Abstract: A frequency conversion circuit having a plurality of N signal channels, each being fed an input signal and a train of pluses having a period T and a duty cycle T/N. Each channel includes: a sampler coupled the input signal and being responsive to sampling signals; and a controllable time delay for producing the train of sampling signals in response to the train of pulses, the time delay imparting a time delay to the pulses in accordance with a time delay command signal fed to the time delay. Each one of the sampling signals is produced by the time delay in each one of the channels with the period T and the duty cycle T/N with the sampling signals in one of the trains of the sampling signals being delayed with respect to the sampling signals in another one of the trains the sampling signals a time T/N.

Abstract: A transmit drive circuit with high signal to noise and frequency agility. In one embodiment, a transmit circuit includes a digital to analog converter, an amplifier, and a signal to noise enhancer, the signal to noise enhancer being a nonlinear passive device that attenuates low-power signals while transmitting high power signals with little loss. The signal to noise enhancer may be fabricated as a thin film of yttrium iron garnet (YIG) epitaxially grown on a gadolinium gallium garnet (GGG) substrate, the GGG substrate secured to a microwave transmission line from the input to the output of the signal to noise enhancer, such that the thin film of yttrium iron garnet is close to the transmission line.

Abstract: A frequency conversion system with improved performance. In one embodiment an image reject mixer is used to perform frequency conversion providing an initial degree of suppression of the image and local oscillator leakage signals, and a signal to noise enhancer (SNE) is used to further suppress the image and local oscillator signals, the signal to noise enhancer being a nonlinear passive device that attenuates low-power signals while transmitting high power signals with little loss. The signal to noise enhancer may be fabricated as a thin film of yttrium iron garnet (YIG) epitaxially grown on a gadolinium gallium garnet (GGG) substrate, the GGG substrate secured to a microwave transmission line from the input to the output of the signal to noise enhancer, such that the thin film of yttrium iron garnet is close to the transmission line.

Abstract: A transmit drive circuit with high signal to noise and frequency agility. In one embodiment, a transmit circuit includes a digital to analog converter, an amplifier, and a signal to noise enhancer, the signal to noise enhancer being a nonlinear passive device that attenuates low-power signals while transmitting high power signals with little loss. The signal to noise enhancer may be fabricated as a thin film of yttrium iron garnet (YIG) epitaxially grown on a gadolinium gallium garnet (GGG) substrate, the GGG substrate secured to a microwave transmission line from the input to the output of the signal to noise enhancer, such that the thin film of yttrium iron garnet is close to the transmission line.

Abstract: A frequency conversion system with improved performance. In one embodiment an image reject mixer is used to perform frequency conversion providing an initial degree of suppression of the image and local oscillator leakage signals, and a signal to noise enhancer (SNE) is used to further suppress the image and local oscillator signals, the signal to noise enhancer being a nonlinear passive device that attenuates low-power signals while transmitting high power signals with little loss. The signal to noise enhancer may be fabricated as a thin film of yttrium iron garnet (YIG) epitaxially grown on a gadolinium gallium garnet (GGG) substrate, the GGG substrate secured to a microwave transmission line from the input to the output of the signal to noise enhancer, such that the thin film of yttrium iron garnet is close to the transmission line.

Abstract: The present disclosure is directed towards a frequency selective limiter having a first magnetic material disposed over a first dielectric material and a strip conductor disposed over the magnetic material. In some embodiments, the frequency selective limiter includes a second magnetic material disposed over the strip conductor and a second dielectric material disposed over the second magnetic material. The first and second dielectric material may have a lower relative permittivity than the first and second magnetic material. In an embodiment, the frequency selective limiter includes a slow wave structure disposed to magnetically couple a magnetic field, produced by electromagnetic energy propagating through the slow wave structure, into the magnetic material.

Abstract: A frequency conversion system with improved performance. In one embodiment an image reject mixer is used to perform frequency conversion providing an initial degree of suppression of the image and local oscillator leakage signals, and a signal to noise enhancer (SNE) is used to further suppress the image and local oscillator signals, the signal to noise enhancer being a nonlinear passive device that attenuates low-power signals while transmitting high power signals with little loss. The signal to noise enhancer may be fabricated as a thin film of yttrium iron garnet (YIG) epitaxially grown on a gadolinium gallium garnet (GGG) substrate, the GGG substrate secured to a microwave transmission line from the input to the output of the signal to noise enhancer, such that the thin film of yttrium iron garnet is close to the transmission line.

Abstract: A transmit drive circuit with high signal to noise and frequency agility. In one embodiment, a transmit circuit includes a digital to analog converter, an amplifier, and a signal to noise enhancer, the signal to noise enhancer being a nonlinear passive device that attenuates low-power signals while transmitting high power signals with little loss. The signal to noise enhancer may be fabricated as a thin film of yttrium iron garnet (YIG) epitaxially grown on a gadolinium gallium garnet (GGG) substrate, the GGG substrate secured to a microwave transmission line from the input to the output of the signal to noise enhancer, such that the thin film of yttrium iron garnet is close to the transmission line.

Abstract: A frequency source with improved phase noise. In one embodiment a phase-locked loop is used as a component of a frequency source and a signal to noise enhancer (SNE) is used to suppress phase noise produced by the phase-locked loop. The signal to noise enhancer is a nonlinear passive device that attenuates low-power signals while transmitting high power signals with little loss. The signal to noise enhancer may be fabricated as a thin film of yttrium iron garnet (YIG) epitaxially grown on a gadolinium gallium garnet (GGG) substrate, the GGG substrate being secured to a microwave transmission line from the input to the output of the signal to noise enhancer, such that the thin film of yttrium iron garnet is close to the transmission line.

