Characterization of a Smartphone’s CMOS Image Sensor Response to Radiation

2015 ◽  
Vol 742 ◽  
pp. 17-20
Author(s):  
Chao Qun Xu ◽  
Jie Jiang ◽  
Zhi Yuan Ouyang ◽  
Chuang He Qiu

As part of studies into the use of Smartphones as solar-radiation monitors, this article characterizes the violet response of a consumer complementary metal oxide semiconductor (CMOS)-based Smartphone image sensor in a controlled laboratory environment, with an adjustable Lamp as a radiation source, a band-pass filter (central wavelength is 400nm) covered on Smartphone camera lens and a ASD spectrometer observing synchronously. It is found that a logarithmic relationship appears between CMOS-based sensor imaging DN values and irradiance, and the red (R) component in the chromo-photograph is linearly relative to irradiance. In addition, a Smartphone can be used as a convenient and low-cost scientific instrument in the field of monitoring radiation characterization, due to its capacity to detect usable irradiances.

Sensors ◽  
2019 ◽  
Vol 19 (24) ◽  
pp. 5461 ◽  
Author(s):  
Alain Küng ◽  
Benjamin A. Bircher ◽  
Felix Meli

Accurate traceable measurement systems often use laser interferometers for position measurements in one or more dimensions. Since interferometers provide only incremental information, they are often combined with index sensors to provide a stable reference starting point. Straightness measurements are important for machine axis correction and for systems having several degrees of freedom. In this paper, we investigate the accuracy of an optical two-dimensional (2D) index sensor, which can also be used in a straightness measurement system, based on a fiber-coupled, collimated laser beam pointing onto an image sensor. Additionally, the sensor can directly determine a 2D position over a range of a few millimeters. The device is based on a simple and low-cost complementary metal–oxide–semiconductor (CMOS) image sensor chip and provides sub-micrometer accuracy. The system is an interesting alternative to standard techniques and can even be implemented on machines for real-time corrections. This paper presents the developed sensor properties for various applications and introduces a novel error separation method for straightness measurements.


2013 ◽  
Vol 27 (26) ◽  
pp. 1350159
Author(s):  
HYUNJUNE LYU ◽  
JUN RIM CHOI

For the purpose of biomagnetic measurements, a magnetic sensor chip is manufactured using a 0.18 μm complementary metal–oxide–semiconductor (CMOS) process. A high-inductance coil and an instrumentation amplifier (IA) are embedded on this chip. The embedded high-inductance coil sensor contains suitable sensitivity and bandwidth for biomagnetic measurements, and is designed via electromagnetic field simulation. A low-gm operational transconductance amplifier (OTA) is also implemented on the chip to reduce the transconductance value. The output signal sensitivity of the magnetic sensor chip is 3.25 fT/μV, and the output reference noise is [Formula: see text]. The instrumentation amplifier is designed to minimize the magnetic signal noise using current feedback and a band-pass filter (BPF) with a bandwidth between 0.5 kHz and 5 kHz. The common-mode rejection ratio (CMRR) is measured at 117.5 dB by the Multi-Project Chip test. The proposed magnetic sensor chip is designed such that the input reference noise is maintained below 0.87 μV.


Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 805
Author(s):  
Josep Altet ◽  
Enrique Barajas ◽  
Diego Mateo ◽  
Alexandre Billong ◽  
Xavier Aragones ◽  
...  

A new sensor topology meant to extract figures of merit of radio-frequency analog integrated circuits (RF-ICs) was experimentally validated. Implemented in a standard 0.35 μm complementary metal-oxide-semiconductor (CMOS) technology, it comprised two blocks: a single metal-oxide-semiconductor (MOS) transistor acting as temperature transducer, which was placed near the circuit to monitor, and an active band-pass filter amplifier. For validation purposes, the temperature sensor was integrated with a tuned radio-frequency power amplifier (420 MHz) and MOS transistors acting as controllable dissipating devices. First, using the MOS dissipating devices, the performance and limitations of the different blocks that constitute the temperature sensor were characterized. Second, by using the heterodyne technique (applying two nearby tones) to the power amplifier (PA) and connecting the sensor output voltage to a low-cost AC voltmeter, the PA’s output power and its central frequency were monitored. As a result, this topology resulted in a low-cost approach, with high linearity and sensitivity, for RF-IC testing and variability monitoring.


