Methods, systems, and devices are described that include one or more sidewall features to improve performance of a waveguide device. In particular, the sidewall features may be utilized within a polarizer section of a polarizer device such as a septum polarizers. The sidewall feature(s) may include recesses and/or protrusions. When a plurality of sidewall features are employed, the size, shape, spacing and kind (e.g., recess or protrusion) may vary according to a particular design.

A waveguide structure for a compact and scalable dual-polarized antenna array. In one example, a waveguide device comprises septum polarizers dividing common waveguides into first waveguides associated with a first polarization and second waveguides associated with a second polarization. The sets of septum polarizers may be inverted relative to each other to form first groups of four adjacent first waveguides for each type of waveguide. The waveguide device may also include a waveguide feed network including a first waveguide feed stage including waveguide combiner/dividers coupled between the four adjacent waveguides intermediate waveguides. The waveguide device may further include a second waveguide feed stage coupled with the first intermediate waveguides and the second intermediate waveguides, wherein the second waveguide feed stage extends in a direction perpendicular to the first waveguide feed stage.

In an example embodiment, a waveguide device comprises: a first common waveguide; a polarizer section, the polarizer section including a conductive septum dividing the first common waveguide into a first divided waveguide portion and a second waveguide divided portion; a second waveguide coupled to the first divided waveguide portion of the polarizer section; a third waveguide coupled to the second divided waveguide portion of the polarizer section; and a dielectric insert. The dielectric insert includes a first dielectric portion partially filling the polarizer section. The conductive septum and the dielectric portion convert a signal between a polarized state in the first common waveguide and a first polarization component in the second waveguide and a second polarization component in the third waveguide.

Methods, systems, and devices are described for improving a performance of a waveguide device. A waveguide device that includes a common port and divided ports may also include a sidewall feature that extends across a first set of opposing sidewalls and a second set of opposing sidewalls of the waveguide device. The sidewall feature may have a same shape on each of the first set of opposing sidewalls and a second set of opposing sidewalls. In some cases, the sidewall feature is positioned outside a divided waveguide section of the waveguide device. The position of the sidewall feature may be determined based on an impedance matching metric between the common port and the divided ports, an isolation metric between the divided ports, or both.

A compact antenna feeder and associated circulator plate are disclosed. The antenna feeder includes: an orthomode transducer (OMT) polarizer, a first circulator and a second circulator. The OMT -polarizer includes a septum, a first port, a second port, and a third port. The first circulator is coupled to the first port of the OMT polarizer to define one orthogonally polarized microwave signal path between the first circulator and the third port of the OMT-polarizer. The second circulator is coupled to the second port of the OMT polarizer to define another orthogonally polarized microwave signal path between the second circulator to the third port of the OMT-polarizer. The OMT polarizer includes a waveguide with the septum located therein separating the two orthogonally polarized microwave signal paths. The septum has a base mounted on the circulator plate and a step-shape body extending from the base and out of the circulator plate.

Methods, systems, and devices are described that include one or more septum features to improve performance of a waveguide device. In particular, the septum features may be utilized within a polarizer section of a polarizer device such as a septum polarizers. The septum feature(s) may be a ridge. When a plurality of septum features are employed, the location, size, shape and spacing may vary according to a particular design.

In an example embodiment, a waveguide device comprises: a first common waveguide; a polarizer section, the polarizer section including a conductive septum dividing the first common waveguide into a first divided waveguide portion and a second waveguide divided portion; a second waveguide coupled to the first divided waveguide portion of the polarizer section; a third waveguide coupled to the second divided waveguide portion of the polarizer section; and a dielectric insert. The dielectric insert includes a first dielectric portion partially filling the polarizer section. The conductive septum and the dielectric portion convert a signal between a polarized state in the first common waveguide and a first polarization component in the second waveguide and a second polarization component in the third waveguide.

A three-dimensional resonant chamber is described. The three-dimensional resonant chamber may support a plurality of circularly polarized modes at a desired frequency. The desired frequency may be in an ISM (Industrial, Scientific, Medical) frequency band, such as in the 902 MHz-928 MHz or in the 2.4 GHz-2.5 GHz. The three-dimensional resonant chamber may comprise one or more openings for coupling electromagnetic radiation outside the three-dimensional resonant chamber. The three-dimensional resonant chamber may be disposed in a cavity, such as a microwave oven, and may be configured to excite the cavity through the one or more openings. The three-dimensional resonant chamber may be connected to a waveguide support a circularly polarized mode.

Apparatus and associated methods relate to determining, based on a detected portion of a projected pulse of quasi-optical energy backscattered by water particles within a divergent projection volume of a cloud atmosphere, properties of the backscattering water particles. The pulse of quasi-optical energy is projected into the divergent projection volume of the cloud atmosphere. The divergent projection volume is defined by an axis of projection and an angle of projection about the axis of projection. The portion of the projected pulse of optical energy backscattered by water particles within the divergent projection volume of the cloud atmosphere is received and detected. Various properties of the backscattering water particles, which can be determined from the detected portion of the projected pulse backscattered by water particles can include particle density and/or particle size.

In an example embodiment, a waveguide device comprises: a first common waveguide; a polarizer section, the polarizer section including a conductive septum dividing the first common waveguide into a first divided waveguide portion and a second waveguide divided portion; a second waveguide coupled to the first divided waveguide portion of the polarizer section; a third waveguide coupled to the second divided waveguide portion of the polarizer section; and a dielectric insert. The dielectric insert includes a first dielectric portion partially filling the polarizer section. The conductive septum and the dielectric portion convert a signal between a polarized state in the first common waveguide and a first polarization component in the second waveguide and a second polarization component in the third waveguide.