Space Systems/loral, LLC

George A Fiedziuszko

Slawomir J Fiedziuszko

Jonathan D Chang

Stephen D Berry

Robert N Seehorn

Hoover R Lee

Gary W White

Victor Tam

A heat transfer interface is provided for radio-frequency resonator cavity filters used in vacuum environments such as are encountered by spacecraft and satellites. The heat transfer interface may include a thermally conductive structure that encircles or partially encircles a tubular structure of the resonator cavity filter and heat transfer legs that extend from positions that are on opposite sides of the thermally conductive structure and at approximately the same distance from a support surface to the support surface. The heat transfer legs and the thermally conductive structure may be made from a material or materials having a thermal conductivity of 350 W/(m&#xb7;K) or greater.

High-frequency cavity resonator filter with diametrically-opposed heat transfer legs

A multiplexer includes a filter channelizer having at least two output filters, each output filter being coupled with a respective hybrid coupler. The multiplexer channelizes an input radio frequency (RF) band of electromagnetic energy into a set of output ports. Each hybrid coupler includes an input port (port 1), two output ports and an isolated port (port 4). Each output filter is coupled to a first one of the two output ports of a respective hybrid coupler, a second one of the two output ports being connected to an open stub microstrip transmission line. The respective hybrid coupler is coupled in a daisy chain, by way of port 1 and port 4, with one or more of the input of the multiplexer, and at least one other hybrid coupler. Advantageously, each output channel may include no more than one filter and no more than one hybrid coupler.

Compact microstrip hybrid coupled input multiplexer

A flexible waveguide has a flexible wall enclosing an elongated cylindrical passage for transmission of an electromagnetic wave along the passage. A succession of corrugations is disposed along an interior surface of the wall facing the passage. The corrugations are spaced apart by a distance less than approximately 0.2 wavelength of the electromagnetic wave, each of the corrugations having a height greater than the distance but less than approximately 0.5 wavelength of the electromagnetic wave, and each corrugation having a curved surface to minimize loss in the transmission of the electromagnetic wave.

Flexible waveguide with rounded corrugations

An equalizer that couples a dual-mode dielectric resonator to a planar transmission line, creating an all-pass network. Coupling is achieved using circular polarization of the electromagnetic field in the dielectric resonator. The all-pass, non-reciprocal network is realized by the use of circular polarized energy and an offset cross shaped, through transmission line.

Dielectric resonator equalizer

An electromagnetic cavity filter is formed by at least two cavities having electrically conductive walls. Each cavity is the equivalent of two filter poles because two orthogonal modes of electromagnetic radiation can resonate within each cavity. Characterizing vector tuning elements are coupled to each of the cavities that are each aligned along respective axes. The tuning elements are used to provoke derivative orthogonal modes and determine the degree of coupling between orthogonal modes. One or more intercavity couplers interconnect the cavities and are rotated at arbitrary angles that are different from the axes of the characterizing vector tuning elements. Electrically adjacent and nonadjacent modes of proximate cavities can be coupled, permitting elliptic filter functions. Electrically nonadjacent modes are coupled by means of an iris interconnecting the two cavities. Electrically adjacent modes are coupled by means of an electrically conductive probe penetrating each of the cavities. A dielectric resonator may be disposed within each cavity to reduce the physical size of the cavity while preserving its electrical characteristics. Input and output coupling elements, coupled to selected cavities may be disposed at locations that are angularly rotated with respect to a corresponding characterizing vector tuning element by a selectable angle that varies between 0 and &plusmn;180 degrees.

Planar general response dual-mode cavity filter

A ceramic resonator element having high Q, high dielectric constant, and a low temperature coefficient of resonant frequency is enclosed within a cavity to form a composite microwave resonator having reduced dimensions and weight as compared to a simple cavity resonator. In an exemplary embodiment, a pair of tuning screws extend into the cavity along orthogonal axes to tune the structure to resonance along these axes at frequencies near the fundamental resonance of the ceramic element. Several such cavities can be formed in a short length of waveguide by the use of transverse partitions at spaced intervals and coupling between cavities can be accomplished by using simple slot, cross or circular irises. In each cavity, a mode-perturbing screw is positioned along an axis 45&deg; from each of the orthogonal tuning screws, such that resonance along either of the orthogonal axes is coupled to excite resonance also along the other. The input and output coupling devices are disposed at locations that are angularly separated from the corresponding tuning devices by a selectable angle that varies between 0 degrees and &plusmn;180 degrees. This Variability in location of the input and output coupling devices provides for a filter having adjustable input/output coupling. The realization of complex filter functions requiring cross couplings is feasible by means of coupling separately to only one of the two orthogonal resonant-modes in the cavities.

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San Jose, CA, United States of America

George A Fiedziuszko