Methods and devices for ultra wideband wireless communications

Abstract

Ultra-Wideband (UWB) technology is a wireless technology supporting the transmission of large amounts of digital data over short distances using coded impulses over a wide frequency spectrum with very low power. Enhanced link performance and functionality of such UWB systems is presented exploiting multiple directive antennas for spatially filtering undesired signals and increasing signal strength whilst circuit complexity is reduced by eliminating baluns in prior art solutions. Further enhancements support payloads with flexible encoding schemes, improved channel utilization, reduced processing logic, improved robustness in correlation techniques, versatile synchronization techniques, improved ranging, as well as providing for improved inter-symbol interference tolerance and detection.

Description

METHODS AND DEVICES FOR ULTRA WIDEBAND WIRELESS COMMUNICATIONSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to U.S. Provisional Patent Application 63 / 665,440 filed June 28, 2024; the entire contents of which are incorporated herein by reference.FIELD OF THE INVENTION

[0002] This invention relates to ultra-wideband (UWB) wireless radios and more particularly to UWB antenna circuits and modules, UWB ranging protocols and UWB radio and network protocols.BACKGROUND OF THE INVENTION

[0003] Ultra-Wideband (UWB) technology is a wireless technology for the transmission of large amounts of digital data as modulated coded impulses over a very wide frequency spectrum with very low power over a short distance.

[0004] Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.SUMMARY OF THE INVENTION

[0005] It is an object of the present invention to mitigate limitations within the prior art relating to ultra-wideband (UWB) wireless radios and more particularly to UWB antenna circuits and modules, UWB ranging protocols and UWB radio and network protocols..

[0006] In accordance with an embodiment of the invention there is provided a method comprising: providing a differential Vivaldi antenna comprising a pair of arms disposed on a first layer of a printed circuit board (PCB) and a ground plane disposed on a second layer of the PCB; and providing a low pass differential filter disposed between the differential Vivaldi antenna and the differential outputs of an ultra-wideband (UWB) radio; whereinthe low pass differential filter comprises: a pair of conductors each conductor disposed on the first layer of the PCB and coupled to an output of the differential outputs of the UWB radio at a first end and an arm of the differential Vivaldi antenna at a second distal end; a pair of ground plane slots disposed within another ground plane disposed on a third later of the PCB where each ground plane slot is disposed beneath a conductor of the pair of conductors.

[0007] In accordance with an embodiment of the invention there is provided a method comprising: providing an antenna assembly comprising: providing a spiral antenna comprising a pair of spiral conductors each coupled to an input port on a first circuit board where the pair of spiral conductors are disposed on a first side of the first circuit board; providing a reflector comprising a ground plane on a second circuit board disposed at a defined distance from a second side of the first circuit board distal to the first circuit board; and providing an ultra-wideband (UWB) radio having a pair of differential outputs where each differential output of the pair of differential outputs is coupled to a defined spiral conductor of the pair of spiral conductors; wherein the spiral antenna at least one of receives circularly polarized wireless signals which are coupled to the UWB radio and transmits other circularly polarized wireless signals generated by the UWB radio.

[0008] In accordance with an embodiment of the invention there is provided a method comprising: providing an ultra-wideband (UWB) network comprising a plurality of UWB radios which operates upon a plurality of channels; wherein the UWB network cycles through the plurality of channels within a defined window cycle time; the channel for a frame to be transmitted by a UWB radio of the plurality of UWB radios is defined by a start time of the channel within the window cycle time; and the power settings of the UWB radio of the plurality of UWB radios are dynamically configured in dependence upon a length of the frame to be transmitted.

[0009] In accordance with an embodiment of the invention there is provided a method comprising:performing a non-coherent (NC) ranging measurement between a first ultra-wideband (UWB) radio and a second UWB radio; modifying one or more parameters of the first UWB radio; performing a Presence Detection (PDK) measurement with respect to a link between the first UWB radio and the second UWB radio to establish a received signal strength indication (RSSI) of the link; validating the NC ranging measurement in dependence upon the RSSI of the link based upon a relationship between the distance between the first UWB radio and the second UWB radio and the RSSI value.

[0010] In accordance with an embodiment of the invention there is provided a method comprising: iteratively performing a sequence of: performing a non-coherent (NC) ranging measurement between a first ultra-wideband (UWB) radio and a second UWB radio; and modifying one or more parameters of the first UWB radio to reduce the output power of the first UWB radio; and upon establishing failure to establish a link between the first UWB radio and the second UWB radio employing the final NC ranging measurement in the last NC ranging measurement when a link was established between the first UWB radio and the second UWB radio as the range between the first UWB radio and the second UWB radio.

[0011] In accordance with an embodiment of the invention there is provided a method comprising: providing a serially connected set of delay gates each comprising a delay element providing a defined time delay of a signal to the next delay gate 3610 in the serially connected set of delay gates and a gate connecting an input signal at that delay gate of the serially connected set of delay gates to a summation circuit; wherein an output of the summation circuit is a summation of the signals from the gates of the serially connected set of delay gates which due to the time delay inducted between each serially connected pair of delay gates is a step wise approximation of a Gaussian output signal for each input pulse connected to the serially connected set of delay gates.

[0012] Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Embodiments of the present invention will now be described, by way of example only, with reference to the attached Figures, wherein:

[0014] Figure 1 depicts applications of UWB transmitters, receivers, and systems according to embodiments of the invention;

[0015] Figure 2 depicts a block diagram of a UWB transmitter according to an embodiment of the invention;

[0016] Figure 3A depicts a block diagram of a UWB transmitter according to an embodiment of the invention supporting biphasic phase scrambling;

[0017] Figure 3B depicts a block diagram of a UWB transmitter according to an embodiment of the invention employing dynamically configurable and programmable pulse sequences;

[0018] Figure 3C depicts schematically a multi-pulse symbol UWB protocol according to an embodiment of the invention;

[0019] Figure 3D depicts a pulse sequence for a bit transmitted by a UWB transmitter according to an embodiment of the invention together with its emitted power spectrum with and without biphasic phase scrambling;

[0020] Figure 4 depicts a block diagram of a UWB receiver according to an embodiment of the invention;

[0021] Figure 5 depicts a receiver circuit schematic for a UWB receiver / transceiver according to an embodiment of the invention;

[0022] Figure 6 depicts a circuit schematic for a UWB transceiver according to an embodiment of the invention;

[0023] Figure 7A depicts a filtered Vivaldi antenna module integrating a low pass filter according to an embodiment of the invention;

[0024] Figure 7B depicts schematics of the top electrical and ground plane layers for the filtered Vivaldi antenna module integrating a low pass filter according to the design of Figure 7A;

[0025] Figure 7C depicts schematics of the filtered Vivaldi antenna portion of the filtered Vivaldi antenna module of Figure 7 A;

[0026] Figure 7D depicts a three-dimensional perspective view of the filtered Vivaldi antenna module of Figure 7 A;

[0027] Figure 8 depicts simulated Si l results of the a radio-frequency (RF) front-end of a module according to the design depicted in Figures 7A to 7D respectively;

[0028] Figure 9 depicts a plot of radiation efficiency for a Vivaldi antenna according to the design depicted in Figures 7 A to 7D respectively;

[0029] Figure 10 depicts a plot of peak realized gain for a Vivaldi antenna according to the design depicted in Figures 7A to 7D respectively;

[0030] Figures 11 to 13 depict the realized gain in XY, XZ and YZ planes respectively for a Vivaldi antenna according to the design depicted in Figures 7A to 7D respectively;

[0031] Figure 14 depicts a three-dimensional (3D) radiation pattern for a Vivaldi antenna according to the design depicted in Figures 7A to 7D respectively at 7.5 GHz;

[0032] Figure 15 depicts perspective and side views of a universal serial bus (USB) dongle employing a Vivaldi antenna according to the design depicted in Figures 7A to 7D respectively;

[0033] Figure 16 depicts top and bottom views of the USB dongle of Figure 15 employing the Vivaldi antenna according to the design depicted in Figures 7A to 7D respectively;

[0034] Figure 17 depicts top and bottom views of a USB dongle similar to that of Figure 15 employing the folded variant of the Vivaldi antenna according to the design depicted in Figures 7A to 7D respectively;

[0035] Figure 18 depicts perspective and top views of a PCB employing the Vivaldi antenna according to the design depicted in Figures 7A to 7D respectively;

[0036] Figure 19A depicts top, bottom and perspective views of a spiral antenna module for presence detection according to an embodiment of the invention;

[0037] Figure 19B depicts schematics of a spiral antenna board and reflector board for the spiral antenna according to the design depicted in Figure 19A;

[0038] Figure 19C depicts schematics of a circuit board for a UWB radio forming part of the spiral antenna according to the design depicted in Figure 19A;

[0039] Figure 20 depicts simulated differential reflection coefficient of the spiral antenna according to design depicted in Figure 19;

[0040] Figure 21 depicts simulated radiation efficiency of the spiral antenna according to design depicted in Figure 19;

[0041] Figure 22 depicts simulated peak realized gain of the spiral antenna according to design depicted in Figure 19;

[0042] Figures 23 to 25 depict the realized gain in XY, XZ and YZ planes respectively for a spiral antenna according to the design depicted in Figure 19;

[0043] Figure 26 depicts a three-dimensional (3D) radiation pattern for a spiral antenna according to the design depicted in Figure 19 at 7.7 GHz;

[0044] Figure 27 depicts a plot of the two-dimensional (2D) axial ration of the spiral antenna according to design depicted in Figure 19;

[0045] Figure 28 depicts a 3D axial ratio plot of the spiral antenna according to the design depicted in Figure 19 at 7.7 GHz;

[0046] Figure 29 depicts a channel hopping mechanism according to an embodiment of the invention;

[0047] Figure 30 depicts adjusting a communication distance configuration via center frequency shift within a non-coherent two-way ranging with Received Signal Strength Indicator (RSSI) measurement according to an embodiment of the invention;

[0048] Figure 31 depicts multipath impact reduction by power emission and frequency shift optimization within the non-coherent two-way ranging with RSSI measurement according to an embodiment of the invention;

[0049] Figure 32 depicts simplified schematics of module integration using a UWB System- on-a-Chip (SOC) with dual antennas for non-coherent radar and a conceptual design of the UWB SOC according to an embodiment of the invention;

[0050] Figure 33 depicts perspective views of a dual polarization Fermi antenna according to an embodiment of the invention within an anechoic chamber;

[0051] Figure 34 depicts the antenna pattern for the dual polarization Fermi antenna according to an embodiment of the invention;

[0052] Figure 35 depicts schematically an embodiment of the invention wherein a synchronization adjustment at every received frame; and

[0053] Figure 36 depicts the generation of an output pulse sequence from a power amplifier of a UWB radio with an overall Gaussian profile.DETAILED DESCRIPTION

[0054] The present invention is directed to ultra-wideband (UWB) wireless radios and more particularly to UWB antenna circuits and modules, UWB ranging protocols and UWB radio and network protocols..

