128 results about "Distributed amplifier" patented technology

A device for decoupling a supply voltage for HF amplifier circuits is described which includes an output line for coupling out an amplified signal, wherein one end of the output line, which is not used for coupling out signals, is connected to a circuit element designed as decoupling circuit. The circuit element has a low ohmic d.c. resistance and presents an HF-power absorption capacity that increases as the frequency increases, thus constituting a reflection-free termination for high frequencies. The circuit element is preferably constituted by several discrete subcircuits connected in succession. The device permits the operation of integrated distributed amplifiers of high performance at a low power loss caused by the decoupling circuit.

A resistive level-shifting biasing network is used with a capacitor in parallel to couple FET-based amplifier stages from DC to several GHz in a multi-stage amplifier. The output of the first amplifier stage is connected to the input of the second amplifier stage without a blocking capacitor or level-shifting diodes, allowing a portion of the drain current for the first amplifier stage to be supplied from the second amplifier stage. In a particular embodiment, a distributed amplifier achieved over 20 dB gain from DC to about 80 GHz using three traveling wave amplifier chips.

In a cascode distributed amplifier of the present invention, a plurality of unit circuits are connected in parallel, and each unit circuit includes a pair of first and second transistors connected in series between an input transmission wire and an output transmission wire. The first transistor has a gate connected to the input transmission wire, a source grounded and a drain connected to the second transistor. The second transistor has a gate grounded, a source connected to the drain of the first transistor and a drain connected to the output transmission wire. Each unit circuit includes a damping resistor having a first end connected to the gate of the second transistor and a second end, and a capacitor having a first end connected to the second end of the damping resistor and a second end grounded.

The collectors of transistors are connected via respective resistances to a power supply terminal receiving a power supply voltage. The emitters of the transistors are connected to a ground terminal via respective resistances. A shunt resistance, a FET, and a shunt resistance are connected in series between nodes connected to the respective emitters of the transistors. The gate of the FET is connected via a resistance to a control terminal receiving a control voltage. The shunt resistances and FET form a variable resistance circuit.

Provided is a distributed amplifier in communication systems, including: an input transmission line; an output transmission line; an input impedance match and an output impedance match, for providing termination of the input transmission line and the output transmission line, respectively and for preventing signal reflection in the input transmission line and the output transmission line, respectively; multi-stage Gm cells with common mode feedback, the input transmission line being coupled to the output transmission line by the transconductance of the Gm cells; and an input gate bias circuit, for providing bias for the multi-stage Gm cells. In at least one of the Gm cells, one inverter performs V / I conversion while other inverters provide negative resistance to control common mode of output voltage and to enhance DC gain of the Gm cell. Due to common mode feedback, no output gate bias is needed.

High speed optical modulators can be made of k modulators connected in series disposed on one of a variety of semiconductor substrates. An electrical signal propagating in a microwave transmission line is tapped off of the transmission line at regular intervals and is amplified by k distributed amplifiers. Each of the outputs of the k distributed amplifiers is connected to a respective one of the k modulators. Distributed amplifier modulators can have much higher modulating speeds than a comparable lumped element modulator, due to the lower capacitance of each of the k modulators. Distributed amplifier modulators can have much higher modulating speeds than a comparable traveling wave modulator, due to the impedance matching provided by the distributed amplifiers.

High speed optical modulators can be made of k modulators connected in series disposed on one of a variety of semiconductor substrates. An electrical signal propagating in a microwave transmission line is tapped off of the transmission line at regular intervals and is amplified by k distributed amplifiers. Each of the outputs of the k distributed amplifiers is connected to a respective one of the k modulators. Distributed amplifier modulators can have much higher modulating speeds than a comparable lumped element modulator, due to the lower capacitance of each of the k modulators. Distributed amplifier modulators can have much higher modulating speeds than a comparable traveling wave modulator, due to the impedance matching provided by the distributed amplifiers.

