Abstract: A method and apparatus for diversity switching control are generally described herein. According to one embodiment, a diversity control network is introduced which effectively reduces the number of coaxial cables required to interface with N antennas from the conventional N cables, to N/2 thereby providing significant cost saving.

Abstract: Methods and apparatus are provided for gain and phase compensation in a radio frequency (RF) transmitter (108). The RF transmitter (108) has at least one power amplifier (PA) (205) for providing a transmitted signal having a signal power therefrom. An RF power detector (208) is coupled to the at least one PA (205) for detecting the signal power of the transmitted signal and an analog to digital (A/D) converter (210) is coupled to the RF power detector (208). A hysteresis unit (214) is coupled to the A/D converter (210) for generating a pulse (222) in response to a power threshold being crossed and a load switch control unit (218, 232) is coupled to the hysteresis unit and the at least one power amplifier for providing gain and phase compensation in response to the pulse.

Abstract: Methods and apparatus are provided to enable a transceiver (200) or transmitter including a single PA line-up (210) to transmit signals having frequencies in two or more different frequency bands, and/or having two or more different modulation types, and/or having two or more different RF power levels. The single PA line-up includes at least one variable matching circuit (216) and a variable harmonic filter (240) to tune match and tune filter communication signals prior to transmission. The variable matching circuit and the variable harmonic filter each include at least one variable capacitive element (2160 and 2400) that switches ON/OFF depending on whether a low frequency signal or a high frequency signal is being transmitted. Each variable capacitive element includes separate direct current and radio frequency terminals to enable the single PA line-up to change signal modulation and/or RF power levels in addition to frequencies.

Abstract: The invention includes a first antenna section, a second antenna section, a transmitting signal generating section configured to generate a predetermined transmitting signal for a wireless tag, a transmitting section configured to transmit the transmitting signal generated by the transmitting signal generation section from the first antenna section, and a receiving section configured to receive a response signal from the wireless tag through the second antenna section. Furthermore, the invention is constituted to include an error detecting section configured to detect a predetermined error in the response signal sent from the wireless tag and received by the antenna section, and an antenna switching section configured to carry out switching for receiving the response signal sent from the tag through the first antenna section and transmitting the predetermined transmitting signal through the second antenna section based on a result of the detection obtained by the error detecting section.

Abstract: A novel amplifier for a wireless device is disclosed. The system employing the preferred embodiment can deliver a radio signal with output power up to 500 mW for 64QAM (48 Mb/s bit rate) modulation and a radio signal up to 700 mW for 16QAM (36 Mb/s bit rate) modulation with the packet error rate below 1%. The increase of the signal from 10 to 500 mW (64QAM modulation) thus increases the base station coverage area 50 times.

Abstract: An impedance matching system, a network analyzer having the same, and an impedance matching method thereof are disclosed. The system includes a signal extractor to extract an output signal and an input signal having at least a portion of an electric current outputted through a load and at least a portion of an electric current inputted through the load, respectively, a processor to process the output signal and the input signal extracted from the signal extractor, a comparator to compare a phase and an amplitude of the output signal with a phase and an amplitude of the input signal, respectively, a coefficient calculator to calculate a reflection coefficient using the comparative result provided from the comparator, and a circuit controller to generate a signal for controlling a matching circuit, which matches the phase and the amplitude of the output signal with the phase and the amplitude of the input signal, respectively, so as to ensure the reflection coefficient to have a predetermined value.

Abstract: A cellular phone covering a plurality of frequency bands, includes (a) an antenna, (b) a high-frequency circuit, (c) an antenna-matching circuit electrically connecting in series between the antenna and the high-frequency circuit, and (d) a first unit which varies a ground length in accordance with a frequency band in which the cellular phone makes communication with others, the ground length being defined as a length of a ground area for the antenna-matching circuit.

