Waveguide filters comprising ridges disposed within a waveguide cavity for selecting electromagnetic signals within a frequency passband. An apparatus includes a waveguide filter comprising a waveguide cavity and a plurality of ridges disposed within the waveguide cavity. The apparatus is such that each of the plurality of ridges comprises a first side and a second side, and wherein the first side and the second side are disposed at a non-orthogonal angle relative to one other. The apparatus is optimized for fabrication using metal additive manufacturing techniques.

Waveguide filters comprising ridges disposed within a waveguide cavity for selecting electromagnetic signals within a frequency passband. An apparatus includes a waveguide filter comprising a waveguide cavity and a plurality of ridges disposed within the waveguide cavity. The apparatus is such that each of the plurality of ridges comprises a first side and a second side, and wherein the first side and the second side are disposed at a non-orthogonal angle relative to one other. The apparatus is optimized for fabrication using metal additive manufacturing techniques.

Waveguide filters comprising ridges disposed within a waveguide cavity for selecting electromagnetic signals within a frequency passband. An apparatus includes a waveguide filter comprising a waveguide cavity and a plurality of ridges disposed within the waveguide cavity. The apparatus is such that each of the plurality of ridges comprises a first side and a second side, and wherein the first side and the second side are disposed at a non-orthogonal angle relative to one other. The apparatus is optimized for fabrication using metal additive manufacturing techniques.

Methods and devices suitable for monitoring the frequency of microwave tunable filters in real time. The frequency readout relies on the natural response of such a filter when excited by a pulse. Methods of measuring an operating frequency of a pole in a tunable filter include measuring a number of cycles in a natural response in the filter when the filter is excited by an electric current pulse, and determining a resonance frequency based on the number of cycles measured in the natural response. Such a method can provide the operating frequency information in a binary digital format, making it relatively easy to read and process. A measuring resonator may be mounted to the filter resonator and connected by a common actuator.

An evanescent-mode cavity filter with an improved MEMS tuner design is disclosed. The MEMS tuner design allows for the independent control of individual poles in a multi-pole filter, which increases the adaptability of the filter in a crowded RF environment. The filter is further designed to minimize tuning voltages and hysteresis effects. A closed loop control system provides highly responsive tuning of the filter. The closed loop control allows for accurate and stable tuning that compensates for temperature and vibrational effects, while the tuner design enables fast tuning and significantly increases the resolution of the feedback measurement by eliminating charge buildup in the tuner substrate.

An evanescent-mode cavity filter with an improved MEMS tuner design is disclosed. The MEMS tuner design allows for the independent control of individual poles in a multi-pole filter, which increases the adaptability of the filter in a crowded RF environment. The filter is further designed to minimize tuning voltages and hysteresis effects. A closed loop control system provides highly responsive tuning of the filter. The closed loop control allows for accurate and stable tuning that compensates for temperature and vibrational effects, while the tuner design enables fast tuning and significantly increases the resolution of the feedback measurement by eliminating charge buildup in the tuner substrate.

Methods and devices suitable for monitoring the frequency of microwave tunable filters in real time. The frequency readout relies on the natural response of such a filter when excited by a pulse. Methods of measuring an operating frequency of a pole in a tunable filter include measuring a number of cycles in a natural response in the filter when the filter is excited by an electric current pulse, and determining a resonance frequency based on the number of cycles measured in the natural response. Such a method can provide the operating frequency information in a binary digital format, making it relatively easy to read and process. A measuring resonator may be mounted to the filter resonator and connected by a common actuator.

Plasma jet assemblies utilizing evanescent mode cavity resonators, and methods of making the same and using the same, are described.

Plasma jet assemblies utilizing evanescent mode cavity resonators, and methods of making the same and using the same, are described.

A radiofrequency filter exhibiting at least one resonant mode comprises: at least one cavity at least partially closed using conductive walls, having a cylindrical outer surface defined by a directing curve described by a generatrix and having a point of symmetry, an axis passing through a point of symmetry and parallel to the generatrix being a longitudinal axis of the cavity. At least one dielectric element is arranged in the cavity and comprises: a first portion having a thickness according to the longitudinal axis and a section according to a plane perpendicular to the longitudinal axis whose vertices are distributed according to a polygon, at least two vertices being short-circuited between them by the conductive walls of the cavity, via an electrical or radiofrequency contact between the vertices and walls, at least one pyramidal portion comprising an apex and a base coinciding with an extreme section of the first portion.