Abstract: A system for testing a device-under-test (DUT) over-the air (OTA) includes a probe antenna, an azimuth positioner, a linear positioner and a roll positioner. The probe antenna measures radiated fields from the DUT and emits radiated fields to the DUT by illuminating active antenna elements of the DUT. The azimuth positioner rotates the DUT in a first plane about an azimuth axis. The linear positioner drives the DUT linearly along a first Y-axis in a second plane orthogonal to the first plane and drives the DUT linearly along a second X-axis perpendicular to the first Y-axis in the second plane to stay within a quiet zone of the system. The roll positioner is provided between the second plane and the azimuth positioner and is configured to rotate the DUT about a roll axis orthogonal to the azimuth axis.

Abstract: A miniature radar target simulator (MRTS) and a system comprising a plurality of MRTS's are described. The MRTS and system are useful for emulating echo signals for a radar DUT with reduced interference. Illustrative radar test systems desirably generate the intended (emulated) radar targets and reduce unwanted (“ghost”) signals, which can result in “ghost targets,” and errant/ambient electromagnetic radiation that reduces the performance and reliability of known re-illuminators and systems including same.

Abstract: A system is provided for characterizing a device under test (DUT) including an integrated antenna array. The system includes an optical subsystem having first and second focal planes, where the integrated antenna array is positioned in a beam overlap region extending from the first focal plane of the optical subsystem. The system further includes a measurement array having multiple array elements positioned substantially on the second focal plane of the optical subsystem, the measurement array being configured to receive signals from the DUT, and/or to transmit substantially collimated beams to the DUT, via the optical subsystem. Far-field characteristics of the DUT are measured, as well as angular dependence of each of the far-field characteristics.

Abstract: A system and method are provided for emulating echo signals using test equipment, including an antenna and an I/Q mixer, in response to a radar signal transmitted by a radar under test. The method includes receiving the radar signal from the radar under test, where a reflection component of the radar signal is reflected from at least the antenna; mixing the received radar signal as a local oscillator (LO) signal with I and Q signals at the I/Q mixer to output a mixing product as a radio frequency (RF) signal, where a leakage component of the LO signal leaks through the I/Q mixer; substantially canceling the reflection component of the radar signal using the leakage component of the LO signal; and transmitting the RF signal as the emulated echo signal to the radar under test, wherein the emulated echo signal indicates at least a range to the emulated target.

Abstract: A miniature radar target simulator (MRTS) and a system comprising a plurality of MRTS's are described. The MRTS and system are useful for emulating echo signals for a radar DUT with reduced interference. Illustrative radar test systems desirably generate the intended (emulated) radar targets and reduce unwanted (“ghost”) signals, which can result in “ghost targets,” and errant/ambient electromagnetic radiation that reduces the performance and reliability of known re-illuminators and systems including same.

Abstract: A system and method are provided for emulating echo signals using test equipment, including an antenna and an I/Q mixer, in response to a radar signal transmitted by a radar under test. The method includes receiving the radar signal from the radar under test, where a reflection component of the radar signal is reflected from at least the antenna; mixing the received radar signal as a local oscillator (LO) signal with I and Q signals at the I/Q mixer to output a mixing product as a radio frequency (RF) signal, where a leakage component of the LO signal leaks through the I/Q mixer; substantially canceling the reflection component of the radar signal using the leakage component of the LO signal; and transmitting the RF signal as the emulated echo signal to the radar under test, wherein the emulated echo signal indicates at least a range to the emulated target.

Abstract: A system for testing vehicular radar is disclosed. The system includes a re-illumination element adapted to receive electromagnetic waves, and to transmit response signals. The re-illumination element includes: a plurality of miniature radar target simulators (MRTS's), each comprising: a receive antenna; a variable gain amplifier (VGA); an in-phase-quadrature (IQ) mixer; a variable attenuator; and a transmit antenna. The MRTS's are disposed in an array comprising rows and columns of the MRTS's, and each MRTS of the array is laterally spaced a distance px and vertically spaced a distance py from an adjacent MRTS. An incremental subtended azimuth angle (??) and an incremental subtended elevation (??) angle are finer than an azimuth resolution specification (?res) and an elevation resolution specification (?res) of a radar device under test (DUT).

