Abstract: An antenna comprising: a ground plane having a center; six receive ports mounted to the ground plane in a circular configuration around the center and separated from each other by approximately 60 degrees; three conductive half-loops, disposed in mutually orthogonal planes, wherein each half-loop has two ends that are connected to separate receive ports; and three 180° hybrids, each 180° hybrid having two input ports, a delta output port, and a sum output port, wherein the two input ports of each 180° hybrid are connected to the two receive ports of one of the half-loops.

Abstract: An antenna comprising: a loop made of conductive material; two baluns connected to, and intersecting, opposing sides of the loop, wherein each balun has an output; a 180° hybrid coupler having two input ports, a sum output port, and a delta output port, wherein the two input ports are connected to the outputs of the baluns; a first low noise amplifier (LNA) connected to the sum output port; a second LNA connected to the delta output port; first and second receivers connected to the first and second LNAs respectively; and wherein the antenna is electrically small and is designed to simultaneously receive wideband signals in real time from 3 to 30 MHz.

Abstract: A method for identifying performance bounds of a transmit-receive (T/R) module over a bandwidth ƒb when connected to an antenna, a transmitter, and a receiver all with known reflectance within the bandwidth ƒb; measuring a raw T/R module point representing isolation and insertion loss of the T/R module when connected to the antenna, the transmitter, and the receiver without a matching circuit; plotting the raw T/R module point on a performance image graph; using a mathematical representation of a multiport matching circuit that contains no gyrators and comprises a fixed number of capacitors and inductors to approximate a Pareto front comprised of a plurality of Pareto points; and connecting each Pareto point to the raw T/R module point on the performance image graph such that the performance image becomes a visual representation of the performance bounds of a class of multiport matching circuits having capacitors and inductors.

Abstract: An antenna comprising: a loop made of conductive material; two baluns connected to, and intersecting, opposing sides of the loop, wherein each balun has an output; a 180° hybrid coupler having two input ports, a sum output port, and a delta output port, wherein the two input ports are connected to the outputs of the baluns; a first low noise amplifier (LNA) connected to the sum output port; a second LNA connected to the delta output port; first and second receivers connected to the first and second LNAs respectively; and wherein the antenna is electrically small and is designed to simultaneously receive wideband signals in real time from 3 to 30 MHz.

Abstract: An antenna comprising: a ground plane having a center; six receive ports mounted to the ground plane in a circular configuration around the center and separated from each other by approximately 60 degrees; three conductive half-loops, disposed in mutually orthogonal planes, wherein each half-loop has two ends that are connected to separate receive ports; and three 180° hybrids, each 180° hybrid having two input ports, a delta output port, and a sum output port, wherein the two input ports of each 180° hybrid are connected to the two receive ports of one of the half-loops.

Abstract: A system includes a first low noise amplifier, a second low noise amplifier, a local analog oscillator signal, a signal splitter, a mixer, a mixer, an analog to digital converter and a digital channelizer. The first low noise amplifier outputs a first amplified analog signal based on a received analog antenna signal at a time t0. The second low noise amplifier outputs a second amplified analog signal based on the received analog antenna signal at a time t1. The local analog oscillator signal outputs a local analog oscillator signal. The signal splitter outputs a split analog oscillator signal and a split analog oscillator signal. The mixer outputs a first mixed signal. The mixer outputs a second mixed signal. The analog to digital converter outputs a combined digital signal. The digital channelizer outputs a received signal based on the combined digital signal.

Abstract: Aspects of the present invention provide a system and method for using a filter controller and an adjustable narrow-band filter within each sub-band of a communication system. If a channel of the sub-band is being jammed, the filter controller will adjust the adjustable narrow-band filter to notch-filter out only the channel of the sub-band that is being jammed. In this manner, the remaining channel of the sub-band may be used for communication.

Abstract: A circulator-enabled signals suppressor (CENSOR) for reducing co-site interference comprising: a first circulator comprising first, second, and third ports, wherein the first port is disposed to receive an incoming signal from an antenna, wherein the incoming signal comprises a desired signal and an interference signal; a first reflective, tunable bandpass filter-bank operatively coupled to the second port, disposed to reflect a reflected signal back into the second port and also to produce a filtered signal, wherein the reflected signal comprises the desired signal and a reflected portion of the interference signal, and the filtered signal comprises a majority portion of the interference signal; and a receiver operatively coupled to the third port and disposed to receive the reflected signal.

Abstract: A multi-band antenna comprising a tree and a plurality of current probes coupled around the tree. Each current probe is designed to receive and transmit in a substantially different frequency band than the other current probes. The current probes are positioned on the tree so as to effectively create a plurality of transmit/receive antennas such that each respective antenna has a voltage standing wave ratio (VSWR) of less than or equal to approximately 3:1 for a given range within each respective frequency band.