Abstract: A transmitter-combining broadcast system and method is provided that allows IBOC-compatible broadcast with simple analog-to-IBOC upgradeability with high efficiency. At full power, a standard analog signal and an IBOC-compatible digital signal are transmitted by combining the output of a wide-band transmitter containing VHF-FM analog and in-band digital signals with the output of a second transmitter containing VHF-FM analog alone. By shifting signal phase, two analog signals can be combined with low loss, and net power waste can be reduced by at least 80%. The approach enables full IBOC upgradeability for existing analog-only systems, including reuse of existing transmitting equipment. Full IBOC compliance is supported, including during operation with reduced power. Switchover between partial and full power operating modes can be performed without full system shutdown.

Abstract: In a first embodiment, the invention relates to an arrangement for operating a plurality of terminal devices (6) on a common antenna (4) with a coupling network (2) comprising a first separator (8) associated with the antenna (4) and a second separator (10) associated with the respective terminal (6). In a second embodiment, the invention relates to an arrangement for operating a plurality of terminal devices (6) on a common transmitting antenna (4?) and on a common receiving antenna (4) which is separate from the common transmitting antenna (4?) with a coupling network (2) comprising a separator (10) which is associated with the respective terminal.

Abstract: The invention relates to a multiband antenna switch, and more particularly an antenna switch implemented in the radio interface of a mobile telephone device. The antenna switch comprises a power amplifier module with an antenna port 1 connectable to an antenna, and at least one input port connectable to a transmitter section of a transceiver 5; a front end module connectable to the antenna port and a reception section of a transceiver; wherein said power amplifier module and said front end module are capable of covering a number of frequency bands. The transmission/reception duplexing function is obtained by means of a circulator 6, 7 or a power splitter arrangement. The antenna switch offers a packed solution for using four GSM and eight WCDMA bands in the same phone.

Abstract: An apparatus and method for automatically matching a frequency of an antenna in a wireless terminal are provided. The apparatus includes a duplexer for classifying frequencies transmitted/received through the antenna of the wireless terminal, transmitting the reception frequency received in the antenna to an automatic matching module, and transmitting a transmission frequency, which is received from the automatic matching module, to the antenna; the automatic matching module for automatically matching impedance for the reception frequency received from the duplexer, transmitting the impedance-matched reception frequency to an amplifier, automatically matching impedance for the transmission frequency received from the amplifier, and transmitting the impedance-matched transmission frequency to the duplexer; and a controller for controlling the automatic matching module to automatically match the impedance for the transmission/reception frequencies.

Abstract: An impedance matching circuit (140) includes a capacitive element (C1, 220), having a capacitance C, coupled in parallel with an output node (215) of the matching circuit, and an inductor (L1, 225) coupled in series with a transmission line (T1, 230) between the input node and the output node. The transmission line has a length that, in combination with the inductor, provides impedance substantially equal to the input impedance of the transmission circuit (150) at a frequency of interest. In one embodiment, the inductor is connected to an output (195) of an amplifier (180), and the transmission line is connected to the inductor and to the output (215). The capacitive element is connected to the transmission line such that the length of the transmission line between the inductor and the capacitive element provides the desired inductance.

Abstract: Briefly, a method and apparatus for decoding and authenticating an antenna is disclosed. The method may include detecting attachment of an antenna to a transmitter by authenticating a cipher received from the antenna. The method further includes suspending transmission if the antenna is not attached to the transmitter.

Abstract: A hand-held electronic device comprises an IC-card chip unit, a watch CPU, a power source unit, a display unit, and a switch connected between the power source unit and the IC-card chip unit. The watch CPU has a power supply controlling unit. The IC-card chip unit performs contactless data communication with an external transmitter-receiver in close range. The watch CPU operates on power from the power source unit, receives data from the IC-card chip unit to display the data on the display unit or to process the data before displaying them on the display unit. The power supply controlling unit closes a switch at least during the period of time that the watch CPU receives data from the IC-card chip unit, thereby causing power to be supplied from the power source unit to the IC-card chip unit.

