190results about How to "Improve isolation characteristics" patented technology

The present invention relates to a dual polarization broadband antenna having a single pattern, which is provide with a radiation device having a square structure, in which a plurality of folded dipole elements are formed in a single continuously-connected pattern, and a feeding portion for feeding signals to the plurality of folded dipole elements is formed on the radiation device. Accordingly, the plurality of folded dipole elements formed on the radiation device are connected in a single square and rectangular pattern, so that the structure thereof is simplified, with the result that the cost can be reduced. Furthermore, the feeding portion, that dually feeds signals, and the plurality of folded dipole elements, connected in a single pattern, are coupled, so that the dual polarization characteristic can be easily acquired. Furthermore, currents input to the feeding points of the feeding portion are induced only to the folded dipole elements without having to flow into other feeding points, so that excellent isolation can be achieved.

A high-frequency module includes a propagation path that has a simple structure and improves filter characteristics by causing an inductor and a matching network to electromagnetic field couple with each other such that attenuation characteristics outside of a frequency band of a transmission signal are improved without increasing the size of the high-frequency module. In addition, unintended electromagnetic field coupling between a first filter and the inductor is significantly reduced or prevented by a shield electrode. Therefore, unintended propagation of a high-frequency signal is significantly reduced or prevented. Therefore, the attenuation characteristics outside of the frequency band of transmission signal input to the transmission terminal are improved more effectively.

A transmission filter in a high frequency module includes serial arm resonators electrically connected in series to a serial arm electrically connecting a shared terminal and a transmission terminal, parallel arm resonators each electrically connected in series to each of parallel arms electrically connecting the serial arm and a ground, a first inductor electrically connected between the ground and a connection end electrically connecting at least the two parallel arm resonators of the parallel arm resonators, and a second inductor electrically connected between the ground and one parallel arm resonator different from the at least two parallel arm resonators of the parallel arm resonators. The second inductor is electromagnetic field coupled to at least one of an antenna side matching element, a transmission side matching element, and a portion of the serial arm in the transmission filter. The first and second inductors obstruct electromagnetic field coupling therebetween.

A duplexer that includes: a transmission filter and a reception filter that are connected to a common terminal; and a reactance circuit that is connected to at least one of the transmission filter and the reception filter. The reactance circuit includes an insulating substrate, lumped-constant inductors, and at least one capacitor. The lumped-constant inductors and the capacitor are formed directly on the surface of the insulating substrate.

A duplexer that includes: a transmission filter and a reception filter that are connected to a common terminal; and a reactance circuit that is connected to at least one of the transmission filter and the reception filter. The reactance circuit includes an insulating substrate, lumped-constant inductors, and at least one capacitor. The lumped-constant inductors and the capacitor are formed directly on the surface of the insulating substrate.

Provided is a dual polarization antenna realized by using four inverted F-type radiators and a Radio Frequency Identification (RFID) reader employing the dual polarization antenna. The dual polarization antenna includes a ground plate and four inverted F-type radiators set up on the ground plate. Currents of the same phase are fed to the first and second inverted F-type radiators each other. Currents of an inverted phase are fed to the third and fourth inverted F-type radiators each other. The four inverted F-type radiators form an angle of 90° with one another. The first and second inverted F-type radiators radiate electric wave of vertical polarization and the third and fourth inverted F-type radiators radiate electric wave of horizontal polarization. Since the dual polarization antenna has excellent orthogonal and isolation characteristics, the antenna can extend a transmission distance between the reader and the tag and improve a communication quality.

A second substrate 21 composed of a material having a lower dielectric constant than that of a piezoelectric substrate 2 having a transmission-side filter region 12 and a receiving-side filter region 13 formed therein is joined to the other main surface of the piezoelectric substrate 2, and a conductor layer 22 is formed throughout the other main surface of the second substrate 21. The effective dielectric constant of the substrate is reduced, thereby making it possible to reduce a parasitic capacitance formed between an input electrode section 5 in the transmission-side filter region 12 and an output electrode section 6 in the receiving-side filter region 13 and to improve isolation characteristics.

An antenna element and balun are described. The antenna includes a plurality of droopy bowtie antenna elements disposed on dielectric block and a feed point. The balun includes a central member having dielectric slabs symmetrically disposed on external surfaces thereof. At least one end of the balun is provided having a shape such that conductors on the dielectric slabs of the balun can be coupled to the the droopy bowtie antenna elements.

