An adjustable multi-band planar antenna especially applicable in mobile terminals. A conductive element is placed in the structure of an antenna of PIFA type such that the conductive element has a significant electromagnetic coupling to the radiating plane. The parasitic element at issue is connected to a matching circuit ( 550 ) consisting of several reactive element. The parasitic element, the matching circuit and a line ( 540 ) between them constitute an adjusting circuit of the antenna. The circuit values of the matching circuit can be chosen from at least two alternatives. Alteration in the circuit values changes the coupling between the parasitic element and the ground, in which case an operation band of the antenna is displaced, because the electric length of the antenna's part corresponding that band is changed, measured from the short-circuit point. Regarding the shiftable operation band, proper impedance matching and a proper efficiency can be arranged for the antenna.

Adjustable multi-band antenna

An impedance matching circuit includes a conductor line having an input port and an output port, a ground conductor, a tunable dielectric material positioned between a first section of the conductor line and the ground conductor, a non-tunable dielectric material positioned between a second section of the conductor line and the ground conductor, and means for applying a DC voltage between the conductor line and the ground conductor. The impedance matching circuit may alternatively include a first planar ground conductor, a second planar ground conductor, a strip conductor having an input port and an output port, and positioned between the first and second planar ground conductors to define first and second gaps, the first gap being positioned between the strip conductor and the first planar ground conductor and the second gap being positioned between the strip conductor and the second planar ground conductor. A non-tunable dielectric material supports the first and second planar ground conductors and the strip conductor in the same plane. A connection is provided for applying a DC voltage between the strip conductor and the first and second planar ground conductors. A plurality of tunable dielectric layer sections are positioned between the strip conductor and the first and second planar ground conductors so as to bridge the gaps between the said first and second planar ground conductors and the strip conductor at a plurality of locations, leaving non-bridged sections in between, defining a plurality of alternating bridged and non-bridged co-planar waveguide sections.

Tunable microwave devices with auto-adjusting matching circuit

An RF switch circuit and method for switching RF signals that may be fabricated using common integrated circuit materials such as silicon, particularly using insulating substrate technologies. The RF switch includes switching and shunting transistor groupings to alternatively couple RF input signals to a common RF node, each controlled by a switching control voltage (SW) or its inverse (SW_), which are approximately symmetrical about ground. The transistor groupings each comprise one or more insulating gate FET transistors connected together in a “stacked” series channel configuration, which increases the breakdown voltage across the series connected transistors and improves RF switch compression. A fully integrated RF switch is described including control logic and a negative voltage generator with the RF switch elements. In one embodiment, the fully integrated RF switch includes an oscillator, a charge pump, CMOS logic circuitry, level-shifting and voltage divider circuits, and an RF buffer circuit.

Switch Circuit and Method of Switching Radio Frequency Signals

Isolation techniques for multiple co-located radio modules are disclosed. For example, an apparatus may include an antenna, a first transceiver to communicate wirelessly across a first link, a second transceiver to communicate wirelessly across a second link, a shared antenna structure operative to allow the first transceiver and the second transceiver to share the antenna for simultaneous operations, and an active signal canceller operative to generate a cancellation signal to cancel an interference signal for a radio-frequency coupling channel between the first and second transceivers. Other embodiments are disclosed and claimed.

Isolation techniques for multiple co-located radio modules

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. The multi-band antenna switch circuit includes a high pass filter having an input terminal and an output terminal and provided at least between the diplexer and the antenna terminal and including a first inductor connected between the input terminal and the ground, a first capacitor connected between the input terminal and the output terminal, a second inductor connected to the output terminal, and a second capacitor connected between the second inductor and the ground.

Bypass filter; multi;band antenna switch circuit; and layered module composite part and communication device using them

A high-frequency switch module which comprises a high-frequency switch circuit connected among an antenna, a transmission circuit, and a reception circuit and comprising switching elements and a surface acoustic wave filter connected between the high-frequency switch circuit and the reception circuit, uses a laminate constituted of dielectric layers having electrode patterns as the multilayered board, and has a phase correction circuit disposed between the switch circuit and the surface acoustic wave filter, wherein the high-frequency switch circuit comprises a switching element, a transmission line, and a capacitor as main elements, with at least a part of the transmission line and the capacitor constituted of an electrode pattern in the laminate, and with the surface acoustic wave filter mounted on the laminate.

High-frequency switch module

An inventive high frequency circuit includes a switch circuit (SPDT1), connected to an antenna terminal (Ant1), using a field-effect transistor for switching between a connection with first to third transmitting terminals (Tx1-1, Tx2-1, Tx3-1) and a connection with first to third receiving terminals (Rx1-1, Rx2-1, Rx3-1); a transmitting-side triplexer (Trip1) for branching a transmitting path connected to the switch circuit into transmitting paths of first to third frequency bands; and a receiving-side triplexer (Trip2) for branching a receiving path connected to the switch circuit into receiving paths of the first to third frequency bands. The switch circuit can be formed as an IC to downsize the circuit. For example, in constructing the high frequency circuit with a laminated module using a ceramic laminated substrate or the like, particularly when the number of triplexers occupying a large space is large, the switch circuit is formed as an IC and mounted on the laminated body, whereby the whole structure can be downsized.

High-frequency circuit, high-frequency component, and communication device

A high-frequency circuit comprising a switch circuit connected to an antenna terminal, first and second diplexer circuits connected to the switch circuit, first and second power amplifier circuits connected to the first diplexer circuit, first and second bandpass filter circuits connected to the first and second power amplifier circuits, a third bandpass filter circuit connected to the second diplexer circuit, a detection circuit disposed between the switch circuit and the first diplexer circuit, and a low-noise amplifier circuit disposed between the switch circuit and the second diplexer circuit.

High-frequency circuit, high-frequency device and communications apparatus

A multi-band high-frequency circuit for performing wireless communications among pluralities of communication systems having different communication frequencies, comprising a high-frequency switch circuit comprising switching elements for switching the connection of pluralities of multi-band antennas to transmitting circuits and receiving circuits; a first diplexer circuit disposed between the high-frequency switch circuit and transmitting circuits for branching a high-frequency signal into frequency bands of the communication systems; a second diplexer circuit disposed between the high-frequency switch circuit and receiving circuits for branching a high-frequency signal into frequency bands of the communication systems; the first and second diplexer circuits each comprising a lower-frequency filter circuit and a higher-frequency filter circuit, a bandpass filter circuit being used as the lower-frequency filter circuit in the second diplexer circuit, or disposed between the lower-frequency filter circuit in the second diplexer circuit and the receiving circuit, the high-frequency switch circuit comprising first to fourth ports, the first port being connected to a first multi-band antenna, the second port being connected to a second multi-band antenna, the third port being connected to the first diplexer circuit, and the fourth port being connected to the second diplexer circuit; and the switching elements being controlled in an ON or OFF state to select a multi-band antenna for performing wireless communications and to switch the connection of the selected multi-band antenna to the transmitting circuit or the receiving circuit.

Keisuke Fukamachi

Papers

Bypass filter; multi;band antenna switch circuit; and layered module composite part and communication device using them

High-frequency switch module

High-frequency circuit, high-frequency component, and communication device

High-frequency circuit, high-frequency device and communications apparatus

Multi-band high-frequency circuit, multi-band high-frequency circuit component and multi-band communication apparatus using same