218 results about "Coupling impedance" patented technology

An integrated RF circuit has an RF input port and an RF output port coupled to an external circuit element having known impedance such as an antenna. An RF circuit element is disposed between the RF input port and the RF output port and has a first input port and a first output port. The RF circuit element affects a signal received at the first input port and provides the affected signal to the first output port. The integrated RF circuit also has a VSWR detector circuit that measures a ratio of a characteristic of RF signals at the first input port and the first output port and that provides an indication of the ratio at a VSWR output port. The measured ratio of the characteristic is affected by an impedance of the coupling thereby providing an indication relating to the coupling.

The invention discloses a V-shaped micro-strip meander-line slow wave structure, belongs to the technical field of microwave vacuum electronics, and relates to a traveling wave tube amplifier. The V-shaped micro-strip meander-line slow wave structure comprises a micro-strip transmission line structure consisting of a metal bottom plate (3), a dielectric layer (2) and a planar metal wire (1) and is characterized in that: the dielectric layer (2) is positioned between the metal bottom plate (3) and the planar metal wire (1); the planar metal wire (1) has a zigzag structure formed by connecting a plurality of sections of planar metal wires which have the same shape and dimension end to end; and the adjacent two sections of planar metal wires constitute a V shape or a reverse V shape, and the included angle 2theta of the V shape or reverse V shape is less than 180 degrees. The shape of the dielectric layer (2) can be the same as that of the metal bottom plate (3) or the planar metal wire (1). Compared with the conventional right-angle micro-strip meander-line slow wave structure, the V-shaped micro-strip meander-line slow wave structure has wider working band and higher coupling impedance and can further meet the requirements of an equipment system on the device in aspects of working bandwidth, output power, weight and volume.

The invention discloses a power-adjustable backward wave oscillator. The power-adjustable backward wave oscillator is characterized in that: by inserting upper and lower two rows of periodically complementary split-ring resonator structure into the middle part of a cavity of rectangular waveguide vertically, the complementary split-ring resonator structure has a relatively higher electric field resonant response at the slit of the opening, that is, between the horizontal branches of the two half parts, and shows the meta-material electromagnetic characteristic with a negative dielectric constant epsilon and a negative magnetic permeability Mu; longitudinal resonant field intensity is formed at the upper surface and lower surface of the periodically complementary split-ring resonator structure, thus being conductive to interaction between charged particles of band-shaped electron beams and electromagnetic waves; and at the same time, three electron beam channels are formed. Therefore, compared with a traditional relativism backward wave oscillator, the power-adjustable backward wave oscillator has higher coupling impedance and can obtain very high power output and electron efficiency. Besides, the structure enables one electron beam to work individually, or enables two electron beams or three electron beams to work, so that three kinds of adjustable power output of single beam, double beam and three-beam can be formed and then multi-band-shaped power can be adjustable.

The present invention relates to a transceiver for bidirectional frequency division multiplexed transmission, a communication system including one or more transceivers. Optionally, the communication system is a communication system for a digital subscriber line. The transceiver comprises transmission means with a voltage source output or a current source output for transmitting data in a transmission frequency range, receiving means for receiving data in a receiving frequency range, and a coupling impedance for connecting the transmission means and the receiving means to a transmission medium. The magnitude of the coupling impedance in the transmission frequency range is smaller than the magnitude of the coupling impedance in the receiving frequency range if the transmission means has a voltage source output and is higher than the magnitude of the coupling impedance in the receiving frequency range if the transmission means has a current source output.