Abstract: With a redundant GPS antenna splitter two GPS antennas are connected through an amplifier to a passive antenna splitter in parallel feeding mode, whereby the direct current supply of the antennas is provided by a DC driver stage, whose inputs (DC1 to DC8) are coupled with outputs of the antenna splitter of the connected transmitters in order to control the power supply with current measuring stages depending on the operating condition of the GPS antennas and to deliver a supply voltage both to the GPS antenna and HF-amplifier, if the antenna is active.

Abstract: An apparatus for reducing the electromagnetic interference between two or more co-located antennas is described herein. In one embodiment, the apparatus is positioned proximate to a second antenna for intercepting electromagnetic energy radiated from a first antenna during transmission of a signal. To reduce interference at the second antenna, the apparatus includes a plurality of resonant circuit elements, each being configured to resonate at or near a carrier frequency of the transmitted signal for redirecting at least a portion of the electromagnetic energy away from the second antenna. A method for reducing the electromagnetic interference between two or more antennas coupled to a wireless communication device is also disclosed herein.

Abstract: A mobile terminal can include a printed circuit board with a reference voltage conductor, an antenna coupled to the first side of the printed circuit board, and a parasitic resonator coupled to the second side of the printed circuit board. More particularly, the parasitic resonator can be connected to the printed circuit board by first and second couplings, which provide first and second impedances, respectively, between the parasitic resonator and the reference voltage conductor. The impedances can be of different values, and can be provided by discrete impedance components. The resonant frequency of the parasitic resonator can be adjusted by altering the impedances of the first and second couplings.

Abstract: An apparatus and method are provided for monitoring an antenna state of a mobile station. A resister may be provided between a battery voltage terminal and a power source voltage terminal of a power amplifier. A voltage level corresponding to a dropped amount of a voltage due to the resister may be generated and compared with a previously stored voltage level to determine whether current consumption of the power amplifier has been increased. If the increased amount of the current consumption of the power amplifier is large, the currently connected antenna may be determined to be in an abnormal state and a transmission path may be switched to another antenna. If two antennas provided in the mobile communication are in an electrically abnormal state, a baseband chip may inform a user of the abnormal state of the antenna. Accordingly, an output level degradation generated when the antenna is operated in an electrically abnormal state and shortening of the life span of a battery can be prevented.

Abstract: A portable wireless apparatus with transmission capability. An inner common antenna, including a metal frame embedded in an LCD and an inverse F-type antenna device, is provided, such that performance of the electromagnetic wave is increased to a maximum and resonance characteristics or mechanism of the antenna device is reduced, and the common antenna is adequately provided and embedded in the portable wireless apparatus.

Abstract: A high-frequency device includes an antenna terminal, a signal line connected to the antenna terminal, a high-frequency signal processing circuit connected to the signal line, a capacitance element having one end connected to the signal line and other end grounded, and an inductor having one end connected to the signal line and other end grounded. The high-frequency device can protect the high-frequency signal processing circuit from a high voltage noise, such as a static electricity, having a frequency close to a signal pass band.

Abstract: The invention concerns a circuit arrangement for compensation of attenuation in an antenna lead for a mobile wireless device. The circuit arrangement is suitable for operation in a wireless network, in which the higher or the lower of two frequency ranges defined in one frequency band is used selectively for transmitting and the other frequency range is used for receiving the wireless signals within the one frequency band.

Abstract: For combining two received signals (#1, #2) from different reception routes, a control process for maximizing the level of a combined signal (maximum level combining process), a control process for combining the signals in phase with each other (in-phase combining process), a control process for minimizing a waveform distortion of the combined signal (minimum amplitude deviation type combining process), and a control process for performing both the minimum amplitude deviation type combining process and the maximum level combining process are alternatively switched by an EPS (endless phase shifter) control circuit (8) depending on a level detector output (101) and a waveform distortion detector output (102). These control processes are performed by controlling the EPS (1) to control the phase of the received signal (#2).

