.g., in an orthogonal arrangement) around the DRA antenna. Each probe has a dedicated inverse RF chain so that the frequency does not change during translation, and each probe connects to all digital beamforming network (DBFN) layers to calibrate them separately. In a LEO system, for example, there may be two transmit layers and one receive layer. Similarly, in an MEO system, there may be four transmit layers and four receive layers.

[0089] Each probe can be connected to a separate digital beamformer chip, which increases reliability and reduces calibration time.

[0090] The DBFN connection pins have reverse functions so that they can act as analog-to-digital converters (ADCs) for the transmit DRA antennas and digital-to-analog converters (DACs) for the receive DRA antennas. Four DRA antenna elements can be removed or disconnected (e.g., out of 512 elements, 508 can remain connected).

[0091] The system 100 can be modified for transmission and reception, and since it is capable of both signal generation and reception, it allows both transmission and reception to be calibrated.

[0092] Additionally, the present disclosure provides greater control over the beam sidelobes of the DRA antenna 104, the beam pointing of the DRA antenna 104, and the beam gain of the DRA antenna 104. This can be achieved by controlling the amplitude and phase excitation of each antenna element so that they combine coherently to provide an optimal radiation beam shape.

[0093] Calibration can help ensure that imbalances between elements are corrected. Relative adjustment can help improve the beam by lowering sidelobe levels and better focusing the beam. Additionally, relative adjustment can help in monitoring the gain in transmit and receive. If the gain is found to be degrading over the mission, this can be an indication to compensate for it in the long term.

[0094] Additionally, the present disclosure allows for greater control over traffic power on user links. Another use of the calibration subsystem is the ability to measure absolute equivalent isotropic radiated power (EIRP) on transmit and absolute receiver gain on receive. This can be done by using calibration data and mathematically deriving absolute level changes on transmit or receive. For example, if transmit power becomes reduced over the life of the spacecraft, commanded compensation can be implemented to help restore it.

[0095] It will also be apparent to one skilled in the art that it becomes possible to track impairments of individual radiating elements 110 of the DRA antenna 104 because individual radiating elements 110 can be selected for calibration.

[0096] The present disclosure enables monitoring of the effective isotropically radiated power (EIRP) and antenna gain of the DRA antenna 104. Such benefits aid in the integration of the DRA antenna into existing structures or systems and with testing.

[0097] Specific benefits associated with the calibration algorithm include a reduction in deviation errors of the probe and DRA antenna elements.

[0098] The calibration algorithm is also insensitive to variations in the probe's RF path over time and temperature (i.e., differential methods). Typically, a DRA antenna has an RF path at each element. If this probe RF path moves over time, errors can occur. The techniques disclosed herein avoid such errors by performing differential measurements. If the RF probe gain increases by 1 dB, the calibration algorithm will not need to change the calibration coefficients because it is performing a relative measurement. However, if a gain measurement is required, the algorithm will be affected because the gain is absolute, not relative.

[0099] Calibration can typically be performed in just a few seconds up to a minute for all reference frequencies covering the RF band.

[0100] The calibration can be performed without traffic, but can also be arranged to be performed with traffic.

[0101] In one embodiment, calibration error performance is typically better than 0.3 dB gain and 3° phase for 1 σ deviation.

[0102] The calibration algorithm is hardware agnostic, allowing it to be implemented in a wide range of systems.

[0103] Additionally, for failure tolerance immunity, there are three levels of failsafe on the probe RF path, but this results in increased calibration error (graceful degradation).

[0104] The calibration can perform N frequency measurements within the RF band to improve accuracy versus frequency.

[0105] Coefficient normalization is performed to maintain control of the DRA antenna gain.

[0106] The calibration algorithm is independent of the DRA antenna geometry and operating frequency band.

[0107] Tracking and compensation across the operating frequency band can be achieved using several reference frequencies and interpolation.

[0108] The calibration algorithm may be able to run in saturated conditions for the transmitting DRA antenna.

[0109] Lifetime DRA antenna receiver gain and DRA antenna transmit (equivalent isotropically radiated power) EIRP level tracking (e.g., within ±1.0 dB using accuracy enhancement methods).

