USA As Represented by Secretary of the Navy

Purdue Research Foundation

Bae Systems Information and Electronic Systems Integration Inc.

Eric J Naglich

Andrew C Guyette

Dimitrios Peroulis

Paul D Zemany

William Johnson Chappell

Jack Chuang

Mark D Hickle

Mark E Stuenkel

Thomas J Johnson

Curtis M Grens

Michael Dimitri Sinanis

Souleymane Gnanou

Hjalti Hreinn Sigmarsson

Adrew C Guyette

Sanghoon Shin

JuSeop Lee

Systems and method are provided for implementing filters whose response automatically and continuously reconfigures between an all-pass response and a bandstop response as the power level of signals within their bandwidth changes. Embodiments of the present disclosure allow high power signals within a designable bandwidth to be strongly attenuated while minimally affecting signals in adjacent bandwidths and further allow low power signals in the designable bandwidth to pass with minimal attenuation.

Bandstop filters with power-dependent stopband attenuation

Systems and methods are provided for implementing bandstop filters (e.g., RF/microwave bandstop filters) that can automatically tune to a frequency of an interfering signal. Embodiments of the present disclosure provide automatically tunable signal-tracking bandstop filters with a significant reduction in response time, complexity, size, weight, and cost when compared to conventional devices.

Signal-tracking RF bandstop filter

Systems and methods are provided for creating higher order microwave bandstop filters with total through-line length of significantly less than one-quarter wavelength at the filter center frequency. The mixed electric and magnetic field coupling bandstop filter topologies provided by embodiments of the present disclosure can be used to reduce the size, weight, and throughline insertion loss of microwave bandstop filters. In an embodiment, if the relative field strengths are intelligently designed for each coupling structure, effective phase offsets can be produced between resonators along the through line. These phase offsets can be used to absorb some or all of the length of the &#x3bb;/4 inverters between resonators.

Bandstop filters with minimum through-line length

Systems and method are provided for a switching circuit that enables attenuation of high power signals in relatively small band(s) without attenuating information in other bands. Embodiments of the present disclosure provide switching circuits with intrinsically switched filters that enable channelized limiting without affecting adjacent channels. Further, embodiments of the present disclosure provide a unique filter coupling topology that enables filters to be switched on or off without changing the input impedance of the filters.

Switched multiplexer with flat group delay and channelized limiting

Systems and methods are provided for implementing a switched microwave bandstop filter with minimum insertion loss and phase distortion in the bypass state. For example, embodiments of the present disclosure provide systems and methods for implementing self-switching bandstop filters that do not require signal-routing RF switches, allowing for very low passband insertion loss and improved power handling.

Switched bandstop filter with low-loss linear-phase bypass state

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.

Tunable evanescent-mode cavity filter with closed loop control

A field programmable filter array with high spectral isolation and reconfigurability. A bank of resonators can be programmed at will and on the fly to give any type of filtering response. The order, type and bandwidth of the filter are electronically reconfigured. Each subset of resonators can switch between bandstop and bandpass configurations and form custom filter shapes consisting of combinations of bandstop and bandpass filters. The filter can include a unit cell of a resonator with a series of switches to enable coupling to any of its nearest neighbors. The path in which the flow of energy takes through the array of resonators is dynamic, and the filtering function which is created is dialable on demand.

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Alexandria, VA, United States of America

Eric J Naglich