Antenna unit for the doppler measurement of grain flow
US6025814A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 7, 1997 |
| Grant date | Feb 15, 2000 |
| Priority date | — |
| Expiry date | Nov 7, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01Q17/001
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An antenna unit for measuring the velocity of a flowing material by the Doppler effect is particularly suited for use where only a limited space is available. The antenna unit comprises a support block having first and second surfaces disposed at an acute angle (optimally 45.degree.) relative to each other. A printed circuit antenna card having thereon a high gain antenna comprising a phased array of antenna elements is mounted to the second surface and radiates microwave energy toward the first surface. A plate having an opening therein is disposed adjacent the first surface, the plate being made of a material which absorbs radiated energy incident thereon. The support block is provided with a recess for receiving an absorber wedge which absorbs the energy radiated in near side lobes. The absorber wedge and plate shape the radiation pattern so that energy radiated by the antenna intercepts the material at an angle of 45.degree..+-.15.degree. when the first surface is disposed parallel to the axis of flow.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.