Abstract: A system for connecting at least two receivers to a common antenna is proposed, antenna signal lines being supplied to the receivers, which stands out in that the input impedances of the at least two receivers are matched only in a narrow-band fashion in the range of their current reception frequencies to the impedances of the antenna signal lines supplied to them. An antenna signal splitter is also proposed. Finally, a method for controlling the reception frequencies of at least two receivers connected to a common receiving antenna is proposed, which is distinguished by the fact that the reception frequencies of the at least two receivers are set in such a way that they maintain a predefined minimum frequency distance from one another. A reduction of an antenna signal attenuation in an antenna signal splitter for multiple receiver systems is thereby possible, provided the receivers are tuned to different reception frequencies.

Abstract: Inductor topologies for filters used in broadband applications are described. In one implementation, an apparatus, such as an interface module includes a printed circuit board and a filter. The filter includes a generally circular high Quality factor (Q) value spiral planar inductor etched directly into the printed circuit board. The generally circular high Q value spiral planar inductor is configured to operate in a broadband application. Other implementations involve the use of decoupling structures with respect to the planar inductors as well as a design methodology for the filters.

Abstract: A dual band full duplex mobile radio is provided that includes a transmit portion including a dual band filter and a receive portion including a dual band filter. The dual band full duplex mobile radio further includes a circulator connecting the transmit portion and the receive portion and configured to provide transmit and receive switching.

Abstract: A duplexer (1) with two band-pass filters (5, 6) comprising film bulk acoustic wave resonators (FBAR) (8, 9, 10, 11, 12, 13) has an extra antiresonant circuit in order to block the transmission signal. It has an extra resonant circuit in order to allow the desired receive signal to pass. The antiresonant circuit comprises the first FBAR (11) and a parallel inductor (14). The resonant circuit comprises the first FBAR (11) and a series inductor (7).

Abstract: The present invention provides a transceiver circuit that includes a transmission amplifier coupled with an antenna input/output node. The transmission amplifier is configured to amplify communications to be transmitted from the transceiver circuit. The transceiver circuit further includes a receiver and a field effect transistor. The receiver includes a receiver input coupled with the antenna input/output node. The field effect transistor is coupled between the receiver input and an electrical reference. The field effect transistor is configured to provide an open circuit when communications are received at the receiver input and to provide a closed circuit when communications are not being received at the receiver input.

Abstract: A multilayer diplexer has a first I/O terminal, a second I/O terminal, an antenna terminal, a high-pass filter coupled between the antenna terminal and the second I/O terminal, and a low-pass filter coupled between the antenna terminal and the first I/O terminal. The high-pass filter has a first capacitor and a second capacitor connected in serial coupled between the antenna terminal and the second I/O terminal, a fourth capacitor coupled between the antenna terminal and the second I/O terminal, and a first inductor coupled between a connection node of the first and second capacitors and a reference ground. The low-pass filter has a second inductor coupled between the antenna terminal and the first I/O terminal, and a third and fifth capacitor connected in parallel coupled between the antenna terminal and the first I/O terminal.

Abstract: The present invention provides an antenna duplexer comprising a package having a plurality of ceramic layers superposed, and a transmitting filter and a receiving filter which are mounted on a surface of the package. A phase-matching strip line is formed on a surface of one ceramic layer. The package has grounding layers formed respectively on surfaces of upper and lower ceramic layers with the phase-matching strip line interposed therebetween. A plurality of via holes are formed around the phase-matching strip line for connecting the two grounding layers to each other.

Abstract: A matching unit includes a switching means for switching an inductance of a first inductor. This switching means sets an inductance such that a first inductor shows an inductance property to both of the VHF low-band and high-band, and shows a capacitance property to the UHF band. This structure allows the matching unit to achieve the matching for both the VHF low-band and high-band by just switching the two circuits of the VHF low-band and high-band, also allows the matching unit to show a capacitance property to the UHF band. Thus the loss produced in transmitting signals can be reduced, and the circuit can be simplified. As a result, the matching unit can be downsized, and the cost can be reduced.

Abstract: A lumped-element diplexer formed in a multi-layered substrate includes a high-pass filter circuit, a low-pass filter circuit, and a ground plane, the elements of the filter circuits being disposed as follows: a first capacitor plate on a first layer of the substrate connected to a first port and a first inductor plate on a third layer, a second capacitor plate on a second layer of the substrate connected to the first inductor plate and a third capacitor plate on a fourth layer, the third capacitor plate in turn being connected to a second port. A fourth capacitor plate on a fifth layer of the substrate is connected to a second inductor plate on a seventh layer, the second inductor plate in turn being connected to the ground plane on a zeroth layer. A fifth capacitor plate on a sixth layer of the substrate is connected to a third port.

