A wireless RF CMOS mixed-signal interface for soil moisture measurements
Autor(a) principal: | |
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Data de Publicação: | 2004 |
Outros Autores: | , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/1822/4263 |
Resumo: | This paper describes a wireless RF CMOS interface for soil moisture measurements. The interface basically comprises a Delta-Sigma (ΔΣ) modulator for acquiring an external sensor signal, and a RF section where data is transmitted to a local processing unit. The ΔΣ modulator is a single-bit, second-order modulator and it is implemented using switched-capacitors techniques in a fully-differential topology. With a sampling frequency of 423.75 kHz and an oversampling ratio (OSR) of 256, the modulator achieves a dynamic range of 98.7 dB (16.1 bit). The output of the modulator is applied to a counter, as a first-order decimation filter, and the result is stored. Prior to transmission, data is encoded as a pulse width modulated signal and assembled in a frame containing preamble and checksum control fields. This frame is then transmitted through a power amplifier operating at 433.92 MHz in class-E mode. To evaluate the ΔΣ modulator performance, the bitstream was acquired and transferred to a personal computer to perform digital filtering and decimation using MATLAB. The soil moisture sensor is based on dual-probe heat-pulse (DPHP) method and is implemented by using an integrated temperature sensor and a heater. After applying a heat-pulse for a fixed period of time, the temperature rise, that is a function of soil moisture, generates a differential voltage that is amplified and applied to the mixed-signal interface input. The described interface can also be used with other kinds of environmental sensors in a wireless sensors network. The CMOS mixed-signal interface has been implemented in a single-chip using a standard CMOS 0.7 μm process (AMI C07M-A, n-well, 2 metals and 1 poly). |
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A wireless RF CMOS mixed-signal interface for soil moisture measurementsWireless soil moisture sensorsSensor interfaceswirelessdelta-sigmasoil moisture sensorsScience & TechnologyThis paper describes a wireless RF CMOS interface for soil moisture measurements. The interface basically comprises a Delta-Sigma (ΔΣ) modulator for acquiring an external sensor signal, and a RF section where data is transmitted to a local processing unit. The ΔΣ modulator is a single-bit, second-order modulator and it is implemented using switched-capacitors techniques in a fully-differential topology. With a sampling frequency of 423.75 kHz and an oversampling ratio (OSR) of 256, the modulator achieves a dynamic range of 98.7 dB (16.1 bit). The output of the modulator is applied to a counter, as a first-order decimation filter, and the result is stored. Prior to transmission, data is encoded as a pulse width modulated signal and assembled in a frame containing preamble and checksum control fields. This frame is then transmitted through a power amplifier operating at 433.92 MHz in class-E mode. To evaluate the ΔΣ modulator performance, the bitstream was acquired and transferred to a personal computer to perform digital filtering and decimation using MATLAB. The soil moisture sensor is based on dual-probe heat-pulse (DPHP) method and is implemented by using an integrated temperature sensor and a heater. After applying a heat-pulse for a fixed period of time, the temperature rise, that is a function of soil moisture, generates a differential voltage that is amplified and applied to the mixed-signal interface input. The described interface can also be used with other kinds of environmental sensors in a wireless sensors network. The CMOS mixed-signal interface has been implemented in a single-chip using a standard CMOS 0.7 μm process (AMI C07M-A, n-well, 2 metals and 1 poly).ElsevierUniversidade do MinhoMorais, RaulValente, A.Couto, CarlosCorreia, J. H.2004-092004-09-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/1822/4263eng"Sensors and Actuators A : Physical". ISSN 0924-4247. 115:2-3 (Sept. 2004) 376-384.0924-424710.1016/j.sna.2004.04.046info:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2023-07-21T12:09:14Zoai:repositorium.sdum.uminho.pt:1822/4263Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T19:00:35.523055Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
A wireless RF CMOS mixed-signal interface for soil moisture measurements |
title |
A wireless RF CMOS mixed-signal interface for soil moisture measurements |
spellingShingle |
A wireless RF CMOS mixed-signal interface for soil moisture measurements Morais, Raul Wireless soil moisture sensors Sensor interfaces wireless delta-sigma soil moisture sensors Science & Technology |
title_short |
A wireless RF CMOS mixed-signal interface for soil moisture measurements |
title_full |
A wireless RF CMOS mixed-signal interface for soil moisture measurements |
title_fullStr |
A wireless RF CMOS mixed-signal interface for soil moisture measurements |
title_full_unstemmed |
A wireless RF CMOS mixed-signal interface for soil moisture measurements |
title_sort |
A wireless RF CMOS mixed-signal interface for soil moisture measurements |
author |
Morais, Raul |
author_facet |
Morais, Raul Valente, A. Couto, Carlos Correia, J. H. |
author_role |
author |
author2 |
Valente, A. Couto, Carlos Correia, J. H. |
author2_role |
author author author |
dc.contributor.none.fl_str_mv |
Universidade do Minho |
dc.contributor.author.fl_str_mv |
Morais, Raul Valente, A. Couto, Carlos Correia, J. H. |
dc.subject.por.fl_str_mv |
Wireless soil moisture sensors Sensor interfaces wireless delta-sigma soil moisture sensors Science & Technology |
topic |
Wireless soil moisture sensors Sensor interfaces wireless delta-sigma soil moisture sensors Science & Technology |
description |
This paper describes a wireless RF CMOS interface for soil moisture measurements. The interface basically comprises a Delta-Sigma (ΔΣ) modulator for acquiring an external sensor signal, and a RF section where data is transmitted to a local processing unit. The ΔΣ modulator is a single-bit, second-order modulator and it is implemented using switched-capacitors techniques in a fully-differential topology. With a sampling frequency of 423.75 kHz and an oversampling ratio (OSR) of 256, the modulator achieves a dynamic range of 98.7 dB (16.1 bit). The output of the modulator is applied to a counter, as a first-order decimation filter, and the result is stored. Prior to transmission, data is encoded as a pulse width modulated signal and assembled in a frame containing preamble and checksum control fields. This frame is then transmitted through a power amplifier operating at 433.92 MHz in class-E mode. To evaluate the ΔΣ modulator performance, the bitstream was acquired and transferred to a personal computer to perform digital filtering and decimation using MATLAB. The soil moisture sensor is based on dual-probe heat-pulse (DPHP) method and is implemented by using an integrated temperature sensor and a heater. After applying a heat-pulse for a fixed period of time, the temperature rise, that is a function of soil moisture, generates a differential voltage that is amplified and applied to the mixed-signal interface input. The described interface can also be used with other kinds of environmental sensors in a wireless sensors network. The CMOS mixed-signal interface has been implemented in a single-chip using a standard CMOS 0.7 μm process (AMI C07M-A, n-well, 2 metals and 1 poly). |
publishDate |
2004 |
dc.date.none.fl_str_mv |
2004-09 2004-09-01T00:00:00Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/1822/4263 |
url |
http://hdl.handle.net/1822/4263 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
"Sensors and Actuators A : Physical". ISSN 0924-4247. 115:2-3 (Sept. 2004) 376-384. 0924-4247 10.1016/j.sna.2004.04.046 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Elsevier |
publisher.none.fl_str_mv |
Elsevier |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
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Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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RCAAP |
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RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
repository.mail.fl_str_mv |
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1799132401829412864 |