83 results about "Smith chart" patented technology

The present invention is an adaptable pre-matched tuner system and calibration method for measuring reflection factors above Gamma=0.85 for a DUT. The system includes a first and second large-band microwave tuners connected in series, the first and second large-band tuners being mechanically and electronically integrated; and a controller for controlling the two large-band tuners. The first tuner is adapted to act as a pre-matching tuner and the second tuner is adapted to investigate an area of a Smith Chart that is difficult to characterise with a single tuner, so that the combination of the first and second large-band tuners permits the measurement of reflection factors above Gamma=0.85. The pre-matched tuner system allows the generation of a very high reflection factor at any point of the reflection factor plane (Smith Chart). The pre-matched tuner must be properly calibrated, such as to be able to concentrate the search for optimum performance of the DUT in the exact location of the reflection factor plane where the DUT performs best, using a pre-search algorithm.

A segmented, electro-mechanical, remotely controlled programmable impedance tuner for the frequency range between 10 and 200 MHz uses a cascade of three continuously variable mechanical capacitors interconnected by a set of two low loss flexible or semi-rigid cables; the electrical length of the interconnecting cables between the capacitors determines the frequency at which tuning coverage of the entire area of the Smith chart is optimum; for maximum impedance coverage the length is to be chosen such as to generate a transmission phase shift of 60 degrees at the center frequency between each capacitor stage. Remote tuning is possible by changing the value of the capacitors using electrical stepper motors. The tuner is calibrated using a vector network analyzer and the data are saved in the memory of the control computer, which then allows tuning to any user defined impedance within the tuning range. Reflection factor values between 0 and higher than 0.9 can be obtained using this tuner.

The invention discloses an impedance matching method for a gold bonding wire. The method comprises the following steps: establishing a gold bonding wire model; extracting model parameters in a circuit application frequency band; causing the gold bonding wire model to be equivalent to a TT-shaped low-pass filter network; fitting equivalent network parameters by using the extracted model parameters; and introducing the extracted model parameters into a to-be-matched schematic diagram and adding a Smith chart matching control. In the Smith chart, 2-4 sections of micro-strip wires are serially connected so as to establish a matching network; a load impedance is converted into an actual impedance by first to second sections; the actual impedance is converted into a source impedance by a third section which is a Lambda/4 converting wire, thereby achieving impedance matching; and a fourth section is a gradual changing wire used for transition. The impedance matching method has the advantagesof simple design concept, easiness in application, capability of saving a circuit board space, small frequency limitation, wide frequency band width and excellent compensation effect. The impedance matching method is used for interconnecting monolithic microwave integrated circuits, coplanar waveguides, microwave transmission lines or RF (Radio Frequency) grounding sides.

An indirect-fed antenna system is disclosed. In an embodiment, a coupler is electrically coupled to a feed. The coupler capacitively couples to a resonating element and the resonating element is electrically coupled to a ground plane. The system allows for improved band-width and also allows for an antenna design where the resonant frequency, the bandwidth of the antenna, the location of the curl on a Smith chart and the associated impendence matching network can be separately adjusted.

An electro-mechanical harmonic load pull tuner uses three variable and adjustable shunt air capacitors and three variable and adjustable series phase shifters and creates independently controllable impedances at three harmonic frequencies in the frequency range between 30 and 250 MHz. Independent harmonic tuning is possible because the combination of adjustable shunt capacitors and series phase shifters allows generating more than 10¹⁹ impedance states at each frequency covering the entire Smith chart; appropriate impedance-search Error Function-based optimization algorithms allow fast harmonic tuning for impedance tuning and matching the output of RF transistors and amplifiers at the fundamental and harmonic frequencies. Stepper motors, drivers and control software are used to automate, calibrate and use the harmonic tuner in an automated harmonic load pull measuring setup.

The invention relates to the dielectric substrate characteristic measurement field and especially discloses a dielectric substrate measurement apparatus based on a multi-resonant waveguide substrate integration vibration cavity method. The apparatus comprises a standard W frequency band metal feed waveguide and N resonant cavities. The apparatus is characterized in that the shape of the N resonant cavities is square and the N resonant cavities are arranged in a slotted shape from left to right; resonant frequencies are successively decreased according to a fixed frequency interval. The measurement method is characterized in that a vector network analyzer is used and is connected to a feed port of a standard metal waveguide through coaxial feed; according to the recorded S parameter data on the vector network analyzer and Smith chart data, a no-load resonant frequency f110 is calculated through a formula; and then simulation software HFSS is used to carry out intrinsic model simulation so as to acquire values of dielectric constants epsilon r and tan delta of the dielectric from the f110. By using the apparatus and the method in the invention, high precision measurement can be performed on the dielectric constant of the dielectric substrate and a loss tangent in a wide frequency band.

