INTEGRATED DATA BUS RF SIGNATURE EXTRACTION AND AMPLIFICATION

Abstract

A device to extract digital and unintended analog signals from a data bus with a non-contact common mode probe and a differential mode probe, each with a low noise amplifier. The analog and digital signals can be monitored contemporaneously.

Claims

1. A device to simultaneously extract and amplify unintended analog signals and digital signals on a data bus, the device comprising: a shielded coupler box having walls, an exterior, and an interior; a common mode probe (CMP) and a differential mode probe (DMP); a plurality of connectors through the walls of the shielded coupler box to receive cables exterior to the shielded coupler box, at least one input connector configured to receive each data bus wire pair exterior to the shielded coupler box, at least one data bus output connector configured to receive exterior to the shielded coupler box each data bus wire pair, a connector configured to receive a power source, a connector to receive a CMP output, and a connector configured to receive a DMP output; at least one unshielded wire pair having a first wire and a second wire, each attached to a data bus input connector and a data bus output connector interior to the shielded coupler box; the CMP having one of a non-contact inductive coil and capacitive electrical probe in close proximity to both the first unshielded wire and second unshielded wire and the DMP having a first non-contact inductive coil in close proximity to the first wire and a second inductive coil in close proximity to the second unshielded wire; a first conductor wound around the CMP inductive coil and a second conductor wound around the DMP first and second inductive coils; a first Low Noise Amplifier (LNA) connected to a power supply connector, connected to the first conductor as an input and connected to the CMP output; and a second LNA connected to said power supply, connected to the second conductor and connected to said DMP output; the device designed to simultaneously extract and amplify unintended analog signals and digital signals on the data bus.

2. The device according to claim 1 further having a digital output coupled to the data bus.

3. The device according to claim 1 an isolating transformer s connected between the data bus first unshielded wire and the data bus second unshielded wire and a digital output connector.

4. The device according to claim 1 wherein said CMP and DMP generally normal to the first and second data bus unshielded wires and are offset from each other.

5. The device according to claim 1 wherein said first conductor is wrapped a plurality of turns around the CMP inductive coil.

6. The device according to claim 1 wherein the first conductor is wrapped between 1 and 3 turns around the CMP inductive coil.

7. The device according to claim 1 wherein said second conductor is wrapped a plurality of turns around the DMP first inductive coil and the DMP second inductive coil.

8. The device according to claim 1 wherein the second conductor is wrapped between 1 and 3 turns around the DMP first inductive coil and the DMP second inductive coil.

9. The device according to claim 1 wherein windings of the second conductor around the first inductive coil and windings of the second conductor around the second inductive coil are wound in opposite rotational directions.

10. The device according to claim 1 wherein said CMP inductive coil has a ferrite core.

11. The device according to claim 1 wherein said CMP inductive coil has a generally toroidal ferrite core.

12. The device according to claim 1 wherein said DMP first and second inductive coils have a magnetic core.

13. The device according to claim 1 wherein said DMP first and second inductive coils have ferrite cores.

14. The device according to claim 1 wherein each of said DMP first and second inductive coils have generally toroidal ferrite cores.

15. The device according to claim 1 wherein said shielded coupler box is grounded and manufactured of an electrically conductive material and said first and second LNA are electrically connected to said shielded coupler box and grounded.

16. The device according to claim 1 wherein said shielded coupler box is manufactured of an electrically conductive material and each of said first and second LNAs is attached to said shielded coupler box with an electrically insulating adhesive.

17. A device according claim 1 wherein said shielded coupler box is manufactured of a thermally conductive material and said first and second LNA are adjacent to said shielded coupler box so that said shielded coupler box is a heat sink.

18. The device according claim 1 wherein said shielded coupler box is manufactured of a thermally conductive material and said first and second LNA are each attached to said shielded coupler box by a thermally conductive adhesive so that the shielded coupler box is a heat sink.

19. The device according to claim 2 wherein said digital output is isolated from the data bus is by one of an isolating transformer and isolating resistors.

20. The device according to claim 1 to extract RF signals from one or more of MIL-ST-1153, A429, A629, USB, Universal Powerline Bus, Optical network, CAN data buses.