A bidirectional amplifier circuit includes first and second input ports, first and second output ports, a power amplifier, and first, second, third, and fourth filter circuits. The power amplifier includes at least first and second input terminals and first and second output terminals. The first filter circuit is coupled between the first input port and the power amplifier first input terminal. The second filter circuit is coupled between the second input port and the power amplifier second input terminal. The third filter circuit is coupled between the first output port and the power amplifier first output terminal. The fourth filter circuit is coupled between the second output port and the power amplifier second output terminal. Carrier waves of differing frequencies may be injected into the amplifier circuit first and second input ports, and transmitted from the first and second output ports. The configuration provides broadband operation with flat gain and high efficiency at the frequencies of each of the carrier waves.

The image sensor makes use of a distributed amplifier having its non-inverting input provided by a pixel amplifier transistor, and its inverting input and output provided in the pixel's column circuitry. The distributed amplifier is directly integrated with the image sensor's ADC circuit, and sampling and autozero are performed in a single step, thus reducing the number of noise contributions made by the components of the image sensor's readout chain.

A number of identical non-uniformly distributed ultra-wideband power amplifier string building blocks are coupled together to form an ultra-wide bandwidth high-power amplifier. The non-uniform distribution results in an amplifier utilizing modular string building blocks that have input and output impedances with only real values. This permits the strings to be replicated and connected together with simple impedance matching. The internal impedance matching associated with the non-linear distribution also absorbs parasitic capacitance to permit the ultra-broadband operation. In one embodiment identical transistors are used for each cell so that the strings may be identically replicated. This permits modular re-use without reconfiguration. In one embodiment a non-uniform distributed power amplifier built using the subject building blocks provides an ultra-wideband multi-octave device suitable for electronic warfare and communications applications, especially to replace traveling wave tubes.

A distributed amplifier uses non-uniform filtering structures to provide better control over pass-band and stop-band characteristics. The various sections can have different tap coefficients. A notch filter can be implemented for interference suppression or pulse shaping in an ultra-wideband transceiver.

A system and method in a distributed amplifier system for correcting for RF losses between head end and coverage nodes by measuring RF losses in both directions; generating gains for amplifiers in both the head ends and coverage nodes; generating maximum output power limits; and adjusting the generated gains and output power limits based on downlink signal strength of cellular signals at a donor antenna.

Doherty and distributed amplifier (DA) designs are combined to achieve, wideband amplifiers with high efficiency dynamic range. A modified Doherty amplifier includes a wideband phase shifter providing first and second outputs, a main amplifier coupled to the first output, an auxiliary amplifier coupled to the second output, and a wideband combining network combining the outputs in phase. A multi-stage DA has a main output and a termination port, and a phase delay module and transforming network allowing power at the termination port to be combined in phase with power at the main output. In one combination, one or more stages of the DA may comprise a Doherty amplifier. In another combination, a modified series-type Doherty amplifying system is achieved by cascading main and auxiliary DAs. In any combination, Doherty topology may include a bias control module.

A distributed amplifier uses non-uniform filtering structures to provide better control over pass-band and stop-band characteristics. The various sections can have different tap coefficients. A notch filter can be implemented for interference suppression or pulse shaping in an ultra-wideband transceiver.

The image sensor makes use of a distributed amplifier having its non-inverting input provided by a pixel amplifier transistor, and its inverting input and output provided in the pixel's column circuitry. The distributed amplifier is directly integrated with the image sensor's ADC circuit, and sampling and autozero are performed in a single step, thus reducing the number of noise contributions made by the components of the image sensor's readout chain.

A controlled RF active duplexer comprises two distributed amplifiers and means for controlling them. Each distributed amplifier comprises an input line and an output line, the output line of the first distributed amplifier being common to the input line of the second distributed amplifier. An end of the input line of the first distributed amplifier forms the input port, an end of the output line of the second distributed amplifier forms the output port and an end of the line common to the two distributed amplifiers forms the input / output port. The distributed amplifiers are placed in the on state or in the off state in opposition to one another as a function of the ports to be made to communicate. The invention makes it possible to carry out the splitting of the RF signals within a compact space and isolation between input port and output port.