Abstract: A wireless network card includes an adaptable antenna connection structure that includes connections for one or more internal antennas and for one or more Radio Frequency (RF) connectors that may be coupled to one or more external antennas. A Printed Circuit Board (PCB) and electronic components located thereon form the wireless network card. The PCB includes a removable portion that, when removed, leaves an opening that receives an RF antenna connector. When the PCB is used to create a client wireless network card, one or more surface mount antennas are mounted on the PCB and coupled to surface mount antenna conductive pads formed thereon. The wireless network card may include (1) the surface mount antenna; (2) the RF connector; or (3) both the surface mount antenna and the RF connector.

Abstract: A mobile communication terminal having adaptive array antennas is provided that is capable of transmitting signals to an intended base station without interfering other devices, even when a reception error occurs. The mobile communication terminal basically performs array transmission/reception using weight vectors produced in reception to weight and combine signals received via antennas, and thereby receives a desired signal. In transmission, the mobile communication terminal uses the weight vectors used in reception to weight and combine transmission signals and transmits them. However, when an error detection circuit detects a reception error in the desired signal, a transmission control unit turns off a switch for the antenna and transmits the transmission signals in a non-directional pattern via the antenna, so that the transmission signal reaches the intended base station.

Abstract: A monolithic integrated circuit (IC), and method of manufacturing same, that includes all RF front end or transceiver elements for a portable communication device, including a power amplifier (PA), a matching, coupling and filtering network, and an antenna switch to couple the conditioned PA signal to an antenna. An output signal sensor senses at least a voltage amplitude of the signal switched by the antenna switch, and signals a PA control circuit to limit PA output power in response to excessive values of sensed output. Preferred fabrication techniques include stacking multiple FETs to form switching devices. An iClass PA architecture is described that dissipatively terminates unwanted harmonics of the PA output signal. A preferred embodiment of the RF transceiver IC includes two distinct PA circuits, two distinct receive signal amplifier circuits, and a four-way antenna switch to selectably couple a single antenna connection to any one of the four circuits.

Abstract: A system and method for maximizing throughput in a telecommunications system is disclosed. The system includes an antenna system using fixed narrow beams that transmits and allows improved capacity gain to be realized without degrading call performance. The system can include: forming a plurality of directional narrow uplink beams at a main antenna; receiving communications signals on the plurality of directional uplink beams; periodically scanning across the plurality of uplink beams associated with a given call; assessing a set of beams from the plurality of uplink beams based upon a quality of reverse link information; selecting a first subset from the set of beams to be turned off when the quality of reverse link information reaches a first predetermined value; and instructing the subset to not transmit a traffic channel and to continue to transmit the power control sub channel.

Abstract: A radio frequency (RF) module for use in a communication device of a communication system includes integrated RF circuitry comprising at least one of a transmitter and a receiver, and an antenna element having at least one portion thereof arranged substantially adjacent to and operatively coupled to the integrated RF circuitry. For example, the antenna element may include at least first and second portions having opposing edges arranged immediately adjacent respective first and second sides of the integrated RF circuitry. A plurality of the modules can be used to implement a transceiver in a communication system base station or other communication device.

Abstract: An apparatus and method for testing a voltage standing wave ratio (VSWR) in a wideband code division multiple access (W-CDMA) mobile communication system. Upon detecting a VSWR test request, a controller determines an oscillation frequency information and a power level information of a test signal for a VSWR test, and generates a test signal generation request including the determined oscillation frequency information and power level information. Upon detecting the test signal generation request, a test signal generator generates a test signal corresponding to the oscillation frequency information and power level information, and provides the generated test signal to an antenna. A VSWR detector receives the test signal and a reflected signal of the test signal from the antenna, and calculates a VSWR using the received test signal and reflected signal.

