3871 results about "Low-noise amplifier" patented technology

A radio frequency (RF) transmit / receive switch. The transmit / receive switch comprises an impedance matching circuit and a voltage scaling circuit. The impedance matching circuit matches an incoming RF signal to a low noise amplifier and an outgoing RF signal from a power amplifier. The voltage scaling circuit, coupled to the impedance matching circuit, the power amplifier, and the low noise amplifier, attenuates the outgoing RF signal to a scaled signal within a breakdown voltage of a transistor device in the low noise amplifier during transmission of the outgoing RF signal.

Low cost millimeter wave imagers using two-dimensional focal plane arrays based on backward tunneling diode (BTD) detectors. Two-dimensional focal arrays of BTD detectors are used as focal plane arrays in imagers. High responsivity of BTD detectors near zero bias results in low noise detectors that alleviate the need for expensive and heat generating low noise amplifiers or Dicke switches in the imager. BTD detectors are installed on a printed circuit board using flip chip packaging technology and horn antennas direct the waves toward the flip chip including the BTD detectors. The assembly of the horn antennas, flip chips, printed circuit board substrate, and interconnects together work as an imaging sensor. Corrugated surfaces of the components prevent re-radiation of the incident waves.

A front end circuit for coupling an antenna to a first radio frequency (RF) transceiver and a second RF transceiver is contemplated. The RF transceivers have a signal input, a signal output, a receive enable line and a transmit enable line. In addition to an antenna port, the front end circuit has a first power amplifier and a first low noise amplifier both coupled to first RF transceiver, and a second power amplifier and a second low noise amplifier both coupled to the second RF transceiver. The front end circuit includes a matching network that couples the power amplifiers and the low noise amplifiers, the various outputs and inputs thereof being common.

An RF antenna coupling structure includes a first transformer, a second transformer, and a transformer balun. The first transformer includes a primary winding and a secondary winding, wherein the primary winding of the first transformer is operably coupled to a power amplifier, and wherein the secondary winding of the first transformer has a desired output impedance corresponding to the operational needs of the power amplifier. The second transformer includes a primary winding and a secondary winding, wherein the primary winding of the second transformer is operably coupled to a low noise amplifier, and wherein the secondary winding of the second transformer has a desired output impedance corresponding to the needs of the low noise amplifier. The transformer balun includes a differential winding and a single-ended winding, wherein the differential winding is operably coupled to the secondary windings of the first and second transformers and the single-ended winding is operably coupled to an antenna.

Methods and systems for an integrated voltage controlled oscillator (VCO)-based transmitter and on-chip power distribution network are disclosed and may include supplying bias voltages and / or ground to a chip utilizing conductive lines. One or more VCOs and low-noise amplifiers (LNAs) may each be coupled to a leaky wave antenna (LWA) integrated in the bias voltage and / or ground lines. One or more clock signals may be generated utilizing the VCOs, which may be transmitted from the LWAs coupled to the VCOs, to the LWAs coupled to the LNAs. RF signals may be transmitted via the LWAs, and may include 60 GHz signals. The LWAs may include microstrip and / or coplanar waveguides, where a cavity length of the LWAs may be dependent on a spacing between conductive lines in the waveguides. The LWAs may be dynamically configured to transmit the clock signals at a desired angle from a surface of the chip.

A full duplex transceiver has cancellation circuitry that includes an auxiliary receiver and an auxiliary transmitter. More specifically, an analog received signal that includes transmission signal leakage is provided to a low noise amplifier (LNA), which then provides its output to a main receiver and the auxiliary receiver. The auxiliary receiver includes a portion operable to convert the received signal from the analog domain to the digital domain. The auxiliary receiver additionally includes a cancellation processor that determines the transmission signal leakage and generates a signal based on the determined leakage. This signal generated by the auxiliary receiver is provided to the auxiliary transmitter, which converts the digital signal back to the analog domain and generates a cancellation signal. The analog cancellation signal is fed back and added to the received signal at the input of the LNA. As a result of the feedback system including an auxiliary receiver and an auxiliary transmitter, transmission signal leakage of many types may be canceled from a received signal.

A low noise amplifier (LNA) operates over multiple frequency bands while occupying less silicon area than known LNA implementations. The LNA includes output matching that can be tuned by an adjustable inductor together with a tunable capacitor bank.

The present invention relates to transceiver systems and methods which employ shunt switches during transmit and receive operating modes. The shunt switches may be configured with various reactive networks to achieve high or low impedance states at power amplifiers or low noise amplifiers in order to reflect or transmit power along a given path. The shunt switches are designed for protection against excessive voltage swings that would otherwise damage components in the transceiver switching circuit. The switching circuits may be implemented in a single chip architecture, which results in manufacturing efficiencies, lower cost and higher reliability circuits. Single or multi band devices may also be employed.