[0055] The ensuing description provides exemplary embodiment(s) only, and is not intended to limit the scope, applicability or configuration of the disclosure. Rather, the ensuing description of the exemplary embodiment(s) will provide those skilled in the art with an enabling description for implementing an exemplary embodiment. It being understood thatvarious changes may be made in the function and arrangement of elements without departing from the spirit and scope as set forth in the appended claims.

[0056] 0. IMPULSE RADIO ULTRA WIDEBAND SYSTEM

[0057] As discussed supra UWB offers many potential advantages such as high data rate, low- cost implementation, and low transmit power, ranging, multipath immunity, and low interference. However, due to low emission levels permitted by regulatory agencies such UWB systems tend to be short-range indoor applications but it would be evident that a variety of other applications may be considered where such regulatory restrictions are relaxed and / or not present addressing military and civilian requirements for communications between individuals, electronic devices, control centers, and electronic systems for example.

[0058] Accordingly, UWB systems are well-suited to short-distance applications in a variety of environments, such as depicted in Figure 1 including peripheral and device interconnections, as exemplified by first Residential Environment 110, sensor networks, as exemplified by second Residential Environment 120, control and communications, as exemplified by Industrial Environment 130, Medical Systems 150, and personal area networks (PAN), as exemplified by PAN 140. For example, with PAN 140 a user may have associated with them, for example worn discretely, implanted or within an item of smart clothing etc. a variety of sensors including, but not limited to, those providing acoustic environment information via MEMS microphone, user breathing analysis through lung capacity sensor, global positioning via GPS sensor, their temperature and / or ambient temperature via thermometer, and blood oxygenation through pulse oximeter. These are augmented by exertion data acquired by muscle activity sensor, motion data via 3D motion sensor (e.g. 3D accelerometer), user weight / carrying data from pressure sensor and walking / running data from a pedometer. These may be employed in isolation or in conjunction with other data including, for example, data acquired from medical devices associated with the user such as depicted in Medical Systems 150. As depicted these medical devices may include, but are not limited to, deep brain neurostimulators / implants, cochlearimplant, cardiac defibrillator / pacemaker, gastric stimulator, insulin pump, and foot implants.

[0059] The Federal Communications Commission (FCC) regulations for UWB reserved the unlicensed frequency band between 3.1GHz and 10.6GHz for indoor UWB wireless communication system wherein the low regulated transmitted power allows such UWB systems to coexist with other licensed and unlicensed narrowband systems. Therefore, the limited resources of spectrum can be used more efficiently. On the other hand, with its ultrawide bandwidth, a UWB system has a capacity much higher than the current narrowbandsystems for short range applications. Two possible techniques for implementing UWB communications are Impulse Radio (IR) UWB and multi -carrier or multi -band (MB) UWB. IR-UWB exploits the transmission of ultra-short (of the order of nanosecond) pulses, although in some instances in order to increase the processing gain more than one pulse represents a symbol. In contrast MB -UWB systems use orthogonal frequency division multiplexing (OFDM) techniques to transmit the information on each of the sub-bands. Whilst OFDM has several good properties, including high spectral efficiency, robustness to RF and multi-path interferences. However, it has several drawbacks such as up and down conversion, requiring mixers and their associated high power consumption, and is very sensitive to inaccuracies in frequency, clock, and phase. Similarly, nonlinear amplification destroys the orthogonality of OFDM. Accordingly, MB-UWB is not suitable for low-power and low cost applications.

[0060] In contrast IR-UWB offers several advantages, including unlicensed usage of several gigahertz of spectrum, offers great flexibility of spectrum usage, and adaptive transceiver designs can be used for optimizing system performance as a function of the data rate, operation range, available power, demanded quality of service, and user preference. Further, multi-Gb / s data-rate transmission over very short range is possible and due to the ultra-short pulses within IR-UWB it is very robust against multipath interference, and more multipath components can be resolved at the receiver in some implementations, resulting in higher performance. Further, the ultra-short pulses support sub-centimeter ranging whilst the lack of up and down conversion allows for reduced implementation costs and lower power transceiver implementations. Beneficially, ultra-short pulses and low power transmissions make IR-UWB communications hard to eavesdrop upon.

[0061] An IR-UWB transmitter as described below in respect of embodiments of the invention in with reference to Figures 2 and 3 respectively exploits an on-demand oscillator following a pulse generator in order to up-convert the pulses from the pulse generated whilst avoiding the requirement of a separate mixer. Implementable in standard CMOS logic both the pulse generator and the on-demand oscillator are digitally tunable in order to provide control over the pulse bandwidth and center frequency. Further, by exploiting a digitally controlled ring oscillator for the on-demand oscillator the IR-UWB transmitter is designed to allow very quick frequency adjustments on the order of the pulse repetition rate (PRR). Beneficially this technique provides the same advantages as MB-OFDM in respect of spectrum configurability, achieved by sequentially changing the transmitted spectrum using a frequency hopping scheme, whilst maintaining the benefits of IR-UWB. Further, by providing advanced duty cycling with fast power up time combined with On-Off Shift Keying (OOK) modulation theIR-UWB according to embodiments of the invention allows significant reductions in power consumption by exploiting the low duty cycle of a UWB symbol and the fact that only half the symbols require sending energy.

[0062] In addition to defining the operating frequency range for UWB systems the different regulatory bodies all specify and enforce a specific power spectral density (PSD) mask for UWB communications. A PSD mask as may be employed in respect of embodiments of the invention is the FCC mask for which mask data are summarized in Table 1 below for the 3100MHz- 10600MHz (3.1GHz-10.6GHz) range.Table 1: FCC Masks for Indoor - Outdoor for Different Frequency Bands

[0063] Accordingly, it would be evident that the upper limit of -41.3 dB / MHz across the 3.1 GHz- 10.6GHz frequency range is the same limit imposed on unintentional radiation for a given frequency in order not to interfere with other radios. Basically, for a given frequency, the UWB radio operates under the allowed noise level which creates the relationship presented in Equation (1) between Ep, the transmitted energy per pulse, the maximum spectral power S' , the bandwidth B , the bit rateand the number of pulses per bits Nppl.EpNppbRb<S B (1)

[0064] The IEEE has published a few standards for a physical layer (PHY) for UWB radio in Personal Area Networks (IEEE 802.15.4a- 2007), Body Area Networks (IEEE 802.15.4a-2007) and Radio-Frequency Identification (IEEE 802.15.4f-2012). These standards use mostly relatively large pulses resulting in relatively narrow bandwidth which is up-converted to a specific center frequency in order to fill predetermined channels. The data is encoded using pulse-position-modulation (PPM) and bi-phasic shift keying (BPSK) is used to encode redundancy data. Every bit consists of one or more pulses scrambled in phase depending on the target data rate. These standards allow considerable flexibility on channel availability anddata rates. The standard also defines the preamble, headers for the data packet and ranging protocol.

[0065] These IEEE standards are designed with multiple users in mind and use different channels to transmit the data, thereby putting a heavy constraint on pulse bandwidth and limiting the transmitted energy. Prior art on non-standard transmitter attempts to make better use of the available spectrum by using narrow pulses, which therefore have a larger bandwidth thereby increasing the maximum transmitted energy according to Equation (1). Accordingly, these transmitters are non-standard and were also designed for different data rates, frequencies, pulse width, etc. Additionally, they also used various encoding schemes, most notably PPM, OOK or BPSK.

[0066] Within the work described below the inventors have established improvements with respect to UWB systems, UWB transmitters and energy based UWB receivers which are capable of generating and adapting to a variety of IR-UWB pulses and bit encoding schemes thereby supporting communications from both IR-UWB transmitters compliant to IEEE standards as well as those that are non-standard. These improvements are made with respect to UWB transmitters, UWB receivers, UWB transceivers and UWB systems such as those described and depicted by the inventors within WO / 2015 / 103,692 “Systems and Methods Relating to Ultra-Wideband Broadcasting comprising Dynamic Frequency and Bandwidth Hopping” (PCT / CA2015 / 000,007, filed January 7, 2015); WO / 2016 / 191,851 “Systems and Methods for Spectrally Efficient and Energy Efficient Ultra-Wideband Impulse Radios with Scalable Data Rates” (PCT / CA2016 / 000, 161 filed May 31, 2016); WO / 2019 / 000,075 “Energy Efficient Ultra-Wideband Impulse Radio Systems and Methods” (PCT / CA2018 / 000, 135 filed June 29, 2018); WO / 2020 / 186,332 “Methods and Systems for Ultra-Wideband (UWB) Receivers” (PCT / CA2020 / 000,029 filed March 18, 2020); WO / 2020 / 186,333 “Ultra- Wideband (UWB) Transmitter and Receiver Circuits” filed March 18, 2020; and WO / 2020 / 186,334 “Ultra-Wideband (UWB) Link Configuration Methods and Systems” filed March 18, 2020.

[0067] 1. IR-UWB TRANSMITTER CIRCUIT

[0068] Referring to Figure 2 there is depicted schematically an exemplary architecture for an IR-UWB transmitter 200 according to embodiments of the invention which is composed of five main blocks plus the antenna. First a programmable impulse is produced by a pulse generator 230 at clocked intervals when the data signal from AND gate 210 is high based upon control signals presented to the AND gate 210. The pulses from the pulse generator 230 are then up- converted with a programmable multi-loop digitally controlled ring oscillator (DCRO) 240.The output from the DCRO 240 is then coupled to a variable gain amplifier (VGA) 250 in order to compensate for any frequency dependency of the pulse amplitude. Finally, a driver 260 feeds the antenna 270, overcoming typical package parasitics, such as arising from packaging the transceiver within a quad-flat no-leads (QFN) package. In order to further reduce the power consumption of the IR-UWB transmitter (IR-UWB-Tx) 200 according to embodiments of the invention a power cycling controller 220 dynamically switches on or off these functional blocks when the data signal is low.

