Abstract: A radio communication system performs data communication by a backscatter system using absorption and reflection of a received radio wave. In the system, a data reading device transmits an unmodulated carrier of frequency fO; a data transmitting device subjects transmission data to primary modulation using a center frequency fS to obtain a primary modulated signal, and subjects the primary modulated signal to secondary modulation by multiplying the primary modulated signal by an input of the unmodulated carrier of the backscatter system to generate a reflected modulated wave in which one of frequencies fO+fS and fO?fS is suppressed; and the data reading device receives the reflected modulated wave from the data transmitting device.

Abstract: The present invention relates to a method for adapting transmission parameters in a transmitter Tx in communication with at least one antenna 27; 38; 47; 57; 77, 88. The method comprises: transmitting a signal from the transmitter Tx measuring at least one reflection coefficient S11 of said signal for each antenna 27; 38; 47; 57; 77, 88, and adapting the transmission parameters based on the measured reflection coefficient S11. The antenna could be a transmit antenna and/or a receive antenna. In a preferred embodiment antenna calibration may be performed by measuring propagation time for each individual transmitter chain 481, 482; 781, 782, and compensate for differences in time delay between the individual transmitter chains 481, 482; 781, 782 to assure that the signal is transmitted simultaneously from all transmit antennas.

Abstract: The disclosure relates to a radio frequency (RF) and/or microwave power amplification device which is intended, for example, for a radio communication terminal, comprising means for shielding the device and means for controlling the power delivered as output from said device, said power-control means comprising a power servo loop having power-amplification means, reference means, detection means and comparison means. The aforementioned control means also comprise at least one sensor to detect the energy radiated inside the device.

Abstract: The present invention provides an RF transmission leakage mitigator for use with a full-duplex, wireless transceiver. In one embodiment, the RF transmission leakage mitigator includes an inversion generator configured to provide an RF transmission inversion signal of an interfering transceiver RF transmission to a receiving portion of the transceiver thereby creating a residual leakage signal. Additionally, the RF transmission leakage mitigator also includes a residual processor coupled to the inversion generator and configured to adjust the RF transmission inversion signal of the interfering transceiver RF transmission based on reducing the residual leakage signal to a specified level.

Abstract: In circumstance of a wearable computing system, in order to effectively transfer data between electronic devices using electric property of human body, minimization, low power, and high-speed are required. Human body data communication apparatus and module using broadband signaling technology is provided to perform high-speed peer-to-peer data communication with a signal electrode and low power. The apparatus and module have a direct coupling interface with a single electrode without an antenna and a sensor, and a transmitter transmitting digital signal without modulation, and a receiver recovering a clock and data by detecting a broadband pulse signal.

Abstract: There is provided a highly reliable transmission/reception integrated radio-frequency apparatus which can achieve a high communication quality in a cable modem. A reception RF signal is input to a reception system block via an input/output terminal, converted to an intermediate-frequency signal, and output from a terminal. An output terminal of a transmission processing section of a transmission system block is connected to the input/output terminal via an overvoltage protection circuit, a high-pass filter functioning as a countermeasure to overvoltage, and a low-pass filter for suppressing harmonics produced from the high-pass filter.

Abstract: A system for identifying radio-frequency identification (RFID) devices is described. In one embodiment, RFID devices include an antenna and metallic pattern printed on a substrate. A probing platform is used to radiate the RFID devices with an electromagnetic signal (e.g., radio-frequency signal, microwave signal, etc.). Each RFID device generates a quantifiable backscatter depending on the unique impedance of the passive RFID device in response to the electromagnetic signal. The backscatter is employed to uniquely identify the passive RFID device's impendence with respect to the probing platform uniquely characterized at predetermined frequencies of the electromagnetic signal.

