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Magnetic nanoparticle (MNP) thermometry will be necessary for safe therapeutic implementation of magnetic nanoparticle hyperthermia, a developing cancer treatment. One realization of a MNP thermometer works by detecting harmonic signal (the fundamental f and 3f harmonics) generated by MNPs exposed to ac magnetic field. In this paper, we aim to measure accurately the harmonic signal in a MNP thermometer,...
Performance of a detector based on AlGaAs/InGaAs/GaAs-material system was studied. The detector was comprised of large serpentine array of high-electron mobility transistors (HEMTs) connected in series. The floating drain contact of each transistor (except the last one) served as a source for the next one. Detection of terahertz (THz) radiation was based on the excitation of electron plasma oscillations...
This work describes a method of Terahertz (THz) imaging, which consists of irradiating different materials with THz radiation, emitted by a photoconductive antenna, excited by a femtosecond laser pulse. The detector used is a pyroelectric detector (thermal detector) operating at room temperature, calibrated for this frequency band. The method consists in recording the amplitude of the radiation transmitted...
We report on the photoresponse of 0.7-μm InP double heterojunction bipolar transistor to THz radiation of low and high intensities, when the collector is unbiased. At low intensities, the photoresponse is linear in radiation intensity. Under intense laser radiation, we observe a saturation at intensities > 15 kW/cm2, sample damaging arising around ∼ 40 kW/cm2. The photoresponse as a function of...
Terahertz (THz) direct detectors based on superconducting niobium nitride (NbN) hot electron bolometers (HEBs) with microwave (MW) injection have been studied. Compared to the thermal biasing method, the injected MW is used here to bias the HEB to the optimum point. MW can be expected to be used as the easy read out for the detecting array. The used NbN HEB has an excellent performance as heterodyne...
Asymmetric-dual-grating-gate high-electron-mobility-transistors (ADGG-HEMTs) are expected for on-chip, sensitive, room-temperature operating, high-speed THz detectors. In this paper, we experimentally verify the high-speed response of an ADGG-HEMT by measuring its response to THz pulse generated from an injection-seeded THz-wave parametric generator (is-TPG). From the pulse response waveform of the...
NASA's Soil Moisture Active and Passive (SMAP) satellite was launched in January 2015 to provide global measurements of soil moisture and freeze/thaw state. Soil moisture products are derived from SMAP radiometer measurements acquired at L Band (1.4 GHz). Even though this is a protected band, unauthorized transmitters emitting either within the band or in adjacent bands cause radio frequency interference...
Gated graphene has been used to realize a microwave power detector. A Corbino disc structure with Ti/Ag contacts has been fabricated on top of graphene deposited on P-type Si substrates with SiO2 gate oxides. This device exhibits power detection with a sensitivity reaching 0.87 mV/mW at a frequency of 433.92 MHz using lock-in detection at room temperature.
It has recently been found that the visibility denormalization process introduces a spatial error distribution due to small sporadic offset jumps in the PMS detectors. The radiometric impact of this error at system level is very low. However, due to the good performance of the SMOS instrument, a study has recently been conducted to evaluate the amplitude of such visibility errors and develop a mitigation...
Radio-Frequency Interference (RFI) is a growing problem for applications based on the Global Navigation Satellite Systems (GNSS), including Earth observation using GNSS — Reflectometry (GNSS-R). Nowadays, many efforts are being concentrated to develop RFI signal detectors with high sensitivity, which can help to control the proliferation of RFI generators or jammers. This work aims at designing and...
The model of 1/f noise of p+-p-n detector made of type-11 InAs/GaSb superlattice material (designed for a mid-wavelength infrared detection) is described. It is shown that 1/f noise magnitude can be reasonably estimated if dark current contributions are determined and respective (empirical) noise coefficients are known.
It is well known that clustering sensor nodes and letting those with superior resources act as cluster heads help to address the network scalability problem in wireless sensor networks (WSNs). However, the clustered architecture provides the opportunity for an adversary to attack sensor nodes within a cluster by simply compromising the cluster head. This paper investigates the attack detection issues...
Spatially entangled photon states are used in experiments addressing fundamental properties of quantum mechanics as well as practical applications [1]. Thereby, the use of these states demands for time-saving detection mechanisms, capable of measuring coincidences between spatially separated photons with high spatial and temporal resolution. In this work, we demonstrate coincidence detection of spatially...
In order to reduce measure standard uncertainty and achieve precise calibration of Port Quick Leak Detector in different temperatures under full range, the special calibration apparatus was designed on basis of theoretical studies. This apparatus consists of pressure standard leak system, calibration system, temperature control system, gas supply and pump system. Pressure standard leak system is made...
An Application Specific Integrated Circuit (ASIC) that is able to digitize input current starting from a few femtoamperes (fA) up to microamperes (μA), was designed for the environmental monitoring of the background radiation and for radiation protection at CERN. The Ultra-low Picoammeter 2 (Utopia 2) ASIC, is based on the current to frequency converter (CFC) architecture and can compensate for the...
The development of novel superconducting photon detectors requires the investigation of non-traditional materials to exploit their specific properties and realize novel/enhanced devices. Nd2−xCexCuO4±5 is a moderate high transition temperature cuprate superconductor exhibiting n-type conduction which properties can be changed by modifying its cerium and oxygen content. Ultra-thin films of this compound...
In this paper, a functional principle for a broadband thermal detector suited for a monolithical integration is shown. Two tantalum load resistors are heated by an input signal, while the temperature at a fixed distance is recorded on chip with a differential temperature sensing bridge. An integrated differential to single-ended stage amplifies the bridges differential voltage and provides an output...
VFAT3 is the last version of a family of multichannel trigger and tracking ASICs designed for the upgrade of the CMS experiment in the LHC. The chip has been developed to provide fast trigger information from the readout of gas particle detectors improving the resolution of the time measurement. The VFAT3 architecture comprises 128 analog channels, each one composed by a low noise and low power charge...
The high speed thermal imaging is necessary in many applications. However, the traditional column-wise readout implementations reduce the achievable frame-rate. Also, the analog integration of each individual pixel is not possible without sacrificing the pixel area. In this paper we present an algorithm that can be used in parallel focal-plane processing for fast imaging. First we prove that our method...
This paper presents the study, manufacturing and characterization of a single-axis jet flow gyrometer. The operating principle of the device is based on the deflection of a laminar gas stream due to the Coriolis effect; it is then a gyrometer with no solid proof mass. A warm gas jet is generated by a micropump through a microfluidic channel opening into a cavity. Two temperature detectors are placed...
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