Abstract: A decryption module is enabled on one or more authorized devices. A user's financial account information is encrypted using a card verification number, or some secret known to the user and replicated onto the authorized devices. The user requests processing of a financial transaction using the previously-encrypted financial account information. The authorized device retrieves the encrypted financial account information and prompts the user to enter the card verification number (or other secret known to the user that was used to encrypt the financial account information). The decryption module decrypts the financial account information using the card verification number entered by the user, and the decrypted financial account information resembles a valid credit card or debit card number and will pass a Luhn test. The decrypted financial account information is transmitted to process the financial transaction initiated by the user.

Abstract: The invention relates to a modular system for assembling a hollow structure. The system comprises segments for assembly into modules to assemble hollow structures such as culverts and water-retention systems. The segments comprise opposing sidewalls and a deck spanning said sidewalls having opposing sides and opposing ends which are assembled in inverted, vertically aligned relation to each other to form a hollow module. The segments engage each other with mutually engaging three dimensional structures that prevent lateral and vertical slippage between the segments. The segments may include half-columns that meet along the plane of engagement to form full-height load bearing columns in the assembled structure.

Abstract: A selective frequency limiter having a magnetic material and a slow wave structure disposed to magnetically couple a magnetic field, produced by electromagnetic energy propagating through the slow wave structure, into the magnetic material.

Abstract: A frequency conversion circuit having a plurality of N signal channels, each being fed an input signal and a train of pluses having a period T and a duty cycle T/N. Each signal channel includes: a column III-V semiconductor sampler coupled the input signal and being responsive to sampling signals; and a column IV semiconductor controllable time delay for producing the train of sampling signals in response to a train of pulses produced on the column IV semiconductor, the time delay imparting a time delay to the pulses in accordance with a time delay command signal fed to the time delay. Each one of the sampling signals is produced by the time delay in each one of the channels with the period T and the duty cycle T/N with the sampling signals in one of the trains of the sampling signals being delayed with respect to the sampling signals in another one of the trains the sampling signals a time T/N.

Abstract: A frequency conversion circuit having a plurality of N signal channels, each being fed an input signal and a train of pluses having a period T and a duty cycle T/N. Each channel includes: a sampler coupled the input signal and being responsive to sampling signals; and a controllable time delay for producing the train of sampling signals in response to the train of pulses, the time delay imparting a time delay to the pulses in accordance with a time delay command signal fed to the time delay. Each one of the sampling signals is produced by the time delay in each one of the channels with the period T and the duty cycle T/N with the sampling signals in one of the to trains of the sampling signals being delayed with respect to the sampling signals in another one of the trains the sampling signals a time T/N.

Abstract: A frequency conversion circuit having a plurality of N signal channels, each being fed an input signal and a train of pluses having a period T and a duty cycle T/N. Each signal channel includes: a column III-V semiconductor sampler coupled the input signal and being responsive to sampling signals; and a column IV semiconductor controllable time delay for producing the train of sampling signals in response to a train of pulses produced on the column IV semiconductor, the time delay imparting a time delay to the pulses in accordance with a time delay command signal fed to the time delay. Each one of the sampling signals is produced by the time delay in each one of the channels with the period T and the duty cycle T/N with the sampling signals in one of the trains of the sampling signals being delayed with respect to the sampling signals in another one of the trains the sampling signals a time T/N.

Abstract: A selective frequency limiter having a magnetic material and a slow wave structure disposed to magnetically couple a magnetic field, produced by electromagnetic energy propagating through the slow wave structure, into the magnetic material.

Abstract: A phase shifter-attenuator system having: a controller for producing a digital word representative of a predetermined phase shift and attenuation provided to an input signal; and a phase shifter-attenuation section. The phase shifter-attenuation section includes: a phase rotator for providing one of a plurality combinations of phase shifts-attenuation states to the input signal selectively in accordance with one portion of the produced digital word; and an attenuation section for distributing the plurality of combinations of phase shift-attenuation states over a selected range of attenuations, such range being selected in accordance with a second portion of the produced digital word.

Abstract: An interfering signal canceller has a passive isolation element fed by an input signal in a primary path. A first frequency converter is in an auxiliary path and is fed by an input signal for converting the input signal to an intermediate or baseband signal. A bandpass filter is tuned to the interfering signal component for passing the interfering signal component of the converted input signal and suppressing the desired signal component. A second frequency converter/phase rotator section has a phase rotator fed by a local oscillator signal and a second frequency converter fed by the phase rotator and the bandpass filter. The second frequency converter/phase rotator section convert and phase adjust the passed the interfering signal component and the suppressed desired signal component to the predetermined band of frequencies. A combiner combines signals in the primary signal path and from the second frequency converter/phase rotator section.

Abstract: A harmonic rejection mixer having a phase rotator fed by a local oscillator signal. The local oscillator signal has a reference frequency. The phase rotator produces a plurality of output signals, each one of the signals having a common frequency related to the reference frequency and having different relative phase shifts. A plurality of mixer sections, each one of the sections being fed an input signal and a corresponding one of the plurality of output signals mixes the local oscillator signal with the corresponding one of the plurality of output signals fed thereto. A combiner combines the mixer signal from the plurality of mixer sections into a composite output signal. A detector detects energy in a harmonic of the composite signal and for adjusting the output signal of the phase rotator to reduce the selected harmonic of the composite signal.

Abstract: A metamaterial radome/isolator system includes a radiation source for providing a radiation beam through the radome/isolator having a frequency beyond the bandgap region where the metamaterial permittivity and permeability are both positive and the metamaterial medium has a low, matched relative permittivity and relative permeability.