- Patent Title: Particulate matter detection circuit and filter processing device
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Application No.: US16207803Application Date: 2018-12-03
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Publication No.: US10746076B2Publication Date: 2020-08-18
- Inventor: Tatsuya Hirose
- Applicant: FUJITSU LIMITED
- Applicant Address: JP Kawasaki
- Assignee: FUJITSU LIMITED
- Current Assignee: FUJITSU LIMITED
- Current Assignee Address: JP Kawasaki
- Agency: Fujitsu Patent Center
- Priority: com.zzzhc.datahub.patent.etl.us.BibliographicData$PriorityClaim@1f8d69a9
- Main IPC: G01R27/32
- IPC: G01R27/32 ; F01N3/00 ; F01N9/00 ; F01N3/023 ; G01N15/06 ; B01D46/44 ; G01N27/04 ; F01N11/00 ; F01N3/10 ; F01N3/021 ; G01N15/08

Abstract:
A particulate matter detection circuit includes, a negative resistance circuit that couples to a first antenna inserted in a housing accommodating a first filter that filters an exhaust gas, couples to a second antenna inserted in the housing via a matching circuit that performs an impedance matching and a second filter that narrows the frequency band of a passing signal, and oscillates at a resonance frequency of the housing, and a detection circuit that outputs a voltage value corresponding to a signal strength of a radio wave received by a third antenna or the second antenna inserted in the housing. The resonance frequency of the housing varies depending on an amount of matter adhered to the first filter.
Public/Granted literature
- US20190195111A1 PARTICULATE MATTER DETECTION CIRCUIT AND FILTER PROCESSING DEVICE Public/Granted day:2019-06-27
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