Abstract: An impedance matching circuit (140) includes a capacitive element (C1, 220), having a capacitance C, coupled in parallel with an output node (215) of the matching circuit, and an inductor (L1, 225) coupled in series with a transmission line (T1, 230) between the input node and the output node. The transmission line has a length that, in combination with the inductor, provides impedance substantially equal to the input impedance of the transmission circuit (150) at a frequency of interest. In one embodiment, the inductor is connected to an output (195) of an amplifier (180), and the transmission line is connected to the inductor and to the output (215). The capacitive element is connected to the transmission line such that the length of the transmission line between the inductor and the capacitive element provides the desired inductance.

Abstract: A portable wireless communication terminal device has a data communications function and a telephone function and includes a casing, a display having a display section exposed through an opening of the casing, a circuit board installed in the casing and having the display on one surface of the circuit board, a first antenna electrically connected to the circuit board and disposed on an opposite side to the display inside the casing, and a second antenna electrically connected to the circuit board and mounted on a periphery of the display inside the casing. The device maintains a stable antenna characteristic and communication quality even if it is placed on a table or if the fingers of a user cover the backside of the device.

Abstract: A transmission system or apparatus includes a transmitter or source of transmitted RF or microwave power which is selectively connectable via a transmitter connector to an antenna having an antenna feed via an antenna connector so that a variety of antennas with differing characteristics can be used with a given transmitter. Each antenna preferably has a marker or indicating element incorporated into the antenna feed. The marker or indicating element includes a physically measurable property or parameter corresponding to a physical characteristic of the attached antenna. In the preferred embodiment, the indicating element is a resistance connected in parallel with the antenna feed and having a selected resistance value (e.g., in ohms) which indicates the physical characteristic of gain for antenna. The transmission system also includes an indicating element sensor configured to sense or measure the marker or indicating element and generate a transmitter control signal in response to that measurement.

Abstract: Received signal inputted from an antenna 1 is fed via a received signal mixer 2 and an A/D converter 3 to a demodulator 4. The demodulator 4 is operated according to software down-loaded in a software memory 5 from a program memory 6. A demodulator output digital signal is fed to a base-band signal processor 8 for signal processing, and then fed out through a man-machine interface 9 to the outside. On the transmission side, a signal to be transmitted is inputted to a modulator 10 though a route converse to that of the received signal. The modulator output is fed to a D/A converter 11 for conversion to an analog signal, which is in turn fed to a transmission signal mixer 12 for conversion to a carrier frequency, and then fed to a module, which includes a power amplifier 21, a transmission signal filter 22 and an isolator 23, to be transmitted via the antenna 1.

Abstract: A high-frequency coupler for extracting a secondary signal representative of a main signal carried by a conductive line, including two series-coupled, respectively high-pass and low-pass, filters, and the input of which is intended to be connected to said line while its output is intended to provide the secondary signal, the filters being sized so that the sum of their respective attenuations is substantially constant over the coupler passband, and so that their respective cut-off frequencies are in said passband.

Abstract: According to some embodiments of the present invention, an impedance transformation circuit is provided for use with a transmitter, a receiver, and an antenna. The transmitter may provide transmission signals for transmission by the antenna. The antenna may provide received signals having an associated signal parameter to the receiver. The impedance transformation circuit includes an impedance adjusting circuit and a controller. The impedance adjusting circuit is connected between the antenna, the receiver, and the transmitter. The impedance adjusting circuit is configured to change an impedance difference presented between at least one of: 1) the transmitter and the antenna, and 2) the antenna and the receiver, in response to a control signal. The controller generates the control signal to change the presented impedance difference in response to a signal parameter.

Abstract: A distributed antenna system comprising a plurality of antenna elements, duplexers and amplifiers, each amplifier and duplexer operatively coupled with one of said antenna elements and mounted closely adjacent to the associated antenna element in such a manner as incidences of insertion loss, noise and system failure are reduced.