A mounting assembly for a wheel suspension system of a vehicle. The mounting assembly includes a support structure mounted to the vehicle body. A piston rod, along with a plate, is displaceable relative to the support structure along a line of travel. An insulator is disposed between the support structure and the plate for coupling the piston rod to the support structure. The insulator has a first portion defining a first resistance for isolating the displacement of the piston rod and the plate during an application of a first force which compresses the first portion only. The insulator also has a second portion defining a second resistance, with the second resistance being greater than the first resistance, for limiting the displacement of the piston rod and the plate during an application of a second force wherein the second force is greater than the first force such that both the first and second portions are compressed.

A second substrate 21 composed of a material having a lower dielectric constant than that of a piezoelectric substrate 2 having a transmission-side filter region 12 and a receiving-side filter region 13 formed therein is joined to the other main surface of the piezoelectric substrate 2, and a conductor layer 22 is formed throughout the other main surface of the second substrate 21. The effective dielectric constant of the substrate is reduced, thereby making it possible to reduce a parasitic capacitance formed between an input electrode section 5 in the transmission-side filter region 12 and an output electrode section 6 in the receiving-side filter region 13 and to improve isolation characteristics.

Provided is a demultiplexer capable of improving attenuation characteristic and isolation characteristic of a filter having a lower transmission frequency band among two filters having different transmission frequency bands, outside the transmission frequency band of a high-frequency side. A communication device using the demultiplexer is also disclosed. A first spiral wiring portion (55) and a sixth wiring portion (56) are formed so that an angle defined by a direction of a part (L1) of the first spiral wiring portion (55) and a direction of a part (L2) of the sixth spiral wiring portion (56) on a predetermined virtual plane is, for >example, 0 degree and the direction of the current flowing in the part (L1) of the first spiral wiring portion (55) is opposite to the direction of the current flowing in the part (L2) if the sixth wiring portion (56).

A branching filter includes an antenna terminal, a transmission-side filter and a reception-side filter which are connected in parallel to the antenna terminal, and a matching circuit positioned between the antenna terminal and the reception-side filter. The reception-side filter is a ladder-type filter in which the frequency of a series resonator is higher than the antiresonant frequency of a parallel resonator. The transmission-side filter is a ladder-type filter and is the capacitance in the passband of the reception-side filter, and, because of the capacitance, the inductance of the impedance of the reception-side filter, when seen from the antenna terminal side, is reduced.

A compact elastic wave duplexer is provided. The elastic wave duplexer includes a transmission filter chip and a reception filter chip mounted on a laminated board. An impedance matching circuit is formed inside the laminated board. The isolation characteristics in a transmission band and a reception band are improved. The balance between the two is improved. The elastic wave duplexer (1) includes a transmission filter chip (6) and a reception filter chip (7) each formed from an elastic wave filter chip and flip-chip bonded to a laminated board (43). A coil-shaped line including coil-shaped line patterns (52, 54, and 56) is formed inside the laminated board (43). The coil-shaped line serves as an impedance matching circuit. In plan view, the transmission filter chip (6) is disposed on one side of a center line (X) passing through the center of the laminated board (43) and extending between a first edge (43A) and a second edge (43B), and the reception filter chip (7) is disposed on the other side. The coil-shaped line is disposed on the side on which the reception filter chip (7) is disposed.

A switch circuit 1 includes a unit circuit including capacitors 12, 14, an inductor 20, and a FET 30 (switching element). The capacitors 12, 14 are provided in a path P1 (first path) connecting I / O terminals 92, 94. The capacitors 12, 14 are serially connected to each other. To the path P1, a path P2 (second path) is connected. The path P2 includes the inductor 20 and the FET 30, which are serially connected to each other. To be more detailed, an end of the inductor 20 is connected to a connection point N, and the drain (or source) of the FET 30 is connected to the other end of the inductor 20. The source (or drain) of the FET 30 is grounded.

An elastic wave duplexer includes a transmission filter chip and a reception filter chip each defined by an elastic wave filter chip and flip-chip bonded to a laminated board. A coil-shaped line including coil-shaped line patterns is provided inside the laminated board. The coil-shaped line defines an impedance matching circuit. In plan view, the transmission filter chip is disposed on one side of a center line passing through the approximate center of the laminated board and extending between a first edge and a second edge, and the reception filter chip is disposed on the other side of the center line. The coil-shaped line is disposed on the side on which the reception filter chip is disposed.