High reflection load pull tuners are proposed, which include two or more RF probes, placed in series into the same slotted airline (slabline) and being controlled simultaneously horizontally and vertically by remote electric control, allowing the creation of controlled reflection factors which are distributed over and cover the entire Smith Chart, from very low reflection factors up to very high reflection factors and a method allowing to align such tuners and to calibrate such tuners on a vector network analyzer.

The present invention discloses a load-pull slide-screw tuner consisting of a radio-frequency (RF) or microwave slotted airline (slabline) containing a single corrugated RF slug, said corrugated RF slug being controlled horizontally and vertically by remote electric control, allowing the creation of impedances which are distributed over and cover the entire Smith chart, from perfect transparency to high reflection factors. The corrugation structure of the RF slug of this invention provides the slide-screw tuner, with a single RF slug, the same electromagnetic performances than double slugs slide-screw tuner, i.e. same frequency bandwidth of use and equivalent high gamma performances, at a much lower cost of manufacturing.

A matching device includes: a directional coupler that detects a traveling wave and a reflected wave; a matching circuit that has a first variable capacitance capacitor, a second variable capacitance capacitor and an inductance; and a control unit that calculates a reflection coefficient based on the traveling wave and the reflected wave and controls a capacitance value VC1 of the first variable capacitance capacitor and a capacitance value VC2 of the second variable capacitance capacitor. The control unit changes VC2 such that VC2 moves toward a circle drawn by the trajectory of the reflection coefficient passing through a matching point on a Smith chart, fine-tunes VC1 on the basis of a predicted intersection point with the circle, and when the distance between the calculated reflection coefficient and the circle becomes a predetermined value or less, changes VC1 such that the calculated reflection coefficient approaches zero, and fine-tunes VC2.

An electro-mechanical impedance tuner generates wideband and complete Smith chart reflection factor coverage at frequencies as low as 1 MHz. It comprises an in-line adjustable linear phase shifter and a variable capacitor connected in parallel to ground. The transmission line, which serves as an adjustable phase shifter of variable electrical length, is made as a cylindrical rotating spiral wire-over-ground transmission line, on which runs a sliding contact, connected with a variable capacitor; the capacitor can be, depending on the frequency, immersed in a dielectric liquid, such as oil (∈_r≈3) or alcohol (∈_r≈20) for increased capacitance. The cylindrical structure of the spiral transmission line allows for a compact, 1 meter long apparatus at 1 MHz, whereas the required linear electrical length for this type of impedance tuner would be 150 meters in air, or 100 meters when low cost polyethylene dielectric (∈_r≈2.25) is used. Cascading two or more tuners allows pre-matching and harmonic tuning.

A high-frequency module includes a plurality of filters, a switch that commonly connects a plurality of paths, and a low noise amplifier that amplifies a high-frequency signal input from the plurality of filters with the switch interposed therebetween, wherein paths in which first and second filters are respectively provided among the plurality of paths connect the respective filters and the switch without connecting impedance elements, and each of the first and second filters has an output impedance located in a matching region between a NF matching impedance at which an NF of the low noise amplifier is minimum and a gain matching impedance at which a gain of the low noise amplifier is maximum in its respective pass band thereof on a Smith chart.

The invention provides an antenna structure and a communication terminal. The antenna structure comprises an antenna radiator, a signal source, a first capacitor and a first tuning circuit; the firstend of the antenna radiator is grounded; the first end of the first capacitor and the first end of the first tuning circuit are both electrically connected with the connection point of the antenna radiator, the second end of the first capacitor is electrically connected with the signal source, and the second end of the first tuning circuit is grounded, wherein the antenna impedance of the first end of the first capacitor at a target frequency point is located in the first quadrant of the Smith chart, and the target frequency point is at least part of the frequency points in a frequency band covered by the antenna radiator. According to the scheme of the invention, on the one hand, the antenna structure can generate a new resonance mode, and the resonance mode excited by the antenna structure can be optimized; and on the other hand, the problem of impedance mismatch loss of the antenna can be improved, the impedance mismatch loss can be reduced, and the transmission efficiency of the antenna can be further improved.

