Space Systems/loral, LLC

Stephen D Berry

Stephen C Holme

Slawomir J Fiedziuszko

Jonathan D Chang

George A Fiedziuszko

David Max Solomon

Lawrence Alan Carastro

A radio frequency (RF) dielectric resonator filter includes at least a first cavity and a second cavity, each cavity being loaded with a dielectric resonator. The first cavity is separated from the second cavity by a common wall, the common wall including a first and second aperture that couple an electromagnetic field between the first cavity and the second cavity. A first externally adjustable tuning screw extends from the second aperture, a portion of the tuning screw being external to the filter. The first aperture is an iris disposed in a central portion of the wall and the second aperture is disposed proximate to a perimeter of the wall. The second aperture has an effective area that is adjustable by the first externally adjustable tuning screw.

Dielectric resonator filter and multiplexer having a common wall with a centrally located coupling iris and a larger peripheral aperture adjustable by a tuning screw

A multiplexer includes a microstrip manifold, and a filter bank having at least two output filters. The multiplexer channelizes an input radio frequency (RF) band of electromagnetic energy into a set of output channels by way of the filter bank. The microstrip manifold has an input port that receives an input RF signal, and at least two output ports. The microstrip manifold distributes the input RF signal to each output port, each said output port being coupled to a respective one of the at least two output filters. The multiplexer may be an input multiplexer for a spacecraft communications payload system.

Microstrip manifold coupled multiplexer

An RF bandpass filter includes a cascaded series of a first subfilter and a second subfilter. Each subfilter includes a respective inverter, voltage-controlled capacitor and inductor. A first selected one of the first subfilter and the second subfilter is a pseudo low pass filter and a second selected one of the first subfilter and the second subfilter is a pseudo high pass filter. The RF bandpass filter is configured to separately control a bandwidth and center frequency of output RF energy. The bandwidth may be controlled to be substantially fixed over a significant substantial range. The center frequency and bandwidth are controlled by adjusting a voltage input to one or more of the voltage-controlled capacitors.

Frequency and bandwidth tunable microwave filter

A dual mode dielectric resonator (DR) filter has a first DR, and is configured to operate at a HE12&#x3b4; mode within a first frequency band while exhibiting a Q factor of no less than 5000. A first characteristic size of the first DR may be substantially similar to a size of a second DR, where the second DR is configured to operate in a conventional DR filter at a HE11&#x3b4; mode within a second frequency band, the second frequency band being substantially lower than the first frequency band.

Dual mode dielectric resonator operating in a HE mode with a Q factor no less than 5000

A multi-cavity RF filter has at least one electrically conductive coupling probe disposed between two resonator cavities. The coupling probe is provided with an ESD protective arrangement such that the coupling probe is electrically connected to a metallic housing of the RF filter only by the ESD protective arrangement. The ESD protective arrangement is configured to provide (i) a low resistance electrical path from the coupling probe to the metallic housing and (ii) a high impedance to RF energy having wavelengths proximate to a center frequency wavelength of the RF filter.

Electrostatic discharge control for a multi-cavity microwave filter

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.

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San Ramon, CA, United States of America

Stephen D Berry