[0110] Furthermore, the calibration algorithm can enable robust calibration correction factor (CCF) validation prior to use in the beamforming network (BFN). The coefficients can be validated with respect to a history of previous changes, minimum / maximum thresholds, one-sigma deviations, and a determination of overall signal quality (SNR) over the measurement interval.

[0111] The calibration algorithm can also detect failed elements using various inputs to determine which physical root cause (RF front end, beamformer chip, etc.) is involved. This can be achieved by measuring coefficient deviations and raising a flag to indicate that a particular element has failed. Furthermore, if an element is completely off over the expected range of variation and in a small number of other trials, the element will be declared as permanently failed.

[0112] The optimal number of probes depends on the targeted signal dynamic range reduction and antenna pattern.

[0113] Regardless of the position of the radiating element in the antenna array, measurements from different probes can be combined together to obtain a desired signal quality.

[0114] Referring now to FIG. 2, shown therein is a method 200 for factory calibration of a node in a communication network, according to one embodiment.

[0115] The method 200 may be performed by or implemented using the system 100 of FIG.

[0116] Aspects of method 200 may be performed in a processing unit. The processing unit may be located on a spacecraft on which the antenna being calibrated is disposed (e.g., a spacecraft onboard processor, a processing unit that is part of the DRA antenna, a processing unit separate from the OBP and DRA antenna, etc.). The processing unit may be an onboard processing unit (i.e., a processor configured for use onboard the satellite on which the DRA being calibrated is disposed).

[0117] Although method 200 describes factory calibration of a transmit DRA antenna, one skilled in the art will reasonably appreciate that the process for a receive DRA antenna will be similar.

[0118] At 202, the method 200 includes generating a waveform.

[0119] At 204, the method 200 further includes sending the generated waveform to one or more elements under calibration.

[0120] In various embodiments, the generated waveform may also be provided to a comparison module.

[0121] At 206, the method 200 further includes transmitting a waveform by the one or more elements under calibration.

[0122] The element under calibration may be an element in a DRA antenna that includes an array of radiating elements, such as DRA antenna 104 in FIG.

[0123] At 208, the method 200 further includes receiving the transmitted signal at one far-field receiver antenna.

[0124] In some embodiments, the transmitted signal is received at a single receiving device.

[0125] In some embodiments, the receiving device (eg, one far-field receiver antenna) is a quasi-far-field (QFF) probe.

[0126] In some embodiments, the transmitted signal is received by multiple receiving devices.

[0127] In some embodiments, four receiving devices are arranged in an orthogonal configuration around the element under calibration.

[0128] The use of four receiving devices arranged in an orthogonal configuration around a transmitting device provides the advantages of robust redundancy along with graceful degradation in performance. The four-probe configuration may reduce the effects of noise and interference. The four-probe configuration may reduce physical deviation impairment due to temperature and aging.

[0129] In various embodiments, the transmitted signal is provided to a comparison module.

[0130] In some embodiments, the method 200 includes digitizing and correlating the received waveform signal with the test waveform signal to obtain only the information that is important, for example, the phase and amplitude of the waveform signal.

[0131] At 210, the method 200 further includes performing a signal correlation on the received signal.

[0132] In some embodiments, the method 200 includes digitizing and correlating the received waveform signal with the test waveform signal to improve the signal-to-noise ratio (SNR). More specifically, the PRN code length and repetition can be used to increase the processing gain, thereby improving the final SNR.

[0133] In some embodiments, pseudorandom noise (PRN) codes are used to mitigate the effects of noisy environments: the longer the code, the longer the correlation and the better the interference mitigation.

[0134] At 212, the method 200 further includes storing the correlation results in a memory.

[0135] At 214, the method 200 further includes repeating 202-212 for each element in the array to be calibrated.

[0136] In some embodiments, repeating 202-212 for each element includes digitizing and correlating the received waveform with the generated test waveform to improve the signal-to-noise ratio (SNR).

[0137] In some cases, this involves code repetition for a single element to increase processing gain, which may be optional but may help to achieve satisfactory performance.

