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 positioning device for a radio frequency matcher comprises mainly a micro controller, and at least two detecting elements connected to the micro controller. The detecting elements are disposed on electric motors to detect the rotation angles of the electric motors. When the electric motors adjust the positions of the moving pieces of the tuning elements based on the volume of error signals to change the electrical reactance values so that they may approximately meet the requirement of the radio frequency load and that the radio frequency load may achieve a highest possible power, the micro controller may interpret the signals of the rotation angle detecting elements and output the interpreted values for a user to determine whether the moving pieces of the tuning elements are at right positions to approximately meet the requirement of the radio frequency load and maximize the power of the radio frequency load of the radio frequency matcher.

Auto-tunable antenna devices and methods of using the same are described herein. One method for tuning an antenna of a device includes comparing a reference phase of a reference signal to a return phase of a return signal of the antenna and sending a correction signal to a tunable circuit element of the antenna in response to the reference phase being out of phase with the return phase.

An improved switchable capacitor array comprises a plurality of n2 capacitor units, each comprising a capacitor with a capacitance and a switch unit. The capacitor units are electrically connected in series. Equidistantly spaced impedance values can be obtained if the values of the capacitances are chosen properly.

The invention relates to a method for automatically adjusting one or more tunable passive antennas and a single-input-port and single-output-port tuning unit. The invention also relates to an apparatus for radio communication using this method, for instance a radio transceiver. An apparatus for radio communication of the invention comprises: a tunable passive antenna; a feeder; a single-input-port and single-output-port tuning unit having an input port and an output port; a sensing unit; a transmission and signal processing unit which applies an excitation to the input port, which delivers one or more antenna adjustment instructions, and which delivers one or more tuning unit adjustment instructions; and a control unit which delivers one or more antenna control signals to the tunable passive antenna, and one or more tuning control signals to the single-input-port and single-output-port tuning unit.

In some examples, an interactive audio system includes a receiver for receiving a broadcasted radio frequency (RF) carrier signal. The system may demodulate a portion of the RF carrier signal to receive a demodulated output signal. For example, the demodulated output signal may include a demodulated audio program having embedded data contained within the demodulated audio signal. The system may extract the embedded data from the demodulated audio program. The system may present information related to the extracted embedded data on a display and/or may send at least a portion of the extracted embedded data to another device.

A system, method and computer readable medium are provided. One system includes a transmit antenna, at least one receive antenna, and a controller configured to operate the transmit antenna and the at least one receive antenna to acquire coupled signal information from a device under test. The system also includes a processor configured to approximate a shape of a structure within the device under test using changes in resonance determined from the coupled reflected signal information and caused by different materials forming the structure.

Methods and circuitry for calibrating inductive-capacitive resonant circuits are disclosed. An example of the circuitry includes an inductive-capacitive (L-C) resonant circuit operable to receive signals in response to induced electromagnetic signals transmitted on a carrier frequency. A demodulator has a signal source and is operable to demodulate signals generated by the L-C resonant circuit. Switching circuitry is operable to inject signals generated by the signal source into the L-C resonant circuit during a calibration mode. The calibration mode is for adjusting the capacitance in the L-C resonant circuit to tune the L-C resonant circuit to the carrier frequency.

A system, method and computer readable medium are provided. One system includes a transmit antenna, at least one receive antenna, and a controller configured to operate the transmit antenna and the at least one receive antenna to acquire coupled signal information from a device under test. The system also includes a processor configured to approximate a shape of a structure within the device under test using changes in resonance determined from the coupled reflected signal information and caused by different materials forming the structure.

Disclosed here is an interactive audio system and a method of operating the same. In one embodiment, the interactive audio system comprises a processor and a receiving module for receiving a radio frequency (RF) carrier signal associated with a broadcast station. The audio system further comprises a memory storing computer-executable instructions, where the processing module is configured to access and execute the computer-executable instructions to perform a set of acts. The acts include shifting a frequency associated with the received RF carrier signal to an intermediate frequency (IF). The acts include demodulating the frequency shifted portion of the RF carrier signal associated with the broadcast station, the demodulation resulting in an output signal. The acts further include extracting an embedded data from the demodulated output signal. The acts further include serving the embedded data in conjunction with the demodulated audio signal.