437 results about "Impedance transformer" patented technology

A duplexer has an asymmetrical antenna port and a symmetrical reception output, and therefore can be interconnected (without any intermediate stages) to an amplifier with a differential input. A reception bandpass filter is arranged in the reception path of the duplexer. The reception bandpass filter can have the functionality of a balun. The transmission input of the duplexer can be designed symmetrically, in which case a transmission bandpass filter arranged in the transmission path should be designed symmetrically on the input side. The impedance of the antenna port of the duplexer can differ from the impedance of the reception output or the transmission input. No intermediate stages (such as a balun or—in cases of impedances that differ between the duplexer and its corresponding amplifier—an impedance transformer) are required between the duplexer and the amplifier that is interconnected (whether before or after) in the transmission or reception path.

A surgical antenna for radiating microwave energy (e.g. frequency 500 MHz to 60 GHz) from a e.g. ceramic insertion tip (60) into biological tissue is disclosed. The tip is provided at the end of an elongate body which delivers the microwave energy to the tip via an inner conductor (30), an outer conductor (20) surrounding the inner conductor and a dielectric material (50) therebetween. The impedance of the insertion tip (60) is selected to improve impedance matching with the complex conjugate of the complex impedance of the tissue at a treatment frequency. For example the insertion tip may act as or include at least one quarter wavelength impedance transformer. By closely matching the antenna's impedance to the tissue, dynamic tuning (if used) can be performed much more efficiently. Impedance matching at the tip can also focus the radiated energy distribution.

A switched-mode power amplifier is configured for performing power amplification of a plurality of signals input thereto and integrally summing (combining) those signals. Conceptually, this is achieved by replacing the input winding of the transformer component of a transformer-coupled voltage switching amplifier with separate input components, one for each input signal, in similar manner to the configuration of the input components of a three-port combiner (trifilar). In a first transformer-containing category of embodiments of the invention, the input winding of the amplifier's transformer is comprised of a plurality of series-coupled windings, one for each of the plurality of input components/signals such that the input components constitute a series connection of low output impedance sources applied to the amplifier's resonator and load. This, in turn, provides a high level of isolation between the amplifier input components and results in a low level of loss. In a second non-transformer-containing category of embodiments of the invention, the transformer component is replaced by a transmission line impedance transformer, or a lumped element equivalent circuit, which transforms the low output impedance sources to high output impedance sources and those sources are connected in parallel (rather than in series per the first category of embodiments).

A multiple power mode amplifier provides a low and a high power mode without using switches. This amplifier may be used in radio frequency (RF) applications such as mobile telephones, pagers, portable digital assistants, and wireless e-mail devices. In the low power mode, the power consumption of the amplifier is reduced, which will increase operation time, especially important for battery-operated devices. In one implementation, the amplifier includes a number of impedance matching network units (130, 140, 150, and 160), impedance transformer (170), and a power stage (120). An implementation provides further power consumption savings by modulating a bias of an amplifier stage.

A mechanism for coupling a coaxial waveguide to another waveguide. The mechanism includes a lower or matching waveguide and an impedance transformer. A coaxial port couples the coaxial waveguide to the matching waveguide. The matching waveguide has a waveguide impedance which is close to the impedance of the coaxial waveguide. This arrangement allows matching between the coaxial waveguide and the matching waveguide over a wider frequency band. The impedance transformer couples the matching waveguide to the other waveguide. The impedance transformer comprises a single-stage, double-stage, or multi-stage transformer. The mechanism is suitable for coupling an antenna to a coaxial cable interface in a radar or microwave based level measurement or time of flight ranging systems.

A method of providing an impedance match for an integrated semiconductor circuit to other microwave elements is provided by allowing the selection of one of a plurality of impedance matching ratios between the circuit and other elements. The tunable impedance match comprises a microwave impedance transformer with at least a single primary winding, and a plurality of secondary windings, wherein the winding configuration is determined by an electrical switching apparatus allowing the secondary windings to be connected in series, parallel and combinations thereof to provide the required impedance matching. The method allows for both dynamic matching of an integrated semiconductor circuit for increased efficiency, and hence reduced power consumption, and directly matching said circuit to high impedance antennae etc.