Abstract: This invention relates to a switching circuit for use at the antenna of a multi-band cellular handset to select between the TX and RX modes of the bands. A number of high isolation switching circuits for selectively connecting a common antenna port to a TX port 2 or an RX port 3 of a multi-band cellular handset are described.

Abstract: A multi-band antenna switch circuit including a diplexer connected to an antenna terminal for demultiplexing signals of different passing bands, a first and a second switch circuit for switching a high frequency signal and a low frequency signal demultiplexed by the diplexer to a plurality of transmission/reception terminals, a first and a second low pass filter connected to a transmission path between the diplexer and the transmission terminal or between the first and the second switch circuit and the transmission terminal, and a notch filter provided between the diplexer and the first switch circuit or between the diplexer and the second switch circuit.

Abstract: The invention relates to a high-pass branch (7) of a frequency separating filter for ADSL systems comprising inductive components (11, 14) which dispose of magnet cores made of a soft magnetic amorphous or nanocrystalline. As a result, frequency separating filters are provided which comprise small structural shapes and which have especially beneficial properties in the relevant frequency and temperature range.

Abstract: An antenna duplexer has an antenna terminal; a transmitting phase-shift circuit, one side of which is connected to the antenna terminal; a receiving phase-shift circuit, one side of which is connected to the antenna terminal; a transmitting filter connected to the other side of the transmitting phase-shift circuit and a transmitting terminal; and a receiving filter connected to the other side of the receiving phase-shift circuit and a receiving terminal; wherein the transmitting filter and/or the receiving filter is a composite filter, and the composite filter attains a characteristic having an attenuation pole at simultaneous transmission and reception time when transmission and reception are simultaneously performed, and controls respective impedances by the transmitting phase-shift circuit and the receiving phase-shift circuit to operate as a sharing unit and attains a characteristic where the attenuation pole is removed at non simultaneous transmission and reception time when transmission and reception

Abstract: Multi-tuner receivers with cross talk reduction are disclosed. In one embodiment, a multi-tuner receiver with cross talk reduction includes a low noise amplifier, a set of interstage filters and a set of corresponding tuners. In an alternative embodiment, a multi-tuner receiver with cross talk reduction includes a passive splitter, a set of interstage filters and a set of corresponding tuners. The interstage filters can be low-pass, high-pass or band-pass filters depending on the particular frequency range of interest. Typical embodiments can have two or three tuners, however, the invention applies to multi-receiver tuners with more than three tuners. The multi-tuner receivers can be used within television, cable set top boxes and other devices that receive multiple video signals.

Abstract: A laminated high-frequency switch module for selecting either a transmission circuit or a reception circuit of each of transmission/reception systems by switching, comprising a demultiplexer for demultiplexing signals of the transmission/reception systems, high-frequency switch circuits for selecting either the signal path of a reception signal from the demultiplexer to the reception circuit or the signal path of a transmission signal from the transmission circuit to the demultiplexer, and circuit for measuring the power of the transmission signal from the transmission circuit, characterized in that the laminate is composed of dielectric layers having electrode patterns, and the demultiplexer, the high-frequency switch circuits, and the power measuring circuit are constituted of electrode patterns in the laminate.

Abstract: A high-frequency module is connected to a transmitting circuit, a receiving circuit, and an antenna to control the connections between the transmitting circuit and the antenna and between the receiving circuit and the antenna. The module includes means for controlling transmitted signals, which includes a first phase-shift circuit and a high-frequency amplifier provided between the antenna and the transmitting circuit. The high-frequency amplifier and the first phase-shift circuit are integrated into a module composed of a plurality of dielectric layers.

