Communications: radio wave antennas – Antennas – Balanced doublet - centerfed
Patent
1976-08-06
1977-08-23
Hubler, Malcolm F.
Communications: radio wave antennas
Antennas
Balanced doublet - centerfed
343 14, G01S 938
Patent
active
040443531
ABSTRACT:
A method and apparatus for measuring liquid level. A generated broad-band swept-frequency C.W. microwave signal (2-4 GHz) is upverted to a high frequency band signal (34-36 GHz), which is transmitted towards, and reflected from, a liquid surface. The reflected signal is downverted to the frequency band of the original generated signal, and then the phase difference between the original and downverted signals is measured by a microwave phase discriminator and a quantizer, which generates video pulses proportional to the total phase shift across the swept C.W. band. During an adjacent sweep in the same direction, the original signal is compared with a signal transmitted through a calibration cable equivalent to a known free-space path length. The unknown signal path to and from the liquid surface, can then be calculated by comparison of the video pulse train outputs during the CALIBRATE and OPERATE modes of operation, either by the ratio of the number of pulses, or the average time between pulses during each sweep.
Alternately, the mode of operation can be switched several hundred times during a single sweep across the bandwidth, and the unknown signal path corresponding to a particular liquid level can be calculated by comparison of the spacing during adjacent CALIBRATE and OPERATE modes to give several hundred measurements at different frequencies. Deviate measurements can then be eliminated, and the remaining measurements can be averaged to give a highly accurate true average measurement by known methods.
REFERENCES:
patent: 2147810 (1939-02-01), Alford
patent: 3226714 (1965-12-01), Applegarth, Jr.
patent: 3730628 (1973-05-01), Wolcott et al.
patent: 3921169 (1975-11-01), Lazarchik et al.
patent: RE21955 (1941-11-01), Chaffee
Greigg Edwin E.
Hubler Malcolm F.
Simmonds Precision Products Inc.
LandOfFree
Microwave level gaging system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Microwave level gaging system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Microwave level gaging system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2318694