21. The device according to claim 1 wherein the first and second conductors are connected to a terminal block, the terminal block is also connected to digital output ports.

22. The device according to claim 21 where at least one of a CMP or DMP use at least one of inductive or capacitive coupling to extract weak analog signatures from a communication architecture.

23. The device of claim 21 where the extracted weak analog signatures are used for at least one of cyber monitoring, cyber intrusion monitoring, health monitoring, anomaly monitoring, status monitoring or quality control.

24. The device of claim 21 where extracted analog signatures are connected to at least one LNA to amplify the analog signatures for analysis.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0041] FIG. 1 illustrates a plan view of the device box, unfolded.

[0042] FIG. 2 illustrates a block diagram of the Differential Mode Probe.

[0043] FIG. 3 illustrates a perspective view of the Common Mode Probe and Low Noise Amplifier Board.

[0044] FIG. 4A illustrates a top view of a toroidal ferrite core.

[0045] FIG. 4B illustrates a side view of a toroidal ferrite core.

[0046] FIG. 4C illustrates a perspective view of a toroidal magnetic core.

[0047] FIG. 5 illustrates a perspective cutaway view of the Differential Mode Probe and low noise amplifier board.

[0048] FIG. 6 illustrates a diagram of toroid CMP equivalent circuit diagram.

[0049] FIG. 7 illustrates a perspective view of the exterior of the bus coupler box.

[0050] FIG. 8 illustrates a plan view of generally toroidal magnetic core.

[0051] FIG. 9 illustrates a plan view of the CMP and CMP LNA circuit board.

[0052] FIG. 10 illustrates a plan view of the box.

[0053] FIG. 11 illustrates an elevation view of the box.

[0054] FIG. 12 illustrates a perspective view of the box.

[0055] FIG. 13 illustrates a perspective view of 3 wind ferrite toroid.

[0056] FIG. 14 is a partially perspective view of the LNAs, and SMA connectors.

[0057] FIG. 15 illustrates a perspective view of a terminal block.

[0058] FIG. 16 illustrates a unidirectional block diagram.

[0059] FIG. 17A illustrates a cross sectional view of a MIL-STD-1553 data bus cable.

[0060] FIG. 17B illustrates a cross sectional view of an A429 data base cable.

[0061] FIG. 17C illustrates a cross sectional view of a CAN Bus (single pair) data bus cable.

[0062] FIG. 17D illustrates a cross sectional view of a CAN Bus (double pair) data base cable.

[0063] FIG. 18A illustrates a cross sectional view of an A629 data bus cables.

[0064] FIG. 18B illustrates a cross sectional view of an Ethernet data bus cable.

[0065] FIG. 18C illustrates a cross sectional view of a USB data base cable.

[0066] FIG. 19A illustrates a block diagram of the device connected to LRUs in a preferred embodiment.

[0067] FIG. 19B illustrates a block diagram of the device connected to LRUs in a preferred embodiment. with communications output.

[0068] FIG. 20A illustrates a block diagram of the device connected to LRUs is a second embodiment with communications output.

[0069] FIG. 20B illustrates a block diagram of the device connected to LRUs is a second embodiment with communications output.

[0070] FIG. 21A illustrates a block diagram the device connected to LRUs in a 3rd Embodiment.

[0071] FIG. 21B illustrates a block diagram the device connected to LRUs in a 3rd Embodiment with communications output.

[0072] FIG. 22A illustrates a diagram of a 1553 data bus with a coupled transformer.

[0073] FIG. 22B illustrates a diagram of a 1553 data bus with a direct connection and isolating resistors.

DETAILED DESCRIPTION OF INVENTION

[0074] There are military and civilian standards, as well as operational constraints, that make it difficult to detect the weak analog signatures that are caused by changes in electrical activity in at least one of the time domain or frequency domain on the data bus of avionics systems and other vehicles. The present device extracts these analog signatures within a data bus coupler from the communication bus line. In a preferred configuration the acquired communications bitstream is simultaneously monitored in addition to the CMP and DMP signals. The CMP and DMP signals are independently amplified and output all within the weight and size requirements for applications such as avionics platforms without degrading the digital signal or compromising the signal's security. The probes are arranged to monitor analog signals contemporaneously.