A distributed amplifier with improved stabilization includes an input transmission circuit, an output transmission circuit, at least one cascode amplifier coupled between said input and output transmission circuits. Each cascode amplifier includes a common-gate configured transistor coupled to the output transmission circuit, and a common-source configured transistor coupled between the input transmission circuit and the common-gate configured transistor. The distributed amplifier also includes a non-parasitic resistance and capacitance coupled in series between a drain and a gate of at least one of the common-gate configured transistors for increasing the amplifier stability.

The invention discloses a distributed amplifier circuit for perfecting linearity. The distributed amplifier circuit comprises a plurality of gain units, an input on-chip inductor connected to an input end of each gain unit, and an output on-chip inductor connected to an output end of each gain unit, wherein an interstage matching capacitor is arranged in front of or behind at least one input on-chip inductor, the input end of each gain unit is connected with a biasing resistor, and a bias voltage is applied from the other end of the biasing resistor. According to the distributed amplifier circuit for perfecting linearity disclosed by the invention, the gain units of different circuit structures are adopted, different bias voltages are applied to change the static working points of the gain units so as to change the linearity thereof, the interstage matching capacitor is introduced to offset and isolate direct current at the input ends of the gain units, so that different bias voltages can be applied to the input ends of the gain units, and then the degree of freedom of design and debugging is increased.

A system comprises a first device and a second device. The first device comprises a receiver, a spectrum analyzer, a controller, an amplifier, a filter and a transmitter. The first device receives from at least one antenna a plurality of signals from different sources. The spectrum analyzer is coupled to the receiver and determines whether a downlink signal power from each of the sources to the system exceeds a predetermined threshold. The controller is coupled to the spectrum analyzer and generates a first indication indicating lowering gains of an amplifier on signals from at least one source with downlink signal power larger than the predetermined threshold. The amplifier is coupled to the controller and lowers gains of the amplifier according to the indication from the controller. The transmitter transmits the plurality of signals after adjustment to at least one second device distributed within a site.

A number of identical non-uniformly distributed ultra-wideband power amplifier string building blocks are coupled together to form an ultra-wide bandwidth high-power amplifier. The non-uniform distribution results in an amplifier utilizing modular string building blocks that have input and output impedances with only real values. This permits the strings to be replicated and connected together with simple impedance matching. The internal impedance matching associated with the non-linear distribution also absorbs parasitic capacitance to permit the ultra-broadband operation. In one embodiment identical transistors are used for each cell so that the strings may be identically replicated. This permits modular re-use without reconfiguration. In one embodiment a non-uniform distributed power amplifier built using the subject building blocks provides an ultra-wideband multi-octave device suitable for electronic warfare and communications applications, especially to replace traveling wave tubes.

A distributed amplifier is disclosed herein, which includes a signal amplification unit amplifying a RF input signal fed into the RF signal, a first biasing circuit providing a direct current (DC) bias signal, a second biasing circuit providing a DC bias signal, the variable terminal resistance providing an adjustable resistance, a RF signal input terminal provided for input of the RF input signal and a RF signal output terminal for output of a RF output signal. The output RF signal from the distributed amplifier is obtained from a gained version of the input RF signal. Since a load mismatch issue is compensated, a gain flatness issue is considerably improved and thus a gain-adjustable range is increased with respect to the distributed amplifier.

A wideband distributed or feedback amplifier monolithic microwave integrated circuit (MMIC) is disclosed that contains an integrated group delay equalizer circuit to compensate for the group delay variation of the amplifier circuitry. The MMIC amplifier is capable of achieving a predicted constant group delay with little variation over a wide frequency range. In addition, the group delay equalizer circuit enables the amplifier to achieve flat (constant) gain over a wide bandwidth, while maintaining constant group delay. Furthermore, the group delay equalizer circuitry requires only a small portion of the total MMIC area.

