191 results about "True time delay" patented technology

A method for determining a process variable of a product in a tank based on a time delay of electromagnetic waves. The method further comprises forming a measurement signal comprising a sequence of values, each value representing a time correlation between a pulse of a reference signal and a reflected signal, sampling and digitizing this measurement signal to form a digital signal, identifying a time window of the digital signal including the surface echo peak, determining a relative time period between a reference time corresponding to the predefined reference and a beginning of the time window, time-to-frequency transforming the digital signal in the time window to obtain a phase spectrum, determining a relative phase shift of the spectrum and using the relative phase shift to calculate a corresponding time shift, and determining the time delay by adding the relative time period and the time shift.The invention is based on the realization that major improvement of measurement performance, compared to amplitude detection only, can be achieved by discrimination of the phase difference between the reflected signal and a reference. The detection is further independent of the pulse waveform and modulation, significantly reducing the requirements on pulse modulation.

The present invention concerns methods and apparatus for implementing a true-time-delay wideband digital beamformer. In true-time-delay wideband digital beamformers of the present invention, improved control over beam properties formed by the combination of the beamformer and a multi-element antenna coupled to the beamformer is achieved through finer control of delays imparted to data signals. In beamformers of the present invention, data is delayed using a coarse control that provides a delay in whole increments of a clock cycle of a digital clock reference and a fine control that provides a delay corresponding to a fraction of a whole clock cycle of the digital clock reference. In the true time delay method of the present invention, transmission and reception across a wide frequency band is accommodated. In the true time delay method of the present invention, multiple simultaneous beams are formed independently, beam-to-beam, across a wide frequency band.

A nano-optomechanical transducer provides ultrabroadband coherent optomechanical transduction based on Mach-wave emission that uses enhanced photon-phonon coupling efficiencies by low impedance effective phononic medium, both electrostriction and radiation pressure to boost and tailor optomechanical forces, and highly dispersive electromagnetic modes that amplify both electrostriction and radiation pressure. The optomechanical transducer provides a large operating bandwidth and high efficiency while simultaneously having a small size and minimal power consumption, enabling a host of transformative phonon and signal processing capabilities. These capabilities include optomechanical transduction via pulsed phonon emission and up-conversion, broadband stimulated phonon emission and amplification, picosecond pulsed phonon lasers, broadband phononic modulators, and ultrahigh bandwidth true time delay and signal processing technologies.

Optical variable delay devices for providing variable true time delay to multiple optical beams simultaneously. A ladder-structured variable delay device comprises multiple basic building blocks stacked on top of each other resembling a ladder. Each basic building block has two polarization beamsplitters and a polarization rotator array arranged to form a trihedron; Controlling an array element of the polarization rotator array causes a beam passing through the array element either going up to a basic building block above it or reflect back towards a block below it. The beams going higher on the “ladder” experience longer optical path delay. An index-switched optical variable delay device comprises of many birefringent crystal segments connected with one another, with a polarization rotator array sandwiched between any two adjacent crystal segments. An array element in the polarization rotator array controls the polarization state of a beam passing through the element, causing the beam experience different refractive indices or path delays in the following crystal segment. By independently control each element in each polarization rotator array, variable optical path delays of each beam can be achieved. Finally, an index-switched variable delay device and a ladder-structured variable device are cascaded to form a new device which combines the advantages of the two individual devices. This programmable optic device has the properties of high packing density, low loss, easy fabrication, and virtually infinite bandwidth. The device is inherently two dimensional and has a packing density exceeding 25 lines / cm2. The delay resolution of the device is on the order of a femtosecond (one micron in space) and the total delay exceeds 10 nanosecond. In addition, the delay is reversible so that the same delay device can be used for both antenna transmitting and receiving.

