Ziva Corporation | Date: 2016-09-29
Distributed cooperating nodes of a cluster are used for communications, object location, and other purposes. The nodes can move relative to each other and an intended receiver. The nodes are synchronized and data for transmission from the cluster is distributed to the nodes. The intended receiver sends a sounding signal to the nodes. Each node receives the sounding signal, obtains the channel response between the intended receiver and the node, and time-reverses the channel response. Each node convolves its time-reversed channel response with the data to obtain the nodes convolved data. A master node sends a time reference signal to the other nodes. Each node waits a predetermined time following the time reference signal, as determined based on a common time reference. At the expiration of the predetermined time period, the nodes simultaneously transmit their convolved data. The transmissions from the nodes combine coherently in time-space at the intended receiver.
Ziva Corporation | Date: 2016-09-27
In examples, two arrays of Radio Frequency nodes achieve enhanced beamforming for communications between the arrays by successively sending sounding signals from one array to the other array. Each sounding signal sent by the first of the two arrays is beamformed through time reversal of an immediately preceding sounding signal received by the first array from the second array, and each sounding signal (except the initial sounding signal) sent by the second array is beamformed through time reversal of an immediately preceding sounding signal received by the second array from the first array. The initial sounding signal sent by the second array may be omnidirectional, beamformed through a guesstimate, random, predetermined, or determined through a search of the area where the arrays are located. With sufficient beamfocusing, the arrays may communicate by sending and receiving data from one array to the other array.
Ziva Corporation | Date: 2016-08-15
In selected embodiments, a process of geolocation of a transmitter uses a receiver with an antenna array that is non-line-of-sight (NLoS) to the transmitter. A first plurality of scatterers within line-of-sight (LoS) of the array is located using multilateration based on time difference of arrival (TDoA) from the first scatterers, and applying a spatial consistency requirement. Time of emission/reflection from the first scatterers is also determined. The coordinates and timing of the first scatterers are used to locate either the transmitter or another set of scatterers, by applying multilateration to the TDoA at the first scatterers, and applying the spatial consistency requirement. The process is iteratively repeated until the transmitter is identified. The multilateration may be linearized without sacrificing precision. In each iteration, a non-singularity requirement is applied to ensure that the selected scatterers produce unambiguous results.
Ziva Corporation | Date: 2016-12-09
Dynamic, untethered array nodes are frequency, phase, and time aligned, and used to focus their transmissions of the same data coherently on a target, using time reversal. Alignment may be achieved separately for the radio frequency (RF) carriers and the data envelopes. Carrier alignment may be by phase conjugation. The data is distributed across the nodes. Data distribution and/or alignment may be performed by a Master node of the array. The nodes capture a sounding signal from the target, in the same time window. Each node converts the captured sounding signal to baseband, for example, using in-phase/quadrature downconversion. Each node stores the baseband samples of the sounding pulse. Each node convolves time-reversed samples of the sounding signal with the data, and upconverts the convolved data to radio frequency. The nodes emit their respective convolved and upconverted data so that the emissions focus coherently at the target.
Ziva Corporation | Date: 2016-04-12
A plasmonic waveguide structure with highly confined field and low propagation loss is disclosed. In selected embodiments, the structure has a sub-wavelength size dielectric core surrounded by stacks. Each stack includes multiple repeating, alternating metal layers and dielectric layers. The stacks operate in bandgap condition to render a highly-confined and low propagation loss waveguide structures that can be made using commercially available fabrication techniques.
Agency: Department of Defense | Branch: Defense Advanced Research Projects Agency | Program: SBIR | Phase: Phase II | Award Amount: 1.50M | Year: 2014
Through the combined development of advanced waveguide architectures and meta-material synthesis techniques, Zivas approach to meta- plasmonic interconnects promises to provide low loss photonic waveguides and devices with sizes comparable to electronic wires and circuitslight on a wire. Zivas novel plasmonic waveguide architectures addresses the loss limitation of highly confined plasmonic waveguides by enhancing the performance of conventional MIM-plasmonic waveguides through implementation of a synthesized meta-material cladding surrounding the dielectric wave-guiding core of the structure. This idealized metal cladding (IMC)-MIM waveguide architecture promises to enable a new generation of passive and high speed active optical devices on a scale compatible with the size of electronics at the chip level. Meta-plasmonics enabled interconnects provide a perfect synthesis between conventional electronic and optical interconnect technologies where electronic waves are harnessed at optical frequencies. Zivas IMC-MIM architecture is scalable and capable of simultaneously supporting waveguide pitches ~100nm and ~10dB/cm propagation loss requirements of next generation interconnect applications. This technique promises to have a revolutionary impact to computation, communications, nano-scale interconnects, imaging, and sensing.
Ziva Corporation | Date: 2016-07-22
In examples, Radio Frequency Iterative Time-Reversal (RF-ITR) and singular value decomposition (SVD) are used by an array of nodes to characterize environment by identifying scatterer objects. The array may be ad hoc dynamic or stationary. The environment is cancelled from the RF-ITR by adjusting Time-Reversal (TR) prefilters, reducing illumination of the scatterer objects in the environment. This enables the RF-ITR process to focus on a moving target, which can then be sensed (discovered, identified, monitoring, tracked, and/or imaged). The moving target on which the RF-ITR process focuses may then be cancelled from the RF-ITR in the same way as the environment, allowing the RF-ITR to focus on another target. Multiple moving targets can thus be sensed. Defensive measures such as jamming may then be taken against the targets. ii The targets may be distinguished from the scatterer objects in the environment through differential, Doppler processing, and other classification techniques.
Ziva Corporation | Date: 2015-10-27
Methods, apparatus, and articles of manufacture make Geolocation of a source transmitter more difficult or impossible. Scatterers common to a source transmitter and an intended receiver are identified using a variety of techniques, such as iterative time reversal (ITR) and Singular Value Decomposition (SVD) of a scatter matrix. The source transmitter then uses time reversal and knowledge of the signatures of the scatterers to focus its transmissions on one or more of the scatterers, instead of the intended receiver. The source transmitter may have multiple antennas or antenna elements. The source transmitter and/or the intended receiver may include antenna elements with Near-Field Scatterers to enable spatial focusing below the diffraction limit at the frequencies of interest. The source transmitter may be a plurality of ad hoc nodes cooperating with each other.
Ziva Corporation | Date: 2015-03-25
Dynamic, untethered array nodes are frequency, phase, and time aligned/synchronized, and used to focus their transmissions of the same data coherently on a target or in the targets direction, using time reversal or directional beamforming. Information for alignment/synchronization may be sent from a master node of the array to other nodes, over non-RF links, such as optical and acoustic links. Some nodes may be connected directly to the master nodes, while other nodes may be connected to the master node through one or more transit nodes. A transit nodes may operate to (2) terminate the link when the alignment/synchronization information is intended for the node, and (2) pass through the alignment/synchronization information to another node without imposing its local clock properties on the passed through alignment/synchronization information. In this way, an end point node may be aligned/synchronized to the master node without a direct link between the two nodes.
Ziva Corporation | Date: 2015-03-23
Techniques, apparatus and systems for providing radio frequency wireless communications based on time reversal of the channel impulse response of an RF pulse in a transmission channel between an RF transmitter and an RF receiver to enhance reception and detection of an RF pulse at the RF receiver against various effects that can adversely affect and complicate the reception and detection of the RF pulse at the RF receiver.