Abstract: Disclosed are a mobile station unit which can obtain azimuth information with a simple construction and a radio communication system including the mobile terminal unit. According to the present invention, in a terminal station, an arrival direction obtaining section 203 obtains an arrival direction of a received azimuth designation signal from a reference station or another terminal station using an arithmetic operation or the like. A transmitting direction forming section 204 determines the direction opposite to the arrival direction obtained by the arrival direction obtaining section 203 as a transmitting direction. A reference azimuth detecting section 207 detects the transmitting direction determined by the transmitting direction forming section 204 as a reference azimuth. An azimuth designation signal generating section 205 generates an azimuth designation signal so as to radiate radio waves having directivity in the transmitting direction determined by the transmitting direction forming section 204.

Abstract: A wireless communication system includes a portable, typically hand-held transmitter which includes RF absorbing material and/or one or more dissipative parasitic antennas for reducing RF fields in close proximity to the operator to such an extent as to substantially preempt the effect of the operator presence, specifically the operator's hand, in field operation. As a result, the RF absorbing material and/or one or more dissipative parasitic antennas reduces the proportionate effect upon the RF radiation level caused by the operator's hand or other body part. The RF absorbing material may comprise a layer of such material upon a surface of a ground plane within a housing of the transmitter, and/or on an interior surface of the housing, and/or on an exterior surface of the housing. The dissipative parasitic antenna may comprise a printed antenna and resistive load integrated on the transmitter's printed circuit board or elsewhere in or on the housing.

Abstract: A system and method of encoding and transmitting data includes a data receiver/carrier transmitter which transmits a sinusoidal carrier signal to a data source/carrier receiver. The data source encodes at least one transmission channel during a corresponding period. The carrier is reflected back to the data receiver with an amplitude proportional to the degree of applied impedance such that the total amplitude of the transmitted and reflected cycles represents encoded data, yet the underlying carrier signal remains an un-modulated sinusoid.

Abstract: A signal converter capable of stabling converting input signals in an extended operation margin, a radio frequency identification (RFID) tag having the signal converter and a method of driving a RFID tag. The signal converter includes a first signal converter which converts an incoming analog signal into a power signal, a second signal converter which converts the analog signal into a first demodulation signal, a signal amplifier which amplifies the first demodulation signal to output a second demodulation signal such that a value of an externally-supplied reference signal is included in a peak-to-peak range of the second demodulation signal, and a logic signal generator which converts the second demodulation signal into a digital signal in response to the power signal. Because the second demodulation signal has an extended operation margin in converting analog signal into digital signal, stable conversion of the input signals is possible, and rate of recognizing RFID tag is improved.

Abstract: A wireless communication system includes an interrogator including a housing including circuitry configured to generate a forward link communication signal; communication circuitry configured to communicate the forward link communication signal; and a communication station remotely located with respect to the housing and configured to receive the forward link communication signal from the communication circuitry and to radiate a forward link wireless signal corresponding to the forward link communication signal; and at least one remote communication device configured to receive the forward link wireless signal.

Abstract: The present invention comprises a docking system for connecting a portable communication device to a further signal transmission line. The docking system may be arranged within a workstation such as a desk or a tray. The system may also envelope a room in a building or be located in a vehicle, to control and restrict the radiative emission from the communication device and to direct such radiation to a further remote antenna and or signal distribution system connected to the transmission line.

Abstract: A data communication apparatus includes an antenna, an analog front-end circuit, and a controller. The analog front-end circuit is connected between the antenna and the controller and includes first and second modulators, a driver, a demodulator, and an input switch. The first modulator modulates data to be transmitted to a read-write device as a response to a request from said read-write device and sends the modulated data to the antenna. The second modulation circuit modulates data to be transmitted to other ID tags. The driver amplifies an output from the second modulator to drive the antenna. The demodulator demodulates data sent from the other ID tags and ID-tag read-write devices. The input switch selectively inputs the data to the first or second modulator. This abstract is provided to comply with rules requiring an abstract, and it is submitted with the intention that it will not be used to interpret or limit the scope or meaning of the claims.