A radial power divider-combiner is disclosed. Such a radial divider-combiner may include a plurality of waveguides, each of which extends between a central monopole antenna and a respective peripheral monopole antenna. Such a waveguide may have a central portion with a height-to-width ratio of two, and a peripheral portion having an aspect ratio of one. To improve impedance-matching, a transformer portion may be disposed between the central portion and the peripheral portion. Such a transformer portion may have any number of sections, from one to infinity, with each section having a respective height between that of the central portion and that of the peripheral portion. In the extreme case, where the number of “sections” is infinite, the height of the transformer portion may vary linearly from that of the central portion and that of the peripheral portion.

The invention discloses a circuit structure which utilizes an adjustable inductor and improves linearity of a power amplifier as well as a method. The circuit structure contains an on-chip transformercoupling input network, a transistor amplifier circuit, an output network, a control and bias generating circuit and an envelope detection circuit; the transistor amplifier circuit is respectively connected with the on-chip transformer coupling input network and the output network; the transistor amplifier circuit is provided with a capacitor-inductor parallel resonance loop as well as a capacitor and the adjustable inductor connected in parallel in the capacitor-inductor parallel resonance loop; and the envelope detection circuit is connected with the control and bias generating circuit, detects an envelope signal of a radio frequency signal of the input network or output network and generates the required bias signal and a control signal for the adjustable inductor. The circuit structure disclosed by the invention realizes dynamic and adjustable low-resistance bias loop by adopting a parallel adjustable LC loop way, AM-AM nonlinearity is improved, and the adjustable inductor eliminates AM-PM nonlinearity; and the circuit structure can be conveniently used in an inter-stage matching and impedance transformer network of a multistage amplifier, and cascade connection of a multistage radio frequency power amplifier can be realized conveniently.

The invention provides a millimeter wave array antenna design method and an array antenna device. The design method comprises the following steps of: firstly designing an array model with a feed network, and enabling structure parameters of the feed network to be equivalent to feed current of an array element, so as to directly solve structure parameters of an antenna during array synthesis; replacing a factor directional diagram by a radiation directional diagram of an antenna array, designing a target function through design indexes of the array antenna, and searching an optimum solution of the physical size of an impedance transformer along the direction of the target function via an optimization algorithm. According to the method, the influences of cross-coupling factors are considered in the array synthesis process, the final result does not need coupling compensation, and a simulation manner is adopted to save the cost and simplify the design process. By adoption of joint simulation, a lot of fussy work in the design optimization process of the array antenna is avoided, and the automatic design of the antenna is achieved.

The invention discloses a broadband LTCC (Low Temperature Co-Fired Ceramic) power divider which is formed by connecting two stages of impedance transformers in series. Each stage of impedance transformer is formed by a reactance network formed by elements with lumped parameters; and the elements are implemented by a LTCC multilayer structure. The two stages of impedance transformers adopt a vertical series connection structure. The elements of the first stage of impedance transformer are positioned on a second layer to a ninth layer of a LTCC medium; and the elements of the second stage of impedance transformer are positioned on an eleventh layer to an eighteenth layer of the LTCC medium. An isolation resistance at the tail end of the first stage of impedance transformer is positioned on a tenth layer of the LTCC medium and is implemented by printing resistance paste; and an isolation resistance at the tail end of the second stage of impedance transformer is positioned on a nineteenth layer of the LTCC medium and is implemented by printing the resistance paste. The two stages of impedance transformers are isolated by metal grounds on the ninth layer and the eleventh layer in phase mode. The power divider has the advantages of small volume, low cost, wide bandwidth, high isolation, high temperature stability, convenience in use and the like and is beneficial to batch production.

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.

