Abstract: A radio frequency (RF) unit and a method for RF isolation. The RF unit includes first and second RF couplers, an RF filter, and an RF canceler connected in parallel with the RF filter. The first RF coupler is configured to receive an input signal. The RF filter is configured to receive a first portion of the input signal from the first RF coupler and attenuate frequencies outside of a passband of the RF filter from the first portion of the input signal. The RF canceler is configured to receive a second portion of the input signal from the first RF coupler and generate a cancellation signal from the second portion of the input signal based on a target frequency band of the RF canceler. The second RF coupler is configured to combine the cancellation signal with an output of the RF filter to generate an output signal.

Abstract: Methods and apparatuses for facilitating wide bandwidth power amplification with high efficiency for analog RF signals. A passive load modulated balanced amplifier (LMBA) device comprises a balanced power amplifier (BPA) and a directional coupler. The BPA comprises a first power amplifier (PA) configured to amplify a first portion of an input power, a second PA configured to amplify a second portion of the input power, an isolation port, and an output port that outputs the amplified first and second portions of the input power as an output power. The directional coupler is configured to provide a portion of the output power from the output port to the isolation port to modulate a load impedance of the first and second PAs.

Abstract: The invention is related to a parametric light generation method and its application and belongs to the technical field of laser and nonlinear optics. The generation method comprises steps as follows: a nonlinear optical material that meets the sum-frequency phase-matched conditions, namely it shall satisfy the energy conservation condition ?p+?i=?s and the momentum conservation condition np?p+ni?i=ns?s simultaneously, is provided; laser light with a wavelength of ?p is injected into the said nonlinear optical material as pump light; then, the material will output signal light with a wavelength of ?S, namely the tunable sum-frequency parametric light. With sum-frequency as the basic principle, the invention can realize frequency up-conversion and obtain visible and UV light sources through simple infrared light sources easily.

Abstract: A communication device includes an antenna configured to receive a signal in a receive band and transmit a signal in a transmit band through a duplexer, analog transmitter-side radio frequency (RF) self-interference cancelation (SIC) circuitry configured to reduce power of the transmit signal in the receive band before input to the antenna, analog receiver-side RF SIC circuitry configured to reduce power of the receive signal in the transmit band before input to a first analog-to-digital converter (ADC) to convert the receive signal from analog to digital, a coupler configured to couple a small part of the transmit signal to a second ADC to convert the transmit signal from analog to digital, and digital SIC circuitry configured to process the digital sample to generate and apply an SIC signal to the digital receive signal to cancel interference induced in the receive signal by the transmit signal.

Abstract: An apparatus includes a substrate, a first antenna panel, a second antenna panel, and an antenna isolator. The first antenna panel is coupled on the substrate and includes an array of first antenna elements. The second antenna panel is coupled on the substrate and includes an array of second antenna elements. The antenna isolator is coupled on the substrate and including a plurality of walls extending outwardly from the substrate along a length of the substrate between the first antenna panel and the second antenna panel. The antenna isolator reduces reduce wave propagation between the array of first antenna elements and the array of second antenna elements.

Abstract: An apparatus can include a substrate, a first antenna panel, a second antenna panel and a wall isolator. The first antenna panel can be coupled on the substrate and comprising an array of first antenna elements. The second antenna panel can be coupled on the substrate comprising an array of second antenna elements. The wall isolator can be coupled on the substrate. The wall isolator can include a first EBG element and a second EBG element. The first EBG element can be positioned along an edge of the first antenna panel for a length of the substrate and configured to reduce surface wave propagation from the array of first antenna elements. The second EBG element can be positioned along an edge of the second antenna panel for a length of the substrate and configured to reduce surface wave propagation from the array of second antenna elements.

Abstract: A radio frequency (RF) unit and a method for RF isolation. The RF unit includes first and second RF couplers, an RF filter, and an RF canceler connected in parallel with the RF filter. The first RF coupler is configured to receive an input signal. The RF filter is configured to receive a first portion of the input signal from the first RF coupler and attenuate frequencies outside of a passband of the RF filter from the first portion of the input signal. The RF canceler is configured to receive a second portion of the input signal from the first RF coupler and generate a cancellation signal from the second portion of the input signal based on a target frequency band of the RF canceler. The second RF coupler is configured to combine the cancellation signal with an output of the RF filter to generate an output signal.

Abstract: A communication device includes an antenna configured to receive a signal in a receive band and transmit a signal in a transmit band through a duplexer, analog transmitter-side radio frequency (RF) self-interference cancelation (SIC) circuitry configured to reduce power of the transmit signal in the receive band before input to the antenna, analog receiver-side RF SIC circuitry configured to reduce power of the receive signal in the transmit band before input to a first analog-to-digital converter (ADC) to convert the receive signal from analog to digital, a coupler configured to couple a small part of the transmit signal to a second ADC to convert the transmit signal from analog to digital, and digital SIC circuitry configured to process the digital sample to generate and apply an SIC signal to the digital receive signal to cancel interference induced in the receive signal by the transmit signal.