[0069] Now referring to Figure 3A there is depicted schematically a block diagram 300 of an exemplary IR-UWB transmitter according to embodiments of the invention supporting biphasic phase scrambling. In comparison to the IR-UWB transmitter 200 in Figure 2 for an IR-UWB according to embodiments of the invention without biphasic phase shifting rather than being composed of five main blocks plus the antenna the Biphasic Phase Shifting IR- UWB (BPS-IR-UWB) transmitter comprises 6 main blocks. First a programmable impulse is produced by a pulse generator 330 at clocked intervals when the data signal from AND gate 310 is high based upon control signals presented to the AND gate 310. The pulses from the pulse generator 330 are then up-converted with a programmable multi-loop digitally controlled ring oscillator (DCRO) 340. The output from the DCRO 340 is then coupled to a dual-output amplifier (VGA) 350 both in order to compensate for any frequency dependency of the pulse amplitude but also to generate dual phase shifted output signals that are coupled to a switch 360 which selects one of the two signals to couple to the output power amplifier (driver) 380 under the action of the switch control signal “S” applied to the switch 360. Note that a similar phase selection scheme could be implemented by affecting the startup conditions for DCRO 340 in order to provide the two phases. This would preclude the need for switch 360 at the cost of an added control startup condition control signal on DCRO 340.

[0070] The output power amplifier 380 feeds the antenna 370, overcoming typical package parasitics, such as arising from packaging the transceiver within a quad-flat no-leads (QFN) package. In order to reduce the power consumption of the BPS-IR-UWB transmitter represented by block diagram 300 according to an embodiment of the invention a power cycling controller 320 dynamically switches on or off these functional blocks when the data signal “PC” is low. Accordingly, a BPS-IR-UWB transmitter according to embodiments of the invention transmits pulses with or without phase shift based upon the control signal “S” applied to switch 360. If this control signal is now fed from a random data generator or a pseudorandom data generator then the resulting pulses coupled to the antenna of the BPS-IR-UWB transmitter will be pseudo-randomly or randomly phase shifted.

[0071] Now referring to Figure 3B there is depicted schematically a block diagram 3000 of an exemplary IR-UWB transmitter according to embodiments of the invention. As depicted a Pulse Pattern block 3010 holds a configuration for the pulses used to represent the current symbol. From the symbol-rate clock (i.e. 20 MHz), multiple phases are generated by a Delay Locked Loop (DLL) 3030. The rising edge of each clock phase represents the start of one pulse in the symbol pulse bundle. A multiplexer 3020 is triggered by the edges of the clock phases and selects the configuration of the current pulse out of the Pulse Pattern block 3010. A pulse generator (Pulser) 3050 generates pulses with a pulse width set by the multiplexer 3020 and enables the Digitally Controlled Oscillator (DCO) 3040 and Power Amplifier (PA) 3060. When enabled, the DCO 3040 generates a Gaussian shaped pulse with frequency set by the multiplexer 3020, which is then amplified by the PA 3060 and radiated by the antenna 3070.

[0072] Accordingly, the Pulse Pattern block 3010 establishes the pulses for a symbol or sequence of symbols. In this manner updating the Pulse Pattern block 3010 adjusts the pulse sequence employed for each symbol and accordingly the Pulse Pattern block 3010 may be dynamically updated based upon one or more factors including, but not limited to, network environment data, predetermined sequence, date, time, geographic location, signal-to-noise ratio (SNR) of received signals, and regulatory mask.

[0073] Referring to Figure 3C there is depicted schematically a multi-pulse symbol UWB protocol according to an embodiment of the invention. Referring to first image 3100A there is depicted a bit 3160 comprising a series of sub-pulses 3160A to 3160C which are each at frequencies■ Accordingly, the multi -pulse spectrum 3180 of a symbol (bit 3160) is depicted in second image 3100B as obtained conceptually (phase scrambling is omitted for clarity) by summing the individual pulse spectra of the sub-pulses 3160A to 3160C, which increases the bandwidth whilst increasing the total symbol duration, in contrast with singlepulse prior art methods, whilst maintaining the maximum power below the UWB mask 3120. This allows the symbol energy to be maximized while relaxing the timing requirements and level of synchronization required at the receiver. An arbitrary number of pulses with different sets of parameters may be included within a bundle to tailor the pulse spectrum to a given requirement.

[0074] Now referring to Figure 3D there are depicted the power spectrum and pulse train for a pulse bundle according to WO 2016 / 191,851 and as depicted in Figure 3A supporting operating over a frequency range from approximately 3GHz to approximately 7GHz. First and second images 3400A and 3400B respectively representing the power spectrum and pulse sequencewherein there is no random frequency or phase scrambling during the generation and transmission. Third and fourth images 3400C and 3400D depict the results for random frequency and random phase scrambling of the pulses wherein phase is set per pulse through data established by a pseudo-random data generator. Accordingly, it would be evident that when comparing first and third images 3400A and 3400C that the introduction of random frequency and random phase shifting reduces the spectral lines significantly within the emitted spectrum of a UWB transmitter according to embodiments of the invention.

[0075] 2. IR-UWB RECEIVER

[0076] Referring to Figure 4 there is depicted schematically the architecture of an IR-UWB receiver 400 according to embodiments of the invention. Accordingly, the signal from an IR- UWB transmitter is received via an antenna 410 and coupled to a low noise amplifier (ENA) 420 followed by first amplifier 430 wherein the resulting signal is squared by squaring circuit 440 in order to evaluate the amount of energy in the signal. The output of the squaring circuit 440 is then amplified with second amplifier 450, integrated with integration circuit 460 and evaluated by a flash ADC 470 to generate the output signals. Also depicted is Power Cycling Controller 480 which, in a similar manner to the power cycling controller 220 of IR-UWB transmitter 200 in Figure 2, dynamically powers up and down the LNA 420, first and second amplifiers 430 and 450 respectively, squaring circuit 440, and flash ADC 470 to further reduce power consumption in dependence of the circuit’s requirements.

[0077] Referring to Figure 5 there is depicted a schematic of a receiver 500 according to an embodiment of the invention. The RF signal from the antenna 510 is initially amplified by a Low Noise Amplifier (LNA) 520 before being passed to a two stage RF amplifier (AMP1) 530. A first squaring mixer (MIX1) 540 multiplies the signal with itself to convert to the Intermediate Frequency (IF). A three-stage Variable Gain Amplifier (VGA) 550 amplifies the signal further and implements a bandpass filter function. The VGA 550 output is then coupled to a second squaring mixer (MIX2) 560 which down-converts the signal to the baseband frequency. An energy detection circuit 580 comprising a parallel of integrator (INTI and INT2) sums the signal energy, which is digitized by the Analog-to-Digital Converters (ADC1 and ADC2) and sent to a digital processor (not depicted for clarity).

[0078] 3. IR-UWB RECEIVER

[0079] As described within WO / 2019 / 000,075 and WO 2016 / 191,851 the inventors have established design parameters of millisecond range start-up time from sleep mode and microsecond range start-up time from idle mode by establishing a custom integrated DC / DCconverter and duty cycled transceiver circuitry that enables fast circuit start-up I shut-down for optimal power consumption under low (1 kbps') and moderate data rates (10 Mbps ).

[0080] In order to sustain good energy efficiency, the elements of a total UWB transceiver, such as depicted with transceiver 600 in Figure 6 according to embodiments of the invention, has been designed for low static sleep current and fast startup / sleep times. Referring to Figure 6, a battery (3.0 V < VBATT< 3.6 V ) (not depicted for clarity) powers a low-frequency crystal oscillator 615, sleep counter 620 and bandgap reference 610, all of which are typically always operational although the bandgap reference 610 could be duty cycled within other embodiments of the invention without altering the scope of the claimed invention). Their power consumption limits the minimum power consumption of the system to sub-microwatt level. An integrated buck DC-DC converter 605 is powered by the battery when the system is not in sleep mode, and this provides the supply voltage to the rest of the system with high conversion efficiency. The startup time of the DC-DC converter 605 is on the order of several symbol periods in order to minimize wasted energy. Between sleep periods, the PLL 655 is active to provide the base clock for the system. The receiver 625 and DLL 660 have dedicated power down controls and are only activated during frame transmission / reception. Further, the transmitter is also power cycled through its all-digital architecture which is not depicted as having a separate control. The power consumption of the digital synthesized blocks is low due to the low base clock (e.g. 20 MHz).

[0081] In principle, a power-cycled transceiver achieves linear scaling of power consumption with data rate, thus achieving constant energy efficiency. With a fixed frame size, multiple data rates are obtained by adjusting the length of the sleep period, with the maximum attainable data rate determined by the symbol rate in the frame itself. In order to preserve energy efficiency, the power consumption during sleep must be lower than the average power consumption. For high data rates, powering down the PLL is not required when its consumption does not significantly degrade the overall efficiency. For low data rates, the whole system except the bandgap reference, crystal oscillator, and sleep counter can be shut down during sleep mode. In this case, the millisecond range startup time of the PLL can be insignificant compared to the sleep period, and overall efficiency is also not significantly degraded.

[0082] As depicted the UWB transceiver 600 also comprises a receive / transmit switch 690 coupled to the antenna to selectively couple the transmitter 6000 or receiver 625 to the antenna during transmission and reception respectively. The UWB transceiver 600 also comprises a spectrum configuration circuit 665 (equivalent to Pulse Pattern 3010 in transmitter 3000 inFigure 3B), PHY Processing circuit 650, Link Controller 645, Buffer and Interface circuit 640, and PHY Formatting circuit 635. The UWB transceiver 600 communicates via Link Controller 645 to the Client 605. As such, Link Controller 645 may communicate using a wired protocol (e.g., serial peripheral interface (SPI)) to Client 605, for example.

[0083] 4. FILTERED VIVALDI ANTENNA

[0084] UWB transmitters, UWB receivers and UWB transceivers employ an antenna as a transducer between the wireless UWB signals and the electrical signals coupled to or generated by the UWB circuitry of a UWB transmitter, UWB receiver or UWB transceiver. Many antenna structures have been presented in the prior art for either discrete UWB antennas or UWB antennas supporting diversity techniques to help mitigate effects such as multipath interference. Within Figures 7 to 14 a design is presented for a differential Vivaldi antenna and module forming part of a module for use with a UWB radio to provide compact UWB transmitters, UWB receivers or UWB transceivers.

