Abstract: A communication system includes the following elements: a transmitter including a transmission circuit unit configured to generate an RF signal for transmitting data and an electric-field-coupling antenna configured to transmit the RF signal as an electrostatic field; a receiver including an electric-field-coupling antenna and a reception circuit unit configured to receive and process the RF signal received by the electric-field-coupling antenna; and a surface-wave propagation medium configured to provide a surface-wave transmission line to transmit a surface wave emanating from the electric-field-coupling antenna of the transmitter with low propagation loss.

Abstract: A communication system includes: a transmitter including a transmission circuit unit generating an RF signal for transmitting data and an electrical-field coupling antenna transmitting the RF signal as an electrostatic field or an induction field; a receiver including an electrical-field coupling antenna and a reception circuit unit subjecting an RF signal received by the electrical-field coupling antenna to reception processing; and a surface-wave propagation device including a plurality of linear surface-wave transmission lines for propagating a surface wave radiated from the electrical-field coupling antenna of the transmitter.

Abstract: A communication system includes the following elements: a transmitter including a transmission circuit unit configured to generate an RF signal for transmitting data and an electric-field-coupling antenna configured to transmit the RF signal as an electrostatic field; a receiver including an electric-field-coupling antenna and a reception circuit unit configured to receive and process the RF signal received by the electric-field-coupling antenna; and a surface-wave propagation medium configured to provide a surface-wave transmission line to transmit a surface wave emanating from the electric-field-coupling antenna of the transmitter with low propagation loss.

Abstract: A communication system includes a transmitter including a transmission circuit unit that generates an RF signal for transmitting data and an electric-field-coupling antenna that transmits the RF signal as an electrostatic field, a receiver including an electric-field-coupling antenna and a reception circuit unit that subjects an RF signal received by the electric-field-coupling antenna to reception processing, and a surface-wave propagating means for providing a surface wave transmission line made of a conductor that propagates a surface wave radiated from the electric-field-coupling antenna of the transmitter along a surface of the surface wave transmission line.

Abstract: A high frequency coupler includes a ground, a first coupling electrode connected via a first resonator unit to an input and output terminal of a communication circuit, and one or more second coupling electrodes connected via a second resonator unit designed utilizing a ground to a ground terminal of the communication circuit.

Abstract: A high-frequency coupler includes ground; a coupling electrode being supported so that the coupling electrode is placed opposite the ground and separately placed at a height from the ground, the height being negligible relative to the wavelength of the high-frequency signal; a resonator increasing electric current entering the coupling electrode through a transmission path; and a stretchable/retractable connection section connecting a predetermined position on the coupling electrode and the resonator; wherein an infinitesimal dipole is formed, the infinitesimal dipole including a line segment which connects the center of electric charge accumulated in the coupling electrode and the center of mirror-electric charge accumulated in the ground, and the high-frequency signal is transmitted to another high-frequency coupler at a communication partner side, which is placed opposite the high-frequency coupler so that the angle between the direction of the infinitesimal dipole and the direction from the high-frequency

Abstract: A communication system, including a transmitter having a transmitting circuit unit to generate a data transmission-adaptive RF signal and an electric-field-coupling antenna to send out the RF signal as an induction field and/or an electrostatic field, a receiver having a electric-field-coupling antenna and a receiving circuit unit to receive and process the RF signal received by the electric-field-coupling antenna, and a coupling apparatus having a plurality of transmitter-side electric-field-coupling antennas to receive the RF signal which is in capacitive coupling with the transmitter-side electric-field-coupling antenna and outputted from the electric-field-coupling antenna, a signal line to transmit the received RF signal, and a plurality of receiver-side electric-field-coupling antennas to output the RF signal which is in capacitive coupling with said the receiver-side electric-field-coupling antenna and transmitted through the signal line.

Abstract: A communication device includes a communication circuit unit processing a high-frequency signal, a transmission path connected to the communication circuit, a ground, a coupling electrode supported so as to face the ground and to be separated by a height negligible with respect to a wavelength of the high-frequency signal, a resonating unit increasing a current flowing into the coupling electrode via the transmission path, and an extended section formed of a conductor disposed near a front of the coupling electrode with an angle ? formed relative to a direction of a microdipole being approximately 0 degree, the microdipole being formed of a line segment connecting a center of charges stored in the coupling electrode and a center of mirror-image charges stored in the ground, the conductor extended in a lateral direction approximately orthogonal to a propagating direction of an electric-field signal occurring from the front of the coupling electrode.

Abstract: A communication device includes a communication circuit unit, a transmission path, a ground, a coupling electrode, and a resonating unit. The resonating unit includes a first resonating unit connected to the transmission path and a second resonating unit having one end connected to the first resonating unit and another end short-circuited to the ground, the second resonating unit having terminals of the coupling electrode connected thereto. A microdipole is formed of a line segment connecting a center of charges stored in the coupling electrode and a center of mirror-image charges stored in the ground. The high-frequency signal is transmitted to a distant side disposed so as to face the communication device with an angle ? formed relative to a direction of the microdipole being approximately 0 degree.