Abstract: An AM-FM hybrid signal is created which may be used to communicate simultaneously with both RFID tags that receive AM signals and wireless devices that receive FM or PM signals. The AM-FM hybrid signal may be fed back into the system's receiver at the local oscillator in order to recover the RFID tag's FM response, thus enabling simultaneous reception and decoding of both RFID tag FM response and FM wireless device response.

Abstract: A modulator circuit comprises a negative impedance amplifier which is operable such that a signal applied to the amplifier is reflected and amplified. Switching means are provided for switching the impedance of the amplifier between two reflecting states such that the reflected and amplified signal is phase modulated. The impedances of the negative impedance amplifier are selected such that the phase of the reflected and amplified signal in the first reflecting state differs substantially from the phase of the reflected and amplified signal in a second reflecting state. For example, the phase switches by substantially 180 degrees. Preferably the impedances of the negative impedance amplifier in the two reflecting states are selected such that the reflection gain of the amplifier in the two reflecting states is substantially the same such that the reflected and amplified signal is a binary phase shift keyed.

Abstract: An apparatus and method is provided to shield contactless portable electronic consumer devices such as radio frequency identification devices (RFID), tokens, mini-cards, key fobs, cellular phones, smartcards, etc. from wireless interrogation. In one embodiment, a contactless portable consumer device which includes a first antenna is shielded from unauthorized wireless interrogation with a radio frequency (RF) shield. The RF shield includes electrically conductive, non-ferromagnetic material and is configured to prevent unauthorized data transfer between a second antenna external to the portable consumer device and the first antenna.

Abstract: Systems, software, devices, and methods are described for an RFID reader system to communicate with RFID tags. RF energy encountered in conjunction with using a selected channel is detected. The RF energy can be a signal from another RFID reader. The detected signal is used to adjust a waveform shaping parameter. RF waves can be transmitted from the reader to the RFID tags and RF waves can be backscattered from the RFID tags. At least some of the RF waves transmitted to or backscattered from the RFID tags have a waveform with a shape according to the adjusted waveform shaping parameter.

Abstract: System and method for creating a time alignment analog notch. An embodiment includes a digital power amplifier coupled to an enable signal line and to a digital control bits bus, and a matching network coupled to the digital power amplifier. The matching network to provide impedance matching and the digital power amplifier to produce a current based on a value on the digital control bits bus. The digital power amplifier comprises a selection circuit and a plurality of transistors. The transistors, controlled by outputs of the selection circuit, provide a current based on the value on the digital control bits bus. The adjustment of a delay between a signal on the enable signal line and the values on the digital control bits bus creates an analog notch at about Fs/2, where Fs is a sampling frequency of a sigma-delta modulator used to modulate data provided to the digital power amplifier.

Abstract: A novel single wideband retroreflector is disclosed that eliminates the need for a local oscillator and a local transmitter. The wideband retroreflector of the present invention comprises an antenna, a circulator, and a mixer. An externally produced continuous wave radio wave transmission within the microwave-millimeter wave frequency band is modulated with a wideband signal with a minimum operating instantaneous bandwidth of 5 KHz-500 MHz and retransmitted as a modulated waveform by the antenna.

Abstract: An object of the invention is to obtain a high-speed and high-accuracy radio-wave propagation characteristic forecasting system in combination with the launching method by correctly estimating a diffraction phenomenon when a ray passes the vicinity of an edge of a structure. To estimate a radio-wave propagation characteristic in accordance with the ray launching method, when a ray passes the vicinity of an edge of a structure, a diffracted wave is generated at the edge if the distance between the edge and the ray is smaller than the radius of a ray spread. Thereby, it is easy to combine the ray launching method with the conventional ray launching method and it is possible to estimate a high-speed high-accuracy radio-wave propagation characteristic also considering a ray diffracted wave.

Abstract: The invention relates to a method of rendering telecommunication devices ineffective, by creating a substantially radio frequency radiation-free environment by providing an interference generating pattern (IGP) adjacent to the environment in a position between the environment and a source of radio frequency radiation signals so as to substantially reduce, or interfere with such signals thus preventing typical operation of the wireless telecommunications devices. The IGP is generally one that is non-conductive and is or includes a diffraction grating. The IGP is positioned adjacent the environment between the environment and a source of radio frequency radiation signals. Preferably, the IGP is provided as a support member configured in the shape of a diffraction grating, and includes a paint or coating of a non-conductive material having a high dielectric constant thereon.