[0138] At 216, the method 200 further includes calculating the CCF.

[0139] In some embodiments, the correlation results are used to calculate the CCF.

[0140] In some embodiments, the method 200 includes a comparison module that compares the test waveform and the received waveform to a CRF performed at factory calibration. d This includes calculating

[0141] In some embodiments, the method 200 may include: d Normalizing the CCF ensures that there is no gain change when the CCF is applied. Similarly, the phase error may be normalized to be centered around 0 degrees.

[0142] In some embodiments, the method 200 performs a CRF performed at factory calibration. d This includes verifying the following:

[0143] In some embodiments, the method 200 comprises: d and performing measurements at each near-field probe, including measurements of the composite signal (e.g., amplitude and phase), to obtain the near-field probe calibration reference factor (CRF p )

[0144] Referring now to FIG. 3A, shown therein is a method 300 for transmit on-orbit calibration of nodes in a communication network, according to one embodiment.

[0145] The method 300 may be performed by or implemented using the system 100 of FIG.

[0146] Aspects of method 300 may be performed in a processing unit. The processing unit may be located on a spacecraft on which the antenna being calibrated is disposed (e.g., a spacecraft onboard processor, a processing unit that is part of the DRA antenna, a processing unit separate from the OBP and DRA antenna, etc.). The processing unit may be an onboard processing unit (i.e., a processor configured for use onboard the satellite on which the DRA being calibrated is disposed).

[0147] Although method 300 describes on-orbit calibration of a transmitting DRA antenna, one skilled in the art will reasonably appreciate that the process for a receiving DRA antenna will be similar.

[0148] At 302, the method 300 includes generating, by a waveform generator, a waveform.

[0149] At 304, a waveform is provided to one or more elements under calibration.

[0150] At 306, the method 300 further includes transmitting a waveform by the one or more elements under calibration.

[0151] In some embodiments, the transmitting element is part of a DRA antenna having multiple radiating elements.

[0152] In some embodiments, the waveform is transmitted through multiple elements of a transmitting device (eg, a DRA antenna).

[0153] At 308, the method 300 further includes simultaneously receiving the transmitted signal by each receiving device of the plurality of receiving devices (e.g., probes) and providing the received signal to a comparison module.

[0154] In some embodiments, four receiving devices are arranged in an orthogonal configuration around the transmitting device.

[0155] The use of four receiving devices arranged in an orthogonal configuration around a transmitting device provides the advantages of robust redundancy with graceful degradation in performance. The four-probe configuration may reduce the effects of noise and interference. The four-probe configuration may reduce physical deviation damage due to temperature and aging.

[0156] At 310, the method 300 includes performing a signal correlation on the received signal.

[0157] In some embodiments, this involves digitizing and correlating the received signal with the waveform to obtain only the information that is important.

[0158] After a correlation is performed between the received waveform signal 130 and the test waveform 123, the relative amplitude and phase can be estimated from the output of the correlator.

[0159] In some embodiments, the method 300 includes digitizing and correlating the received signal with the waveform to improve the signal-to-noise ratio (SNR).

[0160] In some embodiments, a long pseudorandom noise (PRN) code is used to mitigate the effects of noisy environments.

[0161] In various embodiments, it is also possible to use a continuous waveform (eg, CW or sinusoidal) in the form of a PRN code, but without a peak-to-average ratio and with a small bandwidth.

[0162] At 312, the method 300 further includes storing the correlation results in a memory.

[0163] At 314, the method 300 further includes repeating 302-312, along with digitizing and correlating the received signal with a waveform to increase the SNR, if necessary.

[0164] In some embodiments, repeating 302-312 for each element includes digitizing and correlating the received waveform with the generated waveform to improve the SNR.

[0165] At 316, the method 300 further includes comparing, by a comparison module, the waveform and each received signal to calculate a CCF.

[0166] In some embodiments, the correlation results are used to calculate the CCF.

[0167] In some embodiments, the method 300 includes calculating an updated raw CCF from the obtained measurements and the reference.