A branching filter includes an antenna terminal, a transmission-side filter and a reception-side filter which are connected in parallel to the antenna terminal, and a matching circuit positioned between the antenna terminal and the reception-side filter. The reception-side filter is a ladder-type filter in which the frequency of a series resonator is higher than the antiresonant frequency of a parallel resonator. The transmission-side filter is a ladder-type filter and is the capacitance in the passband of the reception-side filter, and, because of the capacitance, the inductance of the impedance of the reception-side filter, when seen from the antenna terminal side, is reduced.

A radio-frequency module includes a first transmitter-and-receiver that transmits and receives a signal in a first band, and a second transmitter-and-receiver that transmits and receives a signal in a second band higher than the first band. The first transmitter-and-receiver includes a first amplifier circuit and a first separator circuit and the second transmitter-and-receiver includes a second amplifier circuit and a second separator circuit. The first separator is located on a substrate between the first amplifier circuit and the second separator circuit, such that the first separator circuit is spatially interposed between the first amplifier circuit and the second separator circuit.

A semiconductor device and a method for fabricating the same may improve the isolation characteristics without deterioration of the junction diode characteristics and an increase in a threshold voltage of a MOS transistor. The device includes a semiconductor substrate; an STI layer in a predetermined portion of the semiconductor substrate, dividing the semiconductor substrate into an active region and a field region; and a field channel stop ion implantation layer in the semiconductor substrate under the STI layer.

A high-frequency relay comprises a body containing a contact unit having at least one contact terminal protruding from a bottom surface of the body, contact states switched according to energization of a coil and a base covering at least a bottom surface of the body. The contact unit is connected with at least one contact terminal. The base has a grounding function and includes a conductive layer.

The invention discloses a switched reluctance motor bootstrapping driving circuit with low cost and high isolation characteristic with low cost and high isolation characteristic. The switched reluctance motor bootstrapping driving circuit comprises an upper switching tube driving circuit and a lower switching tube driving circuit, wherein the upper switching tube driving circuit comprises an optical-coupler-based first switching circuit, a first charging circuit, a first discharging circuit, a bootstrap capacitor and a bootstrap diode; and the lower switching tube driving circuit comprises a second switching circuit, a second charging circuit and a second discharging circuit. In the switched reluctance motor bootstrapping driving circuit disclosed by the invention, a single-power-supply operating mode based on the bootstrap capacitor is adopted, and a switching element taking a photoelectric coupler as a core switching circuit is adopted, influence of a high voltage driving signal to a low voltage control signal is avoided, safety of circuit control is improved; besides, conducting and closing times of the driving circuit and a power inverter are strictly consistent with a low voltage control signal of a micro processor, thus the switched reluctance motor bootstrapping driving circuit disclosed by the invention is applicable to a workplace under high frequency PWM (Pulse Width Modulation) control mode.

A signal separation device is a duplexer in which a reception frequency band is located at higher frequencies than a transmission frequency band. A series arm of a ladder transmission filter includes a plurality of series arm resonators, and parallel arms respectively include parallel arm resonators. The parallel arm resonators include the parallel arm resonators having resonant frequencies lower than those of the series arm resonators and the parallel arm resonator that has a resonant frequency which is located within the reception frequency band and which is higher than the resonant frequency of the series arm resonators and that has a lower capacitance than the series arm resonators and the parallel arm resonators.

A common terminal 500 is connected to drains of FETs 101 and 102 via a capacitor 400. FETs 111 to 114 are serially connected, and inserted between a source of the FET 101 and a terminal 501 via a capacitor 401. Similarly, each of: FETs 121 to 124; FETs 131 to 133; FETs 141 to 143; FETs 151 to 153; and FETs 161 to 163 is inserted between the source of the FET 101 or an FET 102 and a corresponding one of terminals 502 to 506. This configuration allows a stray capacitance value of a transmission / reception path to be reduced at the time of transmission / reception, thereby obtaining a favorable radio-frequency characteristic.