Abstract: A high-frequency switch has a first transmission-reception switching circuit for selectively switching between the signal transfer between an antenna terminal and a first transmitting-circuit terminal and the signal transfer between the antenna terminal and a first receiving-circuit terminal; a second transmission-reception switching circuit for selectively switching between the signal transfer between the antenna terminal and a second transmitting-circuit terminal and the signal transfer between the antenna terminal and a second receiving-circuit terminal; a first diplexer disposed between the antenna terminal and the first transmission-reception switching circuit and between the antenna terminal and the second transmission-reception switching circuit; and a second diplexer connected to the second receiving-circuit terminal to selectively switch the signal transfer between the second receiving-circuit terminal and a third receiving-circuit terminal and the signal transfer between the second receiving-circuit

Abstract: A splitter for enabling a power signal and a communication signal to be transmitted over a common communication link is provided. The splitter includes a line port adapted to be coupled to a communication line, a power port adapted to be coupled to a power supply to receive a power signal, and a communication port adapted to be coupled to a communication circuit that generates and receives communication signals. The splitter also includes a low pass filter coupled between the power port and the line port, the low pass filter including a coupled inductor, a high pass filter coupled to the communication port, and wherein the communication signals and the power signal are transported on the communication line at the line port.

Abstract: A GPS-cellular hand-set includes a receive antenna; a separate transmit antenna; a power amplifier; a duplex filter unit having an input connected to the receive antenna, a cellular output, and a GPS output; a cellular unit having a receive input and a transmit output, wherein the receive input is connected to the cellular output of the duplex filter unit and the transmit output is connected to the transmit antenna via the power amplifer; and a GPS unit having an input connected to the GPS output of the duplex filter unit.

Abstract: A duplexer includes a transmitting filter and a receiving filter which are connected in parallel to an antenna terminal, and a matching circuit connected between the antenna terminal and at least one of the transmitting filter and the receiving filter. A portion of the matching circuit defines a trap circuit for harmonic suppression.

Abstract: It is an object of the present invention to provide a high-frequency module whose production yield as a complete module can be prevented from being lowered. The high-frequency module according to the present invention includes a main module including a first high-frequency circuit at least a part of which is constituted by a conductive pattern built in a multi-layered substrate and a sub-module including a second high-frequency circuit, and the sub-module is inserted into a cavity formed in the main module. According to the present invention, the main module including the first high-frequency circuit and the sub-module including the second high-frequency circuit are constituted as separate components and the main module and the sub-module are integrated by inserting the sub-module into the cavity formed in the main module. Therefore, it is possible to use only a main module and sub-module that have been inspected after manufacture and found to be non-defective.

Abstract: A filter assembly includes a transmission filter, a reception filter, a change-over switch, and phase circuits. The transmission filter has first and second ends electrically connected to a first antenna terminal and a transmission terminal, respectively. The reception filter has a first end electrically connected to a second antenna terminal via the change-over switch, and a second end electrically connected to a reception terminal. A main antenna is connected to the first antenna terminal, and a diversity antenna is connected to the second antenna terminal. The change-over switch performs switching control to connect the reception filter to one of the first and second antenna terminals. Thus, the filters utilize a fixed number of resonators regardless of switching control of the change-over switch, thereby achieving optimum filter characteristics.

Abstract: Four frequency components (f1 to f4) (where, f1<f2<f3<f4) are input into a port (10) of a first demultiplexing filter circuit (1), and demultiplexed into low frequency components (f1 and f2) and high frequency components (f3 and f4), and input in a port (20) of a second demultiplexing filter circuit (2) and a port (30) of a third demultiplexing filter circuit (3), respectively. The frequency components (f1 and f2) are demultiplexed into the component (f1) and the component (f2) by the second demultiplexing filter circuit (2), and output from a port (23) and a port (24), respectively. The frequency components (f3 and f4) are demultiplexed into the component (f3) and the component (f4) by the third demultiplexing filter circuit (3), and output from a port (33) and a port (34), respectively.

Abstract: A frequency multiplexer is disclosed. The frequency multiplexer comprises a lumped element transmission line comprising a plurality of inductances and capacitances, and a band pass filter coupled to a node of the lumped element transmission line, where the band pass filter includes a branch port that is coupled to the lumped element transmission line at a pass band of the band pass filter, and where the band pass filter exhibits a capacitive impedance in a stop band of the band pass filter. The band pass filter may comprise a series resonant circuit and a parallel resonant circuit, where the parallel resonant circuit is parallel resonant at nominally the same frequency at which the series resonant circuit is series resonant.

Abstract: The invention relates to a terminal for communication with data supports which function in a non-contact manner, comprising a transreceiver circuit with two resonant circuits with antenna and condenser for the emitting of two radio frequency fields of different carrier frequencies, whereby the common antenna (A) for both resonant circuits comprises a winding.

