Compact microwave device for monitoring grain conditions

A method of monitoring grain conditions comprising,

• with an active planar cavity resonator located in proximity with grain to be monitored, monitoring at least one operating characteristic of said active planar cavity resonator for detectable shifts representative of changing conditions within said grain, said method also comprising a reliability test in which temperature conditions in a region at or near the active planar resonator are varied in a controlled manner to switch between different temperature ranges among which pest activity is known to vary, and with a pest intentionally introduced to said region, monitoring the at least one operating characteristic in said different temperature ranges and comparing a difference in magnitudes of detected shifts measured in said different temperature ranges against an expected difference in pest activity within said different temperature ranges.

In combination with grain bin for storing bulk grain, at least one sensor placed within or proximate an interior of the grain bin and comprising an active planar cavity resonator of which at least one operating characteristic will undergo a shift in response to changes in conditions in said bulk grain proximate said active planar cavity resonator, wherein said active planar cavity resonator comprises a regenerative feedback loop in which there is incorporated a powered amplifier, and said at least one operating characteristic comprises at least one of either a frequency spectrum of the active planar cavity resonator and a collector current drawn by the powered amplifier of said regenerator feedback loop of the active planar cavity resonator.

A grain sample tester comprising a container with an interior space for holding a sample of grain extracted from a larger source of bulk grain, and an active planar cavity resonator situated within or proximate said interior space of the container such that at least one operating characteristic of the active planar cavity resonator will undergo a shift in response to changes in conditions within said sample of grain, wherein said active planar cavity resonator comprises a regenerative feedback loop in which there is incorporated a powered amplifier, and said at least one operating characteristic comprises at least one of either a frequency spectrum of the active planar cavity resonator and a collector current drawn by the powered amplifier of said regenerator feedback loop of the active planar cavity resonator.

A sensor comprising an active planar cavity resonator of which at least one operating characteristic will undergo a shift in response to changes in conditions proximate said active planar cavity resonator, wherein said active planar cavity resonator comprises a regenerative feedback loop in which there is incorporated a powered amplifier, said at least one operating characteristic comprises at least one of either a frequency spectrum of the active planar cavity resonator and a collector current drawn by the powered amplifier of said regenerator feedback loop of the active planar cavity resonator, said active planar cavity resonator resides within a curved plane and is thereby operable to detect conditions in multiple directions faced by said curved plane.

A grain sample tester comprising an active planar cavity resonator and a dielectric support that is affixed to said active planar cavity resonator and comprises a kernel-shaped support surface configured to receive and hold a singular grain kernel thereon in a predetermined position relative to said active planar cavity resonator to enable detection of conditions within said singular grain kernel through monitoring of at least one operating characteristic of said active planar cavity resonator, wherein said active planar cavity resonator comprises a regenerative feedback loop in which there is incorporated a powered amplifier, and said at least one operating characteristic comprises at least one of either a frequency spectrum of the active planar cavity resonator and a collector current drawn by the powered amplifier of said regenerator feedback loop of the active planar cavity resonator.