Abstract: A method and an arrangement for detecting impedance mismatch between an output of a radio frequency amplifier (200, 901, 911, 921, 1101) which has an amplifying component (201, 301, Q46, 701, 801) and an input of a load (203, 302) coupled to the output of the radio frequency amplifier having: first monitoring means (401) to monitor a measurable electric effect (311) at a side of the amplifying component (201, 301, Q46, 701, 801) other than the load (203, 302) and to produce a first measurement signal (411). Second monitoring means (402) monitor a measurable electric effect (312) between the amplifying component (201, 301, Q46, 701, 801) and the load (203, 302) and produce a second measurement signal (412). Decision-making means (204, 902, 912, 923, 1102) receive said first (411) and second (412) measurement signals and decide, whether said first and second measurement signals together indicate impedance mismatch.

Abstract: A composite beamforming technique is provided wherein a first communication device has a plurality of antennas and the second communication has a plurality of antennas. When the first communication device transmits to the second communication device, the transmit signal is multiplied by a transmit weight vector for transmission by each the plurality of antennas and the transmit signals are received by the plurality of antennas at the second communication device. The second communication device determines the best receive weight vector for the its antennas, and from that vector, derives a suitable transmit weight vector for transmission on the plurality of antennas back to the first communication device. Several techniques are provided to determine the optimum transmit weight vector and receive weight vector for communication between the first and second communication devices so that there is effectively joint or composite beamforming between the communication devices.

Abstract: There is provided a power rate enhancement circuit for a power amplifier in a dual mode mobile phone including an RF power amplifier for amplifying an RF input signal, a duplexer connected to an antenna, and an isolator connected to the duplexer. The power enhancement circuit also comprises: a CDMA matching circuit connected to an output end of the RF power amplifier, for matching an output impedance of the RF power amplifier in a CDMA mode of operation; an AMPS matching circuit connected to the output end of the RF power amplifier, for matching the output impedance of the RF power amplifier in an AMPS mode of operation; and an RF switch for selecting the CDMA matching circuit or the AMPS matching circuit according to a mode control signal. The CDMA matching circuit comprises an inductor connected between the output end of the RF power amplifier and the isolator. The AMPS matching circuit comprises a capacitor connected between the RF switch and a contact point formed between the inductor and the isolator.

Abstract: A portable communications system and method is provided in accordance with the present invention. The system includes a chip antenna for transmitting and receiving RF signals and a communications module case for mounting the chip antenna and providing a chip antenna ground plane. A communications subsystem is associated with the communications module case and is operatively coupled to the chip antenna for processing the RF signal.

Abstract: The information terminal unit comprises a transceiver and a processor, while the variable directional antenna comprises a main antenna element to which the transceiver directly supplies a radio frequency signal, and a plurality of sub antenna elements. The sub antenna elements are connected with variable phase shifter circuits for determining a phase shift amount of a reflecting wave, respectively. The control circuit receives the directivity data from the CPU of the information terminal unit and analyzes the received data to control the phase shift amount of each variable phase shifter circuit. Thereby the phase shift amounts of the respective sub antenna elements are adjusted so that the wave fronts of the waves radiated or secondarily radiated from the main antenna element and sub antenna elements are aligned in a certain direction, and then the variable directional antenna is controlled so as to have a directivity in that direction.

Abstract: An apparatus and method is related to a wireless system with an antenna that is automatically tuned to a desired frequency. The antenna is coupled to an adjustable tuning circuit to form a tuned antenna circuit that has a resonant frequency. The adjustable tuning circuit may be adjusted by activating a sweep generator that varies a tuning element over a broad frequency range. The sweep of the sweep generator is terminated after the proper frequency is found. Alternatively, the adjustable tuning circuit may be adjusted using an array of switched capacitors using a successive approximation method. The tuned antenna circuit may be employed to receive and/or transmit information. The resonant frequency is dynamically shifted in response to a data signal such that the antenna transmits FSK encoded signals.