A matching circuit is provided to adapt electrical impedance simultaneously for at least one pair of a higher and a lower frequencies between a plasma reactor and a generator; said matching circuit comprises at least a “load and tune” L-type stage, and includes

• • a “tune circuit” connected in series to the plasma reactor and having at least one of or both an inductor and a capacitor in series;
  • a “load circuit” connected in parallel to the series-connected “tune circuit” and load, and comprising at least one of or both an inductor and a capacitor in parallel; and the component values of the tune and load circuits are chosen such that, for the lower frequency, the matching circuit follows a negative load reactance path in a Smith chart, and for the higher frequency, the matching circuit follows a positive load reactance path in the Smith chart.

The invention relates to a microwave absorber with broadband absorption characteristics, in particular to a broadband microwave absorber based on a folded dipole. According to the broadband microwave absorber, a folded dipole antenna serves as a design starting point, an antenna array with a broadband is designed based on a smith chart impedance adjustment method, furthermore, a feed source is replaced by a load resistor based on the reciprocity principle of the antenna, and therefore the microwave absorber with the broadband absorption characteristics is obtained. A dielectric layer of the absorber is of a double-layer structure, the upper layer is a common dielectric substrate, and the lower layer is common polystyrene foam materials (the dielectric constant is approximately 1.07). Although double-layer dielectric materials are adopted, a single-layer metal SMD circuit is adopted to be used in cooperation with a thin film SMD resistor. The broadband microwave absorber based on the folded dipole is simpler in structure, easier to process, low in cost and light in weight, and therefore mass production can be achieved.

This invention provides a method for designing antenna impedance match circuit used in matching power amplifier and an antenna circuit initially including an antenna and a first antenna impedance match circuit. A second circuit is provided to be matched with that of the first power amplifier to constitute an integral circuit which impedance forms a first trace on the smith chart and its phase error is regulated. In addition, a second power amplifier impedance match circuit is designed to be matched with the first antenna circuit to make up of another integral circuit and the impedance forms a second trace on the smith chart and the system gets the phase error in conformity with the predesigned specifications when the two overlapped.

The invention provides a method for measuring the source reflection coefficient of a load traction system online, comprising the following steps: obtaining the S parameter of a source impedance tunerthrough a vector network analyzer; opening a signal source and a power amplifier, and placing a load impedance tuner in a predetermined position; moving the source impedance tuner to multiple impedance points, and reading the power values corresponding to the multiple impedance points from a power meter; drawing a contour line of Smith chart through interpolation based on the power values corresponding to the multiple impedance points, and conjugating the reflection coefficient corresponding to the highest point of convergence of the contour line to obtain the source impedance; and obtaining the source reflection coefficient through calculation according to the S parameter and the source impedance. The method for measuring the source reflection coefficient of a load traction system onlineprovided by the invention has high accuracy.

The invention relates to a wireless communication technology, and particularly discloses a fast antenna matching method. The method comprises the following steps: step S1, measuring inductance Lant amount, a loss resistance Rant value and a parasitic capacitance Cant value of an antenna equivalent circuit; step S2, adjusting the antenna quality factor Q of the antenna circuit, calculating a series resistance RQ value of the adjustment Q value of the antenna circuit and a normalized impedance (the formula is as shown in the specification) value of the antenna circuit; step S3, calculating conjugate normalized impedance (the formula is as shown in the specification) of an equivalent circuit of a low pass filter circuit, and step S4, adopting a smith chart to perform conjugate match on the calculated (the formula is as shown in the specification) and (the formula is as shown in the specification). According to the fast antenna matching method disclosed by the invention, an antenna circuit test process is processed by using the smith chart and a corresponding matching calculation flow, therefore no network analyzer is needed in the test process, and the matching work can be accomplished just by using one LCR electronic tester, thereby reducing the machine cost, and ensuring faster, simpler and more visual and understandable matching work.