Abstract: The present invention is a method and device for reducing exposure to undesirable electromagnetic radiation. The device uses a target antenna to capture certain radiation from an active emission source, such as a cell phone when it is transmitting or a microwave oven when it is cooking. The target antenna is tuned to the frequencies of the undesirable radiation emitted from the emission source. The device converts the captured radiation into an electric current, and dissipates the collected current by spending it to operate a thermal, mechanical, or electrical device. In the preferred embodiment, the current is directed to an LED display that lights up when supplied with the current, serving a secondary purpose of showing the user that the device is working.

Abstract: The present invention is a carrier state judging device having a multiplexing unit multiplexing carrier signals to be inputted in parallel, output control units inputted to the multiplexing unit and performing ON/OFF control of outputs of the carrier signals inputted to the output control units themselves according to predetermined ON/OFF setting values, frequency shift units and giving predetermined frequency shift quantities to the carrier signals inputted to the frequency shift units themselves, a detection unit detecting as to whether or not there is the carrier signal flowing through on each carrier signal transmission path, and a determining unit determining a state of the carrier signals multiplexed by the multiplexing unit on the basis of the ON/OFF setting value with respect to each of the output control units, the frequency shift quantity with respect to each of the frequency shift units and a result of the detection by the detection unit.

Abstract: An interrogator identifies an interrogated object using a light transceiver and a dynamic optical tag associated with the interrogated object. The dynamic optical tag receives an output light beam from the light transceiver and controllably reflects the light beam back to the light transceiver as an input light beam. The dynamic optical tag includes a controllable light reflector that is controllable between a reflective state and a non-reflective state and having a modulation signal input, and a controller that provides the modulation signal input to the controllable light reflector. In operation, the interrogator transmits an interrogation light beam from the light transceiver to the dynamic optical tag, the dynamic optical tag reflects a modulated interrogation light beam back to the light transceiver as the input light beam, and the light transceiver receives and analyzes the input light beam to determine an identity of the dynamic optical tag and the interrogated object.

Abstract: A modulated reflectance well telemetry apparatus having an electrically conductive pipe extending from above a surface to a point below the surface inside a casing. An electrical conductor is located at a position a distance from the electrically conductive pipe and extending from above the surface to a point below the surface. Modulated reflectance apparatus is located below the surface for modulating well data into a RF carrier transmitted from the surface and reflecting the modulated carrier back to the surface. A RF transceiver is located at the surface and is connected between the electrically conductive pipe and the electrical conductor for transmitting a RF signal that is confined between the electrically conductive well pipe and the electrical conductor to the modulated reflectance apparatus, and for receiving reflected data on the well from the modulated reflectance apparatus.

Abstract: Disclosed are a communication mediation apparatus and a method for controlling the same for performing communication mediation while reducing a communication miss rate caused by collision of data. A performance of a moving object recognition system unavoidably varies with the number of moving objects to be recognized by a controller, and with a mediation parameter for use in a communication mediation algorithm. The apparatus/method dynamically varies a mediation parameter according to a difference in numbers of many moving objects, thus reducing a communication miss rate regardless of the difference (i.e., traffic volume variation) in numbers of the moving objects.

Abstract: A high frequency device includes a transmission/reception amplifier 13 that amplifies and outputs an input signal, and a transmission/reception switch 2 that gang switches internally so that during transmission an input of the transmission/reception amplifier 13 is connected to an up mixer and an output of the transmission/reception amplifier 13 is connected to an antenna unit 5, and so that during reception the output of the transmission/reception amplifier 13 is connected to a down mixer and the input of the transmission/reception amplifier 13 is connected to the antenna unit 5.