Abstract: Illustrative embodiments disclosed herein pertain to a thermal imaging system that includes a thermal imaging sheet having an array of thermal unit cells for generating a thermal footprint in response to receiving an RF signal. The thermal footprint is composed of an array of hotspots having a first set of hotspots indicative of a radiation characteristic of a first polarization component of the RF signal, and a second set of hotspots indicative of a radiation characteristic of a second polarization component of the RF signal. Each thermal unit cell includes a first RF antenna and a second RF antenna oriented orthogonal with respect to each other. The first RF antenna includes a terminating resistor that generates a hotspot among the first set of hotspots and the second RF antenna includes another terminating resistor that generates a hotspot in the second set of hotspots.

Abstract: Various illustrative embodiments disclosed herein generally pertain to detecting defects by using a radio-frequency debugging signal transmitted by a transmitting antenna array towards a receiving antenna located in a far-field region of the transmitting antenna array. The radio-frequency debugging signal, which is configured to provide information pertaining to a signal radiation distribution of the transmitting antenna array, is received in the receiving antenna and conveyed to a test unit. The test unit digitizes the received radio-frequency debugging signal to obtain a digital dataset and applies a back-propagation algorithm to the digital dataset for deriving a reconstructed near-field representation of the transmitting array.

Abstract: Illustrative embodiments disclosed herein pertain to a thermal imaging system that includes a thermal imaging sheet having an array of thermal unit cells for generating a thermal footprint in response to receiving an RF signal. The thermal footprint is composed of an array of hotspots having a first set of hotspots indicative of a radiation characteristic of a first polarization component of the RF signal, and a second set of hotspots indicative of a radiation characteristic of a second polarization component of the RF signal. Each thermal unit cell includes a first RF antenna and a second RF antenna oriented orthogonal with respect to each other. The first RF antenna includes a terminating resistor that generates a hotspot among the first set of hotspots and the second RF antenna includes another terminating resistor that generates a hotspot in the second set of hotspots.

Abstract: A system is provided for characterizing a device under test (DUT) including an integrated antenna array. The system includes an optical subsystem having first and second focal planes, where the integrated antenna array is positioned in a beam overlap region extending from the first focal plane of the optical subsystem. The system further includes a measurement array having multiple array elements positioned substantially on the second focal plane of the optical subsystem, the measurement array being configured to receive signals from the DUT, and/or to transmit substantially collimated beams to the DUT, via the optical subsystem. Far-field characteristics of the DUT are measured, as well as angular dependence of each of the far-field characteristics.

Abstract: Various illustrative embodiments disclosed herein generally pertain to detecting defects by using a radio-frequency debugging signal transmitted by a transmitting antenna array towards a receiving antenna located in a far-field region of the transmitting antenna array. The radio-frequency debugging signal, which is configured to provide information pertaining to a signal radiation distribution of the transmitting antenna array, is received in the receiving antenna and conveyed to a test unit. The test unit digitizes the received radio-frequency debugging signal to obtain a digital dataset and applies a back-propagation algorithm to the digital dataset for deriving a reconstructed near-field representation of the transmitting array.

Abstract: A method determines far field EVM of a DUT using over-the-air (OTA) testing, the DUT having a transmitter/receiver and an antenna that are integrated together such that there is no connection port for interfacing a test system for directly measuring the EVM. Modulated RF signals transmitted by the DUT propagate OTA via the antenna. The method includes performing a near field scan of a bounded radiation surface, which includes measurement points at which waveforms of a repeatedly transmitted modulated RF signal are measured; downconverting the waveforms to intermediate frequency (IF), and digitizing the IF waveforms; synthesizing digital waveforms corresponding to the IF waveforms; accounting for corresponding RF propagation in the far field for the digital waveforms; providing a modulated digital IF waveform using the digital waveforms for which RF propagation has been accounted; and calculating EVM of the DUT in the far field using the modulated digital IF waveform.

