US 12,442,678 B2
High-frequency-based field device
Stefan Pflüger, Munich (DE); and Christian Wegner, Schwörstadt (DE)
Assigned to Endress+Hauser Flowtec AG, Reinach (CH)
Appl. No. 18/257,758
Filed by Endress+Hauser Flowtec AG, Reinach (CH)
PCT Filed Nov. 26, 2021, PCT No. PCT/EP2021/083102
§ 371(c)(1), (2) Date Jun. 15, 2023,
PCT Pub. No. WO2022/128403, PCT Pub. Date Jun. 23, 2022.
Claims priority of application No. 10 2020 134 061.3 (DE), filed on Dec. 17, 2020.
Prior Publication US 2024/0118123 A1, Apr. 11, 2024
Int. Cl. G01F 23/284 (2006.01); G01S 13/88 (2006.01); H01Q 1/22 (2006.01)
CPC G01F 23/284 (2013.01) [G01S 13/88 (2013.01); H01Q 1/225 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A high frequency based field device for determining a measured variable of a medium, comprising:
an antenna arrangement placeable on a container for transmitting a high frequency signal to the medium and after interaction with the medium saving a received signal;
a signal production unit designed to produce the high frequency signal to be transmitted and to supply the high frequency signal via a transmission path to the antenna arrangement;
an evaluation unit connected via a receiving path with the antenna arrangement to determine a defined characteristic variable at least based on the incoming, received signal;
a transmission amplifier arranged in the transmission path and/or a receiving amplifier arranged in the receiving path; and
a first switching unit arranged between the antenna arrangement and the transmission amplifier in the transmission path and the receiving amplifier in the receiving path, wherein the first switching unit is designed to assume such switch positions that the signal production unit and/or the evaluation unit are/is connected, in each case, with the antenna arrangement (i, j=THRU), and the transmission path and/or the receiving path are/is connected to an attenuation element via which the transmission path is connectable with the receiving path (i, j=ATN), wherein the antenna arrangement in the case of this switch position (i, j=ATN) is separated from the signal production unit and/or from the evaluation unit,
wherein the evaluation unit is designed to set the switch position of the first switching unit to determine at the set switch position the corresponding characteristic variable (si,j) as a first calibration factor (ŝi,j), to reconcile a characteristic variable (sTHRU,THRU) ascertained in measurement operation via the first calibration factor (ŝi,j), and to determine the measured variable of the medium based on the reconciled characteristic variable (s′THRU,THRU).