Abstract: In a wireless communication system including at least one Interrogator and a plurality of Tags, the Interrogator transmits a main carrier signal, and each Tag transmits a reflected signal to the Interrogator in response to reception of the main carrier signal. The Tag Includes a receiving/reflecting system that receives the main carrier transmitted by the Interrogator and transmits the reflected signal to the Interrogator and a modulated subcarrier signal hopping system. The modulated subcarrier signal hopping system is provided with a frequency hopping system that applies frequency hopping to a subcarrier signal, and a subcarrier signal modulating system that modulates the subcarrier signal with a predetermined information signal.

Abstract: A receiving device in which the shielding performance is improved to solve a pulling problem in a receiving device of a direct conversion system is provided.

Abstract: A self-service terminal (10 or 200 or 300) comprises a plurality of intercommunicating modules (114 to 126, or 214 to 226, or 314 to 326). Each module includes a transceiver for wireless communication with another module. In one embodiment, the wireless communication is directed between two modules so that only those two modules can participate in the communication. In another embodiment, the wireless communication may be implemented by a transceiver broadcasting information to all of the modules.

Abstract: An optical tag, having a photo-detector, a controller, a piezoelectric translator, a battery and a retro-reflective tape. The photo-detector is responsive to an optical energy at a predetermined wavelength, and the controller is connected to the output of the photo-detector. The piezoelectric translator connected to controller is also connected to the battery when the photo-detector responds to the optical energy. The retro-reflective tape is directly mounted on the piezoelectric translator. When the connection between the piezoelectric translator and the battery is established, a pulse is generated and applied to the retro-reflective tape. Therefore, the optical energy incident on the retro-reflective tape is modulated by the pulse and retro-reflected by the retro-reflective tape.

Abstract: An RF transceiver module for wireless communication devices includes a multi-layered substrate, an RF transceiver IC mounted on the multi-layered substrate for receiving and transmitting voice or data signals, at least one band selection filter mounted on the multi-layered substrate for filtering received RF signals, an antenna switch integrated in the multi-layered substrate which can be switched to transmit RF signals generated by the power amplifiers to the external antenna or to receive RF signals from an external antenna to the RF transceiver IC through the band selection filter, a plurality of passive devices embedded in the multi-layered substrate, and wiring embedded in the multi-layered substrate for electrically connecting the passive devices, the RF transceiver IC, and the band selection filter.

Abstract: A radio frequency (RF) amplifier system includes an RF power amplifier having an input and an output, and a typical gain of 1000 or more between the input and the output. An adaptive feedback channel is coupled between the input and the output of the RF power amplifier. The adaptive feedback channel receives as inputs audio signals for modulation of the input of the RF power amplifier, a frequency command word indicative of a desired frequency and phase of the RF amplifier system, and a control word indicative of a desired power level of the output of the RF power amplifier and of a mode of operation of the RF amplifier system. In response to the inputs, the adaptive feedback channel provides as an output a degenerative feedback signal to the input of the RF power amplifier.

Abstract: The present invention selects a space-time encoding mode to use when transmitting with spatial diversity based on the receive diversity associated with a receiver device and the quality of the transmission channels based on information fed back from the receiver device. The selectable space-time encoding modes are preferably space-time transmit diversity encoding and a version of BLAST-type encoding. Further, modulation modes, error encoding rates, or a combination thereof, may also be based on the quality of the transmission channels and the available diversity of the receiver device.

Abstract: The invention concerns a terminal generating a high-frequency electromagnetic field by means of an oscillating circuit, adapted to co-operate with at least a transponder when the latter enters said field, comprising means (37) for regulating the phase of the signal in the oscillating circuit with respect to a reference value, and means for detecting, on the basis of a current measurement in the oscillating circuit and a voltage measurement at the terminals of a capacitive element (31) of said oscillating circuit, an electric signature of a transponder.