[0085] The differential Vivaldi antenna module depicted in Figure 7A by Module 700 is designed to offer simple modular integration for a variety of Ultra-Wideband (UWB) applications. The design depicted in Figure 7 comprises a printed circuit board (PCB) 740 upon which are formed a UWB Circuit 710, a differential Vivaldi antenna 720 and a differential low- pass filter (DIF-LP Filter) 730. The Module 700 employs a balanced circuit design enabling direct connection to a Spark Microsystems™ SR 1020 UWB radio circuit’s output pins (RFN- RFP) without requiring a balun. The innovative design presented in Figure 7A via the compact low-pass filter and Vivaldi antenna allows users to achieve certification across different regulatory regions with a single hardware design as the SR 1020 UWB radio employs techniques such as those described within Figures 2 to 6 respectively and as described by the inventors within different patent specifications including, but not limited to, WO / 2015 / 103692; WO / 2016 / 191851; WO / 2019 / 000075; WO / 2020 / 186332; WO / 2020 / 186333;WO / 2020 / 186334; WO / 2022 / 213183 and WO / 2023 / 060353 to provide UWB radios employing multiple pulses per bit with reconfiguration to meet different regulatory requirements and / or avoid local spectral interference sources.

[0086] The RF front-end of Module 700 features the DIF-LP Filter 730 that connects directly to the dual Vivaldi antenna 720 as depicted in Figure 7 A. When excited differentially, the system functions as a unified differential antenna, presenting a dipole-like radiation pattern and linear polarization. The PCB 740 of the Module 700 within an embodiment of the invention comprises a 4-layer FR4 PCB characterized by a relative permittivity of 4.4 and a totalthickness of 0.9mm. Referring to Figure 7B there are depicted the Top Layer 750A, the uppermost latter of the 4-layer FR4 PCB and Ground Plane 750B being the upper mid-layer of the 4-layer FR4 PCB. The lower mid-layer provides the power plane for the PCB 740 whilst the bottom layer provides interconnection(s).

[0087] A depicted in Figure 7B the DIF-LP Filter 730 comprises first and second Conductors 732A and 732B respectively for the two arms of the differential filter with Tapered Conductor 735 disposed between them on the Top Layer 750A and first and second Ground Plane Slots (GPS) 734A and 734B within the Ground Plane 750B. Also depicted are the first and second Antenna Arms 736A and 736B on the Top Layer 750A and the first and second Antenna Ground Elements 738A and 738B within the Ground Plane 750B.

[0088] Referring to Figure 7C there are depicted first and second Schematics 7000A and 7000B of the filtered Vivaldi antenna portion of the filtered Vivaldi antenna module of Figure 7A showing the DIF-LP Filter 730 and dual Vivaldi antenna 720. Now referring to Figure 7D there is depicted a three-dimensional perspective view 7000C of the filtered Vivaldi antenna module of Figure 7 A.

[0089] The filtered differential Vivaldi antenna depicted in Figures 7A to 7D presents an innovative UWB Differential Vivaldi Antenna design by incorporating two miniaturized efficient passive PCB filters which form the DIF-LP Filter 730 where each miniaturized efficient passive PCB filter is disposed within one feed of the pair of feeds from the UWB radio of the module to the dual Vivaldi antenna 720 such that the two miniaturized efficient passive PCB filters are directly embedded within the antenna structure. This design efficiently attenuates the second and third harmonics, aligning with communication regulatory requirements in regions like Europe under the ETSI standards and for Japan under the Ministry of Internal Affairs and Communications (MIC) standard. The integration of these two miniaturized efficient passive PCB filters preserves the original antenna's compactness and efficiency while adding suppression for 2nd and 3rd harmonics. These embedded two miniaturized efficient passive PCB filters are designed to operate without impacting the main radiation performance of the antenna in the UWB frequency bandwidth and ensuring optimal functionality for all communication regulatory standards. Moreover, being part of the PCB design, these filters do not increase the bill of materials cost or requires extra space, maintaining the antenna's compact size and low profile. This filtered antenna solution offers a significant technological advancement by combining the benefits of differential signaling and harmonic reduction in a single, compact unit, making it ideal for use in environments with strict electromagnetic interference regulations.

[0090] The simulated differential SI 1 of the RF front-end is presented in Figure 8 where it is evident that the -10 dB impedance cutoffs are at approximately 6.1 GHz and 9.0 GHz for this design of differential Vivaldi antenna with DIF-LP Filter 730. The efficiency of the antenna’s radiation is determined by calculating the ratio of the power radiated by the antenna to the power received at its input, as shown in Figure 9. This method is particularly precise as it accounts for any impedance mismatches and the insertion losses from the feed lines and filter. The combined radiation efficiency and filter insertion loss stays under 1.5 dB across the relevant frequency range. Figure 10 depicts the peak realized gain of the antenna, reaching a maximum of approximately 1.8 dB at 9 GHz, including losses. These figures also demonstrate the antenna’s filtering capability, effectively rejecting signals below 6 GHz and above 10.5 GHz. This selective filtering ensures meeting certification requirements for out of band emissions.

[0091] The radiation pattern of the module is plotted for the XY, XZ, and YZ planes at 500MHz intervals from 6.75 GHz to 8.75 GHz in Figures 11 to 13 respectively. It should be noted that these patterns have been obtained from free space simulation and that the final product radiation pattern of the antenna will be different as it will be affected by the elements around it. The three-dimensional (3D) radiation pattern on the differential Vivaldi antenna according to the design depicted in Figure 7 A is presented in Figure 14.

[0092] The PCB 740 of the differential Vivaldi antenna according to the design depicted in Figure 7A using the SR1020 UWB is 16mm wide and 25mm long rendering it suitable for compact UWB deployments such as a universal serial bus (USB) dongle as depicted below in Figures 15 to 17 or a wireless adapter such as depicted in Figure 18.

[0093] Referring to Figure 15 depicts first and second Views 1500A and 1500B respectively which are perspective and side views of USB dongle employing a low pass filtered differential Vivaldi antenna according to the design depicted in Figure 7 wherein the DIF-UP Vivaldi Antenna 1510 comprises the Vivaldi antenna 720 and DIF-UP Filter 730 as described and depicted above in respect of Figures 7 to 14 upon a PCB, which is variant of the PCB 740, which supports the SR1010 UWB radio and interfaces to a USB Type C Connector 1520. The USB Type C supporting audio, video, other data and power such that the USB dongle is powered by the electronic device it is connected to and provides a UWB radio functionality for communications. Now referring to Figure 16 there are depicted first and second Views 1600A and 1600B of a CAD model of the USB dongle depicted in Figure 15. depicts top and bottom views of the USB dongle of Figure 15 employing the DIF-UP Vivaldi Antenna 1510 according to the design depicted in Figure 7.

[0094] Now referring to Figure 17 there are depicted first and second Views 1700A and 1700B, which are top and bottom views, of a USB dongle similar to that of Figures 15 and 16 but employing a Folded Antenna 1710 comprising a folded variant of the differential Vivaldi antenna (Folded Vivaldi 1720) in conjunction with the DIF-LP Filter 730 according to the design depicted in Figure 7. The Folded Antenna 1710 allowing the overall length of the circuit board to be reduced. In each of Figures 15 to 17 the antenna generates UWB wireless signals that are radiated away from the electronic device to which the USB dongle is attached. Within another variant of the design the Folded Antenna 1710 may be formed upon a shaped PCB or other PCB such that the plane of the Vivaldi antenna is at an angle to that of the PCB with the UWB radio circuit.

[0095] Referring to Figure 18 there are depicted first and second Views 1800A and 1800B, which are perspective and top views of a UWB Transmitter comprising a PCB 1820 with a SRI 020 UWB Radio 1830 and a Ribbon Connector 1810 in conjunction with a DIF-UP Vivaldi Antenna 1510 according to the design depicted in Figure 7. Ribbon Connector 1810 accepting a ribbon cable although it would be evident that with respect to the designs of Figures 15 to 18 other physical connector types may be employed without departing from the scope of the invention which may support electrical and / or optical interfaces according to a standard or according to the protocol of the electrical circuit the UWB radio is communicating with via this interface.

[0096] 5. CIRCULAR ANTENNA AND PRESENCE DETECTION

[0097] Within a range of applications there is a requirement for detecting the presence of a user or item, for example, to automatically open a door, turn on lights in a region the user is about to enter etc. However, within prior art solutions such as those based upon motion detection or wireless presence detection from analysis of wireless signals within an environment (e.g. such as offered by enterprises such as Origin Wireless Inc. and Aerial Technologies Inc.) the detection is generally yes or no such that the door opens when a user moves in front of it even if not intending to enter or the determination of motion direction is poor leading to failure to open or opening when not intended etc.

[0098] Accordingly, the inventors have established an alternative approach based upon a circularly polarized spiral antenna in conjunction with a UWB radio. A printed circular polarized spiral antenna is an efficient radiating element, known for its ability to emit circularly polarized waves as well as its compact design and wide bandwidth. This antenna typically features a spiral conducting element that is printed on a dielectric substrate, accompanied by a ground plane positioned below. The spiral shape of the radiator facilitates circular polarization,enhancing the antenna’s performance in various applications. It is commonly fed through a balanced feed network, with careful consideration given to its geometry, dimensions, and feed mechanism to ensure superior performance over the intended frequency spectrum.

[0099] Accordingly, the inventors have established a printed spiral antenna designed for a presence detection monitor application to achieve nearly uniform radiation patterns in the azimuth plane with circular polarization. Referring to Figure 19 A there are depicted Front View 1900A, Rear View 1900B and Perspective View 1900C of a Spiral Antenna Module exploiting the design methodology established by the inventors. The simulation results presented in respect of Figures 20 to 28 was simulated and optimized such that the parasitic components, such as the casing, fixtures, etc. were included within the analysis and optimization.

[0100] The spiral antenna is designed on a two-layer FR4 PCB, characterized by a relative permittivity of 4.6 and a thickness of 1.5mm as depicted in Figure 19B with Front Antenna View 1900D and first Cross-Section 1900E. In order to mitigate backward radiation, a reflector is placed behind the antenna at a distance of approximately X / 4 at the center frequency of the antenna as depicted in Figure 19B with Front Reflector View 1900G and second Cross-Section 1900F. The spiral antenna and reflector act in conjunction with one another such that the combination exhibits circular polarization and an omnidirectional radiation pattern in the azimuth plane, tailored to encompass, for example, the presence detection application’s targeted frequency bandwidth.

