Abstract: Described is an in-band full-duplex (IBFD) antenna having direction finding capability. The IBFD antenna includes a transmit antenna having an omnidirectional radiation pattern and a receive antenna configured to provide a plurality of difference beams. The IBFD antenna may be disposed on a moving platform to cover all angles around the moving platform.

Abstract: A network device includes a transceiver configured to concurrently transmit signals and receive signals within a single frequency band resulting in radio-frequency signal interference. The device includes an analog canceler configured to mitigate the signal interference. The device includes a neural network that receives data that describes characteristics of the signal interference and provides coefficients for the analog canceler as outputs. The neural network-generated coefficients are applied to the analog canceler which uses them to cancel the signal interference.

Abstract: A system for canceling signal interference (SI) includes a transceiver configured to concurrently transmit signals and receive signals within a single frequency band, which causes signal interference between the transmitted and received signals. The SI canceller is configured to use a set of cancellation coefficients to generate a cancellation signal to mitigate the SI. The system is configured to iteratively change the cancellation coefficients by a step factor to produce tuned cancellation coefficients. The step factor is determined by a cancellation error gradient and one or more of: a tunable coefficient step aggressiveness factor; and a time-based forgetting factor; and cause the SI canceller to cancel the SI using the tuned cancellation coefficients.

Abstract: A network device includes a transceiver configured to concurrently transmit signals and receive signals within a single frequency band resulting in radio-frequency signal interference. The device includes an analog canceler configured to mitigate the signal interference. The device includes a neural network that receives data that describes characteristics of the signal interference and provides coefficients for the analog canceler as outputs. The neural network-generated coefficients are applied to the analog canceler which uses them to cancel the signal interference.

Abstract: A system for canceling signal interference (SI) includes a transceiver configured to concurrently transmit signals and receive signals within a single frequency band, which causes signal interference between the transmitted and received signals. The SI canceller is configured to use a set of cancellation coefficients to generate a cancellation signal to mitigate the SI. The system is configured to iteratively change the cancellation coefficients by a step factor to produce tuned cancellation coefficients. The step factor is determined by a cancellation error gradient and one or more of: a tunable coefficient step aggressiveness factor; and a time-based forgetting factor; and cause the SI canceller to cancel the SI using the tuned cancellation coefficients.

Abstract: A transceiver system is configured to concurrently send TX signals and receive RX signals on an antenna system in the same frequency band. A bi-directional frequency converter circuit modulates the TX signals and RX signals by a modulation frequency. The modulated TX signals and RX are frequency shifted so that they have different frequencies that are not in the same frequency band. For example, the TX signal may be shifted to a higher frequency and the RX signal may be shifted to a lower frequency. Filters can then be used to isolate the TX signal and the RX signal for transmission and/or processing.

Abstract: In-band full-duplex (IBFD) wireless systems offer the ability to revolutionize frequency spectrum utilization for future networks. For IBFD systems to work, the self-interference (SI) generated by each wireless node should be sufficiently mitigated, which becomes more challenging as the bandwidth increases. RF cancellation enables this interference reduction but has been limited so far to narrowband operation or restricted to distinctive environments. Fortunately, a photonic-enabled RF canceller can provide broadband interference cancellation using photonic components in a wideband vector modulator architecture with tunable time-delay taps. An example of this canceller with 20 canceller taps provides 25 and 20 dB of cancellation over 500-MHz and 1-GHz instantaneous bandwidths, respectively, and is tunable between 0.5 and 5.5 GHz. This photonic-enabled RF canceller provides the wideband operation and high tap counts for successfully deploying future wireless systems with IBFD technology.

Abstract: Systems and methods for improving power amplifier operation are provided. A system may include a baseband signal generator communicatively coupled to a baseband signal digital-to-analog converter. The baseband signal digital-to-analog converter may be communicatively coupled to two or more power amplifiers. The system may also include an envelope signal generator communicatively coupled to an envelope signal digital-to-analog converter. The system may further include a supply modulator communicatively coupled to the envelope signal digital-to-analog converter and the two or more power amplifiers for shared envelope tracking across the two or more power amplifiers.