Abstract: Apparatus, and an associated method, for forming a space-generated multilevel coding scheme for a radio communication system. Two or more modulators are positioned at a sending station. The modulators modulate, pursuant to separate modulation schemes, data that is to be communicated by the sending station. The modulation schemes are lower-order modulation schemes. The modulated data is communicated to a receiving station, and detected at a least single receive antenna. The modulated symbols formed by the separate modulators are superimposed theretogether and form symbols of a higher order modulation scheme.

Abstract: Disclosed are a mobile station unit which can obtain azimuth information with a simple construction and a radio communication system including the mobile terminal unit. According to the present invention, in a terminal station, an arrival direction obtaining section 203 obtains an arrival direction of a received azimuth designation signal from a reference station or another terminal station using an arithmetic operation or the like. A transmitting direction forming section 204 determines the direction opposite to the arrival direction obtained by the arrival direction obtaining section 203 as a transmitting direction. A reference azimuth detecting section 207 detects the transmitting direction determined by the transmitting direction forming section 204 as a reference azimuth. An azimuth designation signal generating section 205 generates an azimuth designation signal so as to radiate radio waves having directivity in the transmitting direction determined by the transmitting direction forming section 204.

Abstract: A transponder (1) comprising an antenna (4), a demodulator (5) and a signal processing circuit (6) which converts a modulated signal received via the antenna (4) into a signal suitable for processing in the demodulator (5). The signal processing circuit (6) comprises an amplifier (7) with a predefined amplification factor and a closed loop control circuit (8) serving to maintain the voltage swing of the processed signal applied at the input of the demodulator (5) substantially constant. In a preferred embodiment the closed loop control circuit comprises a capacitor which is continually discharged and differingly charged as a function of the strength of the output signal of the amplifier of the signal processing circuit, the voltage resulting across the capacitor controlling a controllable resistor connected in parallel to the input of the signal processing circuit and forming with a coupling capacitor a voltage divider.

Abstract: A signal separating system 1 comprises a frequency conversion element 3, a dynamic filter component 4 with associated coherent stop slot and non-coherent passband, optionally a signal wave enhancer 7 with bypass, and a frequency reconversion element 8. In operation of the system, mixed incoming signals 12 (CW or pulse signals) having known interference and unknown emission components can be effectively separated, permitting a virtually instantaneous separation of the known interference from the unknown emissions and permitting an unobscured monitoring and/or characterization of the extracted unknown emissions 21, if desired. The arrangement bears definite advantage over known arrangements and retains utility for various frequency/agile or multiple or non-agile unknown signal applications.

Abstract: A translation loop signal upconverter is disclosed. Embodiments of the invention minimize nth order harmonics and spurious tones in the radio frequency output spectrum of a portable transceiver. In one embodiment, the invention is a signal upconverter, comprising a modulator configured to develop a modulated intermediate frequency (IF) signal at a fundamental frequency, the modulated IF signal also including a plurality of nth order components, a synchronous oscillator configured to receive the modulated IF signal, the synchronous oscillator also configured to operate at the fundamental frequency of the modulated IF signal, thereby providing an IF signal substantially free of the nth order components, and a translation loop having a phase locked loop, the translation loop configured to receive the IF signal output of the synchronous oscillator, and supply a radio frequency (RF) output signal to a power amplifier.

Abstract: A rotary non-contact connector and a non-rotary non-contact connector enable data transmission in a non-contact mode by radio transmitters-receivers by combining rotary transformers or stationary transformers and radio transmitters-receivers, and providing power systems with buffer functions by a storage means to receive supplied electric power. Each of the rotary non-contact connector and the non-rotary non-contact connector has first and second radio transmitters-receivers provided between a rotor and an annular stator of a rotary transformer and between first and second stationary members of a stationary transformer to permit two-way radio data communication in a non-contact mode. Furthermore, storage means are provided to implement a buffering function for a power system.