[0101] The Spiral Antenna Module in addition to the spiral antenna and reflector PCBs are employed in conjunction with a UWB Circuit 1930 which employs a UWB Radio 1910 with differential outputs, such as the Spark Microsystems SRI 020 for example, and an Interface 1920 which may be an electrical connector for data and / or power such as from a battery within the Spiral Antenna Module or from a battery or power source external to the Spiral Antenna Module. The spiral antenna’s input impedance is matched to the UWB radio’s differential output impedance.

[0102] Referring to Figure 20 there is depicted the simulated differential reflection coefficient, denoted as Sdd, for the spiral antenna is illustrated in Figures 19A and 19B. From this it is evident that the antenna’s differential reflection coefficient remains below -16 dB across the entire frequency bandwidth of the SPARK’s presence detection application which has been defined as 7.5 GHz to 8.5 GHz. This ensures minimum mismatch loss between the antenna and Spark Microsystems SRI 020 which operates over the frequency range 6.0 GHz to 9.3 GHz. Figure 21 depicts the antenna’s radiation efficiency, providing a precise measure that accounts for impedance matching and insertion losses in the feed lines. The antenna achievesa radiation loss performance of approximately 2.5 dB across the 7.5 GHz to 8.5 GHz frequency band. Figure 22 depicts the peak realized gain of the antenna over the 7.5 GHz to 8.5 GHz indicating a maximum gain of around 3.5 dBi at 7.8 GHz, factoring in all losses. This crucial data assists in selecting the appropriate pulse setting to adjust the output power level, ensuring compliance with the spectral mask limits set by the relevant regulatory authority within which the UWB radio and the presence detection system are operating.

[0103] The simulated normalized radiation patterns of the spiral antenna with reflector are presented for the three main cuts of X-Y, X-Z, and Y-Z from 7.6 to 7.9 GHz in Figures 23 to 25 respectively. The 3D radiation pattern of the antenna at 7.7 GHz is also plotted in Figure 26. As evident from Figure 24 the spiral antenna - reflector combination yield a wide and almost uniform radiation in the azimuth plane.

[0104] The axial ratio in circularly polarized antennas is a measure of the electromagnetic wave’s polarization purity and is defined as the ratio of the major axis to the minor axis of the polarization ellipse, which represents the shape traced by the tip of the electric field vector as it propagates in space. For perfectly circular polarization, the axial ratio would be 1:1, indicating that the magnitudes of the electric field components are equal and the phase difference between them is 90 degrees. The axial ratio is typically expressed as a ratio, often in decibels (dB). In practical terms, an axial ratio closer to 0 dB indicates a more circularly polarized wave. An antenna with an axial ratio of below 3dB is commonly accepted as circularly polarized by the industry.

[0105] The two-dimensional (2D) axial ratio of the spiral antenna - reflector combination in the XZ-plane (azimuth) at 7.7 GHz are depicted in Figure 27 whilst the 3D axial ratio at 7.7 GHz is depicted in Figure 28. The spherical 3D axial ratio plot of Figure 28 serves as a visual aid in understanding polarization characteristics. Figures 27 and 28 clearly illustrate how the antenna’s polarization varies from pure linear to circular across different angular directions. When observing the plot, it becomes evident that areas marked by nulls or cavities indicate circular or elliptical polarization, signifying a consistent polarization orientation regardless of the antenna’s orientation. Conversely, regions depicted with no noticeable cavities indicate purely linear polarization. Based on these Figures, it appears that the signal coverage in azimuth plane is highly uniform for both radiation and axial ratio patterns.

[0106] The characteristics of the Spiral Antenna Module depicted in Figure 19A as evident from the performance presented provides a circularly polarized antenna with good response directly in front with low response towards its plane and behind. Accordingly, the Spiral Antenna Module via the UWB radio can broadcast, receive or broadcast and receive accordingto the functionality of the UWB radio. The directionality and circular polarization limit false signal detections as would the UWB radio data transmission formats such as described and depicted by the inventors have described within, but not limited to, WO / 2019 / 000075; WO / 2020 / 186332; WO / 2020 / 186333; WO / 2020 / 186334; WO / 2022 / 213183 and WO / 2023 / 060353 or according to the prior art. Further, the inventors novel UWB radio technology described and depicted within, but not limited to, WO / 2015 / 103692; WO / 2016 / 191851; WO / 2019 / 000075; WO / 2020 / 186332; WO / 2020 / 186333;WO / 2020 / 186334; WO / 2022 / 213183 and WO / 2023 / 060353 provides for extremely low power consumption such that the Spiral Antenna Module can be powered from ambient light harvesting for example or support small batteries with rapid low cost re-charging via light harvesting or external electrical supply etc. It would be evident that the PCB with the spiral antenna may incorporate a photovoltaic element for such light harvesting or the spiral antenna may be patterned upon an upper transparent layer of a photovoltaic element within another embodiment of the invention.

[0107] The Spiral Antenna Module according to embodiments of the invention as described within this specification can be used for individual and asset tracking, access control, collision avoidance and proximity detection where the benefits of ultra-low power consumption, low cost and a compact design set a new standard for performance and efficiency.

[0108] 6. CHANNEL HOPPING

[0109] UWB radios as described by the inventors within Figures 2 to 6 support dynamic frequency selection and dynamic spectrum management thereby allowing the UWB radios to support channel hopping methodologies as known in the art and as described by the inventors within, but not limited to, WO / 2015 / 103692; WO / 2016 / 191851; WO / 2019 / 000075; WO / 2020 / 186332; WO / 2020 / 186333; WO / 2020 / 186334; WO / 2022 / 213183 and WO / 2023 / 060353. It would be beneficial for the UWB radio to exploit a channel hopping mechanism which removes the need for manual configuration from a user whilst ensuring optimization of transmission power settings and / or compliance with regulatory requirements. Accordingly, the channel hopping mechanism simplifies the user experience and enhances the overall performance of the UWB radio’s Wireless Stack.

[0110] A key consideration in achieving this objective is adherence to power emission regulations and accordingly the inventors have established an algorithm which automatically adjusts to meet these regulations across various scenarios, thereby ensuring compliance without requiring user intervention. This initiative aligns with the broader goals of the inventor’s nextgeneration Wireless Stack, which include ease of use, reliability, and regulatory compliance.

[0111] Within inventive channel hopping mechanism, the existing approach of changing the channel index every timeslot, such as described by the inventors within WO / 2020 / 186334 and WO / 2022 / 213183, is replaced by a time-division-based method.

[0112] Accordingly, within an embodiment of the invention the UWB network cycles through all available channels within a one-millisecond window (WCT = window cycle time), although other time frames may be defined for other UWB systems. The channel for a given frame is determined by its transmission (TX) start time within this window, e.g. the one- millisecond window. The channel hopping mechanism, to ensure compliance with power emission regulations, dynamically configures the power settings of the UWB transmitter based upon the frame length of the data frames to be transmitted. Jurisdictional settings may still be defined by a user or they may be acquired by the UWB radio from another UWB radio, an electronic device providing data to the UWB radio, or from a global navigation satellite system receiver associated with the UWB radio or other location based means associated with the UWB radio.

[0113] The channel hopping mechanism would calculate how many times a frame of a given length can fit within the channel index and adjusts the power settings accordingly. This ensures that regardless of the frame rate, the system remains within the regulatory limits for power emissions. This approach aims to optimize both performance and compliance, while eliminating the need for manual configuration.

[0114] Within the following description the embodiment of the invention is based upon a one-millisecond window. The power settings for each frame in the proposed channel hopping mechanism are determined, for example, by Equation (1) below where AT is the airtime of the frame, CL is the time one channel is used by the network in one millisecond, res is the resolution of the timeslot length in milliseconds, AIFS is the Arbitration Inter-Frame Spacing before an auto-reply, AAT is the auto-reply airtime and IFS is the Inter-Frame Spacing.

[0115] The algorithm employs a lookup table to select the appropriate power setting, ensuring that the transmission is compliant with the power emission regulations. This table is adjusted based on the antenna attenuation, which can be configured by the user (or automatically measured during configuration of the UWB radio) to account for hardwarespecific attenuation levels. For example, user configurable settings may include:• Antenna Attenuation in dBm: To offset the lookup table selection based on hardwarespecific attenuation.• Minimum Inter-Frame Spacing: Configurable based on the UWB radio’s central processing unit performance to ensure efficient data transmission.• Regional Settings: To ensure that the device complies with local regulations, users can specify the region in which the device is intended to be used.

[0116] Within other embodiments of the invention the UWB radio may acquire these settings automatically from another UWB radio or from an electronic device where the UWB radio may request these to be set by the user if it cannot establish them automatically. Through this the proposed channel hopping mechanism automatically configures where possible prior to seeking user customization, thereby ensuring both regulatory compliance and optimal performance.

[0117] In order, to ensure that the channel index is synchronized across all nodes in the network, a channel time index is included within the media access control (MAC) header of each transmitted frame. This index is a one-byte value that ranges from 0 to 1 ms, incremented by TINCwhich is given by Equation (2), where within the embodiment being described WC=lms but other window cycle times can be employed. By incorporating this channel time index in the MAC header, each node in the network can align its channel hopping schedule with that of the other nodes. This ensures that all nodes are operating on the same channel at any given time, thereby maintaining network coherence and facilitating seamless data transmission. This approach not only aids in keeping the network synchronized but also allows for more efficient use of the available spectrum.

[0118] Figure 29 depicts schematically an embodiment of the inventive channel hopping mechanism where the channels cycle through indices 0 to 4, each active for 200 ms before switching. Frames are transmitted within these active channel windows, followed by an Interframe Spacing (IFS) period to allow for frame processing. For example, "Frame 1" and "Frame 2" are transmitted on channel 0, while 'Frame 3' is transmitted on channel 2, and so on. This mechanism ensures efficient utilization of the available channels while adhering to power emission regulations. Within Figure 29 it is not necessary to identify which node transmits the frame. All the node of the network share the same time division channel sequence.

[0119] The inventive channel hopping mechanism offers several advantages but does have a couple of drawbacks. The advantages of the time-based channel hopping mechanism include:• automating the channel selection process and eliminating the need for manual configuration to enhance user experience;• it allows for optimal power settings to be used for each frame, ensuring compliance with emission regulations across different regions which is particularly important for maintaining the integrity of the network while adhering to legal constraints;• the mechanism is highly adaptable and is capable of adjusting to various frame sizes and rates, which makes it versatile for a range of applications; and• the mechanism distributes the transmission energy across multiple channels within a1ms window such that the mechanism effectively manages the Power Spectral Density (PSD) to keep it within regulatory limits.