Methods and systems for a multi-port distributed antenna are disclosed and may include configuring one or more amplifiers to communicate signals via one or more ports on a distributed antenna. A characteristic impedance of the distributed antenna at each of the one or more ports may be configured by a location of the one or more ports on the distributed antenna. The amplifiers may be impedance matched to the distributed antenna by coupling each of the amplifiers to the ports based on the characteristic impedance. The amplifiers may include power amplifiers and / or low noise amplifiers. The signals may be time division duplexed. The signals communicated via the ports on the distributed antenna may include RF signals. The distributed antenna may be integrated on a chip with the amplifiers or may be located external to a chip with the amplifiers. The distributed antenna may include a microstrip antenna.

Methods and systems for receiving signals via a multi-port distributed antenna are disclosed and may include selectively enabling one or more low noise amplifiers (LNAs) coupled to the antenna. The selective enabling may be based on a desired gain level applied to a signal received from the antenna. The LNAs may be coupled to ports on the antenna based on an input impedance of the LNAs and an impedance of the ports. Each of the LNAs may be configured for optimum linearity in different gain ranges, which may be proportional to the input impedance of the LNAs. The antenna may be integrated on a chip with the LNAs, or may be located external to the chip. The antenna may include a microstrip antenna. The LNAs may include variable gain and may be enabled utilizing a processor. Linearity on demand may be enabled via the selective enabling of the LNAs.

A multi-protocol, multi-band array antenna system may be used in Radio Frequency Identification (RFID) system reader and sensory networks. The antenna array may include array elements with an integrated low noise amplifier. The system may employ digital beam forming techniques for transmission and steering of a beam to a specific sensor tag or group of tags in an cell. The receive beam forming network is optimized for detecting signals from each sensor tag. Narrow and wideband interferences may be excised by an interference nulling algorithm. Space division multiplexing may be used by the antenna system to enhance system processing capacity.

A tuner and a broadcasting signal receiver including the tuner. The tuner includes a band selection module that selects an RF broadcasting signal within the frequency band corresponding to a selected channel, and a low noise amplifier module that amplifies the signal with a specific received signal strength indicator (RSSI) to produce an RF broadcasting signal with a specific gain.

A multi-mode wireless device having a transceiver including a multi-mode transmitter and a multi-mode receiver. The transmitter can include a multi-mode transmit baseband portion configured to support all of the transmit modes. Similarly, the receiver can include a multi-mode baseband portion that is configured to support all of the receive modes. The transmitter can also include a frequency conversion stage that can convert the output from the transmit baseband portion to the desired transmit frequency. Multiple power amplifiers in parallel, each configured to support one or more of the operating modes, can selectively amplify the transmit signals. The receiver can include multiple low noise amplifiers (LNAs) in parallel, each configured to selectively amplify the received signals of one or more of the operating modes. The output of the LNAs can be coupled to a frequency conversion stage that downconverts the received signals and provides them to the baseband portion.

A wired relay method for using a remote station and an apparatus thereof for a Radio over Fiber (RoF) wired relay system supporting a Time Division Duplexing (TDD) wireless communication service, which shares an Low-Noise Amplifier (LNA) for both uplink and downlink operations. The remote station includes a block for dividing each of a downlink optical signal carrying service data and an optical signal carrying transmission / reception control information of the RoF wired relay system, which are input from a base station, a gain controller for separating an uplink Radio Frequency (RF) signal input from an antenna or a portion of a downlink RF signal output from a High-Power Amplifier (HPA) and for monitoring the strength of the input and output RF signals in order to control a gain of the LNA. A converter mutually converts an optical signal and an RF signal, an amplifier amplifies the converted RF signal, and an RF signal flow controller automatically controlls uplink and downlink transmission paths of the amplified RF signal according to a transmission / reception status of the RoF wired relay system.

This invention relates to a transmit / receive module for a high power Active Phased Array Antenna system operating in L-band based upon a combination of Hybrid Microwave Integrated Circuit (MIC) as well as Monolithic Microwave Integrated Circuit (MMIC) technology. The transmit / receive module includes a power monitoring means, transmitter protector means, and a receiver protector means. The module comprises a signal transmit chain incorporating power conditioner and a signal receive chain incorporating control electronics and bias- sequencer modulator. The transmit chain has switching means for switching the module to transmit mode which is connected to the transmit amplifier chain through a shared digital phase shifter. The amplified signals from the transmit amplifier chain are conveyed to a duplexer means. In receive mode, the receive chain receives signal through drop-in circulator and high power switch and comprises of high power limiter, low noise amplifier means, and a digital attenuator means connected to the shared digital phase shifter through T / R switch means. Electronic means are connected through integrated control electronic., bias sequencer modulator and power conditioner for controlling the operation of the device.

