65 results about "Impedance inverter" patented technology

A switched-mode Class F power amplifier is provided for parallel connection with at least one other like amplifier, within a Chireix architecture, for combining the signals output therefrom. An input component includes at least one active device configured to be alternately switched by a signal input thereto to present an amplified signal corresponding to the input signal and constituting a low output impedance voltage source. A lumped element impedance inverter is provided between the input component and an output resonator component, the impedance inverter being configured for transforming the low output impedance voltage source to instead constitute a high output impedance current source configured for said parallel connection. In accordance with the invention, the negative reactive component values required by the impedance inverter are eliminated and effectively provided by incorporating those values into pre-selected reactive components of the input and output components. Further, a source-drain parasitic capacitance across the active device is eliminated by one or more pre-selected reactive components of the input component, the value(s) of which effectively compensate for the parasitic capacitance.

According to the general concept disclosed herein, a circuit for adaptive matching of a load impedance to a predetermined load-line impedance of a load-line connected to a power amplifier output includes a fixed matching network between the power transistor and an adaptive matching network, whereby the fixed matching network acts as an impedance inverter which results in a relatively low insertion loss at high power. Results indicate that the impedance-inverting network can be used over more than a factor of 10 in impedance variation. Further, the usage of the fixed matching network, close to the power transistor, allows for the implementation of transmission zeros and/or for a well defined load impedance at a predetermined harmonic frequency, independent of the (variable) load impedance at the fundamental frequency.

A power amplifier stage has a first amplifier subsection and a second amplifier subsection coupled in a parallel configuration. The first amplifier subsection receives a signal to be amplified and the second amplifier subsection receives the signal to be amplified via a first delay line. The amplified output signal of the first amplifier subsection is passed through a second impedance inverter and is combined with the amplified output signal from the second amplifier subsection. In a low power mode, the first amplifier subsection operates as a linear amplifier and the second subsection is biased off. In a high power mode, both the first and second amplifier subsections operate as linear amplifiers. Selecting the impedances of the second delay element and the first amplifier to be equal is essential for high power mode operation and greatly improves the amplifier efficiency in the low power mode.

The invention provides a dual-mode dual-band high-efficiency Doherty power amplifier, which comprises a dual-band power divider module, a dual-band input matching module, a main power amplifier, a peak power amplifier, a dual-band output matching module, a dual-band phase compensation line module, a dual-band impedance inverter and a dual-band impedance transformer, wherein the dual-band phase compensation line module comprises a phase compensation line of a main power amplifier branch and a phase compensation line of the peak power amplifier; the phase compensation line of the main power amplifier branch converts the load impedance of the main power amplifier to approach to the optimum efficiency point at a power back-off point; and the phase compensation line of the peak power amplifier makes the output impedance of the peak power amplifier be in an infinite state in a low-power state. The dual-mode dual-band high-efficiency Doherty power amplifier can be simultaneously operated on two communication frequency bands, the input power enters the main power amplifier and the peak power amplifier in a non-equally divided mode, the incomplete modulation effect is reduced, the overall performance of the Doherty is improved, and the dual-mode dual-band high-efficiency Doherty power amplifier can be applied to multimode base stations and software radio and contributes to saving the energy and reducing the cost.

A tunable impedance inverter is presented for a Doherty amplifier circuit having first and second amplifiers connected in parallel between an input circuit for receiving an input signal and an output circuit for supplying an output signal to a load. An impedance inverter is coupled between the first amplifier and the output circuit. The inverter has an input and an output and a tunable mechanical strip line of variable electrical length interposed between the input and the output. An adjuster adjusts the electrical length of the strip line. The adjuster adjustably varies the electrical length of said pathway to thereby adjust the center frequency of said output signal.

A second-order band-pass filter for generating at least two transmission zeros includes a first signal terminal, a second signal terminal, a first transmission line resonator, a second transmission line resonator and an impedance inverter. The first transmission line resonator and the second transmission line resonator are symmetric to each other and coupled to the first signal terminal and the second signal terminal, which are formed by bending two quarter-wavelength open stubs and have an open circuit gap between the two terminals. The impedance inverter includes an inductor, a first micro strip line and a second micro strip line. The first micro strip line and the second micro strip line are symmetric to each other, and are coupled to the first signal terminal and the second signal terminal and coupled to a ground through the inductor, respectively.