A stereo headphone employing a standard stereo headphone plug is adapted for automatically hearing a monaural signal at both earpieces, when accessing a typical monaural source. In the first embodiment of the invention, an impedance element couples the signal from a first acoustical driver that receives the monaural signal from the stereo plug tip, to a second acoustical driver that is connected to the stereo plug ring and normally receives no signal when plugged into a conventional monaural audio source output jack. The magnitude of the coupling impedance is selected with respect to the impedance of the acoustical driver so that the reduction in loudness at the second earpiece due to the signal voltage drop across the coupling impedance is not perceptible to the listener. This will occur when the reduction in loudness at the second earpiece is less than the threshold of perceivable loudness reduction at one ear when there is no reduction in loudness at the other ear. The effect of the coupling impedance, when listening to a stereo audio source is insignificant, firstly, because the two stereo channel signals appear at their respective drivers with virtually no attenuation due to the coupling impedance. Secondly, although the coupling impedance does contribute a slight amount of additional crosstalk between the stereo channels, the magnitude of the increase in crosstalk is dependent upon the ratio of the coupling impedance to the output impedance of the stereo source. A typical stereo source for which the use of this headphone is intended has an output impedance so low compared to the coupling impedance that the increase in crosstalk is too small to be perceptible as affecting the stereo separation or the stereo imaging afforded by the stereo source. In the second embodiment of the invention two equal impedance elements couple the monaural signal from the stereo plug tip to each acoustical driver. This equalizes the loudness of the monaural signal heard at each earpiece and slightly reduces the level of one stereo channel with respect to the other. Crosstalk and stereo imaging are virtually unaffected, as with the first embodiment.

The invention provides a novel half-cycle staggered double-gate slow-wave structure, which comprises rectangular gates and an electron injection channel, wherein the rectangular gates are in half-cycle staggered arrangement on two wide edges of a rectangular waveguide; the electron injection channel is arranged at the center of the rectangular waveguide and runs through the rectangular waveguide along the axis direction of the rectangular waveguide; and the rectangular gates are intersected with the electron injection channel, so that the coupled impedance is improved; and the novel half-cycle staggered double-gate slow-wave structure is applicable to improvement of the gain and the efficiency of a terahertz device.

The invention discloses an identification method for a sub-synchronous / super-synchronous coupling impedance (admittance) model of a power device. The identification method for the impedance model comprises the steps of providing the sub-synchronous / super-synchronous coupling impedance model of the power device; connecting the power device into a power grid, applying sub-synchronous / super-synchronous excitation to the power grid, and obtaining sub-synchronous and super-synchronous voltage components and current components of the power device based on the sub-synchronous / super-synchronous coupling impedance model; changing sub-synchronous / super-synchronous excitation parameters or parameters of an external power grid, thereby obtaining multiple groups of measurement results of the power device, and generating an impedance measurement equation according to the multiple groups of measurement results; and carrying out a preset numerical optimization method on the impedance measurement equation to obtain impedance parameters of the sub-synchronous / super-synchronous coupling impedance model. The method has the advantages that the indivisibility between complementary frequency dynamic states of two relatively working frequencies is represented, and the sub-synchronous / super-synchronous resonance and vibration problems of a power system are analyzed and explained well.

The invention relates to a slow wave structure of a folding frame, and the structure belongs to the technical field of microwave electric vacuum devices. The structure comprises an upper metal bottom plate and a lower metal bottom plate (2 and 1) which have the same shape and size and are in parallel with each other; medium layers (3 and 4) are respectively arranged on the opposite surfaces of the upper metal bottom plate and the lower metal bottom plate; metal microstrip lines (5 and 6) are respectively arranged on the opposite surfaces of the medium layers (3 and 4); the upper and the lower metal microstrip lines (5 and 6) have the same line width, are respectively folded periodically, and are mutually in mirror symmetry; and folding top points which correspond to the upper and the lower metal microstrip lines (5 and 6) are connected by metal connecting wires (7). Compared with the existing slow wave structure of a symmetric double V-shaped microstrip line, according to the slow wave structure of the folding frame, the inside of a whole working frequency band is provided with a higher coupling impedance value, so that the gain and the efficiency of a traveling wave tube can be further improved. Meanwhile, the manufacturing of the slow wave structure of the folding frame can be realized through a microfabrication technology, and the structure has wide application prospect.