[0168] In some embodiments, the method 300 includes normalizing the CCF based on certain criteria.

[0169] In some embodiments, the method 300 includes validating the CCF.

[0170] In some embodiments, the method 300 includes applying the updated normalized CCF, which will be understood by those skilled in the art to mean correcting for deviations or errors in the phased array antenna elements.

[0171] Referring now to FIG. 3B, shown therein is a method 350 for receive on-orbit calibration of a node in a communication network, according to one embodiment.

[0172] At 352, the method 350 includes generating a waveform.

[0173] At 354, the method 350 includes simultaneously sending the generated waveform to the calibrated probe.

[0174] At 356, the method 350 includes transmitting, by the probe, a waveform.

[0175] In some embodiments, the transmitting element is part of a DRA antenna having multiple radiating elements.

[0176] In some embodiments, the waveform is transmitted through multiple elements of a transmitting device (eg, a DRA antenna).

[0177] At 358, the method 350 includes receiving the transmitted signal at one or more elements under calibration.

[0178] At 360, the method 350 includes performing a signal correlation on the received signal.

[0179] In some embodiments, this involves digitizing and correlating the received signal with the waveform to obtain only the information that is important.

[0180] After a correlation is performed between the received waveform signal and the waveform, it is possible to estimate the relative amplitude and phase from the output of the correlator.

[0181] In some embodiments, the method 350 includes digitizing and correlating the received signal with the waveform to improve the signal-to-noise ratio (SNR).

[0182] In some embodiments, long PRN codes are used to mitigate the effects of noisy environments.

[0183] In various embodiments, it is also possible to use a continuous waveform (eg, CW or sinusoidal) in the form of a PRN code, but without a peak-to-average ratio and with a small bandwidth.

[0184] At 362, the method 350 includes storing the correlation results in a memory.

[0185] At 364, the method 350 includes repeating 352-362 for each element in the array to be calibrated.

[0186] In some embodiments, repeating 352-362 for each element includes digitizing and correlating the received waveform with the generated test waveform to improve SNR.

[0187] At 366, the method 350 includes calculating the CCF.

[0188] In some embodiments, the correlation data is used to calculate the CCF.

[0189] In some embodiments, the method 350 includes calculating an updated raw CCF from the obtained measurements and the reference.

[0190] In some embodiments, the method 350 includes normalizing the CCF based on certain criteria.

[0191] In some embodiments, the method 350 includes validating the CCF.

[0192] In some embodiments, the method 350 includes applying the updated normalized CCF, which will be understood by those skilled in the art to mean correcting for deviations or errors in the phased array antenna elements.

[0193] Referring now to FIG. 4, shown therein is a block diagram of a transmit DRA antenna calibration system 400 according to one embodiment.

[0194] As shown, the system 400 includes a processing unit 402, a transmit DRA antenna 408, and one or more receive probes 412. In one embodiment, the processing unit 402 is an on-board processor.

[0195] The processing unit 402 includes a test wave generator 404 and a comparison module 406 .

[0196] The test wave generator 404 generates a single test wave and provides the test wave 416 to the transmit DRA antenna 408 and the test wave 414 to the comparison module.

[0197] These test waves are listed differently in the figure for clarity, but it will be understood that test wave 414 and test wave 416 are the same test wave.

[0198] The test wave 416 is then transmitted by the transmit DRA antenna 408 as a transmitted test wave 418 .

[0199] The transmission of the transmitted test wave 418 may be performed by one or more of the multiple radiating elements 410 in the transmitting DRA antenna 408, or by the transmitting DRA antenna 408 as a whole. In this regard, a benefit of the present disclosure is that each radiating element 410, a particular radiating element 410, or the transmitting DRA antenna 408 as a whole may be tested to determine its calibration. Similarly, this benefit may provide knowledge of any damaged or inoperable radiating elements 410, allowing them to be bypassed, flagged for repair, or not used in a particular transmission.

[0200] One or more receiving probes 412 receive the transmitted test wave 418 and further provide it as a received wave 420 to the comparison module 406 .

[0201] In some embodiments, the number of receiving probes 412 is four.