[0120] Overall, the inventive time division channel hopping mechanism provides for a balance between usability, regulatory compliance, and operational efficiency. However, mechanism does have potential limitations for small frames and potential channel index desynchronization. With respect to small frames then the time divisional channel hopping mechanism may yield sub-optimal power settings for small frames: When small frames are sent at intervals greater than the channel length, the power settings may not be optimal. To mitigate this when small frames are being transmitted the Interframe Spacing (IFS) may be increased which would indirectly boost the transmission power for the frame. However, this adjustment comes at the cost of reducing the network’s maximum throughput.

[0121] The potential channel index desynchronization arises when the channel index becomes desynchronized between nodes, leading to the loss of a frame. While the innovative mechanism outlined includes a channel time index in the MAC Header for synchronization such that desynchronization should not occur there is potential for it to occur although establishing the frequency and impact of such desynchronization events would require further analysis.

[0122] 7. NON COHERENT TWO-WAY RANGING WITH RSSI MEASUREMENT

[0123] The underlying principle behind the application of ranging using UWB technology is based on precisely measuring the time it takes for a packet of information to travel from a transmitting device to a receiving one and back. This travel time is known as time of flight (ToF). Based upon the speed of light and taking into account device processing times, the distance between the two UWB devices can be calculated through a simple mathematical operation. However, this approach demands the use of high-precision and high-speed symbol clocks for an accurate determination. Additionally, mechanisms for comparing the phasereception of the signal can be implemented, allowing for the determination of relative angular position and compensating for potential signal reflections off nearby objects. These mechanisms are typical features of ranging in a coherent physical layer (PHY) based systems. Despite offering great precision, these mechanisms typically result in high energy consumption.

[0124] The following mechanism is a complementary mechanism to the non-coherent (NC) PHY ranging (NC-PHY) outlined previously by the inventors within, but not limited to, WO / 2019 / 000075; WO / 2020 / 186332; WO / 2022 / 213183 and WO / 2023 / 060353. The mechanism outlined below addresses limitations of current prior art non-coherent ToF ranging techniques.

[0125] Within this NC-PHY ranging system, the presence of nearby objects or obstacles between the UWB radios causes multipaths which can drastically affect the distance measurement. This arises from factors such as the low symbol clock frequency and the receiver sensitivity of the UWB radios. Additionally, without what is known as the angle of arrival (AoA), it is not possible to compensate for unwanted reflections, causing the system to be drastically affected when not in line of sight (LOS) conditions.

[0126] An embodiment of the invention for the NC-PHY ranging mechanism is based upon two mechanisms. The first is the existing NC-PHY ToF mechanism, which yields the distance between the UWB radios. The second mechanism is the control of emitted energy, allowing for the determination of the maximum distance at which the UWB radios can communicate. This second mechanism outputs a simple packet exchange with RS SI measurements where in principle, the RSSI value varies inversely with distance. This feature is known as Presence Detection (PDK).

[0127] As evident from the description with respect to Figures 2 to 6 and as outlined by the inventors within, but not limited to, WO / 2015 / 103692; WO / 2016 / 191851; WO / 2019 / 000075; WO / 2020 / 186332; WO / 2020 / 186333; WO / 2020 / 186334; WO / 2022 / 213183 and WO / 2023 / 060353; the energy emission control can be achieved through the configuration of the UWB radios, such as defining the number of pulses, their modulation, and the UWB transmitter (TX) sensitivity. Additionally, control over the maximum communication distance can be attained through the adjustment of the UWB receiver (RX) sensitivity, where greater sensitivity leads to extended reach.

[0128] Within another embodiment of the invention for the NC-PHY ranging mechanism is based upon two mechanisms. The first is the existing NC-PHY ToF mechanism, which yields the distance between the UWB radios. The second mechanism involves utilizing the centers ofemitted frequencies. In a typical scenario, the emission frequency center matches the reception frequency center. However, for finer granularity in communication distance, a frequency offset can be created between these frequencies. Consequently, the receiver will search for energy within a different range than what is being emitted. This results in an adjustment method with high granularity, enabling radios to achieve a maximum range from a few centimeters to several meters.

[0129] Figure 30 depicts in first and second Images 3000A and 3000B the process of adjusting the communication distance based upon center frequency shift of the UWB radios. First Image 3000A depicts the scenario where the overlap between the first Emission Spectrum 3030A of the UWB radio transmitting (Radio 1 3010) and the first Reception Spectrum 3040A of the UWB radio receiving (Radio 2 3020) is low such that there is no communications link between Radio 1 3010 and Radio 2 3020. With a shift in Radio 1 3010 and / or Radio 2 3020 then the second Emission Spectrum 3030B may be the same as first Emission Spectrum 3030A or shifted and the second Reception Spectrum 3040B may be the same as first Reception Spectrum 3040A or shifted such that there is increased overlap between Radio 1 3010 and Radio 2 3020 such that a link is established.

[0130] The inventors now describe two variants for implementing a NC-PHY ToF process according to embodiments of the invention. The first variant is a sequential method employed to validate non-coherent (NC) ranging measurements and involves performing a ranging sequence to obtain a distance, then modifying the UWB radio parameters and performing a Presence Detection (PDK) measurement. If the RS SI value is greater than 0, it's considered present within a specific region. This allows for validation of the ranging measurement, as there is a relationship between the distance and RSSI value. Further, inconsistent results would indicate a non-line-of-sight (NLOS) situation.

[0131] The second variant is a modification to ToF ranging where the emitted energy from the UWB radio is established regardless of link quality between the pair of UWB radios. This allows ranging to be performed within a defined distance, meaning measurements can only be made within a set maximum separation configured within the system as defined by the emitted energy and the receiver sensitivity. In this variant, the process is straightforward where a ranging cycle is conducted with reduced energy parameters to reduce the maximum distance on the basis that the direct path is the shortest distance so that as the output power is reduced the multi-path links between the pair of UWB radios are removed.

[0132] The advantage of the second variant is that with limited emitted energy the errors caused by multipaths on the ground, ceiling, walls, and nearby objects are reduced. Calibrationis simplified, and energy consumption is reduced. However, under NLOS conditions, the pair of UWB radios are unable to make distance measurements, but due to the characteristics of NC radios, ranging measurements in NLOS are invalid, such that there is no loss of system performance.

[0133] Figure 31 depicts in first Image 3100A the scenario where the first UWB radio 3110 is operating at a first output power and communicates to the second UWB radio 3120 wherein there is a Direct Link 3130 together with first and second Multipath Links 3140A and 3140B. In second Image 3100B the first UWB radio 3110 has lowered its output power to the point that there is only the Direct Link 3130 between it and the second UWB radio 3120.

[0134] 8. NON COHERENT RADAR

[0135] Radar systems, whether acoustic or electromagnetic, operate on the principle of time of flight (ToF), where a signal is emitted, and reflections send the signal back. Unlike ranging there is no consideration of the time it takes for another device to receive the emitted signal, process it and return it. As such non-coherent (NC) ranging does not know what returns the signal, merely that signals are reflected. Within the prior art various models of electromagnetic radars with high frequencies have been developed which whilst achieving excellent precision do so with considerable energy consumption. However, it would be beneficial to provide ranging in a wide range of scenarios with very low or ultra-low power consumption such that the ranging technique can be supported from devices which harvest energy rather than have significant battery capacity or access to an electrical power supply.

[0136] Accordingly, the inventors present below a NC Radar concept using their NC UWB radios which have been demonstrated to exhibit very low and ultra-low energy consumption compared to the Coherent UWB radios. Accordingly, the inventors methodology exploits a ToF with RSSI ranging mechanism, which will accurately determine the distance of objects from the radar. Moreover, due to the control capacity of emitted energy from the NC UWB radio, the detection area can be limited, minimizing concurrency issues with other radars or even other technologies within the spectrum.

[0137] A further benefit over existing radars is that by using the same existing NC UWB transceivers the system can be used for both radar measurements and communications with other UWB radios. This means, for example, that the NC Radar can validate the presence and range of an object but also verify if it's a person carrying another UWB radio and exchange information, which is crucial in security applications. Alternatively, the NC Radar can acquire object distance information and transmit it to another UWB radio for use in control, decision making, monitoring applications etc.

[0138] First Image 3200A in Figure 32 depicts a simplified schematic of a NC Radar module according to an embodiment of the invention comprising TX Antenna 3210, UWB Radio System-on-a-Chip (SOC) 3230 and RX Antenna 3220. An innovation of this system is the antenna designed for this NC Radar module which has a highly azimuthal (vertical) radiation pattern from the plane of the NC Radar to avoid cross-communication between the TX Antenna 3210 and RX Antenna 3220. Additionally, with small form factor to be compatible with mobile devices or small implementation areas. Energy consumption will be very low, and its communication capacity compatible with the UWB Radios within the UWB Radar SOC 3230.

[0139] As the UWB Radar SOC 3230 can be implemented at the bare die level a UWB TX Radio 3240, UWB RX Radio 3250 and Microcontroller Unit (MCU) 3260 can be placed as die to a common carrier and interconnected before encapsulation of the UWB Radio SOC 3230 as depicted in second Image 3200B in Figure 32. The result is a final product with minimal form factor, very low cost, and minimal energy consumption, and deployment opportunities for a wide range of applications.

[0140] Additionally, it offers flexibility to be integrated with mobile (portable) electronic devices that do not have the same transceivers, as the entire process will be developed within the same product. Therefore, the method of communication with external devices may be via quad serial peripheral interface (QSPI) / serial peripheral interface (SPI) for example to provide compatibility with a wide range of electronic devices and products. Beneficially, the rapid tunability and reconfigurability of the inventor’s UWB radios further provide enhanced security for data transmission as well as reduced interference from other wireless sources in the ranging process.

[0141] Third Image 3200C depicts a plot of the radar cross-section (RCS) of a human across the frequency range 5 GHz - 9 GHz which is predominantly covered by the Spark Microsystems SR1020 UWB Radio. Accordingly, at specific frequencies the human body presents a low RCS whilst at others a high RCS such that a UWB Radar SOC according to an embodiment of the invention exploiting a frequency agile UWB radio may determine the distance to an object and some assessment of the object’s type and provide for disambiguation of an inert physical object from a human or other animal.

