Abstract: A wideband multi-channel receiver comprises an antenna configured to receive a radio frequency band. A band-pass filter is in signal communication with the antenna, and a low-noise amplifier is in signal communication with the band-pass filter. A mixer is in signal communication with the low-noise amplifier and is configured to translate a radio frequency band to an intermediate frequency (IF) band. A tunable local oscillator is in signal communication with the mixer. At least one fixed-frequency notch filter is in signal communication with the mixer, with the notch filter configured to reject at least one interference signal in the IF band while passing remaining signals in the IF band. An analog-to-digital converter is in signal communication with the notch filter and is configured to convert the remaining signals in the IF band to digital signals.

Abstract: A wideband multi-channel receiver comprises an antenna configured to receive a radio frequency band. A band-pass filter is in signal communication with the antenna, and a low-noise amplifier is in signal communication with the band-pass filter. A mixer is in signal communication with the low-noise amplifier and is configured to translate a radio frequency band to an intermediate frequency (IF) band. A tunable local oscillator is in signal communication with the mixer. At least one fixed-frequency notch filter is in signal communication with the mixer, with the notch filter configured to reject at least one interference signal in the IF band while passing remaining signals in the IF band. An analog-to-digital converter is in signal communication with the notch filter and is configured to convert the remaining signals in the IF band to digital signals.

Abstract: A wideband multi-channel receiver comprises an antenna configured to receive a radio frequency band comprising an aviation VHF communication band, an aviation VHF navigation band, an aviation L-band, or combinations thereof. A band-pass filter is in signal communication with the antenna, and a low-noise amplifier is in signal communication with the band-pass filter. A mixer is in signal communication with the low-noise amplifier and is configured to translate a radio frequency band to an intermediate frequency (IF) band. A tunable local oscillator is in signal communication with the mixer. At least one fixed-frequency notch filter is in signal communication with the mixer, with the notch filter configured to reject at least one interference signal in the IF band while passing remaining signals in the IF band. An analog-to-digital converter is in signal communication with the notch filter and is configured to convert the remaining signals in the IF band to digital signals.

Abstract: A wideband multi-channel receiver comprises an antenna configured to receive a radio frequency band comprising an aviation VHF communication band, an aviation VHF navigation band, an aviation L-band, or combinations thereof. A band-pass filter is in signal communication with the antenna, and a low-noise amplifier is in signal communication with the band-pass filter. A mixer is in signal communication with the low-noise amplifier and is configured to translate a radio frequency band to an intermediate frequency (IF) band. A tunable local oscillator is in signal communication with the mixer. At least one fixed-frequency notch filter is in signal communication with the mixer, with the notch filter configured to reject at least one interference signal in the IF band while passing remaining signals in the IF band. An analog-to-digital converter is in signal communication with the notch filter and is configured to convert the remaining signals in the IF band to digital signals.

Abstract: A system and method for determining a received signal frequency by sampling the received signal at a rate less than twice a predefined nyquist rate. The system includes a distorting component configured to distort the received signal in a frequency dependent manner, at least one analog to digital converter configured to sample the received signal and the distorted signal at a rate less than twice a predefined nyquist rate, and a processing component configured to determine a frequency of the received signal based on the sampled received signal and the sampled distorted signal. The method includes distorting the received signal, sampling the received signal and the distorted signal at a rate less than twice a predefined nyquist rate, and determining a frequency of the received signal. In an embodiment, distorting includes at least one of distorting an amplitude or a group delay of the received signal.

Abstract: A computer system comprises a processing unit configured to process fixed size data words comprising at least one exponent field of variable size and a mantissa of variable size; an input device configured to provide data words to the processing unit; and an output device configured to output data words processed by the processing unit.

Abstract: A method to receive channels in an undersampled broadband receiver is provided. The method includes converting received radio frequency signals to downshifted-sampled-digital signals at an analog-to-digital converter in a sampling system, outputting the downshifted-sampled-digital signals to a digital system for digital processing, and determining if the unique identifying code associated with a desired channel is detectable. Each channel in the radio frequency signal has an assigned unique identifying code. When the unique identifying code is detectable, the method includes detecting the unique identifying code associated with the desired channel. When the unique identifying code is undetectable, the method includes outputting control signals from the digital system to tune an adjustable sample clock in the sampling system and tuning the adjustable sample clock based on the output control signals.

Abstract: An audio system may comprise a transceiver configured to receive, detect, and transmit audio signals on a first channel frequency and to receive and detect audio signals on at least one additional channel frequency. The at least one additional channel frequency may include a second channel frequency. The system may include a controller configured to output a first audio cue while outputting audio signals received from the at least one additional channel frequency, to output a second audio cue at a time when the controller begins outputting an audio signal received from the first channel frequency, and to output a third audio cue at a time when the controller begins outputting an audio signal received from the second channel frequency. The first, second, and third audio cues may be different from one another.