[0202] In some embodiments, the receive probes 412 are arranged in an orthogonal configuration around the transmit DRA antenna 408.

[0203] According to one embodiment, an exemplary arrangement 700 of system 400 is shown in Figure 7. In Figure 7, four receive probes 710 are arranged in an orthogonal arrangement around the transmit DRA antenna, which includes multiple radiating elements 705. It will be reasonably understood by those skilled in the art that the receive probes may also be arranged in other arrangements around the transmit DRA antenna.

[0204] Referring back to FIG. 4, the comparison module 406 compares the received wave 420 with the original test wave 414 received from the test wave generator 404 .

[0205] In some embodiments, the comparison module 406 may further calculate a CCF based on the comparison.

[0206] Referring now to FIG. 5, shown therein is a block diagram of a receive DRA antenna calibration system 500, according to one embodiment.

[0207] As shown, the system 500 includes a processing unit 502, a receiving DRA antenna 508, and one or more transmitting probes 512. In one embodiment, the processing unit 502 is an on-board processor. The processing unit 502 includes a test wave generator 504 and a comparison module 506.

[0208] The test wave generator 504 generates a single test wave, provides the test wave 514 to the comparison module 506 , and provides the test wave 520 to one or more transmit probes 512 .

[0209] These test waves are listed differently in the figure for clarity, but it will be understood that test wave 514 and test wave 520 are the same test wave.

[0210] In some embodiments, the number of transmitting probes 512 is one or more. The multiple probes 512 may be placed as far apart as possible in a symmetrical or even distribution around the DRA antenna 508. Note, however, that more important than the placement of the probes is the field of view of each probe relative to all elements. In some embodiments, four transmitting probes 512 are placed in an orthogonal configuration around the receiving DRA antenna 508.

[0211] It will be appreciated by those skilled in the art that multiple probes may improve performance and allow for increased redundancy.

[0212] The one or more transmitting probes 512 then transmit a transmitted test wave 518 .

[0213] The transmitted test wave 518 is received by the receiving DRA antenna 508 as a received wave 516 .

[0214] More specifically, reception of the transmitted test wave 518 may be performed by one or more of the multiple receiving elements 510 in the receiving DRA antenna 508, or by the receiving DRA antenna 508 as a whole.

[0215] Thus, a benefit of the present disclosure is that each receiving element 510, a particular receiving element 510, or the receiving DRA antenna 508 as a whole may be tested to determine its calibration.

[0216] Similarly, this benefit may provide knowledge of any receiving elements 510 that are damaged or not operational, allowing them to be bypassed, flagged for repair, or not used in a particular reception.

[0217] According to one embodiment, an exemplary layout of a system 500 is shown in FIG.

[0218] 8, four transmit probes 810 are arranged in an orthogonal arrangement around the receive DRA antenna, which includes multiple receive elements 805. It will be reasonably understood by those skilled in the art that the transmit probes may also be arranged in other arrangements around the receive DRA antenna.

[0219] The receiving DRA antenna 508 then provides the received wave 516 to the comparison module 506 for comparison with the original test wave 514 provided by the test wave generator 504 .

[0220] In some embodiments, the comparison module 506 may further calculate a CRF based on the comparison.

[0221] In some embodiments, the comparison module 506 may further calculate a CCF based on the comparison.

[0222] 6, shown therein is a block diagram of an electronic processing device 600, according to one embodiment. Electronic processing device 600 may be processing unit 402 of FIG. 4 or processing unit 502 of FIG. 5.

[0223] According to different embodiments of the present disclosure, the processing device 600 may perform any or all of the operations of the above methods and features explicitly or implicitly described herein. For example, a computer with network capabilities may be configured as the electronic device 600.

[0224] Device 600 may be any of the processing devices or processing units described above, such as, for example, processing unit 402 and processing unit 502.