[0075] FIG. 1 shows an unfolded view of the shielded coupler box 100 that contains the elements of the device located on the interior surface of the coupler box 100. The coupler box 100 is a generally rectilinear container box though the box could have any shape. The coupler box 100 is preferably a thermally and electrically conductive material. The coupler box 100 is preferably less than 50 cubic inches in volume. The coupler box 100 has multiple apertures to preferably accommodate connectors through walls of the coupler box 100. The device has a power port to supply power to one or more low noise amplifiers (LNAs) 220, 350. One or more data bus input ports 110 through the wall of the coupler box 100 and one or more data bus output ports 130 through the wall of the coupler box 100 are preferably configured for connectors. Ports 180 and 190 are stubs. Input port 110 and output port 130 are the data bus ports. A preferred embodiment to couple to a MIL-STD-1553 data bus requires that the bus coupler provide electrical noise isolation between the data bus and the analog output channels. Preferably the invention uses an isolating transformer 150. The input port 110 is connected to the transformer 150 by communication cable wires 160 and 165 and the transformer 150 is connected by the two strand communication cable wires 170 and 175 to the output port 130. A preferred embodiment to couple to an ARINC 429 bus does not require electrical noise isolation, and will not utilize an isolating transformer 150.

[0076] The coupler box 100 is shown as having a port for transmitting signature data collected by a CMP and a port for transmitting signature data collected by a DMP and a port of extracting communications bitstream data for status monitoring. It is contemplated that the coupler box 100 could have any number of ports with any number of CMP outputs any number of DMP outputs and any number of communications bitstream outputs. For a specific case of a multi-shield communication cable more than one DMP may be installed to measure the differential mode signatures relative to each of the shields that are connected to different subsystems while monitoring one or more CMP may reference both the shields and/or the conductors within the shields.

[0077] To observe the analog signal of electromagnetic transients, the CMP has an inductive coil 210. While any inductive coil could be used, including solid cores, clam cores, air cores, preferably, the device uses a ferrite core and preferably a toroidal ferrite core.

[0078] As used in this application, generally toroidal refers to a ring type toroid meaning that is hollow. Generally toroidal includes a torus and other cores that are not a perfect geometric shape. Preferably, the magnetic core is manufactured of ferrite to provide increased sensitivity. Preferably, for MIL-STD-1553 data bus configuration the ferrite is a “68” material with the following specifications:

[0079] Initial magnetic permeability (μ): 20

[0080] Saturation flux density (Bs): 2500 Gs

[0081] Residual flux density (Br): 700 Gs

[0082] Coercive Force (Hc): 7 Oe

[0083] Curie Temperature: 500° C.

[0084] AL factor 6.6 nH/N2

[0085] Preferably the toroids have the following dimensions:

[0086] Dimensions (OD×ID×H): 12.7 mm×7.1 mm×4.8 mm

[0087] An advantage of a generally toroidal inductive coil is that minimizes electromagnetic interference and magnetic flux leakage. When assembled, the toroid encircles the two strand communication cables 160 and 165. The two strand communication cables 160 and 165 are positioned within and are surrounded by the generally toroidal magnetic core 210 without contact. A non-contact CMP minimizes any impact to the bus or conductor being monitored and thereby minimizes compromising the digital communications integrity and security. Other similar configurations using differing toroid configurations are possible to achieve similar result while optimizing on other factors such as size, sensitivity, or rejection.

[0088] The generally toroidal magnetic CMP core 210 has one or more windings. Preferably, the generally toroidal magnetic core 210 has one winding. While more than one winding is operational, the use of one winding minimizes the impedance of the CMP.

[0089] Adjacent LNA 220 is preferably in generally close proximity to the CMP core 210. The CMP LNA 220 has a power supply input from connector 230 and a RF output to connector 240. Preferably, the LNA 220 is mounted on a circuit board 200. The LNA 220 output and interconnect cable provide the analog RF signal to later construct the signature.

