摘要:
A mainlobe detection process can include a number of tests that are performed to define when the monopulse antenna system will transition from open loop scanning to closed loop scanning and then to tracking. A hybrid tracking technique is also provided which adaptively discovers and corrects for phase alignment error. Magnitude-only tracking can be performed initially to locate the nulls in the azimuth and elevation ratios and to identify the magnitudes of these ratios at these nulls. Phase tracking can be then performed. During phase tracking, phase corrections can be repeatedly applied to the azimuth and elevation difference channels to correct any phase error that may exist. During this process, the magnitudes of the ratios can be used to determine how the phase corrections should be adjusted. Once the hybrid tracking process is complete, the monopulse antenna system is properly phase-aligned and phase tracking will be correctly employed.
摘要:
A transmit signal can be distorted with non-linear distortion, and one or more characteristics of the non-linear distortion can be periodically changed in accordance with a change key. The transmission received at a receiver can thus comprise a severely distorted version of the transmission of the transmit signal. A receiver with the same change key can recognize and decode the transmission, but it can be extraordinarily difficult for receivers that lack the change key to detect and decode the transmission. The transmission can be a communications while jamming (CWJ) transmission. The CWJ transmission can contain a coded message that can be decoded only by friendly RF receivers, and the CWJ transmission can also jam unfriendly RF receivers that lack a change key for decoding the coded message.
摘要:
A transmitter or receiver can include a phased array antenna system in which multiple characteristics of a transmitted or received beam can be controlled electronically. For example, in embodiments that include a transmitter, dual outputs of N signal modifiers can be connected to orthogonal inputs of N dual-orthogonally polarized antenna elements. Each signal modifier can modify the amplitude and phase of a communications signal in two parallel signal paths to produce two signal components each of which is an amplitude-modified/phase-shifted version of the communication signal. Multiple characteristics of the combined beam can be simultaneously controlled by setting the amplitude and/or phase-shift parameter values in the dual signal paths in the signal modifiers to combined values that individually affect each of the multiple characteristics of the combined beam.
摘要:
An antenna system can impart orbital angular momentum (OAM) to an incident electromagnetic (EM) signal from a feed antenna. The antenna system can include a partial OAM antenna with a reflective surface that has only part of a full OAM shaped surface. The antenna system can thus reflect the incident EM signal as a partial OAM beam rather than a full OAM beam.
摘要:
A method for conditioning a network based encoded video stream including receiving the video stream over an RF data link, detecting any missing and/or corrupted data within the data stream, and inserting curative data in place of the missing or corrupted data. A system and method for transmitting a real-time video stream to an end-user at least partially over an RF data link including the video conditioner wherein a camera obtains video footage, an encoder to compresses the video stream, an RF transmitter transmits the encoded video stream over an RF data link, and an RF receiver to receives the encoded video stream from the RF transmitter. The video stream is conditioned by the video conditioner and routed to an end user through a computer network wherein a decoder decodes the encoded video stream and the video stream is viewed on a display.
摘要:
An LDPC decoder includes a check node processor. The check node processor is configured to implement an n-degree check node, where n is a predetermined number. The degree of a check node is the number of edges coupled to the check node. The LDPC decoder also includes a plurality of n time division multiplexers coupled to the check node processor to couple different edge connection input values to the check node processor at different times so as to allow the check node processor to be time division multiplexed for use in implementing different check nodes with the same check node processor. Each of the multiplexers is configured to provide no more than one edge connection input value to the check node processor at any given time. Each edge connection is used to implement an edge into a check node.
摘要:
Electromagnetic (EM) feeds can illuminate a standard primary reflective antenna with a plurality of feed beams each having a different orbital angular momentum (OAM) or polarization. The reflective antenna, which can be a non-OAM antenna, can reflect the feed beams and thereby produce a composite OAM transmission comprising each of the feed beams. A non-OAM primary antenna can thus transmit a plurality of OAM feed beams as a composite OAM transmission.
摘要:
An electronic assembly can include a support structure, a circuit substrate coupled to a first portion of the support structure, and a composite material panel coupled to a second portion of the support structure. An electronic device can be coupled to a mounting surface of the circuit substrate and disposed within a space enclosed by walls of the support structure. The panel can include contiguous sections inner surfaces of which can be oriented within twenty-five degrees of parallel to said mounting surface. Each section can be significantly more thermally conductive generally parallel to the inner surface of the section than generally perpendicular to the inner surface.
摘要:
The present invention is generally directed to using code division multiplexing (CDM) on the beacon and traffic channels while lowering the power of the beacon channel so that it rides under the traffic channel and becomes very difficult to detect. In this way, the beacon channel can contain sensitive information for decoding the traffic channel while remaining hidden from unintended recipients. By hiding the beacon channel, the CDM technique can be particularly beneficial in adaptive waveform systems where sensitive traffic channel acquisition information is regularly transmitted to the receiver.
摘要:
A phase shifting component of a waveguide comparator subsystem can effect a relative phase shift that advances an input signal A relative to an input signal B. A comparator component can then split those signals such that a first part of signal A and a second part of signal B are combined at a difference port, and a first part of signal B and a second part of signal A are combined at a sum port. The comparator can delay the phase of the second parts of the signals such that, with the relative phase shift of the phase shifting component, the first part of signal A and the second part of signal B are one-hundred eighty degrees (180°) out of phase at the difference port, and the second part of signal A and the first part of signal B are in phase at the sum port.