Abstract: An excitation hole is provided inside a dielectric block and, on the outer surface of the dielectric block, an input-output terminal electrically connected to an inner conductor inside the excitation hole is formed at one end portion of the excitation hole. A grounding-electrode-free portion is provided on the surface opposite to an input-output electrode of a mounting substrate with which the input-output terminal makes contact. Thus, the electric field strengths in upward and downward directions toward an outer conductor of the dielectric block from the excitation hole are balanced to suppress spurious TE-mode signals, etc.

Abstract: A duplexer includes a transmission band filter and a reception band filter connected in parallel to each other and connected to an antenna terminal. The transmission band filter and the reception band filter are accommodated in a package covered with an electroconductive lid. The package is mounted on a mounting substrate having the antenna terminal and covered with an electroconductive shield mounted on the mounting substrate. At least one of the transmission band filter and the reception band filter has a ground terminal connected to the lid. The lid is electrically connected to the shield.

Abstract: A cable television diplexer and telephony module that can be employed in CATV data transmission systems to enhance performance levels and reduce manufacturing costs. The cable television diplexer and telephony module includes a printed circuit board substrate, and a diplexer having a low pass filter section and a high pass filter section, each of which has components mounted on the substrate. The respective low pass and high pass filter sections of the diplexer include one or more high Q value planar spiral inductors. Each spiral inductor includes a narrow track of metal disposed on the substrate and wound around a center to form a circular spiral curve having a plurality of turns. The spiral inductor may be fabricated on the substrate of the cable television diplexer and telephony module, or on a separate substrate, using a standard PCB fabrication process.

Abstract: Disclosed is a matching circuit of a laminated duplexer connected to an antenna terminal while being connected between transmitting and receiving filters to match the transmitting and receiving filters with the antenna terminal, the matching circuit being configured to reduce the physical length of each conductor pattern thereof, thereby being capable of achieving an improved miniaturization thereof. The matching circuit includes a transmitting matching unit constituted by a conductor pattern electrically connected to an antenna electrode connected to the antenna terminal while being electrically connected to the transmitting filter, a first ground electrode vertically spaced apart from the conductor pattern, a receiving matching unit constituted by a conductor pattern electrically connected to the antenna electrode and the receiving filter, and a second ground electrode vertically spaced apart from the conductor pattern of the receiving matching unit.

Abstract: A triplexer and a multilayered structure thereof. The triplexer comprises a first filter circuit and a low pass filter circuit connected in parallel to an input terminal, and a second filter circuit and a third filter circuit connected in parallel to an output terminal of the low pass filter circuit. The first filter circuit passes a signal of a first frequency band, and the low pass filter circuit passes a signal of a predetermined frequency band which is lower than the first frequency band. The second filter circuit extracts a signal of a second frequency band from the predetermined frequency band signal, and the third filter circuit extracts a signal of a third frequency band from the predetermined frequency band signal, which third frequency band is lower than the second frequency band. The low pass filter circuit includes a notch circuit for extending a portion of the predetermined frequency band, neighboring the first frequency band.

Abstract: A high-frequency switch has a first transmission-reception switching circuit for selectively switching between the signal transfer between an antenna terminal and a first transmitting-circuit terminal and the signal transfer between the antenna terminal and a first receiving-circuit terminal; a second transmission-reception switching circuit for selectively switching between the signal transfer between the antenna terminal and a second transmitting-circuit terminal and the signal transfer between the antenna terminal and a second receiving-circuit terminal; a first diplexer disposed between the antenna terminal and the first transmission-reception switching circuit and between the antenna terminal and the second transmission-reception switching circuit; and a second diplexer connected to the second receiving-circuit terminal to selectively switch the signal transfer between the second receiving-circuit terminal and a third receiving-circuit terminal and the signal transfer between the second receiving-circuit

Abstract: The present invention provides a dielectric duplexer 10 comprising a receiving filter 1 and a transmitting filter 2 which are connected in parallel with an antenna connecting terminal portion 17, and both the filters 1, 2 are integrally assembled into a common dielectric block 11. A trap circuit 8 for suppressing a predetermined frequency band different from the receiving band of the receiving filter 1 and from the transmission band of the transmitting filter 2 is integrally assembled into the dielectric block 11 along with the filters 1, 2, and is connected to the antenna connecting terminal portion 17.

Abstract: A system and method for providing a global positioning system (GPS) enabled antenna system are provided. The GPS enabled antenna may be used, for example, on a wireless communications device such as a wireless handset. The wireless communications device includes a GPS switching module coupled to a conventional communications antenna, including its associated circuitry. The GPS switching module is adapted to selectively couple the communications antenna to GPS matching circuitry. In this arrangement, the GPS matching circuitry adjusts impedance at approximately 1575 MHz to more closely match the communications antenna to GPS circuitry in the wireless device.

