An anti-fouling, radiation emitter isolation assembly includes an adapter element mounted to a fixed port at the top of a leachate tank. A radiation emitter/detector is further mounted to the adapter element for transmitting radiation through the fixed port to determine a fluid level. The adapter element incorporates an isolation valve that when opened provides an unobstructed window through the fixed port for the transmitted radiation and when closed isolates said radiation emitter/detector from the fixed port. In particular, selectively isolating the radiation emitter/detector from the interior of the tank permits removal of the radiation emitter/detector from the adapter element without requiring a shutdown of leachate tank system operations.

Disclosed in the present disclosure is an ultra-wide band antenna using a wave-absorbing material and a dielectric, which relates to the technical field of antennas. The antenna includes an upper fixing plate and a lower fixing plate, a left side plate and a right side plate are fixed between the upper fixing plate and the lower fixing plate separately, and the upper fixing plate, the lower fixing plate, the left side plate and the right side plate are fixed together to form a cylindrical structure. A cavity is fixed at the left end opening of the cylindrical structure, a first wave-absorbing material block is fixed in the cavity, an upper ridge and a lower ridge are arranged in the cylindrical structure, and tail ends of the upper ridge and the lower ridge are inserted into the first wave-absorbing material block.

It is disclosed a waveguide array antenna for satellite communications. The antenna is configured to transmit and/or receive a first polarization signal and a second polarization signal, the second polarization being orthogonal to the first polarization, and comprises an array of unit cells, each comprising a radiating element. The antenna comprises: a grid configured to divide each radiating element into sub-elements having an inter-element distance lower than or equal to the wavelength at a highest frequency of operation of the antenna; and an electromagnetic band gap layer configured to support the grid above the radiating elements. The grid comprises a number of grid unit portions, and the electromagnetic band gap layer consists of a number of pins protruding from the walls of each grid unit portion.

A millimeter-wave antenna includes a slit which is provided in a GND conductor formed in a first surface of a circuit board, a horn antenna which is provided with a first opening and a second opening, and an impedance matching device which is provided in a slot shape between the slit and the first opening of the horn antenna. The impedance matching device is formed in the slot shape which is filled with a dielectric having a dielectric constant different from that of the circuit board. The impedance matching device is configured such that a length of the slot shape in a propagation direction is less than 1/4 of a wavelength of a use frequency upper limit. The impedance matching device is configured such that a size of a rectangular shape of the slot shape in a magnetic field direction is larger than the first opening of the horn antenna.

A microwave heating device includes a variable frequency microwave power supply, a waveguide launcher, and a fixture to contain a material to be heated, with the fixture located directly adjacent to the end of the launcher. All heating occurs in the near-field region. This condition may be insured by keeping the thickness of the fixture or workpiece under one wavelength (at all microwave frequencies being used). The launcher is preferably a horn or waveguide configured to apply the microwave power to a small area to perform spot curing or repair operations involving adhesives and composites. The spot curing may secure components in place for further handling, after which a thermal or oven treatment will cure the remaining adhesive to develop adequate strength for service.

A related method is also disclosed.

A tapered core waveguide which may be configured as a spectral component splitter, a spectral component combiner, and various combinations thereof including a reflective mode of operation. The tapered core waveguide has an aperture and cladding, and is dimensioned such that radiant energy admitted into the core via the aperture and having at least two spectral components would be emitted via the cladding at a location dependent on its frequency and/or its polarization, and that a plurality of spectral components injected to the core via the cladding will be mixed and emitted via the aperture.

A directionally-tunable antenna element of an antenna is provided. The directionally-tunable antenna element includes a feed structure, a coupling structure, and a ridge structure. The coupling structure is disposed between the feed structure and the ridge structure and communicates electromagnetic energy between the feed structure and the ridge structure. These structures address challenges associated with satellite tracking and frequent satellite handoffs in an electronically scanned array (ESA). The disclosed aspects enhance performance of ESA antenna systems, addressing shortcomings of ESA antenna systems yet while addressing the satellite tracking and frequent satellite handoff challenges. The disclosed aspects provide for antennas with highly efficient useable gain bandwidth, high scan angle performance, and consistent and high cross polar isolation over a full scan angle range.

A corrugated feed horn for antenna has an oval pattern of corrugations, and a series of intermediate ridges spaced between adjacent corrugation ridges only in the regions of the slots near its major axis. The intermediate ridges provide a feed horn that is capable of producing a relatively uniform oval beam, and has enough corrugations per wavelength to guarantee little diffraction on the edges of the horn, thus resulting in an antenna with very low side lobes.

Broadband antennas are described that include a quad-ridge horn inside which two different lenses are inserted creating a broadband horn-lens combination. One of these lenses is a cross-polyrod lens, formed from a pair of polyrods disposed in a crossed arrangement, each polyrod shaped in a predetermined manner. The other one of these lenses is a prolate spheroidal lens. The broadband antennas can produce, at the output thereof, Gaussian-like beams in both principal polarizations from VHF to 20 GHz. As such, the broadband antennas can be used to perform material measurements in a compact admittance tunnel. Simulation results show that directivity of quad-ridge horns can be improved using the combination of lenses of the broadband antennas. Therefore, the broadband antennas can also be of interest for far-field radiation applications.

An antenna horn includes an upper waveguide ridge and a lower waveguide ridge shaped to provide impedance matching. The antenna horn operates unimodally within a 6:1 instantaneous bandwidth. A circular array of antenna horns produces an enhanced radiation pattern in a horizontal plane with reduced radiating in the direction orthogonal to the horizontal plane. Furthermore, two circular arrays of half-height antenna horns may be arranged on a collinear axis, offset by one half of a sector width as defined by each horn aperture to reduce coupling.