A duplexer (1) includes a common terminal (Ant), receiving filters (4a, 4b), a transmitting filter (2), and a hybrid (3) having four terminals (TERMINALS 1 to 4). The first terminal (TERMINAL 1), serving as one of the four terminals of the hybrid (3), is connected to the common terminal (Ant). The second and third terminals (TERMINALS 2, 3), to which a signal supplied to the first terminal is transmitted, are connected to the receiving filters (4a, 4b). The forth terminal (TERMINAL 4) of the hybrid (3) is connected to the transmitting filter (2). Consequently, the isolation of the duplexer can be improved while preventing an increase in the number of parts and complication.

An elastic wave filter device includes a longitudinally coupled resonator-type elastic wave filter formed on a piezoelectric substrate; and a ladder-type elastic wave filter connected to the resonator-type elastic wave filter. The resonator-type filter includes an input IDT and an output IDT. The ladder-type filter includes a series arm resonator and a parallel arm resonator. A first ground electrode connected to the parallel arm resonator is electrically separated from a second ground electrode connected to at least one of the input IDT and the output IDT.

A waveguide diplexer having an electric plane T-junction structure with a resonant iris is disclosed. The waveguide includes: a waveguide having a predetermined shaped cross section; a transmitting filter for preventing to generate a harmonic band and a higher mode in a receiving band by changing impedance to have a low pass characteristic inside the waveguide; a receiving filter for minimizing an insertion loss by changing impedance to have a bandpass characteristic inside the waveguide; an electric plane T-junction for isolating / combining a transmitting signal and a receiving signal without electric interference by connecting the transmitting filter and the receiving filter, and minimizing interference of a frequency transmitted / received through the transmitting filter and the receiving filter; and an impedance converter for differentiating a transmitting port and a receiving port with minimum electric interference to the transmitting filter and the receiving filter by changing the impedance.

The invention relates to a multi-frequency antenna and a low-frequency radiation unit for restraining the common-mode resonance. The low-frequency radiation unit comprises a Balun fixing base, four half-wave oscillator structures and a restraining element. One side surface of the restraining element is a first metal surface, and the other side surface of the restraining element is a second metal surface. The first metal surface is respectively attached to two adjacent radiation arms respectively. The first metal surface and the radiation arms are in insulation fit with each other. The invention further discloses the low-frequency radiation unit for restraining the common-mode resonance. When the low-frequency radiation unit is arranged in the multi-frequency antenna, the adjacent radiationarms of the low-frequency radiation unit are directly equivalent to the full-metal sealing means for radio frequency signals in an ultra-wideband communication frequency band and a high-frequency communication frequency band. Therefore, a half-wave oscillator electromagnetic resonance structure of a high-order mode parasitic coupling resonance component on an oscillator of the low-frequency radiation unit is damaged in the physical structure. Thus, the common-mode resonance can be restrained. The coupling of the low-frequency signal electromagnetic energy of adjacent different polarized oscillation arms on the low-frequency radiation unit is reduced, and the polarization isolation degree of the low-frequency radiation unit is improved.

In the present invention, while minimizing increases in the size of a directional coupler, said directional coupler is provided with good isolation characteristics even in the presence of parasitic impedance. A transmission-line directional coupler (20A) is provided with a main line (21) and a coupled line (22) that is coupled to the main line (21) by electric-field coupling and magnetic-field coupling. The main line (21) has a signal-input port (RFin) and a signal-output port (RFout), and the coupled line (22) has a coupling port (CPL) and an isolation port (ISO). A series capacitance is connected to either the signal-output port (RFout) or the coupling port (CPL), but not both.

Disclosed is a MIMO antenna for improved isolation. The disclosed antenna comprises: a first conductive member electrically connected to a feed point; a second conductive member separated a predetermined distance from the first conductive member and electrically connected to a ground; at least one spiral cell coupled to the first conductive member and the second conductive member between the first conductive member and the second conductive member, and including at least two spiral arms; and an emitter extending from the second conductive member. According to the disclosed antenna, isolation characteristics between multiple antennas can be improved, and good isolation characteristics can be obtained even when the distances between multiple antennas are relatively short.

A duplexer includes a transmission filter with a ladder circuit configuration and a reception filter. The reception filter includes a series trap element connected to an antenna terminal and a longitudinally coupled resonator-type surface acoustic wave filter. In the transmission filter, a coupling capacitance is connected between an end portion at parallel arm resonators side of an inductance and a line connecting the series trap element to the longitudinally coupled resonator-type surface acoustic wave filter in the reception filter.