The invention provides a multiway Doherty amplifier which comprises an amplifier input circuit, an amplifier output circuit, a main amplifier, at least a first peak value amplifier, at least a second peak value amplifier, a first impedance transformer, a second impedance transformer and a third impedance transformer. An input circuit of the main amplifier is connected with the amplifier input circuit. An input circuit of the first peak value amplifier is connected with the amplifier input circuit or an output circuit of the main amplifier, and an input circuit of the second peak value amplifier is connected with the amplifier input circuit, or the output circuit of the main amplifier or an output circuit of the first peak value amplifier. The first impedance transformer is connected between the output circuit of the main amplifier and the amplifier output circuit. The second impedance transformer is connected between the output circuit of the first peak value amplifier and an output circuit of the second peak value amplifier. The third impedance transformer is connected between the output circuit of the second peak value amplifier and the amplifier output circuit.

A multiple power mode amplifier provides a low and a high power mode without using switches. This amplifier may be used in RF applications such as mobile telephones. In the low power mode, the power consumption of the amplifier is reduced, which will increase operation time, especially important for battery-operated devices. In one implementation, the amplifier includes a number of impedance matching network units (130, 140, 150, and 160), impedance transformer (170), and a power stage (120).

The invention relates to a dual-polarization broadband high-isolation microstrip antenna. The microstrip antenna comprises an earth plate, a lower medium plate and an upper medium plate which are arranged at intervals in a parallel manner, wherein the earth plate and the lower medium plate are connected with each other through a coaxial feed inner conductor probe; two lower radiation patches are arranged in parallel on the upper surface of the lower medium plate, and are connected with each other through a 180-degree phase-shifting microstrip line; a microstrip line is led out upwards from the 180-degree phase-shifting microstrip line to be connected with an upper feed port; a lower feed port is formed, below the 180-degree phase-shifting microstrip line, in the surface of the lower medium plate; the lower feed port is connected with corner cutting microstrip connecting lines led out from the lower parts of the two lower radiation patches through an impedance transformer; the upper medium plate comprises upper radiation patches arranged in correspondence with the two lower radiation patches; a ridge trumpet-shaped guiding structure with an upward opening is arranged among the lower radiation patches and the upper radiation patches. The microstrip antenna has the advantages of being dual-polarization, broad in band and high in isolation.

A radio frequency (RF) device includes electronic circuitry having a radio frequency section and power connectors for electrically connecting the electronic circuitry to at least one power source for providing the device with power. At least one quarter wavelength transmission line is connected between the power connectors and the electronic circuitry and acts as a low-to-high impedance transformer at RF, while at low frequencies i.e. DC, it provides a physical connection. Thus, the transmission line section has substantially no effect on the DC connection between the power source and the device.

A multiple power mode amplifier provides a low and a high power mode without using switches. This amplifier may be used in RF applications such as mobile telephones. In the low power mode, the power consumption of the amplifier is reduced, which will increase operation time, especially important for battery-operated devices. In one implementation, the amplifier includes a number of impedance matching network units, impedance transformer, and a power stage.

A power system controller design for controlling fault current or load flow current by applying a variable inductive impedance. The device comprising multiple stages of transformers connected such that their primary coils are in series and carry the primary power. Their secondary circuits containing a device for interruption of secondary current. The secondary circuit of each stage having a small part of the primary energy flowing through them. Under normal conditions the interrupter allows secondary current to flow, producing no impedance on primary side. Upon operation of interrupter, inductive impedance appears across primary. Operation of single stages producing low inductive impedance on primary circuit. Operation of multiple stages producing higher inductive impedance on primary circuit. In a preferred embodiment, the transformers have saturating cores such that operation of single stages saturates their cores, producing low inductive impedance on primary circuit. Operation of multiple stages brings the individual cores back out of saturation, producing higher inductive impedance across primary. Also in a preferred embodiment, to form a stage the secondary circuits of an identical transformer pair are connected in parallel via an interrupting device. Normally, current flowing in the secondary of the first transformer is re-introduced into the primary via the second transformer. Upon operation of interrupter, inductive impedance appears across primary coils of both transformers.