The present invention is a hybrid RF-digital signal processor-based filter for multiband radio architectures systems capable of spectrum re-farming and software defined radios. It performs low-loss frequency agile multiple notch filtering at RF where a large dynamic range exists at a filter input between signals in a stopband and passband. It is a frequency dependent signal attenuation apparatus having two paths connected together by directional couplers. The first path comprising a component such as a delay component or duplexer. The second path comprising a bandstop filter connected to a down converter, a digital filter, and an up converter. At the output of a power amplifier, the invention can be used to attenuate spurs, or noise within bands with strict emission constraints. At the input of a low noise amplifier, the invention can be used to attenuate blockers and transmitter noise outside of the receiver passband.

The invention discloses a configurable multi-mode multi-band satellite navigation receiving method and a radio frequency front end module constructed by the method. The front end module can receive signals of satellite navigation and positioning systems such as a global positioning system (GPS), the Big Dipper, a Galileo positioning system and a global navigation satellite system (Glonass), and comprises a configurable low-noise amplifier (LNA) with a buffer and an active balun, a folding passive mixer with a configurable frequency synthesizer, a configurable multi-mode filter, an automatic gain control (AGC) amplifier, a direct-current bias circuit, and a multi-mode multi-band program controlled and coded on-off control word from a receiving system. The radio frequency front end module can meet the requirement of multi-band multi-mode work through the control word programmed by the receiving system, has a simple and reliable structure, does not need complicated time division multiplexing control system and off-chip module, has low cost and high flexibility, and improves the noise performance of the radio frequency front end of the whole receiver and multi-mode multi-band signal processing capacity; and a one-channel signal is input into the module, and the module outputs a two-channel differential signal. The receiver can be used for receiving and processing multi-mode satellite navigation signals asynchronously, and receiving and processing satellite navigation signals with the required mode in different time intervals according to the requirement.

A tunable receiver is disclosed including a plurality of select filters to perform an initial band selection, a variable-gain low noise amplifier (LNA) whose gain is controlled to prevent its output power level to exceed a predetermined power threshold, a plurality of digitally-tunable tracking filters to pass signals within a selected channel and to reject signals in a corresponding image band, a second LNA to further amplify the received RF signal and to generate differential signal outputs, a down converting stage which converts the received RF signal to an IF signal while rejecting signals in the image band, an IF trap to further reject undesired signals present at the output of the down converting stage, an IF amplifier to amplify the IF signal to compensate for losses, an IF filter to provide channel select and reject undesirable signals, and a variable-gain IF amplifier to amplify the IF signal and maintain its power level within specification.

A multi-band radio module for selectively supplying received signals in a plurality of frequency bands to a low noise amplifier via an input impedance matching circuit by switching over the operation mode of the low noise amplifier is comprised of: a pre-stage amplification unit including a plurality of fundamental amplifiers connected to one another in parallel, the fundamental amplifiers sharing a load impedance connected to a source voltage and a grounded degeneration impedance and having input signal lines commonly connected to an input impedance matching circuit; a post-stage amplifier to which the output signals of the plurality of fundamental amplifiers are commonly inputted; and a bias control unit for selectively turning on the fundamental amplifiers, wherein the input impedance of the low noise amplifier is selectively optimized for the matching circuit depending on the RF band to be received.

The present disclosure relates to a first active tunable low-noise RF bandpass filter that includes at least a first transistor element and a tunable frequency selective degeneration circuit coupled to a first non-inverting output of the first transistor element. The first active tunable low-noise RF bandpass filter combines low noise amplifier (LNA) and tunable bandpass filter functionalities into a single active RF bandpass filter. The tunable frequency selective degeneration circuit uses degeneration at frequencies outside of a passband of the active RF bandpass filter to increase feedback, thereby decreasing gain of the active RF bandpass filter. By decreasing the gain, linearity of the active RF bandpass filter may be improved in the presence of strong interfering RF signals, thereby enabling elimination of passive bandpass filter elements, such as surface acoustic wave (SAW) and bulk acoustic wave (BAW) filters, without degrading reception of in-band RF signals.