[0142] 9. DUAL POLARIZATION FERMI ANTENNA

[0143] Testing of wireless antennas is typically performed within a shielded space designed and constructed to prevent intrusive electromagnetic waves and suppress the emission of electromagnetic waves to the outside world, commonly referred to as an anechoic chamber. However, accurate characterization of wireless devices within an anechoic chamber requires ahigh performance antenna to either generate wireless signals which are received by the device under test (DUT) or receive wireless signals generated by the DUT. Accordingly, the inventors have established a dual polarization Fermi antenna for the measurement setup within the anechoic chamber. This allows for assessment of wireless devices within the antenna anechoic chamber to establish compliance with regulatory standards such as the Federal Communications Commission (FCC), MIC and the European Telecommunications Standards Institute (ETSI).

[0144] Referring to Figure 33 there are depicted first and second Images 3300A and 3300B of the dual polarization Fermi antenna disposed within an anechoic chamber with its support and positioning system. The dual polarization Fermi antenna is mounted upon a positioning system allowing the dual polarization Fermi antenna to be moved relative to the DUT. The DUT itself being mounted onto a dual rotation automated positioner capable of precisely rotating the DUT in both azimuth and elevation planes, situated within the quiet zone of the anechoic chamber. The dual polarization Fermi antenna exploiting a UWB Vivaldi antenna measures both the vertical and horizontal polarizations of the DUT's radiation patterns. Integration of a controllable low-loss RF switch with the dual-polarized Fermi antenna allows for switching between receive and transmit modes, managed by the measurement software controlling the tests within the anechoic chamber. This software automates and synchronizes all operational parameters, including DUT modes, RF switch settings, and RF measurement instruments such as a spectrum analyzer or network analyzer for example. It conducts thorough one-shot measurements and characterizations of the UWB radios, comparing results against regulatory standards to determine compliance. The entire process is automated, requiring minimal human intervention, thus significantly enhancing testing efficiency, speed, and accuracy, providing a robust solution for industry-standard compliance testing of low power UWB systems. The radiation pattern of the dual polarization Fermi antenna is depicted in Figure 34 showing it’s highly directional gain along the axis.

[0145] 10. DUAL RADIO OPERATION

[0146] The inventors within the wireless core of their UWB radios have established a dual radio feature which is designed to enhance coverage in applications where antenna placement can be challenging or the link is subject to degradation. This feature is particularly useful in scenarios, for example, where there is a lot of body blocking, such as in the application of UWB radios within a headset, for example, but it can add a layer of complexity.

[0147] In the dual radio configuration, a pair of UWB transceivers are used to increase coverage. Both transceivers can redundantly receive frames, and the wireless core is free tochoose which transceiver to use for transmission based on the received signal strength. This redundancy allows the system to maintain a reliable connection even when one of the antennas is blocked or has a weak signal.

[0148] However, enabling this feature increases the processor load of the wireless core by approximately 1.5 times the equivalent single radio scenario. This is because the system needs to manage two separate transceivers, each of which requires its own processing resources. The second transceiver employs a dedicated SPI bus and DMA channel, independent of the first one, to allow for simultaneous data transfers to the wireless core. Additionally, a timer, for example a 16-bit timer running at 20.48 MHz provided by the MCU executing the wireless core, is also required. The timer period should be configurable by the wireless core.

[0149] 11. CONNECTION BASED NETWORK

[0150] A connection is defined by a unidirectional link between a source address and a destination address. A single device can use one or multiple connections. For a device to send data, a connection must be associated with one or more timeslots within the schedule. A connection between two devices must share the same network configuration, ensuring that both the sending and the receiving device adopts identical network settings.

[0151] The inventors have established the ability to send data to multiple devices within the same network with one connection using a broadcast address: 255 (or OxFF). The transmitting device will then communicate with every device within reach of it that are part of the same network, i.e. share the same personal area network (PAN) identity.

[0152] 12. AUTO-SYNC

[0153] In order to achieve near-perfect synchronization, the wireless core allows users to activate an Auto Sync feature, which configures the UWB radio to consistently transmit data to the receiving device in order to maintain synchronization. When the wireless core has no data to transmit (due to the application not sending any frames), it generates a Sync packet containing only the necessary information for the wireless core to maintain synchronization.

[0154] 13. 1-BIT STOP AND WAIT A

[0155] A MAC state machine according to an embodiment of the invention employs an autoreply feature of the UWB radio, e.g. the Spark Microsystems SR10X0 UWB radio, as an acknowledgment to support re-transmissions. When a user frame is about to be transmitted, the transmitter will obtain the head of its cross-layer queue for the connection. This frame will only be removed from the queue once the auto reply is received. This way, any frame that is removed from the user transmit queue by the MAC has guaranteed delivery. A 1 -bit sequence numberscheme is also added to filter out duplicate frames. This process is done independently for each connection.

[0156] 14. FALLBACK BASED OFF GIVEN PAYLOAD SIZE

[0157] When an application exploiting a UWB link detects a degradation in the link quality, the inventors have established a fallback mechanism within the wireless core of the UWB radio. This mechanism may be automatically configured or configured by the user. This mechanism allows for various thresholds to be configured based upon payload size. Where these are established by the UWB radio these may be pre -configured or they may be established / varied through the execution of one or more machine learning algorithms or one or more artificial intelligence algorithms. These settings influence the TX power settings of the UWB radio such that there is an increase in transmission power as the payload size decreases.

[0158] 15. LINK THROTTLE

[0159] When an application exploiting a UWB link detects inactivity using its sensor or other peripherals, it may start a link throttle mechanism. This disables some of the timeslots allocated for the throttled connection such that the UWB radio is powered down into a sleep mode for longer periods of time

[0160] 16. EVEN 1 AND 0 SPACING ALGORITHM

[0161] Within an embodiment of the link throttling algorithm a comparison is made of a Boolean value in a generated array of 20 elements. Each time a timeslot occurs for a given connection, the wireless core will disable the timeslot (sleep over it) if the Boolean value at the current index is false. It will then increment the index for the next time. The algorithm has been established to generate thus array such that the synchronization between two devices is optimized. In order to achieve this, the algorithm evenly spreads 0’s and l’s across the array. Accordingly, with a granularity of 5% and a throttling percentage of 50% the generated array is given by Sequence (1) below instead of something like Sequence (2).[1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0] Sequence (1)[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0] Sequence (2)

[0162] 17. CONNECTION PRIORITY

[0163] When an application exploiting a UWB link has retransmission margin available, it can opt to transmit on another connection with lower priority instead of requiring a dedicated timeslot for it. The inventors have established a wireless core that allows users to configure up to 3 connections per timeslot although it would be evident that within other embodiments the number of connections may be 2, 4 or another positive integer value. Each connection of thenumber of connections may be assigned a priority. Thus, when there is no data to be sent on a higher priority connection, the same timeslot can be utilized to transmit lower priority data.

[0164] 18. POWER CYCLE RX

[0165] In order to minimize the power consumption of a UWB radio the inventors have established a protocol wherein the wireless core always puts the UWB radio to sleep in between transmission and reception. The UWB radio is configured to always wake up a little earlier to ensure that the transmission and reception occurs in synchronization with enough margin to not trigger a timeout.

[0166] 19. SYNCHRONIZATION ADJUSTMENT AT EVERY RECEIVED FRAME

[0167] Within UWB radios, according to an embodiment of the invention the inventors have established a protocol wherein accurate synchronization is achieved by maintaining track of the waiting time, tw, between wake up and detection of the synchronization word for the node in RX. When a frame is received, this value twis returned by the PHY and compared with a target time, tt. A time offset, t0, is calculated and added to the next slot time, ts, to compensate for any drift. An example of how the system reacts in the instance of a slave waking too late is depicted in Figure 35.

[0168] Accordingly, a node is re-synchronized to the coordinator device every time it receives, with an accuracy defined by the clock, e.g. 20.48MHz which establishes the accuracy as l / 20.48MHz, i.e. approximately 50 ns. The coarse duty cycling time, ts, is based on the time slots information provided by the scheduler. The timing established by the inventors ensures that a node will always wake up before the transmission occurs to ensure that it is ready to detect the preamble properly.

[0169] 20. RANDOMIZATION OF CHANNEL SEQUENCE TO MAXIMIZE CONCURRENCY

[0170] Each channel has associated within it data defining the frequency and the power settings the transceiver is to apply when a transmission occurs over said channel. The inventive wireless core of the inventor’s UWB radio should therefore be provided with an array of channels on which it will operate; that is the channel sequence. Each connection has its own set of configurations for a given channel.

[0171] Within an embodiment of the invention a random channel sequence is generated by the wireless core to reduce the probability of collisions in the frequency domain. The sequence is generated using the PAN ID as the seed and overrides any existing channel sequence, e.g. achannel sequence specified by the user. Other channel properties are maintained when the channel sequence is changed.

[0172] 21. LATENCY OPTIMIZATION MECHANISM BY DELAYING WAKE

[0173] Within this embodiment of the invention the inventors have established a latency optimization algorithm by delaying a wake up of the UWB radio and increasing an enqueue time for the application.

[0174] Within the algorithm when there is a retransmission margin available, there are some timeslots that are not used for transmission nor reception, so the UWB radio wakes up earlier. The UWB radio will then be put to sleep for a longer period of time, because during normal operation, the UWB radio will be put to sleep after the reception or transmission of a frame. Since the UWB radio is inactive for a longer amount of time, it can increase the latency of a packet enqueued before the early radio wake up. To mitigate that, a delay is added to the UWB radio wake up when there is neither transmission nor reception. This ensure that the maximum latency is not increased by that early wake up.

[0175] 22. GAUSSIAN PULSE SEQUENCE

[0176] The inventors have previously established a mechanism for generating Gaussian RF output pulses from square pulses applied to the power amplifier within a UWB transmitter by adjusting the ground of the power amplifier (PA) with a Gaussian profile, see for example WO / 2016 / 191851. However, this can end up requiring that a large current is switched and therefore require large transistor switching elements increasing die footprint. Within first and second Images 3600A and 3600B in Figure 36 the inventors have established an alternate means of generating the Gaussian RF pulses. As depicted in first Image 3600A, the input pulse sequence is converted to a Gaussian pulse sequence at the input of the PA 3670 by shaping the VDD of the Driver Stage 3640 before the PA 3670. This Gaussian sequence is then amplified by the PA, to generate a high-power Gaussian output pulse to the antenna. Here, during the pulse transmission, two signals are applied to the transmitter: the radio frequency (RF) signal and the on-off-keying (OOK) pulse. The generation of the shaped VDD to the Driver Stage 3640 is implemented via Circuit 3650.