Abstract: A method to receive channels in an undersampled broadband receiver is provided. The method includes converting received radio frequency signals to downshifted-sampled-digital signals at an analog-to-digital converter in a sampling system, outputting the downshifted-sampled-digital signals to a digital system for digital processing, and determining if the unique identifying code associated with a desired channel is detectable. Each channel in the radio frequency signal has an assigned unique identifying code. When the unique identifying code is detectable, the method includes detecting the unique identifying code associated with the desired channel. When the unique identifying code is undetectable, the method includes outputting control signals from the digital system to tune an adjustable sample clock in the sampling system and tuning the adjustable sample clock based on the output control signals.

Abstract: A method of providing visual data to a pilot in an aircraft cockpit includes receiving information in the form of a voice signal, converting the information to visual data, and displaying the visual data to the pilot in the aircraft cockpit.

Abstract: A method to receive channels in an undersampled broadband receiver comprising mixing bands of assigned channels with an oscillator to generate downconverted bands, wherein each assigned channel has an assigned unique identifying code. The method further includes undersampling the downconverted bands and determining if the unique identifying code associated with a desired channel is detectable. When the unique identifying code is detectable, the method further comprises detecting the unique identifying code associated with the desired channel. When the unique identifying code is undetectable, the method further comprises tuning the oscillator and detecting the unique identifying code associated with the desired channel based on the tuning.

Abstract: Disclosed is a system and method for compensating for the effects of aging and temperature on the performance of transistors in an RF transmitter. The system and method use a temperature-based polynomial and a feedback control loop to correlate the drain current of each transistor with the desired performance characteristics of each transistor. The present invention measures drain current and temperature of the transistor; compares the measured drain current with the desired drain current, which corresponds to the desired performance characteristics; computes a transistor bias voltage based on the temperature and a control parameter, wherein the control parameter is adjustable based on the measured drain current; and applies the bias voltage to the transistor. The process may be repeated, with the control parameter adjusted with each iteration, until the desired drain current is reached.

Abstract: A method to receive channels in an undersampled broadband receiver comprising mixing bands of assigned channels with an oscillator to generate downconverted bands, wherein each assigned channel has an assigned unique identifying code. The method further includes undersampling the downconverted bands and determining if the unique identifying code associated with a desired channel is detectable. When the unique identifying code is detectable, the method further comprises detecting the unique identifying code associated with the desired channel. When the unique identifying code is undetectable, the method further comprises tuning the oscillator and detecting the unique identifying code associated with the desired channel based on the tuning.

Abstract: Systems and methods are described for increasing the effective dynamic range of a digital data stream in a software-defined radio receiver. In one system the sample rate of an analog to digital (“A/D”) conversion process is adjusted dynamically to shift harmonic signal interference induced by the A/D conversion process to outside the channels of interest. In another system the sample rate of an A/D conversion process is constant and the frequency of a dynamically controlled local oscillator in a frequency translator is adjusted dynamically to shift harmonic signal interference induced by the A/D conversion process to outside the channels of interest.

Abstract: A computer system comprises a processing unit configured to process fixed size data words comprising at least one exponent field of variable size and a mantissa of variable size; an input device configured to provide data words to the processing unit; and an output device configured to output data words processed by the processing unit.

Abstract: Signal processing systems for radar installations are provided for simultaneous processing of one or more IF signals of dynamically varying frequency and bandwidth with a single analog signal path. The signal processing system includes, but is not limited to, a converter configured to digitize a return signal resulting in a digitized broadband signal, and a signal processor coupled to the converter. The signal processor includes a digital filter having a center frequency and a bandwidth, and the digital filter is configured to select a signal from the digitized broadband signal. The selected signal has a center frequency. The signal processor is configured to match the center frequency of the digital filter with the center frequency of the selected signal, and adjust the bandwidth of the digital filter based on the selected signal.

Abstract: Systems and methods for reducing interference in an enhanced radio receiver from a transmitter when both are located in the same aircraft are provided. The enhanced radio receiver detects and attenuates a signal from the transmitter, without attenuation or interference with other desired signals. An enhanced radio transmitter may inform the enhanced radio receiver of the frequency of transmission via a data communication path such that the enhanced radio receiver attenuates the transmitted frequency for the duration of transmission.

Abstract: Systems and methods for reducing interference in an enhanced radio receiver from a transmitter when both are located in the same aircraft are provided. The enhanced radio receiver detects and attenuates a signal from the transmitter, without attenuation or interference with other desired signals. An enhanced radio transmitter may inform the enhanced radio receiver of the frequency of transmission via a data communication path such that the enhanced radio receiver attenuates the transmitted frequency for the duration of transmission.

Abstract: Systems and methods are described for increasing the effective dynamic range of a digital data stream in a software-defined radio receiver. In one system the sample rate of an analog to digital (“A/D”) conversion process is adjusted dynamically to shift harmonic signal interference induced by the A/D conversion process to outside the channels of interest. In another system the sample rate of an A/D conversion process is constant and the frequency of a dynamically controlled local oscillator in a frequency translator is adjusted dynamically to shift harmonic signal interference induced by the A/D conversion process to outside the channels of interest.