A branch path having a transmission line and a distributed constant line includes a resonant circuit. The resonant circuit resonates at a predetermined operating frequency when the branch path is in OFF state. At this time, the distributed constant line has a predetermined impedance. Further, an impedance of a node between the resonant circuit and distributed constant line can be set on a circle of a reflection coefficient 1 near short on the Smith chart.

The invention provides a design method for a radio frequency power amplifier broadband matching circuit and a smith chart used by the method. The design method adopts a new idea in the broadband power amplification design, i.e. a stereoscopic three-dimensional smith chart which is a new tool for broadband design. According to the stereoscopic smith chart, expansion is carried out on the basis of a conventional classical two-dimensional smith chart; frequency coordinates are added; visualization of a great quantity of data in the broadband design process is implemented; the problem of difficulty in diagrammatizing, which is caused by the case that the conventional classical two-dimensional smith chart is displayed on a broadband to generate the overlapping phenomenon, is avoided; simplified calculation and diagrammatizing also can be carried out in the broadband and particularly in a matching network of broadband power amplification design. Display of the stereoscopic three-dimensional smith chart is convenient for a user to integrally grasp the integral effect of the broadband matching network design, enables a conventional broadband complex network to be visualized and enables broadband design to be more convenient and effective. All in all, the stereoscopic smith chart can be effectively applied to the broadband network impedance analysis and the broadband matching network design.

The invention discloses an antenna impedance matching method on the basis of key index data of a power amplifier. The method mainly comprises the steps of calibrating a vector network analyzer; measuring output impedance value of an antenna; acquiring an impedance matching network value through Smith-Chart software; creating an impedance matching network; acquiring testing data of the created impedance matching network; verifying whether the testing data meet the index requirement; comparing the impedance matching network with the key index data of the power amplifier; determining whether the created impedance matching network reaches the optimal state; if not, debugging the impedance matching network; if so, passing the debugging. With the adoption of the antenna impedance matching method on the basis of the key index of the power amplifier, the accuracy can be ensured on the premise that an intuitive and physical conception is clear, thus the calculation speed is greatly raised, the performances of the antenna are optimized, and meanwhile, the shortages of computer simulation method and the manual calculation method are overcome, and as a result, the performances of the antenna are further optimized.

A method is provided to use a Smith Chart technique to obtain frequency domain network performance information corresponding to a passive network including one or more passive devices comprising: receiving first data representing a first Smith Chart plot of coefficients representing measured mismatch between a source impedance of a network and a load impedance of the network for higher frequency components; and extrapolating a predicted substantially spiral shaped second Smith Chart plot of coefficients based upon the first data, which includes a coefficient representing predicted mismatch between the source impedance of the network and the load impedance of the network for lower frequency components.

The present invention provides a method for designing an impedance matching circuit. The impedance matching circuit is for matching a power amplifier and an antenna circuit. The antenna circuit originally includes an antenna and a first antenna impedance matching circuit. For suiting the design modification of the power amplifier, the method provides a second antenna impedance matching circuit, and matches it with a first power amplifier impedance matching circuit to constitute an overall circuit. The impedance of the overall circuit forms a first locus on the Smith Chart, and is made to have a phase error meeting a predetermined specification. Next, the second power amplifier impedance matching circuit is designed and matched with the first antenna impedance matching circuit to constitute another overall circuit. And the impedance of this overall circuit forms a second locus on the Smith Chart. As the second locus overlaps the first locus, the system has a phase error meeting a predetermined specification.

The invention discloses a method for measuring the electrical conductivity of a metal film under the microwave frequency, and the steps are as follows: a vector network analyzer which can emit microwave frequency signals, a rectangular air wave guide and a movable short circuit device with a piston are utilized; a substrate is arranged between the rectangular air wave guide and the movable short-circuit device, the Smith chart of the vector network analyzer is observed, the piston of the movable short-circuit device is simultaneously regulated till the reflection coefficient of the surface of the substrate is a pure real number, then the measurement position of the piston of the movable short-circuit device is recorded and the substrate is taken out; a metal film sample which comprises the metal film to be measured and a substrate layer with the same material with the substrate is produced; the metal film sample is arranged between the rectangular air wave guide and the movable short-circuit device, thereby allowing the metal film layer to face to one end of the vector network analyzer which emits the frequency signals, the piston of the movable short-circuit device is regulated to the measurement position, and the reflection coefficient of the surface of the metal film sample is read; and the electrical conductivity of the metal film is calculated.