[0225] As shown, device 600 includes a processor 610, such as a central processing unit (CPU) or a dedicated processor such as a graphics processing unit (GPU) or other such processor unit, memory 620, non-transitory mass storage 630, I / O interface 640, network interface 650, and transceiver 660, all of which are communicatively coupled via a bidirectional bus 670. According to some embodiments, any or all of the illustrated elements may be utilized, or only a subset of the elements may be utilized. Furthermore, device 600 may include multiple instances of some elements, such as multiple processors, memories, or transceivers. Elements of a hardware device may also be directly coupled to other elements without a bidirectional bus. In addition to or instead of the processor and memory, other electronics, such as integrated circuits, may be employed to perform the required logical operations.

[0226] The memory 620 may include any type of non-transitory memory, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous DRAM (SDRAM), read-only memory (ROM), or any combination of the like. The mass storage element 630 may include any type of non-transitory storage device, such as a solid-state drive, a hard disk drive, a magnetic disk drive, an optical disk drive, a USB drive, or any computer program product configured to store data and machine-executable program code. According to some embodiments, the memory 620 or mass storage 630 may have stored thereon statements and instructions executable by the processor 610 to perform any of the aforementioned method operations described above.

[0227] Referring now to Figure 9, shown therein is a method 900 of on-board calibration according to one embodiment. Method 900 may be implemented using system 200 of Figure 2. Method 900 may be encoded as computer-executable instructions that, when executed by a processor, cause a computer system to perform method 900. In one embodiment, method 900 may be calibration algorithm 118 of Figure 1, or a portion thereof.

[0228] In various embodiments, the method 900 may be performed on-orbit or in-factory.

[0229] At 905, method 900 includes performing an in-factory far-field or quasi-far-field single-element calibration method at the boresight of the antenna with all beamforming coefficients set to 0 dB and 0° (or 0 delay) using a factory probe.

[0230] In various embodiments, single element calibration involves calibrating each element in turn (ie, one at a time) while switching off the other elements.

[0231] In some embodiments, the performing comprises: d This includes calculating and deriving

[0232] In other embodiments, other configurations may be used, such as using closer distances and different pointing.

[0233] At 910, the method 900 includes providing a CRF to a beamformer of the antenna. d applying

[0234] In some embodiments, if the results show a slight deviation or if the system has insufficient RF isolation, the method 900 includes performing a second similar calibration to partially remove the deviation.

[0235] At 915, method 900 further includes performing a second single-element calibration method using the on-board probe instead of the factory probe. The second single-element calibration method is the same as the first method, but includes calibrating the probe itself at the factory. In other words, the second single-element calibration method uses a reference plane (CRF) for the received signal. p ) is provided.

[0236] In some embodiments, during the second calibration, not all elements are fired at the same time. Furthermore, the coupling and RF isolation problems found in DRA antennas are less severe. Because only one element is fired at a time, this results in better accuracy and elimination of some of the unwanted RF effects.

[0237] In some embodiments, the performing comprises: p This includes calculating and deriving

[0238] At 920, the method 900 further includes performing operational calibration using a single element calibration method to track DRA antenna changes over time and compensate for the DRA antenna changes using the CCF.

[0239] In some embodiments, the performing comprises: d The process of calculating and deriving CRF p and calculating the CCF to be applied to correct for amplitude and phase errors using a process of calculating and deriving

[0240] In some embodiments, calculating the CCF comprises a weighted complex sum of the number (n) of probes (e.g., 4) measurements post-processing.

[0241] This reduces the CCF sensitivity to physical deviations of the probe and elements and may provide noise reduction.

[0242] In some embodiments, the implementing includes performing code iterations K times to increase processing gain for working in noisy environments.

[0243] In some embodiments, CRF d and CRF p is fixed for the satellite operational lifetime, and the CCF varies over time, tracking changes due to aging and temperature effects in the DRA.

[0244] In some embodiments, a pre-calibration evaluation may be performed prior to performing method 900 .

[0245] In some embodiments, a first calibration may be performed to calibrate the DRA antenna without using a probe.

[0246] In various embodiments, the first calibration involves characterizing the DRA antenna and finding RF deviations, including in the radiating elements and everything in the path. Finding deviations of the DRA antenna in the far field at a reference direction (boresight or nadir). This then becomes the first layer of compensation. This layer of compensation is applied, and an assumption is made that the DRA antenna is compensated for a certain direction.