A method and system for processing radar data obtained from a platform which is subjected to non-uniform movement, the distance the platform travels during the formation of an image comprising an aperture; the system comprising software programming for performing a subroutine for building up an average pulse representing a single point on the aperture; the subroutine comprising the steps of inputting radar data from a radar antenna; passing the radar signal through low noise amplifier to reduce impact of electronic noise from the radar system; down converting the signal with a mixer to obtain a lower frequency; filtering out harmonics from the higher frequency range; sampling the radar data using an analog to digital converter at least at Nyquist down range frequency; based upon the IF of the radar; determining a scene center (center of SAR imagery) for the purpose of motion compensation; performing a two stage averaging scheme of the received signals with a variable window function; determining a window function based upon the velocity and acceleration of the platform and scene center; the window function comprising a first stage window; coherently averaging N pulses together to create an average pulse; performing an inverse Fourier transform; compensating to the scene center by multiplying by a complex exponential based upon both the GPS and inertial navigational system; summing the average pulses using low pass filter; the software programming operating to repeat the step of building up an average pulse a first predetermined number of times for a time period that is less than the Nyquist sample time interval; the software programming operating to repeat the step of building an average pulse for a predetermined number of times to generate a second predetermined number of average pulses; the software programming operating to perform a two dimensional inverse Fourier transform to obtain SAR image; outputting the SAR image on a display screen; and a display for displaying the outputted SAR image.

A multi-protocol, multi-band array antenna system may be used in Radio Frequency Identification (RFID) system reader and sensory networks. The antenna array may include array elements with an integrated low noise amplifier. The system may employ digital beam forming techniques for transmission and steering of a beam to a specific sensor tag or group of tags in an cell. The receive beam forming network is optimized for detecting signals from each sensor tag. Narrow and wideband interferences may be excised by an interference nulling algorithm. Space division multiplexing may be used by the antenna system to enhance system processing capacity.

A radio receiver is described that processes multiple wireless standards using a single antenna according to embodiments of the invention. The radio receiver includes a single antenna, and a low noise amplifier that is connected to the antenna, without an intervening power divider or power splitter. The output of the low noise amplifier feeds multiple wireless receivers in a parallel arrangement that are operating according to different communications standards, including for example a Bluetooth and a WLAN 802.11. Additional wireless standards and their corresponding receivers could be added as well. The input impedance of the low noise amplifier defines the impedance seen by the antenna, regardless of which operational standard is actually in use. Each signal path includes an additional low noise amplifier having a gain that can be customized for the particular signal path and receiver in use, and which also improves the reverse isolation between signal paths. Further, a switch can be added to one or more of the signal paths so as to further improve isolation when a particular path is not being used.

A radio frequency front end for a television band receiver and spectrum sensor includes a low noise amplifier that amplifies a received signal output of a radio frequency antenna connected to the radio frequency front end, a pin diode attenuator circuit that selectively attenuates an output of the low noise amplifier, and a buffer amplifier that amplifies an output of the pin diode attenuator.

A high-frequency circuit for wireless communications selectively using a first frequency band and a second frequency band lower than the first frequency band, comprising an antenna terminal; first and second transmission terminals to which transmitting signals in the first and second frequency bands are input; first and second receiving terminals from which received signals in the first and second frequency bands are output; a diplexer circuit for branching a first-frequency-band-signal path and a second-frequency-band-signal path; a switch circuit for switching a path for a transmitting signal and a path for a received signal; a low-noise amplifier circuit disposed between the switch circuit and the second receiving terminal for amplifying a received signal in the second frequency band; and first and second filter circuits disposed between the antenna terminal and the low-noise amplifier circuit in this order from the antenna terminal, both filter circuits passing a received signal in the second frequency band but blocking a frequency band lower than the second frequency band, and the band blocked by the first filter circuit being lower than the band blocked by the second filter circuit.

An antenna configured for low frequency applications on a mobile device includes an antenna element coupled to a conductive structure which, in turn, is coupled to the user of the mobile device such that the user of the mobile device effectively becomes part of the antenna. The conductive structure can include, for example, the device housing being made from a conductive material, a conductive structure embedded inside the device housing, or conductive pads exposed in the device housing. The antenna element is electrically connected to the conductive structure and the user can be coupled to the conductive structure either through direct contact or through capacitive coupling. In addition, the antenna can include an active element configured to boost free space operation efficiency. The active element can include, for example, a low noise amplifier integrated onto a low noise amplifier board. The active element can be at least partially surrounded by a hollow support structure around which an antenna coil is wrapped, where the antenna coil is coupled to the active element. Furthermore, one or more antenna coils can be utilized either separately or in conjunction with the antenna for low frequency applications, where the one or more antenna coils can have integrated therein inductive components and / or active / switching elements that allow the one or more antenna coils to be tuned to a desired frequency.

A high-gain and low-noise low noise amplifier (LNA) includes a differential amplifier, a pre-amplifier and an impedance matching network. The differential amplifier includes a first input end and a second input end coupled to a grounded impedance. The pre-amplifier includes an input end and an output end. The impedance matching network is coupled between the first input end of the differential amplifier and the output end of the pre-amplifier for matching an input impedance of the differential amplifier with an output impedance of the pre-amplifier. The present invention provides a LNA structure with low noise, high gain and easy design.