The present invention provides a method and apparatus for a monolithic device utilizing cascaded, switchable slow-wave CPW sections that are integrated along the length of a planar transmission line. The purpose of the switchable slow-wave CPW sections elements is to enable control of the propagation constant along the transmission line while maintaining a quasi-constant characteristic impedance. The device can be used to produce true time delay phase shifting components in which large amounts of time delay can be achieved without significant variation in the effective characteristic impedance of the transmission line, and thus also the input / output return loss of the component. Additionally, for a particular value of return loss, greater time delay per unit length can be achieved in comparison to tunable capacitance-only delay components.

A true time delay (“TTD”) system with wideband passive amplitude compensation is provided. The TTD system includes an input switch, an output switch, a reference delay line disposed between the input switch and the output switch, and time delay lines disposed between the input switch and the output switch. Each time delay line (“TDL”) has a different line length, and includes a center conductor between two corresponding ground planes. Each center conductor has a width and is separated from the two corresponding ground planes by a gap space. For each TDL, the width of the center conductor is configured such that a loss of the TDL is substantially the same as a loss of every other TDL over a range of operating frequencies. For each TDL, the gap space is configured such that an impedance of the TDL is substantially the same as an impedance of every other TDL.

The invention provides a method for using an SDH optical transmission system to realize high-accuracy time synchronization and a time delay measuring device thereof. The method and the time delay measuring device overcome the defect of inaccurate transmission time delay measurement in a traditional method, realize the automatic accurate measurement of the transmission delay of a time signal and use the high-accuracy time delay measurement value to modify the phase of the time signal, thus realizing the high-accuracy time synchronization. Proved by experimental result, on two SDH network elements connected by a 50-kilometer optical fiber, the invention can be adopted to automatically measure the time relay of a transmission link and modify the phase of the time signal, and the time synchronization error is more accurate than 10ns, manual presetting of a time delay compensation value is not needed. Therefore, the method is greatly superior to the traditional method.

Local oscillator circuitry for an antenna array is disclosed. The circuitry includes an array of rotary traveling wave oscillators which are arranged in a pattern over an area and coupled so as to make them coherent. This provides for a set of phase synchronous local oscillators distributed over a large area. The array also includes a plurality of phase shifters each of which is connected to one of the rotary oscillators to provide a phase shifted local oscillator for the array. The phase shifter optionally includes a cycle counter that is configured to count cycles of the rotary oscillator to which it is connected and control circuitry that is then operative to provide a shifted rotary oscillator output based on the count from the cycle counter.

The invention relates to a radio-over-fibre beamforming device based on an array waveguide grating (AWG) and a method thereof. Radio-frequency signals are modulated onto carriers of multiple wavelengths, and processed by a programmable optical true time delay module in an optical domain; the module is composed of an optical switch and multiple cascade AWGs capable of providing different basic delays between adjacent wavelength channels; the basic delay amounts of different-level AWGs are in geometric distribution by taking 2 as the common ratio; optical carriers different in wavelength enter different branches to perform photoelectric conversion, so that radio-frequency signals different in delay (phase) are recovered; and thus, a far-field beam directional radiation mode is realized. Theradio-over-fibre beamforming device based on the AWG and the method thereof disclosed by the invention have the characteristics of being wide in band, adjustable, flexible, small in volume, easy to integrate and the like, and are very importantly applied in dynamic scenes, such as next generation mobile communication and high-speed railways.

It is an object of the present invention a photonic system to perform beamforming of a radio signal received by a phased array antenna with N antenna elements. It provides true-time delay beamforming enabled by tunable optical delay lines (6) with a periodic frequency response.The present invention provides four key advantages: photonic RF phase shifting; highly-sensitive coherent detection with intrinsic photonic frequency downconversion; phase noise cancellation, since a frequency-shifted optical local oscillator can be derived from a same laser source (1) used to feed electro-optic modulators (5); and the possibility of only requiring a single delay line, shared amongst all tunable optical delay lines. Such set of advantages makes the proposed system extremely attractive for high-end wireless receivers, required for demanding applications such as satellite communication systems and broadband wireless signal transmission.