[0247] In some embodiments, a second calibration may be performed to calibrate the calibration system itself.

[0248] In some embodiments, the second calibration involves evaluating every probe reference signal to each element as it receives it from every element. This becomes the reference plane for the probe to work with. This reference is stored in memory and used to perform the calibration. Calculations are performed for each element, for each probe. The reference plane is collected and placed in memory. Once this is done, the DRA antenna is activated to monitor any changes in each probe. These changes include any imbalances, such as temperature changes, amplitude or phase imbalances, etc. Using two reference systems, it is possible to detect if even one element is unbalanced. This can be achieved relatively.

[0249] A benefit of the above calibration technique is that drift in amplitude or phase may be trackable over the lifetime of the hardware, even while the hardware is deployed in space.

[0250] This advantage can be combined with either ground-based or remotely performed measurements to ensure that amplitude or phase do not drift during the mission.

[0251] In some embodiments, some of the data sets may be sent to a ground station for long-term monitoring and trending. In situations where the calibration system is not working at all, it may be better to stop sending signals to the ground to mitigate damage or identify failed elements. Another option may be to change the way the signals are sent.

[0252] If one or more elements fail, it may be possible to compensate for this using the power at the input. Similarly, in some embodiments, failed elements may be ignored and compensated for.

[0253] In various embodiments, the method 900 is used for a digital DRA antenna.

[0254] The advantage of working with a digital system is that if something needs to be changed, it can be done by uploading a new signal waveform. For example, if interference is detected, the reference waveform can be changed. Thus, calibration can be defined by software, not hardware.

[0255] While the above description provides examples of one or more devices, methods, or systems, it will be appreciated that other devices, methods, or systems may be within the scope of the claims as interpreted by those skilled in the art. Elements of each embodiment may be incorporated into other embodiments; for example, configurations described with respect to one embodiment may be applied to other embodiments disclosed herein. Furthermore, it is apparent that various modifications and combinations may be made without departing from the invention. Accordingly, the specification and drawings should be considered merely as illustrative of the invention as defined by the claims, and it is intended to encompass any modifications, variations, combinations, or equivalents that fall within the scope of the present disclosure. [Explanation of symbols]

[0256] 100 Systems, Exemplary Systems 102 Waveform Generator 104 DRA antenna, DRA, transmitting DRA antenna 106 DRA Radio Frequency (RF) Path, Dedicated RF Path, DRA RF Path 108 Radiating Array, Array 110 Radiation Elements, Elements 112 Probe 114 Calibration Probe RF Path 116, 406, 506 comparison modules 118 Calibration Algorithm 120 Improvement Module 122 Test waveform signal 123 Test waveform signal, test waveform 124 Transmitted waveform signal 126 Calibration Data 128 Improved output (data), improved data 130 Received waveform signal 400, 500 calibration system, system 402, 502 processing units 404, 504 test wave generator 408 Transmitting DRA Antenna 410, 705 Radiation elements 412, 710 receiving probes 414, 416, 514, 520 test waves 418, 518 transmitted test wave 420, 516 received waves 508 Receiving DRA antenna, DRA antenna 510, 805 receiving element 512 Send Probe, Probe 600 Electronic processing devices, processing devices, electronic devices, devices 610 processor 620 memory 630 Non-transitory mass storage, mass storage elements, mass storage 640 I / O interface 650 network interface 660 Transceiver 670 Two-Way Bus 700 Exemplary Arrangements 810 Send Probe

