The invention relates to a method for radio communication using a plurality of antennas, and to an apparatus for radio communication using a plurality of antennas. An apparatus for radio communication of the invention comprises: 4 antennas; a radio device; an antenna tuning apparatus having 2 antenna ports and 2 radio ports; a switching unit comprising 4 input ports each coupled to one of the antennas through a feeder, and 2 output ports, the switching unit operating in an active configuration in which it provides a path between any one of the output ports and one of the input ports, the active configuration being determined by a configuration instruction generated by the radio device; and a tuning control unit, the tuning control unit receiving a tuning instruction generated by the radio device, the tuning control unit delivering a plurality of tuning control signals to the antenna tuning apparatus.

A linearization circuit reduces intermodulation distortion in an amplifier that includes a first stage and a second stage. The linearization circuit receives a first signal that includes a first frequency and a second frequency and generates a difference signal having a frequency approximately equal to the difference of the first frequency and the second frequency, generates an envelope signal based at least in part on a power level of the first signal, and adjusts a magnitude of the difference signal based on the envelope signal. When the amplifier receives the first signal at an input terminal, the first stage receives the adjusted signal, and the second stage does not receive the adjusted signal, intermodulation between the adjusted signal and the first signal cancels at least a portion of the intermodulation between the first frequency and the second frequency from the output of the amplifier.

A filter circuit includes: a variable filter that is connected between a common terminal and a node and configured to change a passband thereof; a receive switch connected between a receive terminal, from which a reception signal in a first band is output, and the node; and a transmit switch connected between a transmit terminal, to which a transmission signal in a second band different from the first band is input, and the node.

A high throw-count multiple-pole FET-based RF switch architecture that provides good RF performance in terms of insertion loss, return loss, isolation, linearity, and power handling. A common port RFC is coupled along a common path to multiple ports RFn. Embodiments introduce additional common RF path branch isolation switches which are controlled by state dependent logic. The branch isolation switches help to isolate the unused branch ports RFn and the unused portion of the common path from the active portion of the common path, and thereby reduce the reactive load attributable to such branches that degrades RF performance of the ports RFn closer to the common port RFC. The branch isolation switches can also be used to reconfigure the switch architecture for a multiplex function as well as separate switch path banks for re-configurability of purpose, tuning, or varying switch throw counts and packaging options.

A FET-based RF switch architecture and method that provides for independent control of FETs within component branches of a switching circuit. With independent control of branch FETs, every RF FET in an inactive branch that is in an open (capacitive) state can be shunted to RF ground and thus mitigate impedance mismatch effects. Providing a sufficiently low impedance to RF ground diminishes such negative effects and reduces the sensitivity of the switch circuit to non-matched impedances.

A linearization circuit that reduces intermodulation distortion in an amplifier output receives a first signal that includes a first frequency and a second frequency and generates a difference signal having a frequency approximately equal to the difference of the first frequency and the second frequency. The linearization circuit generates an envelope signal based at least in part on a power level of the first signal and adjusts a magnitude of the difference signal based on the envelope signal. When the amplifier receives the first signal at an input terminal and the adjusted signal at a second terminal, intermodulation between the adjusted signal and the first signal cancels at least a portion of the intermodulation products that result from the intermodulation of the first frequency and the second frequency.

A radio frequency (RF) signal separation and suppression system includes an input that couples in a radio frequency signal comprising desired and undesired radio frequency signals. The RF signal separation and suppression system also includes a reproduction generator connected to the input. The reproduction generator produces a reproduction from the radio frequency signal of the undesired signal at an output. The RF signal separation and suppression system also includes an electrical subtractor having a first input that is electrically connected to the output of the reproduction generator and a second input that is electrically connected to the input of the radio frequency signal separation system. An output of the subtractor generates an output radio frequency signal comprising the desired radio frequency signal and a suppressed undesired radio frequency signal.

A signal switch includes a first node and a second node. A first transistor is coupled between the first and second nodes, and a plurality of second transistors is coupled in series between the first and second nodes, in parallel with the first transistor. A shunt transistor and inductor, coupled in series, are firstly connected between two of the plurality of second transistors and are secondly connected to a reference node.

The device for jamming a cellular phone within a vehicle is configured for use with one or more personal data devices. The device for jamming a cellular phone within a vehicle partially inhibits the operation of a personal data device selected from the one or more personal data devices. By inhibiting the operation of the selected personal device is meant that the selected personal data device is only capable of hands free operation. The device for jamming a cellular phone within a vehicle comprises a safety device, an automobile, an application for the personal data device, and a blocked device.

An electronic device is provided. The electronic device includes a housing including a first surface, a second surface disposed facing an opposite side of the first surface, and a side surface configured to surround at least a portion of a space between the first surface and the second surface, a first elongated metal member configured to form a first portion of the side surface and including a first end and a second end, at least one communication circuit electrically connected to a first point of the first elongated metal member through a capacitive element, at least one ground member disposed in an interior of the housing, and a first conductive member configured to electrically connect a second point of the first elongated metal member to the ground member. The second point of the first elongated metal member is disposed closer to the second end than to the first point.