Abstract: A diplexer that can demultiplex and multiplex two signals having wide frequency bands, and a wireless communication module and a wireless communication apparatus using the same, are provided. A diplexer has a multilayer body including a first interlayer, a second interlayer and a third interlayer. On the first interlayer, first resonant electrodes are disposed in an interdigital form. On the second interlayer, a plurality of second resonant electrodes are disposed in an interdigital form. On the third interlayer, there are disposed an input coupling electrode that faces the input-stage first resonant electrode and the input-stage second resonant electrode in an interdigital form, a first output coupling electrode that faces the output-stage first resonant electrode in an interdigital form, and a second output coupling electrode that faces the output-stage second resonant electrode.

Abstract: An ultra-wideband bandpass filter having two adequately-wide pass bands, and a wireless communication module and a wireless communication apparatus which employ the bandpass filter are provided. In a bandpass filter, first resonant electrodes are arranged on a first interlayer of a multilayer body in an interdigital form; a plurality of second resonant electrodes are arranged on a second interlayer in an interdigital form; and an input coupling electrode and an output coupling electrode are arranged on a third interlayer located between the first interlayer and the second interlayer. The input coupling electrode faces an input-stage first resonant electrode and an input-stage second resonant electrode in an interdigital form. The output-coupling electrode faces an output-stage first resonant electrode and an output-stage second resonant electrode in an interdigital form.

Abstract: The present invention provides a high-frequency switching circuit comprising: two or more high-frequency switches SW1 and SW2 provided correspondingly to a plurality of communication systems having mutually different frequency bands; and a control circuit DEC1 adapted to control the switching of the two or more high-frequency switches SW1 and SW2, in which a common antenna terminal ANT3 and common terminals ANT1 and ANT2 of the respective high-frequency switches SW1 and SW2 are connected via a matching circuit MAT1 having a filtering function capable of allowing passage of direct current. When one path of the high-frequency switch SW1 is turned on, the other paths of the high-frequency switch SW1 and all paths of the high-frequency switch SW2 can be turned off.

Abstract: The present invention provides a high-frequency switching circuit comprising: two or more high-frequency switches SW1 and SW2 provided correspondingly to a plurality of communication systems having mutually different frequency bands; and a control circuit DEC1 adapted to control the switching of the two or more high-frequency switches SW1 and SW2, in which a common antenna terminal ANT3 and common terminals ANT1 and ANT2 of the respective high-frequency switches SW1 and SW2 are connected via a matching circuit MAT1 having a filtering function capable of allowing passage of direct current. When one path of the high-frequency switch SW1 is turned on, the other paths of the high-frequency switch SW1 and all paths of the high-frequency switch SW2 can be turned off.

Abstract: A high frequency module according to the present invention comprises a laminate board having a plurality of dielectric layers (11 to 18) stacked one on another, a branch filter circuit (DIP10) for separating a plurality of transceiver systems from each other, switch circuits (SW10, SW20) for switching the respective transceiver systems between transmitter branches (TX) and receiver branches (RX), power amplifiers (AMP10, AMP20) each comprising a matching circuit (MAT10, MAT20) and a high frequency amplification semiconductor device for amplifying a transmission signal having a frequency within a pass band of each of the transmitter branches (TX), and couplers (COP10, COP20) for monitoring outputs.

Abstract: A high frequency module according to the present invention comprises a laminate board having a plurality of dielectric layers (11 to 18) stacked one on another, a branch filter circuit (DIP10) for separating a plurality of transceiver systems from each other, switch circuits (SW10, SW20) for switching the respective transceiver systems between transmitter branches (TX) and receiver branches (RX), power amplifiers (AMP10, AMP20) each comprising a matching circuit (MAT10, MAT20) and a high frequency amplification semiconductor device for amplifying a transmission signal having a frequency within a pass band of each of the transmitter branches (TX), and couplers (COP10, COP20) for monitoring outputs.

Abstract: A dielectric ceramic composition comprising main components represented by a composition formula on the weight basis, aMgO.multidot.bCaO.multidot.cTiO.sub.2, wherein a, b and c satisfy the following relationships, 25.ltoreq.a.ltoreq.35, 0.3.ltoreq.b.ltoreq.7, 60.ltoreq.c.ltoreq.70, a+b+c=100, blended with a boron-containing compound in an amount of from 3 to 20 parts by weight reckoned as B.sub.2 O.sub.3 and an alkali metal-containing compound in an amount of from 1 to 12 parts by weight reckoned as the alkali metal carbonate per 100 parts by weight of the main components, as well as a multilayer resonator made of said composition, and a filter using said resonator. The ceramic composition can be fired together with a conductor metal such as Ag or Cu at a relatively low temperature of 900.degree. to 1050.degree. C., exhibits large dielectric constant and Q-value, and a relatively small temperature coefficient .tau.f, lending itself well for use as a material for high-frequency electronic parts.