268 results about "Microwave detectors" patented technology

System and methods are disclosed for fluid measurements which may be utilized to determine mass flow rates such as instantaneous mass flow of a fluid stream. In a preferred embodiment, the present invention may be utilized to compare an input mass flow to an output mass flow of a drilling fluid circulation stream. In one embodiment, a fluid flow rate is determined by utilizing a microwave detector in combination with an acoustic sensor. The acoustic signal is utilized to eliminate 2pi phase ambiguities in a reflected microwave signal. In another embodiment, a fluid flow rate may be determined by detecting a phase shift of an acoustic signal across two different predetermined transmission paths. A fluid density may be determined by detecting a calibrated phase shift of an acoustic signal through the fluid. In another embodiment, a second acoustic signal may be transmitted through the fluid to define a particular 2pi phase range which defines the phase shift. The present invention may comprise multiple transmitters / receivers operating at different frequencies to measure instantaneous fuel levels of cryogenic fuels within containers positioned in zero or near zero gravity environments. In one embodiment, a moveable flexible collar of transmitter / receivers may be utilized to determine inhomogenuities within solid rocket fuel tubes.

A resonant tunneling diode or diode array oscillator (10) including a resonant diode (11) is coupled to a millimeter-wave source (14) and a quench generator (16) for periodically quenching the oscillations so that the average oscillation time of the oscillator is proportional to signal strength of the source (14). The signal source can be from an antenna such as a dipole or tapered slot line antenna.

The invention discloses a human body existence detection method based on hybrid detection, a microwave detector and application, wherein the microwave detector comprises at least one microwave detection module and at least one signal conversion module, a difference signal is generated by the microwave detection module based on the Doppler effect principle, the signal conversion module is connectedwith the microwave detection module in a communication mode, the difference signal is converted into a fluctuation signal by the signal conversion module, at least one conversion channel is formed bythe signal conversion module, the conversion channel only allows the fluctuation signal within a specific frequency range to pass through, and when a human body exists in a detection area, the microwave detector can obtain at least one action characteristic of the human body in the detection area.