Abstract: A radio frequency (RF) communication system may include a first radio and a second radio being relatively movable. The first radio may include an RF transceiver configured to operate on a selected RF channel from among a plurality of different RF channels, and a controller coupled to the RF transceiver. The controller may be configured to obtain historical RF spectral data over time, position and RF channel, as the first and second radios move relative to one another, determine at least one power null from the historical RF spectral data, and dynamically select an RF channel from among the plurality thereof based upon the at least one power null.

Abstract: Vector modulation is illustrated. A method includes receiving an input signal. The input signal is split into a first 0° output and a 90° output. The first 0° output is split into a second 0° output and a first 180° output using a continuous transmission line. The 90° output is split into a third 0° output and a second 180° output using a continuous transmission line. The second 0° output, the first 180° output, the third 0° output, and the second 180° output are modulated. The modulated second 0° output, the first 180° output, the third 0° output, and the second 180° output are recombined to produce an output signal, where all four of the modulated second 0° output, the first 180° output, the third 0° output, and the second 180° output are used to create the output signal.

Abstract: A radio frequency (RF) communication system may include a first radio and a second radio being relatively movable. The first radio may include an RF transceiver configured to operate on a selected RF channel from among a plurality of different RF channels, and a controller coupled to the RF transceiver. The controller may be configured to obtain historical RF spectral data over time, position and RF channel, as the first and second radios move relative to one another, determine at least one power null from the historical RF spectral data, and dynamically select an RF channel from among the plurality thereof based upon the at least one power null.

Abstract: A digitally controlled analog filter device. The digitally controlled analog filter device includes one or more digitally controlled analog signal amplifiers. The digitally controlled analog signal amplifiers are configured to have a gain of the digitally controlled analog signal amplifiers controlled by digital signals. The digitally controlled analog filter device further includes one or more analog time delay circuits coupled to signal input nodes of the digitally controlled analog signal amplifiers. The analog time delay circuits are configured to implement an analog signal delay. The digitally controlled analog filter device further includes a digital closed loop control circuit coupled to the digitally controlled analog signal amplifiers to digitally control the gain of the digitally controlled analog signal amplifiers.

Abstract: A transmit signal can be distorted with non-linear distortion, and one or more characteristics of the non-linear distortion can be periodically changed in accordance with a change key. The transmission received at a receiver can thus comprise a severely distorted version of the transmission of the transmit signal. A receiver with the same change key can recognize and decode the transmission, but it can be extraordinarily difficult for receivers that lack the change key to detect and decode the transmission. The transmission can be a communications while jamming (CWJ) transmission. The CWJ transmission can contain a coded message that can be decoded only by friendly RF receivers, and the CWJ transmission can also jam unfriendly RF receivers that lack a change key for decoding the coded message.

Abstract: Spatially combining signals may include receiving a number of RF input signals at a number of RF input connectors. At least one of the RF input signals is a variable envelope signal. A variable envelope signal is converted into two or more outphased constant envelope signals. The two or more outphased constant envelope signals are amplified. The amplified outphased constant envelope signals are radiated. At a spatial combiner aperture, the radiated amplified outphased constant envelope signals are combined to create a combined signal. The combined signal is output onto an output RF connector.

Abstract: Embodiments are directed to systems, apparatuses and methods for providing self-consistent outphasing signal separation. In one scenario, such an apparatus includes the following: a receiver configured to receive a variable-envelope signal and an outphasing separator including a digital electronic component configured to split the received variable-envelope signal into first and second constant-envelope signals. Splitting the received variable-envelope signal includes implementing various trigonometric or other functions using a consistent phase. The apparatus further includes a first analog component chain that includes various analog electrical components configured to receive and process the first constant-envelope signal, as well as a second analog component chain that includes various analog electrical components configured to receive and process the second constant-envelope signal.

Abstract: Embodiments are directed to an apparatus, method and system for relative or absolute equalization of two or more channels. The apparatus includes a receiver that receives a variable-envelope signal, a self-consistent outphasing separator that splits the received variable-envelope signal into constant-envelope signals, and linear pre-equalizers that equalize the constant-envelope signals relative to each other or to some target. The apparatus also includes an analog combiner that combines the constant-envelope signals, and a feedback loop with a processor that receives the combined constant-envelope signals as inputs, analyzes the combined constant-envelope signals to identify pre-equalization inputs that, when applied to the linear pre-equalizers, will equalize the constant-envelope signals, and provide the identified pre-equalization inputs to the linear pre-equalizers, so that the combined constant-envelope signals are equalized relative to each other or to some target.

Abstract: Spatially combining signals may include receiving a number of RF input signals at a number of RF input connectors. At least one of the RF input signals is a variable envelope signal. A variable envelope signal is converted into two or more outphased constant envelope signals. The two or more outphased constant envelope signals are amplified. The amplified outphased constant envelope signals are radiated. At a spatial combiner aperture, the radiated amplified outphased constant envelope signals are combined to create a combined signal. The combined signal is output onto an output RF connector.

Abstract: Spatially combining signals may include receiving a number of RF input signals at a number of RF input connectors. At least one of the RF input signals is a variable envelope signal. A variable envelope signal is converted into two or more outphased constant envelope signals. The two or more outphased constant envelope signals are amplified. The amplified outphased constant envelope signals are radiated. At a spatial combiner aperture, the radiated amplified outphased constant envelope signals are combined to create a combined signal. The combined signal is output onto an output RF connector.

Abstract: Spatially combining signals may include receiving a number of RF input signals at a number of RF input connectors. At least one of the RF input signals is a variable envelope signal. A variable envelope signal is converted into two or more outphased constant envelope signals. The two or more outphased constant envelope signals are amplified. The amplified outphased constant envelope signals are radiated. At a spatial combiner aperture, the radiated amplified outphased constant envelope signals are combined to create a combined signal. The combined signal is output onto an output RF connector.

Abstract: The perceived sample rate at which a DAC can operate can be increased by allowing multiple DACs to process different portions of a digital signal in parallel. In this way, the outputs of multiple DACs can be combined into a single analog signal to achieve the desired speeds and resolutions of the analog output. This parallel processing can be implemented using a time-interleaving technique or a sub-band reconstruction technique. Pre-distortion can be applied to the digital input signal to compensate for degradation detected in the analog output signal. By applying pre-distortion, waveforms having high sampling rates can be efficiently generated.