Abstract: A mobile communication apparatus (1) includes a transponder unit (15) having transmission means (16) and a transponder circuit (17) and is adapted to accommodate an accessory unit (ESIM), the accessory unit (ESIM) being provided with at least the transponder circuit (17) of the transponder unit (15).

Abstract: The present invention provides methods, systems, devices, and computer program instructions for enabling low-power wireless devices (such as wireless telephones and personal digital assistants, or PDAs) to connect to a fast wired or wireless voice/data network. A novel relay point device, referred to as an “extension point”, is defined that flexibly extends the effective reach of network access points. Use of extension points enables the network infrastructure to be expanded (and subsequently re-configured, if necessary) simply and cost-effectively, requiring little or no additional physical wiring. The defined techniques provide an infrastructure that is scalable, supporting a large number of end users without substantial degradation to connection establishment time and data rates. Using the disclosed techniques, end devices are able to reach network services, and to communicate with other end devices, beyond the nominal working range of these devices and without limitation to the numbers of such devices.

Abstract: A method and apparatus for measuring a change in the insertion loss of a transmission line in a communication system is disclosed. The method provides feeder cable insertion loss detection in a transmission system without interfering with normal operation. The method includes injecting a non-interfering signal at a predetermined frequency onto a cable providing normal operating signals to a narrowband device at a predetermined frequency, measuring the amplitude of the injected signal, measuring the amplitude of a reflected signal, the injected signal being reflected by the narrowband device and processing the amplitude of the injected signal and the amplitude of the reflected signal to derive a current insertion loss for the cable.

Abstract: A portable wireless unit of the invention has a first plane antenna smaller than an antenna size determined by a desired frequency, and a second plane antenna presenting an antenna size determined by the desired frequency on the whole by coupling with the first plane antenna.

Abstract: An antenna has multiple arrays of radiating elements and includes a plurality of single channel power amplifiers, with each amplifier electrically connected with an array. The radiating elements of the arrays are interleaved so that radiation from the arrays combines at a distance from the antenna.

Abstract: An improvement in the shielding design and deployment of collocated radio transceivers for high-speed wireless Internet access accomplished by increased isolation brought about by wrapping each transceiver in a shield of mild steel, enclosing collocated transceivers and associated equipment in non-reflective enclosures, and use of low loss RF coaxial cables.

Abstract: In a semiconductor integrated circuit device and a contactless electronic device, an AC voltage is applied to first and second input terminals. A rectification transistor having a drain (or collector) connected to a second input terminal and gate (or base) and drain (or collector) connected to each other through a first resistor supplies a rectified current between the first and second input terminals. A first voltage detector means produces a control voltage so that the rectified voltage obtained on the source (or emitter) side of the first rectification transistor is equal to a predetermined reference voltage. The first voltage controlled current source can produce current in accordance with the control voltage and supply the current to the first resistor. Such a power supply circuit is mounted in the contactless electronic device.

Abstract: This process is adapted for at least two groups of antennas (4, 6). A modulated signal is emitted by a first group of antennas (4) whilst the antennas (6) of a second group emit a similar modulated parasitic signal but of less amplitude. An unmodulated signal of an amplitude comprised between the amplitude of the parasitic signal and the amplitude of the signal emitted by the first group of antennas (4) is superposed on the parasitic signal emitted by the antennas (6) of the second group. Application to a free hand system for access and/or starting of an automotive vehicle.

Abstract: A radio station including two antennas combined with respective first and second hybrid transmission polarization couplers is disclosed. Each antenna is arranged to generate two orthogonal electric field components in response to two respective quadrature radio signals from the corresponding polarization coupler. The station further includes at least one hybrid distribution coupler with a first output connected to a first input of the first polarization coupler and a second output connected to a first input of the second polarization coupler and at least one radio signal source delivering a radio signal to a first input of the distribution coupler.