Abstract: A high frequency switch module can handle transmit-receive signals of different frequency bands and realize excellent isolation. The high frequency switch module comprises a discriminating filter, a low-band high frequency switch, and a high-band frequency switch, wherein high-band 90-degree phase shifter that forms at least a high-band high frequency switch is configured by a high-pass filter, and a choke line is parallel-connected to the high-pass filter.

Abstract: An improved circuit for splitting or for joining radio-frequency powers, having a main line (7) which is connected between an input port (1) and a first output port (3), and having a branch line (11) which branches off from the main line at a branching point (9) and leads to a second output port (5), is distinguished in that a compensating element (61) is provided which, in particular, is adjustable or can be fitted and removed differently, and which can be varied, varying the capacitance of at least one capacitor (C1, C2, C3) which is connected in the branch line (11), and/or varying the electrical length of a spur line (37) which is coupled to the branch line (11), such that the change in the magnitude of the power which is tapped off also makes it possible to compensate at the same time for the resistance change which is caused by the change in the power split.

Abstract: A loudspeaker system, which has the ability to create a homogeneous sound over large distances, comprising at least one line-source of acoustical radiation, each comprising three or more essentially identical speaker-units arranged adjacent to each other at a center-to-center spacing D1, and at least one elongated high frequency transducer arranged in parallel with said line source(s), said elongated high frequency transducer(s) having an essentially continuous radiating surface along the axis of elongation. Where the crossover frequency FCR and the distance D1, for said line-source(s), is set according to new design criteria, taking into account the frequency response from said speaker units in said line-sources and the optimal performance for a line-source. A method is also included, by which a homogeneous sound over large distances can be accomplished.

Abstract: Switchable path length coupler/dividers. Coupler/divider operation over multiple frequency bands is provided by using switchable path lengths. In one implementation, a Wilkinson-style device with switches to select different path lengths and therefore operating frequencies. In a rat-race style device, switches select races of different lengths, and therefore operating frequencies.

Abstract: The present invention relates to a summing network comprising: a summing point (P) having interfaces for coupling summing network branches to the summing point, and an interface for coupling the summing point (P) to an antenna (ANT), and channel units (TX1 to TX3) arranged in the branches, and channel unit-specific band-pass filters (1 to 3), whose pass frequencies correspond to the frequency or frequencies of the corresponding channel unit. To facilitate tuning the summing network, a compensation element (7) is coupled to the summing network between the summing point (P) and the antenna (ANT), the load effect of said compensation element corresponding substantially to the load caused to the summing point (P) by the branches coupled to the summing point.

Abstract: A low pass filter comprises a first series of transmission line elements connected between an input and an output; and a second series of shunt elements connected from the transmission line elements to a ground of the filter. At least one of the shunt elements has a distributed portion and a lumped portion. The distributed portion may comprise a tube mounted tangentially on a printed circuit board. The lumped portion may comprises a coil with a first lead connected to the first series of transmission line elements, and a second lead extending into the tube. A tuning element is moveably disposed in the tube. The tuning element may have an opening for receiving the second lead of the coil. The low pass filter may be used in a diplexer with one or more high pass filters. The diplexer may include power transmission apparatus.

Abstract: Increasing performance of planar inductors used in broadband applications is described. In one implementation, an apparatus includes a high Quality factor (Q) value spiral planar inductor etched directly into a printed circuit board. A ferrite structure is attached to the printed circuit board and located in proximity to the high Q value spiral planar inductor. The ferrite structure increases the Q of spiral planar inductors, but without the inconvenience and expense of a wire wound terroidal inductors. Various shaped ferrite structures may be used in conjuction with the spiral planar inductors. Additionally, in certain implementations, the ferrite structures are configured to rotate about axis permitting the inductors to be tuned, even after components have been installed on a printed circuit board.

Abstract: Scheme for processing an input signal A(t) by N resonators (17), each having parameters characterizing it, to generate N individual output signals. Then each of the N individual output signals is weighted using a corresponding weight to generate N individual weighted output signals which are superposed to obtain M output signals C(t). One of the parameters or the weight depend on a time signal P(t).

Abstract: An antenna duplexer has a receiving filter having a surface acoustic wave device; a transmitting filter having a dielectric resonator; and a matching circuit for matching the receiving filter and the transmitting filter with an antenna respectively, wherein the transmitting filter, receiving filter, and matching circuit are integrated with each other.

