Utilize este identificador para referenciar este registo:
https://hdl.handle.net/1822/4833
Registo completo
Campo DC | Valor | Idioma |
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dc.contributor.author | Morais, Raul | - |
dc.contributor.author | Valente, A. | - |
dc.contributor.author | Couto, Carlos | - |
dc.contributor.author | Correia, J. H. | - |
dc.date.accessioned | 2006-05-02T15:16:07Z | - |
dc.date.available | 2006-05-02T15:16:07Z | - |
dc.date.issued | 2003-06-22 | - |
dc.identifier.citation | IEEE INTERNATIONAL SYMPOSIUM ON INDUSTRIAL ELECTRONICS, Rio de Janeiro, Brazil, 2003 – “IEEE International Symposium on Industrial Electronics : ISIE’03 : [proceedings]”. New Piscataway : IEEE, 2003. vol. 2. ISBN 0-7803-7912-8. p. 1-4. | eng |
dc.identifier.isbn | 0-7803-7912-8 | - |
dc.identifier.uri | https://hdl.handle.net/1822/4833 | - |
dc.description.abstract | This paper describes a CMOS mixed-signal interface with a RF transmitter. This die is assembled in a Multi-Chip-Module (MCM) micro-system together with the micromachined soil moisture sensor to achieve a cost effective solution with accurate and reliable measurements for soil moisture in agriculture. The soil moisture probe, based on Dual-Probe Heat-Pulse (DPHP) method, is fabricated in bulkmicromachining technology. The DPHP method is based on the measurement of the maximum temperature rise at some distance from the heater, after applying a heat-pulse. The measurement of the temperature rise is obtained by subtracting soil temperature from the probe temperature. The mixed-signal interface is based on a pre-amplification stage and first-order sigma-delta modulator. The bit-stream output of the modulator is then applied to a counter as a first order decimation filter thus providing a 12-bit readout sample. Prior to transmission, data is encoded as a pulse width modulated (PWM) signal and then transmitted by means of an amplitude shift-keying (ASK) modulation. The transmitter features a VCO phase locked to the quartz crystal reference of 13.56 MHz to achieve a carrier frequency of 433.92 MHz. A RF power amplifier based on class E topology was chosen. The CMOS mixed-signal interface with a RF transmitter has been implemented in a single-chip using a standard CMOS process (AMI 0.7 µm, n-well, 2 metals and 1poly). | eng |
dc.language.iso | eng | eng |
dc.publisher | IEEE | eng |
dc.rights | openAccess | eng |
dc.subject | Wireless | eng |
dc.subject | Sigma - Delta | eng |
dc.subject | Soil-Moisture sensors | eng |
dc.subject | RF Transmitter | eng |
dc.title | A CMOS mixed-signal interface with a RF transmitter for a micromachined soil moisture sensor | eng |
dc.type | conferencePaper | eng |
dc.peerreviewed | yes | eng |
Aparece nas coleções: | DEI - Artigos em atas de congressos internacionais |
Ficheiros deste registo:
Ficheiro | Descrição | Tamanho | Formato | |
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ISIE03.pdf | Documento principal | 643,39 kB | Adobe PDF | Ver/Abrir |