Multi-way amplifiers having impedance inverters connected to outputs of one or more peaking amplifiers are described. The output of the main amplifier may connect directly to a combining node and output impedance matching network. The multi-way amplifier configuration can improve efficiency at power back-off and improve RF bandwidth.

The present invention relates to a Multi-Band Doherty amplifier. Embodiments of the present invention provide an amplifying structure including a main amplifier configured to amplify a first signal, a peak amplifier configured to amplify a second signal, a tunable impedance inverter configured to perform impedance inversion to modulate a load impedance of the main amplifier, and a combining node configured to receive the amplified second signal from the peak amplifier and an output of the tunable impedance inverter. The tunable impedance inverter includes a tuner configured to tune the impedance inversion over at least one broad frequency band. The tuner is (i) at least one capacitor, (i) at least one varactor, or (ii) at least one open stub shunted by a diode.

The invention relates to a ridge waveguide filter with a high micro discharging threshold value and a design method thereof. The ridge waveguide filter with the high micro discharging threshold value comprises a cover plate, a filter outer casing, rectangular waveguides, a plurality of sections of ridge waveguides, a filling layer and TNC connectors (threaded Neil-Concelman connector), wherein the inner surface of the cover plate needs to be flattened, the ridge waveguides are connected by the rectangular waveguides, the input ends and the output ends of the ridge waveguides are respectively assembled with each TNC connector, and a polyetherimide material is filled between a ridge of each ridge waveguide and the cover plate. The design method of the filter comprises the following steps of (1) firstly, according to the design parameter requirements of the filter, such as center frequency, working bandwidth and out-of-band inhibition, looking up a table to obtain a lumped parameter model of the filter; (2) carrying out impedance inverting on a filter circuit of the lumped parameters; (3) using the ridge waveguides to replace the lumped parameter elements, such as capacitors and inductors; (4) using the rectangular waveguide structure to realize an impedance inverter; (5) filling the polyetherimide material between the ridge of each ridge waveguide and the cover plate; and (6) optimizing the size of the ridge waveguide filter.

Embodiments described herein relate to a Doherty amplifier. The Doherty amplifier may include a main amplifier and a first peak amplifier, a second peak amplifier, and a third peak amplifier, each amplifier having an input and an output. The Doherty amplifier may also include a combining network configured for combining signals emerging at outputs of the amplifiers. The signals are combined at a combining node. The combining network includes a first impedance inverter arranged in between the output of the main amplifier and the output of the third peak amplifier. The combining network also includes a second impedance inverter arranged in between the output of the first peak amplifier and the output of the second peak amplifier. The combining network also includes a first 180 degrees phase shifter and a second 180 degrees phase shifter. Additionally, the combining network includes a third impedance inverter.

A differential circuit topology that produces a tunable floating negative inductance, negative capacitance, negative resistance/conductance, or a combination of the three. These circuits are commonly referred to as “non-Foster circuits.” The disclosed embodiments of the circuits comprises two differential pairs of transistors that are cross-coupled, a load immittance, multiple current sources, two Common-Mode FeedBack (CMFB) networks, at least one tunable (variable) resistance, and two terminals across which the desired immittance is present. The disclosed embodiments of the circuits may be configured as either a Negative Impedance Inverter (NII) or a Negative Impedance Converter (NIC) and as either Open-Circuit-Stable (OCS) and Short-Circuit-Stable (SCS).

A combination amplifier, in particular a Doherty amplifier allowing dynamic biasing, is provided, the combination amplifier comprising a first amplifier (3,3a,3b) having a first input terminal (11,11a,11b) and a first output terminal (25,25a,25b); a second amplifier (5,5a,5b) having a second input terminal (27,27a,27b) and a second output terminal (29,29a,29b); a first impedance inverter (Li, 43b) connected between the first input terminal and the second input terminal; and an envelope detector (33,33a,33b) comprising a detector output terminal and a detector input terminal which is connected to the first output terminal.