[0177] This is achieved, as depicted in second Image 3600B, by the OOK pulses being coupled to Circuit 3650 which comprises a set of Delay Gates 3610 each comprising a Delay 3630 and a Gate 3620 where the Gates 3620 of the set of Delay Gates 3610 are connected to a Summation Output 3660. Accordingly, the Summation Output 3660 receives from the set of Gates 3620 of the set of Delay Gates 3610 a sequence of delayed versions of the OOK pulse at the input to the Circuit 3650 which are summed by the Summation Output 3660 so that theresulting output from the Summation Output 3660 is a step-wise approximation to a Gaussian baseband signal. This Gaussian baseband signal is then used as the VDD of the Driver Stage 3640 (power amplifier driver), as mentioned earlier, to shape the output of the Driver Stage 3640 prior to the PA 3670. For example, each input bit may have a pulse width of 2ns whilst the delay of each Delay 3630 is lOOps for example. The number of Delay Gates 3610 in the set of Delay Gates 3610 and the delay of each Delay 3630 within each Delay Gate 3610 of the set of Delay Gates 3610 may be established in dependence upon the acceptable “digitization” of the step-wise representation of the ideal Gaussian output.

[0178] Within embodiments of the invention the delay of each Delay Gate 3610 in the set of Delay Gates 3610 may be programmable. The delay of Delay Gate 3610 in the set of Delay Gates 3610 may be established in dependence upon the pulse width of the input pulses established by a pulse generator circuit forming part of the UWB transmitter such as described above in respect of Figures 2 to 3B respectively. Accordingly, in contrast to the adjustment of the ground previously disclosed by the inventors the shaping of VDD via Circuit 3650 provides a lower power solution with a low complexity circuit offering, in some implementations, programmable control of the Gaussian profile of VDD applied to the Driver Stage 3640.

[0179] Specific details are given in the above description to provide a thorough understanding of the embodiments. However, it is understood that the embodiments may be practiced without these specific details. For example, circuits may be shown in block diagrams in order not to obscure the embodiments in unnecessary detail. In other instances, well-known circuits, processes, algorithms, structures, and techniques may be shown without unnecessary detail in order to avoid obscuring the embodiments.

[0180] Implementation of the techniques, blocks, steps and means described above may be done in various ways. For example, these techniques, blocks, steps and means may be implemented in hardware, software, or a combination thereof. For a hardware implementation, the processing units may be implemented within one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, other electronic units designed to perform the functions described above and / or a combination thereof.

[0181] The foregoing disclosure of the exemplary embodiments of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many variations and modifications of the embodiments described herein will be apparent to one of ordinary skill in the art in light ofthe above disclosure. The scope of the invention is to be defined only by the claims appended hereto, and by their equivalents.

[0182] Further, in describing representative embodiments of the present invention, the specification may have presented the method and / or process of the present invention as a particular sequence of steps. However, to the extent that the method or process does not rely on the particular order of steps set forth herein, the method or process should not be limited to the particular sequence of steps described. As one of ordinary skill in the art would appreciate, other sequences of steps may be possible. Therefore, the particular order of the steps set forth in the specification should not be constmed as limitations on the claims. In addition, the claims directed to the method and / or process of the present invention should not be limited to the performance of their steps in the order written, and one skilled in the art can readily appreciate that the sequences may be varied and still remain within the spirit and scope of the present invention.

Claims

CLAIMSWhat is claimed is:

1. A method comprising: providing an ultra-wideband (UWB) radio comprising: providing an antenna; providing a transmitter circuit for generating wireless signals for transmission by the antenna; and providing a receiver circuit for receiving and processing other wireless signals received by the antenna.

2. The method according to claim 1, wherein providing the antenna comprises: providing a differential Vivaldi antenna comprising a pair of arms disposed on a first layer of a printed circuit board (PCB) and a ground plane disposed on a second layer of the PCB; and providing a low pass differential filter disposed between the differential Vivaldi antenna and the differential outputs of an ultra-wideband (UWB) radio; wherein the low pass differential filter comprises: a pair of conductors each conductor disposed on the first layer of the PCB and coupled to an output of the differential outputs of the UWB radio at a first end and an arm of the differential Vivaldi antenna at a second distal end; a pair of ground plane slots disposed within another ground plane disposed on a third later of the PCB where each ground plane slot is disposed beneath a conductor of the pair of conductors.

3. The method according to claim 2, wherein the low pass differential filter further comprises a tapered conductor disposed between the pair of conductors on the first layer of the PCB which tapers from a first width at the first end of each conductor to a second width at the second end of each conductor such that a gap between the tapered conductor and a conductor increases along the tapered conductor from the first end of each conductor to the second end of each conductor.

4. The method according to claim 1 , wherein providing the antenna comprises providing an antenna assembly comprising: providing a spiral antenna comprising a pair of spiral conductors each coupled to an input port on a first circuit board where the pair of spiral conductors are disposed on a first side of the first circuit board; providing a reflector comprising a ground plane on a second circuit board disposed at a defined distance from a second side of the first circuit board distal to the first circuit board; and providing an ultra-wideband (UWB) radio having a pair of differential outputs where each differential output of the pair of differential outputs is coupled to a defined spiral conductor of the pair of spiral conductors; wherein the spiral antenna at least one of receives circularly polarized wireless signals which are coupled to the UWB radio and transmits other circularly polarized wireless signals generated by the UWB radio.

5. The method according to claim 4, wherein the defined distance is a quarter wavelength at a defined operating frequency of the spiral antenna.

6. The method according to claim 4, wherein the antenna assembly forms part of a system with another antenna assembly which at least one of transmits the other circularly polarized wireless signals for receipt by the UWB radio within the antenna assembly and receives the circularly polarized wireless signals from the antenna assembly generated by the UWB radio; and the antenna assembly in conjunction with the another antenna assembly form part of a system providing at least one of tracking an individual, asset tracking, access control, collision avoidance and proximity detection.

7. The method according to claim 1, wherein the UWB radio is one of a plurality of UWB radios which form part of a UWB network where each UWB radio operates upon a plurality of channels; the UWB network cycles through the plurality of channels within a defined window cycle time;the channel for a frame to be transmitted by the UWB radio of the plurality of UWB radios is defined by a start time of the channel within the window cycle time; and the power settings of the UWB radio of the plurality of UWB radios are dynamically configured in dependence upon a length of the frame to be transmitted.

8. The method according to claim 7, wherein a channel time index is included within the media access control (MAC) header of each transmitted frame to synchronize the plurality of nodes within the UWB network.

9. The method according to claim 1 , wherein the UWB radio performs a non-coherent (NC) ranging measurement between the UWB radio and another UWB radio; modifying one or more parameters of the UWB radio; performing a Presence Detection (PDK) measurement with respect to a link between the UWB radio and the another UWB radio to establish a received signal strength indication (RSSI) of the link; validating the NC ranging measurement in dependence upon the RSSI of the link based upon a relationship between the distance between the UWB radio and the another UWB radio and the RSSI value.

10. The method according to claim 1, wherein the UWB radio iteratively performs a sequence of: performing a non-coherent (NC) ranging measurement between the UWB radio and another UWB radio; and modifying one or more parameters of the UWB radio to reduce the output power of the UWB radio; and upon establishing failure to establish a link between the UWB radio and the another UWB radio employing the final NC ranging measurement in the last NC ranging measurement when a link was established between the UWB radio and the another UWB radio as the range between the UWB radio and the another UWB radio.

11. The method according to claim 1, wherein the UWB radio is configurable to:communicate via unidirectional links with other UWB radios of a plurality of UWB radios which form part of a UWB network with the UWB radio and all UWB radios operates upon a plurality of channels; and broadcast to the plurality of UWB radios using a defined broadcast address wherein each UWB radio of the plurality of UWB radios within the UWB network are configured to receive the data from the UWB radio upon receipt of encoded data comprising the defined broadcast address.

12. The method according to claim 11 , wherein the defined broadcast address is 255 or OXFF in hexadecimal.

13. The method according to claim 1, wherein the UWB radio upon having no data to transmit generates a synchronization packet containing solely the information required for the UWB radio to maintain synchronization.

14. The method according to claim 1, wherein the UWB radio is configured to execute a fallback mechanism upon detection of a degradation in link quality; the fallback mechanism adjusts an output power of the transmitter circuit in dependence upon a threshold of a number of thresholds each of which is based upon a payload size of data being transmitted by the UWB radio such that the output power of the transmitter circuit is increased as the pay load size decreases.

15. The method according to claim 14, wherein each threshold of the number of thresholds is at least one of: established through one or more machine learning algorithms; and initially established by at least one of an automatic configuration of the UWB radio and configured by a user of the UWB radio and subsequently varied through one or more machine learning algorithms.

16. The method according to claim 1, wherein the UWB radio upon detection of inactivity with respect to a connection between the UWB radio and another UWB radio executes a link throttle mechanism; andthe link throttle mechanism disables some of the timeslots allocated for the connection such that the UWB radio is powered down into a sleep mode for an increased period of time.

17. The method according to claim 1, wherein the UWB radio upon detection of inactivity with respect to a connection between the UWB radio and another UWB radio executes a link throttle mechanism each time a timeslot for the connection occurs; and the link throttle mechanism comprises: determining whether a Boolean value for a current index within a generated array is false; upon determining the Boolean value for the current index is false the UWB sleeps over the timeslot; and incrementing the index; and the generated array is populated according to a throttling percentage to be applied.

18. The method according to claim 1, wherein the UWB radio executes a synchronization protocol comprising: establishing a waiting time between a wake up of the UWB radio and detection of a synchronization word from another UWB radio received by the UWB radio; establishing a time offset between the established waiting time and a target time; and adding the time offset to a time for the next time slot for the UWB radio to wake up.

19. The method according to claim 1, wherein the UWB radio operates upon a channel of a number of channels where each channel has associated with it data defining the frequency of the channel and a power setting of the channel; and the channel sequence of the UWB radio is randomly generated using an identity of a personal area network comprising the UWB radio as a seed for the random channel sequence generation.

20. The method according to claim 1, wherein providing the transmitter circuit comprises providing a serially connected set of delay gates; whereineach delay gate comprises a delay element providing a defined time delay of a signal to the next delay gate in the serially connected set of delay gates and a gate connecting an input signal at that delay gate of the serially connected set of delay gates to a summation circuit; and an output of the summation circuit is a summation of the signals from the gates of the serially connected set of delay gates which due to the time delay inducted between each serially connected pair of delay gates is a step wise approximation of a Gaussian output signal for each input pulse connected to the serially connected set of delay gates.

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