Abstract: The present disclosure is directed towards direction finding (DF) systems that can detect and locals a radio frequency (RF) signal (e.g. an emergency beacon) is two dimensions (i.e., azimuth and elevation). In one embodiment, a DF system comprises an array of multipolarized loop antennas coupled to a beamformer which provides monopole, dipole, and loop antenna element modal signals. The DF system may also comprise a multi-channel digital receiver system coupled to the beamformer. The multi-channel digital receiver system is configured to receive modal signals provided thereto from the beamformer which can be used for accurate two-dimensional geolocation of RF signals including, but not limited to, location of RF emergency beacon sources.

Abstract: A method and apparatus for achieving simultaneous transmit and receive operation with a digital phased array is described. Digital beamforming and cancellation enables adjacent transmitting and receiving sub-arrays to operate simultaneously in the same frequency band.

Abstract: Systems and methods for improving power amplifier operation are provided. A system may include a baseband signal generator communicatively coupled to a baseband signal digital-to-analog converter. The baseband signal digital-to-analog converter may be communicatively coupled to two or more power amplifiers. The system may also include an envelope signal generator communicatively coupled to an envelope signal digital-to-analog converter. The system may further include a supply modulator communicatively coupled to the envelope signal digital-to-analog converter and the two or more power amplifiers for shared envelope tracking across the two or more power amplifiers.

Abstract: The present disclosure is directed towards direction finding (DF) systems that can detect and locals a radio frequency (RF) signal (e.g. an emergency beacon) is two dimensions (i.e., azimuth and elevation). In one embodiment, a DF system comprises an array of multipolarized loop antennas coupled to a beamformer which provides monopole, dipole, and loop antenna element modal signals. The DF system may also comprise a multi-channel digital receiver system coupled to the beamformer. The multi-channel digital receiver system is configured to receive modal signals provided thereto from the beamformer which can be used for accurate two-dimensional geolocation of RF signals including, but not limited to, location of RF emergency beacon sources.

Abstract: A method and apparatus for achieving simultaneous transmit and receive operation with a digital phased array is described. Digital beamforming and cancellation enables adjacent transmitting and receiving sub-arrays to operate simultaneously in the same frequency band.

Abstract: A compact radio core engine (CE) module uniquely small in size and power consumption, in which only two circuit boards provide all the modem and transceiver functions needed for modern military radios. A modem circuit board has modem devices and a first connector mounted on the board, and a radio frequency (RF) circuit board has RF devices and a second connector mounted on the board. A module frame has an interior wall, and a side wall about the periphery of the interior wall. The modem and the RF circuit boards are positioned on opposite sides of the interior wall, and the connectors on the two boards mate with one another through an opening in the interior wall to exchange operating data and signals between the devices on the boards. The modem circuit board is seated entirely within a recess formed by the interior and the side walls of the frame.

Abstract: Described is a simultaneous transmit and receive antenna system having a ring array of transmit antenna elements and a receive antenna element disposed on an axis that is perpendicular to and passing through the center of the ring array. Alternatively, the ring array includes receive elements and a transmit antenna element is disposed on the axis perpendicular to the ring array. Opposite antenna elements in the ring array differ in phase by 180° so that a radiation pattern null occurs at the antenna element at the center of the ring array. Also included are at least one ground plane and an electrically-conductive cylinder disposed on the perpendicular axis inside the ring array to provide a high degree of isolation between the transmit and receive antenna elements. The system may be configured for wireless communications, for example, according to WIFI IEEE standard 802.11 or WIMAX IEEE standard 802.16.

Abstract: Described is a simultaneous transmit and receive antenna system having a ring array of transmit antenna elements and a receive antenna element disposed on an axis that is perpendicular to and passing through the center of the ring array. Alternatively, the ring array includes receive elements and a transmit antenna element is disposed on the axis perpendicular to the ring array. Opposite antenna elements in the ring array differ in phase by 180° so that a radiation pattern null occurs at the antenna element at the center of the ring array. Also included are at least one ground plane and an electrically-conductive cylinder disposed on the perpendicular axis inside the ring array to provide a high degree of isolation between the transmit and receive antenna elements. The system may be configured for wireless communications, for example, according to WIFI IEEE standard 802.11 or WIMAX IEEE standard 802.16.