摘要:
A 3-frequency branching circuit in the past could not be used for a system wherein a TDMA method such as GSM and DCS and a W-CDMA method such as UMTS are mixed. The 3-frequency branching circuit equipped with branching means having first and second internal terminals, an antenna terminal of connecting to an antenna, a low-pass filter connected between the first internal terminal and the antenna terminal, and a high-pass filter connected between the second internal terminal and the antenna terminal, a switching circuit of switching between GSM TX and GSM RX, a switching circuit of switching between DCS TX, DCS RX and a third internal terminal, and a duplexer connected to the third internal terminal.
摘要:
A ceramic laminated board is provided which has thermal via holes penetrating the inside from the main face of the board. In the thermal via hole, a heat transfer body is placed which has a metallic body and a composite material provided entirely or partially between the metallic body and the ceramic laminated board. The composite material is higher in thermal conductivity than air and is lower in thermal expansion coefficient than the metallic body.
摘要:
With an antenna duplexer having balanced terminals, there has been a problem that the amount of leakage of common-mode signal components in the balanced terminals is large. A balanced high-frequency filter designed to solve this problem comprises a balanced high-frequency element and a phase-shifting circuit which includes a transmission line and placed between output terminals, and which is series resonance circuit having a length set to λT/2 (λT: the wavelength at a frequency in a transmission frequency band) and capable of resonating with common-mode signal components at a predetermined frequency.
摘要:
A series piezoelectric resonator 11 is connected in series between an input terminal 15a and an output terminal 15b. A first electrode of a parallel piezoelectric resonator 12a is connected to a connection point between the input terminal 15a and the series piezoelectric resonator 11, and a second electrode of the parallel piezoelectric resonator 12a is connected to a first terminal of an inductor 13a. A first electrode of a parallel piezoelectric resonator 12b is connected to a connection point between the series piezoelectric resonator 11 and the output terminal 15b, and a second electrode of the parallel piezoelectric resonator 12b is connected to a first terminal of an inductor 13b. Second terminals of the inductors 13a and 13b are grounded. An additional piezoelectric resonator 14 is connected between the second electrode of the parallel piezoelectric resonator 12a and the second electrode of the parallel piezoelectric resonator 12b.
摘要:
An antenna module includes a block, an antenna element provided on the block, and an antenna terminal connected with the antenna element. The block has a first surface and a second surface different from the first surface. The antenna element is provided on the first surface of the block. The antenna terminal is provided on the second surface of the block. This antenna module allows a radio apparatus to have a small size.
摘要:
A filter having an unbalanced terminal, a first stripline resonator of which one end is connected to the unbalanced terminal, a second stripline resonator placed to be electromagnetically coupled to the first stripline resonator, and balanced terminals of which both ends are connected to the second stripline resonator, wherein the first stripline resonator and the second stripline resonator are connected by at least one impedance element, and the second stripline resonator is a ½ wavelength resonator substantially having ½ the length of a wavelength of a resonance frequency.
摘要:
An RF device includes a first substrate having a lower relative dielectric constant, a first RF circuit for a lower frequency band provided in the first substrate, a second substrate having a higher relative dielectric constant larger than the lower relative dielectric constant, and a second RF circuit for a higher frequency band having a part of the second RF circuit sandwiched between the first substrate and the second substrate. The first RF circuit and the second RF circuit are connected to each other and the second substrate is partially overlaid on the first substrate. A semiconductor device or passive device is provided on a region in the surface of the first substrate on which the second substrate is not overlaid, and a multilayered wiring pattern made of copper or silver is formed in the first substrate to form the first RF circuit.
摘要:
With an antenna duplexer having balanced terminals, there has been a problem that the amount of leakage of common-mode signal components in the balanced terminals is large. A balanced high-frequency filter designed to solve this problem comprises a balanced high-frequency element and a phase-shifting circuit which includes a transmission line and placed between output terminals, and which is series resonance circuit having a length set to λT/2 (λT: the wavelength at a frequency in a transmission frequency band) and capable of resonating with common-mode signal components at a predetermined frequency.
摘要:
A composite filter has a dielectric notch filter; and a first surface acoustic wave filter. An attenuation band of the dielectric notch filter and an attenuation band of the first surface acoustic wave filter have at least a common band portion; and the dielectric notch filter and the surface acoustic wave filter are connected in cascade.
摘要:
The present invention provides a small and low loss laminated bandpass filter by placing two strip lines 313 and 314 that form a resonator in a certain distance on the same layer and thereby electromagnetically coupling these strip lines.