Radio frequency motion sensors may be configured for operation in a common vicinity so as to reduce interference. In some versions, interference may be reduced by timing and/or frequency synchronization. In some versions, a master radio frequency motion sensor may transmit a first radio frequency (RF) signal. A slave radio frequency motion sensor may determine a second radio frequency signal which minimizes interference with the first RF frequency. In some versions, interference may be reduced with additional transmission adjustments such as pulse width reduction or frequency and/or timing dithering differences. In some versions, apparatus may be configured with multiple sensors in a configuration to emit the radio frequency signals in different directions to mitigate interference between emitted pulses from the radio frequency motion sensors.

A radar detection system that estimates the received pulse frequency of a pulse in a received radar signal using a signal transmit frequency or one that uses frequency agility during a pulse duration. The radar detector system may include a radar detector that receives the radar signal from an antenna or antenna array. The receiver may be channelized, and each channel path may include Gaussian bandpass filter(s) centered at a different frequencies. The system includes an extended range radar detector that receives the signal in the channels and processing logic that processes the detected channel signals to identify the pulse frequency of emitters with or without frequency agility during a pulse duration. The frequency estimates of the pulse are based on calibrated amplitude differences in adjacent channels.

A radar method is described herein. In accordance with one embodiment the method includes receiving a plurality of chirp echoes of transmitted radar signals, generating a digital signal based on the plurality of chirp echoes, and calculating a range map based on the digital signal. The range map includes a plurality of values, each value is represented by an amplitude value and a phase value, and each value is associated with one frequency bin of a set of frequency bins and one chirp echo of the plurality of chirp echoes. The method further includes identifying chirp echoes which are affected by interference and determining, for one or more selected frequency bins, corrected phase values based on phase values that are associated with chirp echoes not identified as affected by interference.

A radar method is described herein. In accordance with one embodiment the method includes receiving a plurality of chirp echoes of transmitted radar signals, generating a digital signal based on the plurality of chirp echoes, and calculating a range map based on the digital signal. The range map includes a plurality of values, each value is represented by an amplitude value and a phase value, and each value is associated with one frequency bin of a set of frequency bins and one chirp echo of the plurality of chirp echoes. The method further includes identifying chirp echoes which are affected by interference and determining, for one or more selected frequency bins, corrected phase values based on phase values that are associated with chirp echoes not identified as affected by interference.

A method for providing control of surface waves propagating on a surface includes forming a surface treatment on the surface, wherein the surface treatment is configured to achieve a tensor surface admittance distribution matrix on the surface determined according to a modified transformation electromagnetics (tEM) equation.

A method for providing control of surface waves propagating on a surface includes forming a surface treatment on the surface, wherein the surface treatment is configured to achieve a tensor surface admittance distribution matrix on the surface determined according to a modified transformation electromagnetics (tEM) equation.

The present disclosure is directed to scanning radar reflector systems, methods, and apparatuses; even more particularly to a system, method, and apparatus for scanning and reflecting a radar beam transmitted by a radar transmitter onboard an aerial vehicle with radar reflectors equipped on unmanned aerial vehicles. The radar reflection system may include one or more unmanned aerial vehicles equipped with a one or more axis gimbal upon which a radar reflector is mounted. A user may position the unmanned aerial vehicle and the radar reflector to target a specific region for radar scanning.

A radar pulse generator includes a multiplexer, a polyphase synthesizer, a first signal channel and a second signal channel. The multiplexer has a baseband radar pulse input, a multiplexer control input, a first channel output and a second channel output. The baseband radar pulse input signal is a single channel baseband radar pulse signal. The multiplexer control input signal selects one of the group consisting of the first channel output and the second channel output. The polyphase synthesizer synthesizes the first channel output signal, synthesizes the second channel output signal and outputs a desired radar pulse signal based on the synthesized first channel output signal and the synthesized second channel output signal. The first signal channel provides the first channel output signal from the first channel output to the polyphase synthesizer. The second signal channel provides the second channel output signal from the second channel output to the polyphase synthesizer.

A system comprising a hemispherical array antenna having a plurality of antenna elements comprising a set of baseline antenna elements arranged in a first 360 circular antenna array, a set of upper antenna elements arranged in a second 360 circular antenna array and latitudinally aligned with the baseline antenna elements, and a set of lower antenna elements arranged in a third 360 circular antenna array and latitudinally aligned with the baseline antenna elements. The system includes a fleet base station including a plurality of non-shared receiver channels coupled to and dedicated to a particular antenna element. The base station is configured to provide 360 of transmission/reception from horizon to zenith using the antenna elements for command and control fleet communications to and from mobile devices and to provide secondary radar functions using the fleet communications to track the mobile devices based on received signal characteristics received at the antenna elements.

A system comprising a hemispherical array antenna having a plurality of antenna elements comprising a set of baseline antenna elements arranged in a first 360 circular antenna array, a set of upper antenna elements arranged in a second 360 circular antenna array and latitudinally aligned with the baseline antenna elements, and a set of lower antenna elements arranged in a third 360 circular antenna array and latitudinally aligned with the baseline antenna elements. The system includes a fleet base station including a plurality of non-shared receiver channels coupled to and dedicated to a particular antenna element. The base station is configured to provide 360 of transmission/reception from horizon to zenith using the antenna elements for command and control fleet communications to and from mobile devices and to provide secondary radar functions using the fleet communications to track the mobile devices based on received signal characteristics received at the antenna elements.