Abstract: A communication system includes the following elements: a transmitter including a transmission circuit unit configured to generate an RF signal for transmitting data and an EFC antenna configured to transmit the RF signal as an electrostatic field or an induced electric field; and a receiver including an EFC antenna and a reception circuit unit configured to receive and process the RF signal received by the EFC antenna. The EFC antennas of the transmitter and the receiver each include a coupling electrode and a resonating section including a distributed-constant circuit configured to strengthen electrical coupling between the coupling electrodes. The RF signal is transmitted by electric-field coupling between the EFC antennas, facing each other, of the transmitter and the receiver.

Abstract: A communication system includes the following elements: a transmitter including a transmission circuit unit configured to generate an RF signal for transmitting data and an EFC antenna configured to transmit the RF signal as an electrostatic field or an induced electric field; and a receiver including an EFC antenna and a reception circuit unit configured to receive and process the RF signal received by the EFC antenna. The EFC antennas of the transmitter and the receiver each include a coupling electrode and a resonating section including a distributed-constant circuit configured to strengthen electrical coupling between the coupling electrodes. The RF signal is transmitted by electric-field coupling between the EFC antennas, facing each other, of the transmitter and the receiver.

Abstract: The communication apparatus includes a capacitive coupling electrode which is capacitively coupled with an adjacent conductor or an adjacent dielectric and which operates the conductor or the dielectric as an antenna element for electromagnetic waves of a predetermined frequency, and a matching circuit which is connected to the capacitive coupling electrode and which matches impedance of the conductor or the dielectric to be operated as the antenna element for the electromagnetic waves of the predetermined frequency when the conductor or the dielectric is adjacent and capacitively coupled therewith.

Abstract: An electric field coupler includes a strip-like coil formed by bending a strip-like conductor which snakes along a plane perpendicular to a coupling direction in which electric field coupling occurs, such that coil axes are perpendicular to the coupling direction, the strip-like coil having an electrical length of one-half wavelength of a predetermined frequency of a radio-frequency signal and having a form in which the coil axes surround a central portion along the plane. The strip-like coil produces coupling by a longitudinal wave electric field which vibrates in the coupling direction at the central portion.

Abstract: A wireless communication system has a transmitter and a receiver. The transmitter includes a transmission-data-processing device that generates items of data for a first series and items of data for a second series, a transmission-processing device that generates transmission signals for each series based on these items of data, and a wireless-signal-transmitting device that transmits the transmission signals generated by the items of data for the first series and the items of data for the second series as wireless signals of an anti-clockwise polarized scheme and of a clockwise polarized scheme, respectively.

Abstract: A communication apparatus includes a communication unit, a connection establishment processing unit for exchanging connection data between the communication unit and a communication party to perform a connection establishment processing, and a communication controlling unit for statically setting a data rate of the connection data and dynamically setting a data rate of transmission data to be transmitted from the communication unit after the connection establishment processing.

Abstract: There is provided a communication apparatus including a plurality of communication units for making communication through electric field coupling or magnetic field coupling, a detecting unit for detecting an approach between a communication party capable of communication through electric field coupling or magnetic field coupling and any one of the plurality of communication units, and a controlling unit for causing a communication unit whose approach to the communication party is detected by the detecting unit to serve a function of communication assigned to the communication unit, different functions of communication being assigned to each of the plurality of communication units.

Abstract: An antenna includes a coil that is formed such that one end of the coil is short circuited or open to a ground and a current standing wave is generated when a high frequency signal is applied to another end of the coil. The coil generates a magnetic field standing wave having a frequency corresponding to the high frequency signal, and thereby detects or radiates an electromagnetic wave having the frequency.

Abstract: A communication apparatus has a first communication section which makes contactless communication by means of magnetic field coupling and a second communication section which makes contactless communication by means of electric field coupling, and the second communication section generates an electric field which oscillates to a direction approximately parallel with an oscillation direction of a magnetic field on a position where the magnetic field crosses the second communication section.

Abstract: A high-frequency electric field coupler is provided for use in a contactless communication system propagating high frequency signals in a wide band utilizing electric field coupling. The coupler includes a coupling electrode and a resonance unit operating to increase the amplitude of an electrical charge accumulated at the coupling electrode at a predetermined resonance frequency. The coupling electrode is a linear conductor in the form of a coil.

Abstract: A communication system includes a transmitter including a transmitting circuit to generate radio frequency signals for transmitting data and an electrical field coupling antenna to transmit the radio frequency signals as an electrostatic field or an inductive electrical field; and a receiver including an electrical field coupling antenna and a receiving circuit to perform a reception process on radio frequency signals received by the electrical field coupling antenna. Each of the electrical field coupling antennas of the transmitter and the receiver includes a coupling electrode, a resonant portion to strengthen electrical coupling between the coupling electrodes, and a radio wave absorber placed near the coupling electrode. The radio frequency signals are transmitted through electrical field coupling between the electrical field coupling antennas facing each other of the transmitter and the receiver.