Abstract: The invention is related to a parametric light generation method and its application and belongs to the technical field of laser and nonlinear optics. The generation method comprises steps as follows: a nonlinear optical material that meets the sum-frequency phase-matched conditions, namely it shall satisfy the energy conservation condition ?p+?i=?s and the momentum conservation condition np?p+ni?i=ns?s simultaneously, is provided; laser light with a wavelength of ?p is injected into the said nonlinear optical material as pump light; then, the material will output signal light with a wavelength of ?s, namely the tunable sum-frequency parametric light. With sum-frequency as the basic principle, the invention can realize frequency up-conversion and obtain visible and UV light sources through simple infrared light sources easily.

Abstract: A multiple input multiple output signal receiving apparatus includes a first antenna configured to receive a first radio frequency (RF) signal, a second antenna configured to receive a second RF signal, a superheterodyne receiver, a direct conversion receiver, and an antenna switching module. The superheterodyne receiver is configured to convert one or both of the first and second RF signals into at least one first analog signal. The direct conversion receiver is configured to convert one or both of the first and second RF signals into at least one second analog signal. The antenna switching module couples the first and second antennas to the superheterodyne receiver and the direct conversion receiver, and is configured to selectively direct the first and second RF signals to the superheterodyne receiver and/or the direct conversion receiver, depending on an antenna switch control signal indicating a signal quality derived from the first and second analog signals.

Abstract: A MIMO signal receiving apparatus includes a first antenna for receiving a first RF signal; a second antenna for receiving a second RF signal; a superheterodyne receiver for receiving one or all of the first and second RF signals into at least one first analog signal; a direct conversion receiver for converting one or all of the first and second RF signals into at least one second signal; and an antenna switching module coupling the first and second antennas to the superheterodyne receiver and the direct conversion receiver for electively directing the first and second RF signals to the superheterodyne receiver and/or the direct conversion receiver, depending on an antenna switch control signal indicating a signal quality derived from the first and second analog signals.

Abstract: An improved radio frequency (RF) switch circuit is disclosed. The RF switch is typically used in a communication system having one or more transmission paths and one or more reception paths. The RF switch has a first set of diodes connected in parallel among themselves, and a second set of diodes connected in parallel among themselves. Each diode of the second set is coupled with at least one predetermined diode in the first set in a parallel manner by sharing a connection node that is coupled further with at least one antenna. A transmitter is coupled to the first set of diodes and the receiver is separately coupled to the second set of diodes, wherein either one of the first set of diodes or the second set of diodes are activated to establish one path while cutting off all other paths at the same time.

Abstract: An improved enhancer is disclosed which uses a switch matrix to increase the isolation between two antennas. For either an reverse link or forward link communication, the enhancer has a first antenna for receiving an incoming signal, and a receiver sub-system that amplifies and converts the incoming signal from the first antenna to a first predetermined frequency band. The enhancer further has a demodulator coupled to the receiver sub-system for demodulating the converted signal, and detecting timing information thereof. Also contained in the enhancer is a transmitter sub-system operable with the receiver sub-system that converts the signal from the receiver subsystem to a second predetermined frequency band and further amplifies the signal. After the signal is thus enhanced, a second antenna is used for further transmitting the amplified signal from the transmitted sub-system.

Abstract: An improved radio frequency (RF) switch circuit is disclosed. The RF switch is typically used in a communication system having one or more transmission paths and one or more reception paths. The RF switch has a first set of diodes connected in parallel among themselves, and a second set of diodes connected in parallel among themselves. Each diode of the second set is coupled with at least one predetermined diode in the first set in a parallel manner by sharing a connection node that is coupled further with at least one antenna. A transmitter is coupled to the first set of diodes and the receiver is separately coupled to the second set of diodes, wherein either one of the first set of diodes or the second set of diodes are activated to establish one path while cutting off all other paths at the same time.

Abstract: A communication system having an adaptive antenna array subsystem generates calibration information for the adaptive array subsystem by measuring the amplitude and phase of modulated signals within the subsystem at the antenna array mount and at the back plane mount for the transmit and receive array. The calibration information is used to more accurately perform beamforming for both received an transmitted information signals. The communication system uses a time diversity duplex (TDD) synchronous code division multiple access (SCDMA) protocol for wireless communication between remote terminals and a base station. The calibration means uses a combination combiner and splitter having matched micro strip lines incorporated into a printed circuit board in either the antenna array mount or the back plane.