MRS Bulletin ◽  
1996 ◽  
Vol 21 (4) ◽  
pp. 38-44 ◽  
Author(s):  
F.K. LeGoues

Recently much interest has been devoted to Si-based heteroepitaxy, and in particular, to the SiGe/Si system. This is mostly for economical reasons: Si-based technology is much more advanced, is widely available, and is cheaper than GaAs-based technology. SiGe opens the door to the exciting (and lucrative) area of Si-based high-performance devices, although optical applications are still limited to GaAs-based technology. Strained SiGe layers form the base of heterojunction bipolar transistors (HBTs), which are currently used in commercial high-speed analogue applications. They promise to be low-cost compared to their GaAs counterparts and give comparable performance in the 2-20-GHz regime. More recently we have started to investigate the use of relaxed SiGe layers, which opens the door to a wider range of application and to the use of SiGe in complementary metal oxide semiconductor (CMOS) devices, which comprise strained Si and SiGe layers. Some recent successes include record-breaking low-temperature electron mobility in modulation-doped layers where the mobility was found to be up to 50 times better than standard Si-based metal-oxide-semiconductor field-effect transistors (MOSFETs). Even more recently, SiGe-basedp-type MOSFETS were built with oscillation frequency of up to 50 GHz, which is a new record, in anyp-type material for the same design rule.


1999 ◽  
Vol 121 (3) ◽  
pp. 372-377 ◽  
Author(s):  
B. Zheng ◽  
H. J. Wang ◽  
Q. L. Wang ◽  
R. Kovacevic

This paper presents a technique for front image sensing of the weld pool in variable polarity plasma arc welding of aluminum alloys, and describes the determination of the geometrical size of the keyhole for subsequent real-time feedback control of a full penetration weld. Image formation occurs when the arc light reflects off the concave mirror-like surface of the depressed keyhole weld pool, and passes through a band-pass filter onto the image sensor. The image of the visual keyhole (nominal keyhole) is a two-dimensional projected picture of the actual keyhole weld pool. The variation in area of the nominal keyhole is closely correlated with the variation of the bottom width of the weld bead.


Sensors ◽  
2020 ◽  
Vol 20 (12) ◽  
pp. 3610
Author(s):  
Adrián J. Torregrosa ◽  
Emir Karamehmedović ◽  
Haroldo Maestre ◽  
María Luisa Rico ◽  
Juan Capmany

Up-conversion sensing based on optical heterodyning of an IR (infrared) image with a local oscillator laser wave in a nonlinear optical sum-frequency mixing (SFM) process is a practical solution to circumvent some limitations of IR image sensors in terms of signal-to-noise ratio, speed, resolution, or cooling needs in some demanding applications. In this way, the spectral content of an IR image can become spectrally shifted to the visible/near infrared (VIS/NWIR) and then detected with silicon focal plane arrayed sensors (Si-FPA), such as CCD/CMOS (charge-coupled and complementary metal-oxide-semiconductor devices). This work is an extension of a previous study where we recently introduced this technique in the context of optical communications, in particular in FSOC (free-space optical communications). Herein, we present an image up-conversion system based on a 1064 nm Nd3+: YVO4 solid-state laser with a KTP (potassium titanyl phosphate) nonlinear crystal located intra-cavity where a laser beam at 1550 nm 2D spatially-modulated with a binary Quick Response (QR) code is mixed, giving an up-converted code image at 631 nm that is detected with an Si-based camera. The underlying technology allows for the extension of other IR spectral allocations, construction of compact receivers at low cost, and provides a natural way for increased protection against eavesdropping.


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