Abstract: A surface acoustic wave duplexer includes a branching section having a plurality of surface acoustic wave filters provided on a first electrode pattern on the front surface of a multi-layer substrate. An antenna terminal, a transmission terminal, and a receiving terminal are provided on peripheral portions of a fourth electrode pattern on the rear surface of the multi-layer substrate, and are connected to the branching section. A matching stripline disposed on a third electrode pattern in an intermediate layer of the multi-layer substrate, and connected to the antenna terminal is arranged such that it is grounded to at least one side other than the side opposite the side where the antenna terminal is located.

Abstract: A high-frequency filter device includes at least one filter to be connected to a high-frequency stage of a wireless apparatus. The filter includes a voltage-controlled variable frequency resonance element which is made of a resonance element and a voltage-controlled variable impedance element electrically connected to the resonance element. The high-frequency filter device includes a control section for controlling a voltage applied to the variable impedance element, and a signal monitoring section for outputting a control signal, with which the voltage is controlled, to the control section based on frequency data as to an oscillating frequency of a local oscillator of the wireless apparatus. The signal monitoring section controls a band frequency of the at least one filter based on the frequency data in such a manner that the band frequency is adaptively changed.

Abstract: A bandstop filter for use in CATV applications is formed by a pair of diplexers, a lowpass filter and a highpass filter. Signals having a frequency range of, e.g., 0-3 GHz enter at a first node connected to the inputs of both the lowpass and highpass filters. Signals having frequencies below a first, predetermined value pass through the lowpass filter, and signals having frequencies above a second, predetermined value pass through the highpass filter with signals having frequencies between the first and second values being blocked, i.e., “stopped.” The outputs of both the lowpass and highpass filters are connected to the second diplexer at a second node which is connected to the single output.

Abstract: A bandstop filter for use in CATV applications is formed by a pair of diplexers, a lowpass filter and a highpass filter. Signals having a frequency range of, e.g., 0-3 GHz enter at a first node connected to the inputs of both the lowpass and highpass filters. Signals having frequencies below a first, predetermined value pass through the lowpass filter, and signals having frequencies above a second, predetermined value pass through the highpass filter with signals having frequencies between the first and second values being blocked, i.e., “stopped.” The outputs of both the lowpass and highpass filters are connected to the second diplexer at a second node which is connected to the single output.

Abstract: The invention refers to a diplexer, particularly for use in microwave devices, comprising a low-pass filter and a high-pass filter, both having inductors and capacitors. It is suggested that at least one inductor of each of said filters is provided as an active inductor.

Abstract: A high frequency switching component for being connected to a transmission circuit, a reception circuit, and an antenna to be used for switching to either a state in which the transmission circuit is connected to the antenna, or a state in which the reception circuit is connected to the antenna, comprising: a multilayer circuit board, on which there is formed a circuit including: a transmission circuit terminal to be connected to the transmission circuit; a reception circuit terminal to be connected to the reception circuit; an antenna terminal to be connected to be the antenna; a ground terminal; a first diode whose anode is connected to the transmission circuit terminal and the cathode thereof is connected to the antenna terminal; a second diode whose anode is connected to the reception circuit terminal and the cathode thereof is connected to the ground terminal; a signal line for connecting the transmission circuit terminal, the reception circuit terminal, and the antenna terminal via the first diode; and

Abstract: In a high-frequency module, intermediate ground electrodes are provided between a common ground electrode and upper-surface ground electrodes for mounting high-frequency components on an upper surface of a multilayer substrate. With regard to the number of via-hole conductors interconnecting ground electrodes, the number of via-hole conductors between the intermediate ground electrodes and the common ground electrode is larger than the number of via-hole conductors between the upper-surface ground electrodes and the intermediate ground electrodes.

Abstract: Disclosed is an apparatus for commonly using an antenna for a call signal and a television (TV) broadcasting signal in a radio communication terminal including an antenna, a phone duplexer, a TV tuner, an LC parallel circuit, connected between the antenna and the phone duplexer, for forming an LC resonance circuit for a call signal frequency band, an LC series circuit connected to a connected point of the LC parallel circuit and the antenna and to a DC power supply terminal, a stub for impedance matching one terminal of which is connected between a capacitor and an inductor of the LC series circuit and the other terminal of which is connected to the TV tuner, and a path providing section for providing a path between a connected point of the stub and the TV tuner and a ground terminal in accordance with a switching control signal provided according to a TV or call operating mode.