[0090] The DMP inductive coils 310, 320 are preferably positioned on the opposite side of the transformer 150 from the CMP. This allows room with a space constrained coupler box to fit in the box 100 without interfering with the CMP or LNAs. Preferably, the CMP and DMP LNAs are mounted on separate interior walls of the coupler box 100. The DMP has inductive coils 310 and 320. As described above for the CMP, a core of various shapes and materials can be used. Preferably, the DMP and CMP use a generally toroidal ferrite core. This provides increased sensitivity. Each of the generally toroidal ferrite cores has one or more windings. Similarly, as with the CMP core 210, it is preferable for each of the magnetic cores 310 and 320 to have one winding to minimize impedance. The DMP magnetic cores 310 and 320 are offset, as shown in FIG. 1. The offset allows the communication line strands 170 and 175 to be more easily separately threaded through the interior of the toroidal cores without contact.

[0091] The DMP has noncontact cores 310 and 320 with an associated LNA 350 adjacent, or near it. The LNA 350 has a power supply input 230, and RF output 340. Preferably, the DMP magnetic cores 310 and 320 are mounted adjacent near the DMP LNA 350 on a circuit board 300.

[0092] The LNAs 220 and 350 are positioned near the magnetic cores 210 for the CMP and 310 and 320 for the DMP, respectively, to improve performance and efficiently use the space available in applications such as avionics. The CMP circuit board 200 and DMP circuit board 300 are preferably attached to separate faces of the coupler box 100. Circuit boards 200 and 300 are preferably attached with thermo-conductive and electrical-conductive adhesive to the coupler box 100 that is also thermo-conductive and electrically conductive.

[0093] FIG. 2 illustrates a block diagram of the DMP. A wire 345 is wound around the toroidal ferrite cores 310 and 320. LNA 350 is mounted on the circuit board 300.

[0094] FIG. 3 illustrates a perspective view of CMP. The LNA 220 is shown as attached to the circuit board 200. FIG. 3 shows a single wind of wire 245 around the generally toroidal ferrite core 210. The wire 245 connects to RF output 240.

[0095] FIGS. 4A-4C show the generally toroidal ferrite cores that are used in the CMP and DMP. The use of the generally toroidal is meant to include a torus. An illustration of toroidal cores is shown in the side views FIGS. 4A and 4B. An additional toroidal shape is shown in 4C where there is a chamfer in the transition between the top and side of the core.

[0096] Turning to the DMP in FIG. 5, therein is illustrated a partial cutaway view without the coupler box 100, transformer 150, or CMP to illustrate the assembly of the DMP. In this view the SMA connectors carrying the data bus ports 110 and 130 are shown. The DMP is assembled with the two strand communications cable 170 and 175 that are each separately threaded within the generally toroidal magnetic cores 310 and 320. Note that the generally toroidal magnetic cores 310 and 320 are offset to receive the strands 170 and 175, respectively. This cutaway perspective view shows the DMP with three windings. The toroidal magnetic cores mounting on the circuit board is obscured on this view to more easily view the generally toroidal cores 310 and 320. The LNA 350 is mounted generally near the generally toroidal cores 310 and 320 to improve LNA performance. The power supply is not shown.

[0097] FIG. 6 is an equivalent circuit for transformers illustrating the primary and secondary windings. The purpose of transformer 150 is to isolate the data bus from the data bus coupler and is in the MIL-STD-1553 data bus specification for the LRU. The LRUs are avionics devices that are connected to the data bus. The data bus coupler provides stubs 180, 190 to connect the LRUs to the data bus. The data bus digital communications signals can be monitored through the stubs 180, 190. The monitoring would be by a separate board not shown. Np is the data bus through the ferrite core and Ns is the winding through the probe. RL is the resistance of 50Ω associated with an SMA connector.

[0098] FIG. 7 is a perspective view of the exterior of the device attached to the coupler box 100 showing the bus line ports, RF output 240 from CMP, RF output 340 from DMP, stubs 180 and 190, and power supply connection 230.

[0099] FIG. 8 is a plan view of a generally toroidal magnetic core with three windings.

[0100] FIG. 9 is a plan view of the circuit board with an LNA board.

[0101] FIG. 10 is a top view of the device lid showing the coupler box 100 in with the fasteners to complete assembly.

[0102] FIG. 11 illustrates an elevation view of the coupler box 100.

[0103] FIG. 12 illustrates a perspective view of the coupler box 100 showing the cut outs for connectors for the input and output ports, LNA RF outputs for the CMP and DMP, stubs and the power supply.