Abstract: A system is provided for characterizing a device under test (DUT) including an integrated antenna array. The system includes an optical subsystem having first and second focal planes, where the integrated antenna array is positioned substantially on the first focal plane of the optical subsystem. The system further includes a measurement array having one or more array elements positioned substantially on the second focal plane of the optical subsystem, the measurement array being configured to receive signals transmitted from the integrated antenna array via the optical subsystem. A far-field radiation pattern of the integrated antenna array is created at the measurement array, enabling measurements of DUT parameters at each array element of the one or more array elements in the measurement array.

Abstract: A tunable laser comprises a first tuner configured to select an emission wavelength of the laser; a second tuner configured to adjust a cavity mode of the laser by modifying the cavity optical path length. The second tuner is constrained by a finite tuning range. The tunable laser also comprises a controller configured to control the first and second tuners to select the emission wavelength and adjust the cavity mode in synchronization to perform phase-continuous tuning across a range larger than supported by the finite tuning range of the second tuner.

Abstract: A system for measuring a property of a device under test (DUT) includes a stimulus signal generator and a receiver. The stimulus signal generator generates a repetitive stimulus signal under control of a first clock, and provides the stimulus signal to an input port of the DUT. The receiver receives an input signal output from the DUT, the input signal being based on the stimulus signal provided to the input port of the DUT. The receiver includes a second clock syntonized with the first clock, a memory that stores a calibration measurement of a calibration stimulus signal provided to the receiver during a calibration period without the DUT being connected to the stimulus signal generator, and a data processor configured to determine the property of the DUT by comparing the stored calibration measurement with a measurement of the input signal from the DUT performed under control of the second clock.

Abstract: An apparatus adapted for measuring the properties of periodic signals and a method for making such measurements is disclosed. The apparatus includes a LO signal generator, a mixer, a low pass filter and an output device. The LO signal generator generates an LO signal comprising a fundamental frequency ?LO and one or more higher harmonics with arbitrary amplitudes and phases. The mixer receives a periodic input signal having harmonics including a highest harmonic of interest, N, and a fundamental frequency, ?in. The mixer outputs an IF signal that is filtered. The filtered IF signal includes a frequency-compressed signal having M harmonics including a fundamental characterized by a frequency ?c<?in. Each of the harmonics in the frequency-compressed signal corresponds to one of the harmonics in the input signal and has an amplitude related to the amplitude of the corresponding harmonic in the input signal.

Abstract: A surface plasmon measurement instrument measures a change in a property (e.g., refractive index) of a material layer. The method includes providing a prism with a rear surface having a metal layer disposed thereon; providing the material layer on the metal layer on the rear surface of the prism; directing a source beam through the prism toward the rear surface in a vicinity of the material layer; performing at least two sampled measurements to detect light reflected from the rear surface and to produce two corresponding data sets; transforming the data sets to a transform domain; processing the transformed data sets to estimate a sample shift between the two data sets; and determining a change in a property of the material layer using the estimated sample shift.

Abstract: An apparatus adapted for measuring the properties of periodic signals and a method for making such measurements is disclosed. The apparatus includes a LO signal generator, a mixer, a low pass filter and an output device. The LO signal generator generates an LO signal comprising a fundamental frequency ?LO and one or more higher harmonics with arbitrary amplitudes and phases. The mixer receives a periodic input signal having harmonics including a highest harmonic of interest, N, and a fundamental frequency, ?in. The mixer outputs an IF signal that is filtered. The filtered IF signal includes a frequency-compressed signal having M harmonics including a fundamental characterized by a frequency ?c<?in. Each of the harmonics in the frequency-compressed signal corresponds to one of the harmonics in the input signal and has an amplitude related to the amplitude of the corresponding harmonic in the input signal.

Abstract: A surface plasmon measurement instrument measures a change in a property (e.g., refractive index) of a material layer. The method includes providing a prism with a rear surface having a metal layer disposed thereon; providing the material layer on the metal layer on the rear surface of the prism; directing a source beam through the prism toward the rear surface in a vicinity of the material layer; performing at least two sampled measurements to detect light reflected from the rear surface and to produce two corresponding data sets; transforming the data sets to a transform domain; processing the transformed data sets to estimate a sample shift between the two data sets; and determining a change in a property of the material layer using the estimated sample shift.