Abstract: A system includes an input multi-level channelizer, an output multi-level channelizer, and more than one amplifiers connected between the input and output channelizers. The input and output channelizers cover an operating frequency band. Each level of the input multi-level channelizer comprises a plurality of input channels, which may be bandpass filters, and may be grouped into input sub-channelizers. Each successive level of the input multi-level channelizer is configured to divide the incoming signals into smaller frequency bands. Each level of the output multi-level channelizer comprises a plurality of output channels, which may be bandpass filters, and may be grouped into output sub-channelizers. Each successive level of the output multi-level channelizer is configured to combine the incoming signals into larger frequency bands. The signal output from the output multi-level channelizer represents a filtered version of the signal input into the input multi-level channelizer.

Abstract: A system includes a first circulator, a second circulator connected to the first circulator and a load, a third circulator connected to the second circulator, and a filter connected between the first and third circulators. The filter modifies the phase and amplitude of a first signal from the first circulator to produce a modified first signal. The modified first signal amplitude may be equal to the amplitude of a second signal from the second circulator. The phase of the modified first signal is about 180 degrees out of phase with the second signal phase. The third circulator circulates the modified first signal towards the second circulator. The first signal comprises a coupled signal from the first circulator. The second signal comprises a signal reflected from the load and a coupled signal from the second circulator. The filter may be a passive network having lumped, distributed, and resistive elements.

Abstract: A system includes more than one subsystem, each subsystem operating within a different subsystem frequency range, the subsystems comprising a circulator having three or more circulator ports and a direction of circulation, the circulator operating within a specific frequency range of the subsystem frequency range, and a filter, such as a bandpass filter, connected to at least one of the circulator ports. The filters each define a subsystem port and operate within the specific frequency range. Each subsystem port has a port index determined by the direction of circulation of the circulator within the subsystem. Each subsystem port has a specific port index that is connected to a common port having the specific port index. At least one of the circulator ports may be terminated to a matched load. Each subsystem circulator may comprise at least three circulator ports, with a filter connected to each of the circulator ports.

Abstract: A resonance confocal imaging of resonance control points method and system. The method includes receiving a far-field scattered response from a structure. The method further includes determining resonant frequencies from said far-field scattered response. Then, determining resonant control points of said structure from said far-field scattered response at the resonant frequencies.

Abstract: A comb limiter combiner for frequency-hopped communications includes an input signal coupler for coupling to a receiving antenna and distributing the antenna signal to a bank of input bandpass filters. The input bandpass filters have contiguous passbands that comprise the total receiver bandwidth. Each input bandpass filter is connected to a limiter having a threshold substantially equal to the limiting threshold of the receiver. Each limiter is connected to an output bandpass filter similar to the corresponding input bandpass filter to remove out-of-band intermodulation products generated by the limiter. The bank of output bandpass filters is connected to an output signal coupler for coupling to the front end of the receiver.

Abstract: The present invention is a Comb linear amplifier combiner (CLAC) apparatus that allows one or more transmitters to transmit through one transmit antenna. The CLAC apparatus passes low powered transmit signals through a bank of bandpass filters. The transmit signals then pass through Class A amplifiers which amplify the transmit signals to the full transmit power. The full transmit power signals then pass through a second bank of bandpass filters. The transmission signals are then transmitted through a single transmission antenna.

Abstract: A wideband high isolation circulator network reduces or eliminate interfece from a nearby RF transmitted signal in a received RF signal. The network includes a first sampler for dividing a first signal into second and third signals; a circulator for receiving the second signal through a first port, for outputting a fourth signal and receiving a fifth signal through a second port, and for outputting a sixth signal through a third port which represents the vector sum of samples of the second and fifth signals; and a signal processing stage which generates a seventh signal having amplitude and phase characteristics representing the fifth signal in response to receiving the third and sixth signals.

Abstract: A frequency selective surface integrated antenna is provided which compri a frequency selective surface, including an electrically non-conductive substrate and an electrically conductive layer, mounted to the substrate and having a pattern of apertures; and an antenna integrated in the frequency selective surface.

Abstract: An omni-directional antenna is provided which comprises: 1) a first prolate spheroid having an electrically conductive first outer surface and a first center axis, 2) a second prolate spheroid having an electrically conductive second outer surface and a second center axis, 3) a structural member for supporting the first prolate spheroid a fixed distance from the second prolate spheroid so that the first and second center axes are coincident, 4) a first resistive ring mounted to the surface of the first prolate spheroid; 5) a second resistive ring mounted to the surface of the second prolate spheroid; and 5) a coaxial cable having an outer conductor electrically connected to the second surface of the second prolate spheroid and a center conductor electrically connected to the first surface of the first prolate spheroid.