[0104] FIG. 13 shows a perspective view of a 3 wind ferrite core.

[0105] FIG. 14 shows a cutaway perspective view of the connectors 110, 230, and 240 mounted and sealed through openings in the coupler box 100, without the interior wiring, but with the LNA circuit boards 200 and 300.

[0106] The A429 data bus operates at a generally 100 KHz. Monitoring of the A429 data bus uses a terminal block 500, see FIG. 15. The terminal block 500 is preferably fit into the bus coupler box 100 as shown in FIG. 16. The A429 data bus coupler does not require a transformer, but can be connected directly to the unidirectional data bus. Therefore, no transformer 150 is necessary as it uses a direct connection. The A429 data bus (Tx) continues through the coupler box 100 and is connected to the data bus output connector, as shown by arrow from 38999 interface in FIG. 16, without corrupting the signals or compromising security.

[0107] The invention can extract unintentional analog signals and digital signals from multiple buses. The monitoring can be for a single bus individually or for a number of busses simultaneously. FIG. 17A shows the cross section of MIL-STD-1553 data bus, FIG. 17B shows the A429 data bus, FIG. 17C the CAN Bus (single pair) and FIG. 17D shows the CAN Bus (dual pair). All of these buses have a shield 52. Inside the shield 52 are conductors 56 that each have a shielded jacket 54. The MIL-STD-1553 data bus, and the CAN Bus (single pair and dual pair) there are spacers 58 to hold the conductors in place. Similarly, in FIG. 18A shows the A629, FIG. 18B the ethernet, and FIG. 18C the USB data buses are shown in cross sections have a shield 52. The A629 bus also has conductors 56 surrounded by shielded jackets 54. The ethernet and USB data buses have multi-filament conductors 62. The ethernet bus has 4 multi-filament conductors 62 surrounded by a shielded jacket 54. The USB 3.0 data bus has two 3 member multi-filament conductors 62 packages and two 2 member multi filament conductors 62 each in separate packages 64, each conductor package surrounded by a package shield 64. Each of the USB 3.0 conductors is also shielded with a shielded jacket 54. The packages are held in place with spacers 58.

[0108] Though the invention is described with regards to buses, networks of communication networks the invention can be used to measure any conductor or a plurality of conductors that at least one of have data or information flowing on them or do not have information intentionally flowing on them. As an example, a conductor that is situated directly adjacent to a conductor containing communication will couple both the communication signal, noise or weak unintended analog signatures to adjacent conductors. The invention can be configured to monitor at least one of the conductors over which the communications signal directly flows or the adjacent conductors whether those conductors are intended to have communications or data flowing on them or not. For example, the CMP can be configured to monitor at least one of one or multiple ground conductors or shields in a communication cable without monitoring directly the conductor that the communications flow over.

[0109] The invention is usable with data buses and networks in general and with one or more of the MIL-STD-1553 data bus, ARINC 429 (A429) bus, CAN (and its variants), A629, ethernet, USB, optical, serial and Universal Powerline Buses.

[0110] Although specific advantages have been enumerated above, various embodiments may include some, none, or all of the enumerated advantages. Other technical advantages may become readily apparent to one of ordinary skill in the art after review of the following figures and description.

[0111] It should be understood at the outset that, although exemplary embodiments are illustrated in the figures and described below, the principles of the present disclosure may be implemented using any number of techniques, whether currently known or not. The present disclosure should in no way be limited to the exemplary implementations and techniques illustrated in the drawings and described below.

[0112] Unless otherwise specifically noted, articles depicted in the drawings are not necessarily drawn to scale.

[0113] Modifications, additions, or omissions may be made to the systems, apparatuses, and methods described herein without departing from the scope of the disclosure. For example, the components of the systems and apparatuses may be integrated or separated. Moreover, the operations of the systems and apparatuses disclosed herein may be performed by more, fewer, or other components and the methods described may include more, fewer, or other steps. Additionally, steps may be performed in any suitable order. To aid the Patent Office and any readers of any patent issued on this application in interpreting the claims appended hereto, applicants wish to note that they do not intend any of the appended claims or claim elements to invoke 35 U.S.C. 112(f) unless the words “means for” or “step for” are explicitly used in the particular claim.