Device, system and method for rodless guided microwave radiation

Abstract

A rodless guide microwave radiation device, system, and method is disclosed for measuring at least one characteristic of a liquid in a vessel. A hollow metal waveguide conveys microwave radiation and is adapted to be disposed in a vessel for containing a liquid, the waveguide having a first end and a second end. A single chip radar sensor mounted on a PCB is disposed proximal to the first end of the hollow waveguide. The radar sensor is configured to transmit millimeter wavelength signals into the first end of the hollow waveguide for propagating down the waveguide toward the second end, and receive a return echo from the signal based upon a change in impedance upon encountering the liquid and propagating in the reverse direction of the waveguide, the single chip radar sensor including electronic circuitry for determining at least one characteristic of the liquid located in the waveguide based on detection of an impedance change according to time domain reflectometry. A mount assembly is configured to position the single chip radar sensor mounted on the printed circuit board over the first end of the hollow waveguide for transmitting and receiving the microwave radiation via the hollow waveguide; and a barrier structure sealingly protects the single chip radar mounted on said printed circuit board from exposure to contaminants within the hollow waveguide, while permitting microwave propagation between the single chip radar and the liquid through the hollow waveguide. In embodiments, the waveguide may be rigid, bent, curved, or flexible, and the radar and PCB may be outside or within the waveguide.