The invention provides a reconfigurable distributed amplifier circuit which includes an input transmission line and an output transmission line. The input transmission line and the output transmissionline are both formed by cascade connection of an on-chip interconnect structure. The distributed amplifier circuit further includes a plurality of sets of gain units arranged in parallel between theinput transmission line and the output transmission line. Each set of the gain units is inserted and arranged between the on-chip interconnect line structures. The input end of the gain unit is connected with the input transmission line, and the output end of the gain unit is connected with the output transmission line. The distributed amplifier circuit is also coupled with a reset structure. Thereconfigurable distributed amplifier circuit can realize miniaturization and multifunction integration of the circuit structure without changing the circuit main body structure, realizes performance reconstruction of the amplifier working band, gain, linearity, noise and the like, and has the advantages of low power consumption and low cost.

An active selector switch with two inputs and two outputs comprises two parts, each part comprising a distributed amplifier whose elementary cells comprise at least two cascode-mounted transistors (Q1 Q2, Q'1 Q'2), one transistor (Q3, Q'3) controlled through the gate line (Lgc1) of the amplifier being associated with each cell, the associated transistor (Q3) of the first part controlling the state of the common-gate transistor (Q'1) of the second part and the associated transistor (Q'3) of the second part controlling the state of the common-gate transistor (Q1) of the first part, the two inputs (E1, E2) of the selector switch being the free ends of the gate lines (Ldc1) of the two distributed amplifiers (41, 42) and the outputs (S1, S2) of the selector switch being the free ends of these two amplifiers. The invention can be applied especially to digitally controlled phase control devices.

The present disclosure relates to a capacitively-coupled distributed amplifier (DA) having an input line and an output line that are coupled to one another through a broadband interface network and DA segments. The input line receives an input signal and the output line provides an output signal based on amplifying the input signal. The broadband interface network includes a group of capacitive elements coupled between the input line and the DA segments to extend a gain-bandwidth product of the DA. The broadband interface network further includes a resistor divider network coupled between the input line and the DA segments to extend a lower end of an operating bandwidth of the DA. As such, the operating bandwidth of the DA may extend from baseband frequencies to microwave frequencies.

A distributed amplifier system has a predetermined output impedance and input impedance and includes an input transmission circuit; an output transmission circuit; at least two amplifiers connected between the input and output transmission circuits; an input termination on the input transmission circuit; and a feedback output termination on the output transmission circuit connected back to the input transmission circuit for reducing low frequency loss while maintaining the predetermined output impedance and input impedance.

An optical amplifier system is disclosed comprising a discrete amplifier system and a distributed amplifier system. The discrete amplifier system receives optical signals and amplifies the optical signals having wavelengths in a target wavelength band. The target wavelength band has a bandwidth of at least 80 nm. The distributed amplifier system amplifies the optical signals having wavelengths in a longer wavelength band of the target wavelength band, a shorter wavelength band of the target wavelength band, or both.

A wideband distributed or feedback amplifier monolithic microwave integrated circuit (MMIC) is disclosed that contains an integrated group delay equalizer circuit to compensate for the group delay variation of the amplifier circuitry. The MMIC amplifier is capable of achieving a predicted constant group delay with little variation over a wide frequency range. In addition, the group delay equalizer circuit enables the amplifier to achieve flat (constant) gain over a wide bandwidth, while maintaining constant group delay. Furthermore, the group delay equalizer circuitry requires only a small portion of the total MMIC area.

Improved protection circuits are provided for use as voltage overload protection circuits, ESD protection circuits for RF input pins, and unit protection cells for distributed amplifiers. Preferably, the protection circuits include a positive threshold voltage trigger used to trigger a switch wherein the trigger includes a diode string in series with a resistor and the switch includes a bipolar transistor switch in series with a single reverse diode. Alternatively, the trigger includes a diode string in series with a single diode and a single resistor, and is used to trigger a Darlington pair transistor switch in series with a single reverse diode. In another embodiment, a Darlington pair transistor switch is triggered by a capacitor. In use with distributive amplifiers, the ESD protection circuits are preferably absorbed inside the artificial transmission lines of the distributed amplifier.