File:Analyseur spectre SPAN 0 four uondes 2445 MHz T 20 ms redressement monoalternance.jpg
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Summary[edit]
DescriptionAnalyseur spectre SPAN 0 four uondes 2445 MHz T 20 ms redressement monoalternance.jpg |
English: Microwave ovens use an electron tube of the magnetron type which is a self-oscillator whose frequency is unstable and evolves in a range between 2400 MHz and 2485 MHz. The magnetron is powered by the secondary of a 2500 V high voltage transformer which is rectified by a single diode and filtered by a high voltage capacitor: it is a half-wave rectification. The radio-frequency emission is amplitude modulated at the rate of 100% at the frequency of 50 Hz and therefore with a period D2 of 20 ms as measured by the pair of time markers. The SWT time sweep lasts 100 ms. with no frequency sweeping : SPAN 0. The vertical scale is in logarithmic scale with 10 dB per division.
The spectrum analyzer is tuned for a center frequency of 2445 MHz with a resolution bandwidth of 3 MHz and post-detection (video) filtering with a band of 3 MHz. The frequency range polluted by microwave oven leaks is used opportunistically by local radio networks such as Wi-Fi, Bluetooth, Zigbee etc. The power lost in leaks by the microwave oven is a maximum of 1 W and a very simple antenna is sufficient to capture this radiation, whereas the power radiated inside the oven is comprised between 500 W and 900 W. The measuring device is an FPC 1000 spectrum analyzer manufactured by Rhode & SchwarzFrançais : Les fours micro-ondes utilisent un tube électronique du type magnétron qui est un auto-oscillateur dont la fréquence est instable et évolue dans une gamme comprise entre 2400 MHz et 2485 MHz. Le magnétron est alimenté par le secondaire d'un transformateur à haute tension de 2500 V qui est redressé par une seule diode et filtré par une capacité à haute tension : c'est un redressement mono-alternance. L'émission radio-fréquence est modulée en amplitude au taux de 100 % à la fréquence de 50 Hz et avec donc une période D2 de 20 ms comme mesuré par la paire de marqueurs temporels. Le balayage temporel SWT dure 100 ms sans balayage de fréquence autour de 2445 MHz. L'échelle verticale est en échelle logarithmique avec 10 dB par division.
L'analyseur de spectre est réglé pour une fréquence centrale de 2445 MHz avec une bande passante de résolution de 3 MHz et un filtrage post-détection (vidéo) avec une bande de 3 MHz. La gamme de fréquence polluée par les fuites du four à micro-ondes est utilisée de façon opportuniste par les réseaux locaux radio Wi-Fi, Buetooth, Zigbee etc. La puissance perdue en fuites par le four à micro-ondes est au maximum de 1 W et une antenne très simple suffit pour capter ce rayonnement alors que la puissance rayonnée à l'intérieur du four est comprise entre 500 W et 900 W. L'appareil de mesure est un analyseur de spectre FPC 1000 fabriqué par Rhode & Schwarz. |
Date | |
Source | Own work |
Author | Fil22plm |
Camera location | 48° 42′ 18.19″ N, 3° 32′ 06.16″ W | View this and other nearby images on: OpenStreetMap | 48.705053; -3.535044 |
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current | 00:02, 2 March 2023 | 3,520 × 2,326 (5.37 MB) | Fil22plm (talk | contribs) | Uploaded own work with UploadWizard |
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Metadata
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Camera manufacturer | Apple |
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Camera model | iPhone 12 mini |
Exposure time | 1/100 sec (0.01) |
F-number | f/1.6 |
ISO speed rating | 100 |
Date and time of data generation | 17:14, 4 February 2022 |
Lens focal length | 4.2 mm |
Latitude | 48° 42′ 18.19″ N |
Longitude | 3° 32′ 6.16″ W |
Orientation | Normal |
Horizontal resolution | 72 dpi |
Vertical resolution | 72 dpi |
Software used | Camera+ 10.20 |
File change date and time | 17:14, 4 February 2022 |
Y and C positioning | Centered |
Exposure Program | Normal program |
Exif version | 2.32 |
Date and time of digitizing | 17:14, 4 February 2022 |
Meaning of each component |
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APEX shutter speed | 6.6437119234117 |
APEX aperture | 1.3561438092556 |
APEX brightness | 3.5466401262956 |
APEX exposure bias | 0 |
Metering mode | Pattern |
Flash | Flash did not fire, compulsory flash suppression |
DateTimeOriginal subseconds | 313 |
DateTimeDigitized subseconds | 313 |
Supported Flashpix version | 1 |
Color space | Uncalibrated |
Sensing method | One-chip color area sensor |
Scene type | A directly photographed image |
Exposure mode | Auto exposure |
White balance | Auto white balance |
Focal length in 35 mm film | 26 mm |
Scene capture type | Standard |
Subject distance range | Unknown |
GPS time (atomic clock) | 13:02 |
Reference for bearing of destination | True direction |
Bearing of destination | 84.72 |
GPS date | 4 February 2022 |
GPS tag version | 2.2.0.0 |