The invention discloses a hospital environment monitoring system based on Internet of Things. A signal receiving circuit receives a signal in a data transmission channel of an Internet of Things hospital environment monitoring system; a 45Hz low-frequency signal resonant with the signal frequency in the data transmission channel is generated through a duplex filter circuit and a double-T frequencyselection circuit and transmitted to a signal intensifier circuit; amplitude adjustment is performed by using an impedance inverter circuit and an in-phase proportional amplifying circuit, and finally the signal is output through a holding circuit. By means of the on-off state of a gate circuit composed of a triode Q1, a resistor R11 and a resistor R13 and a diode D1 as well as a subtractor AR1,a feedback amplitude modulation circuit couples a difference signal to the input end of an operational amplifier AR2 through a resistor R6 or connects a resistor R5 and a resistor R6 in series in parallel to the equivalent resistance value, so that the linear stable signal amplitude can be transmitted to a terminal server of the monitoring system more effectively after gain amplification. The system solves the problems of signal distortion and incapability of conducting effective monitoring caused by the interference of an electronic device or electromagnetic interference between the numeroussignals and attenuation.

The disclosure relates to wideband power amplifiers with harmonic traps. An amplifier may include a transistor and input and output matching networks. One or more harmonic trap circuits may be electrically connected to a node located between the input matching network and a gate terminal of the transistor or to a node located between the output matching network and a drain terminal of the transistor. Each harmonic trap may provide a low-resistance path to ground for signal energy above a fundamental operating frequency of the amplifier, such as harmonic frequencies thereof. The output matchingnetwork may act as an impedance inverter that provides a 90-degree insertion phase between the input of the output matching network and the load. A variable length drain feeder may connect a voltagesource to an output of the output matching network.

The invention discloses a full-power converter suitable for variable speed wind power generation, which is used for realizing the conversion of variable voltage and variable frequency output to constant voltage and constant frequency of a wind power generator. The full-power converter is composed of a multiple-pulse-wave self-coupled voltage regulating rectifier (1) at a motor side and a source impedance inverter (2) at a power grid side, wherein the self-coupled voltage regulating rectifier is used for converting alternating voltage output by a motor into direct voltage, and the source impedance inverter is used for converting voltage-variable direct current into constant-voltage and constant-frequency alternating current to be combined to the grid. Compared with the current full-power converter, the full-power converter has the advantages of simple structure, high reliability and the like, is greatly suitable for occasions needing less maintenance and even free maintenance of future offshore wind power generation and the like, and has a good application and promotion prospect.

The present invention provides a compound transmitter having power efficiency characteristics and distortion characteristics superior, over a wide band, to those of a Doherty transmitter, and having fewer elements constituting an RF circuit. The present invention is therefore provided with a compound amplifier (201) for generating a signal (z) (efficiency improving signal) obtained by the amplitude modulation of a carrier signal from an RF modulation signal (a) (main signal); power-modulating, using two power amplifiers (50, 51), a signal (S1) obtained by adding together (a) and (z), and a signal (S2) obtained by subtracting (z) from (a); and setting, as a transmitter output point, the point (p1) where the respective outputs are combined via impedance inverters (60, 61), the efficiency improving signal (z) being generated under conditions in which the size of the envelope of either (S1) or (S2) is fixed.

Disclosed is an italic feeding Bluetooth chip antenna, which comprises an impedance inverter (4), a radiating element (5) and a dielectric substrate (6), and is characterized in that: the front end of the radiating element (5) adopts the impedance inverter (4) with an italic structure, and the radiating element (5) adopts a flexural shape; the impedance matcher (4) is composed of a lateral micro-strip line (4b) on top and a pair of italic micro-strip lines (4a, 4c) on bottom; and the antenna adopts the extreme compact italic structure as the impedance matcher and the flexural radiating element, so the Bluetooth chip antenna has advantages of good radiation effects, rather small size and compact structure, and can be properly applied to various short distance communication modules and systems.