Claims

1. 1. A system for calibrating an antenna having a plurality of antenna elements, comprising: At least one processing unit Equipped with The processing unit is configured to operate the antenna in a transmit calibration mode or a receive calibration mode, and in the transmit calibration mode, the processing unit: causing a test waveform generator to generate a first test waveform signal and provide the first test waveform signal to the antenna and comparison module; obtaining the first test waveform signal from the test waveform generator and causing the antenna to transmit the first test waveform signal; causing a probe around the antenna to receive a first received waveform signal and provide the first received waveform signal to the comparison module; causing the comparison module to obtain the first received waveform signal from the probe and compare the first test waveform signal with the first received waveform signal to determine at least one calibration factor to be applied to the antenna; configured to: In the receive calibration mode, the processing unit: causing the test waveform generator to generate a second test waveform signal and provide the second test waveform signal to the probe and the comparison module; causing the probe to transmit the second test waveform signal; causing the antenna to receive a second received waveform signal and provide the second received waveform signal to the comparison module; causing the comparison module to compare the second received waveform signal with the second test waveform signal to determine at least one calibration factor to be applied to the antenna; A system configured to:

2. The system of claim 1 , wherein the antenna is a direct radiating array (DRA).

3. transmitting the first test waveform signal; transmitting via a single antenna element of the plurality of antenna elements at the antenna; transmitting via the set of antenna elements on the antenna; The system of claim 1 , comprising at least one of:

4. receiving the second received waveform signal; receiving by a single antenna element of the plurality of antenna elements at the antenna; receiving by the set of antenna elements on the antenna; The system of claim 1 , comprising at least one of:

5. The system of claim 1 , wherein the probe comprises at least one of a calibration antenna, a quasi-far-field (QFF) probe, and a near-field (NF) probe.

6. The system further comprises an improvement module communicatively coupled to the comparison module and the antenna, the improvement module comprising: receiving calibration data from the comparison module; generating refinement data based on the calibration data; providing said antenna with said refinement data; The system of claim 1 , configured to:

7. 2. The system of claim 1, wherein the improvement data includes at least one of a control signal for controlling or adjusting operation of at least one element of the antenna, an instruction for the antenna to bypass a particular element of the antenna, an instruction for the antenna to disable a particular element of the antenna, and an instruction for the antenna to reconfigure a particular element of the antenna.

8. The comparing comparing the amplitude of the first test waveform signal to the amplitude of the first received waveform signal; comparing the phase of the first test waveform signal with the phase of the first received waveform signal; comparing the amplitude of the second received waveform signal to the amplitude of a reference waveform signal; comparing the phase of the second received waveform signal with the phase of the reference waveform signal; The system of claim 1 , comprising at least one of:

9. The system of claim 1 , further comprising one or more radio frequency (RF) amplifiers communicatively coupled to the antenna.

10. The system of claim 1 , wherein the at least one calibration factor is defined by at least one of a set of mission parameters, a reduction in sidelobe level, or a power attribute.

11. 10. The system of claim 1, wherein the at least one processing unit is further configured to cause a reporting module to report the at least one calibration factor at the antenna as information in a user interface to allow a user to visualize the system.

12. 10. The system of claim 1, wherein the processing unit is located in an on-board processing unit of a satellite on which the DRA is or will be disposed.

13. The system of claim 1 , wherein the processing unit is located in a processor of the DRA.

14. The system of claim 1 , wherein the processing unit is located at a ground station.

15. 1. A method for factory calibration of a node in a communication network in a processing unit, comprising: generating a test waveform signal by a test waveform generator and providing the test waveform signal to an antenna and a comparison module; transmitting the test waveform signal by the antenna element; receiving, by a probe, a received waveform signal and providing the received waveform signal to the comparison module; comparing, by the comparison module, the test waveform signal and the received waveform signal to calculate a calibration reference coefficient for the element; A method comprising:

16. The method of claim 15 further comprising performing signal correlation on the received waveform signals.

17. The method of claim 15 further comprising storing the correlation results in a memory.

18. 1. A method for on-orbit calibration of a node in a communications network in a processing unit, comprising: generating a test waveform signal by a test waveform generator and providing the test waveform signal to an antenna; transmitting the test waveform signal by the antenna element; receiving a received waveform signal by each probe of the plurality of probes and providing each received waveform signal to a comparison module; comparing, by the comparison module, the test waveform signal and each received waveform signal to calculate a calibration correction factor for the element; A method comprising:

19. 20. The method of claim 18, further comprising performing signal correlation on the received waveform signals.

20. The method of claim 18 further comprising storing the correlation results in a memory.

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