Abstract: Disclosed is an antenna apparatus of a relay system. The relay system includes a link antenna apparatus transmitting and receiving electric signals to and from a base station, a coverage antenna apparatus transmitting and receiving electric signals to and from subscriber terminals, and a repeater system connected between the link antenna apparatus and the coverage antenna apparatus to bidirectionally amplify electric signals therebetween. The antenna apparatus is one of the link antenna apparatus and the coverage antenna apparatus and includes: at least one radiation element; and a power feeder controlling electric field intensity and phases of signals transmitted from or received by the radiation element, thereby offsetting beam patterns having an influence on antenna isolation of the antenna apparatus.

Abstract: A cellular communications system includes a base station and at least one mobile station communicating therewith. The base station may include a plurality of antennas and a modulator for providing a transmit signal for each antenna. The modulator may estimate a weighting factor for each transmit signal based upon considering each transmit signal as having an unknown and arbitrary fading factor associated therewith and based upon considering the unknown and arbitrary fading factors to have a predetermined cross-correlation function.

Abstract: An amplifier circuit for amplifying an input signal to generate an amplifier output signal incorporates a cascaded series of reflection amplifiers arranged along a signal path and operative to amplify signals propagating in a forward direction along the signal path. The circuit is operative to counteract signal propagation in a reverse direction along the signal path, thereby hindering spontaneous oscillation from arising within the circuit. Incorporation of reflection amplifiers into the circuit enables it to provide high gain, for example 50 dB, while consuming low currents, for example, tens of microamperes. The circuit is especially suitable for use at intermediate frequencies in radio receivers such as mobile telephones.

Abstract: The invention relates to a method of rendering telecommunication devices ineffective by creating a substantially radio frequency radiation-free environment. An interference generating pattern is provided adjacent the environment in a position between the environment and a source of radio frequency radiation signals so as to substantially reduce, or interfere with such signals thus preventing typical operation of the telecommunications devices therein. Preferably, the interference generating pattern is provided by applying silicon carbide as a coating or as part of a building material onto a structure to reduce attenuation by at least 20 to 50 decibels. Other aspects of the invention include the building materials that have the interference generating pattern associated therewith and the substantially radio frequency radiation-free environments that are created according to the methods disclosed herein.

Abstract: The portable telephone capable of more effectively reducing the electromagnetic energy to be radiated therefrom and absorbed by the human body during its use is provided.

Abstract: The present invention includes an apparatus and method for telemetry communication with oil-well monitoring and recording instruments located in the vicinity of the bottom of gas or oil recovery pipes. Such instruments are currently monitored using electrical cabling that is inserted into the pipes; cabling has a short life in this environment, and requires periodic replacement with the concomitant, costly shutdown of the well. Modulated reflectance, a wireless communication method that does not require signal transmission power from the telemetry package will provide a long-lived and reliable way to monitor down-hole conditions. Normal wireless technology is not practical since batteries and capacitors have to frequently be replaced or recharged, again with the well being removed from service. RF energy generated above ground can also be received, converted and stored down-hole without the use of wires, for actuating down-hole valves, as one example.

Abstract: Two fixed-phase-related signals of arbitrary (unequal) magnitude are combined without incurring combining loss by use of a signal reflection technique wherein the higher magnitude signal is phase-synchronously reinforced along its path through the combining system. In a specific embodiment, two signal sources are fed as equal phase signals through respective counter-rotating circulators to a four-port first combiner, wherein the first output port of the combiner is provided with a one-eighth wavelength phase delay to a termination and the second output port is directly terminated, so that reflected signals as seen at both input ports return exactly in phase and of equal magnitude to one another. Thereupon the reflected signals are directed by the respective circulators as phase-synchronized signals to a second combiner which combines the phase synchronized signals into a common output signal. The resultant output is the sum of the inputs irrespective of relative magnitudes of the inputs.

Abstract: An amplifier circuit for amplifying an input signal to generate an amplifier output signal incorporates a cascaded series of reflection amplifiers arranged along a signal path and operative to amplify signals propagating in a forward direction along the signal path. The circuit is operative to counteract signal propagation in a reverse direction along the signal path, thereby hindering spontaneous oscillation from arising within the circuit. Incorporation of reflection amplifiers into the circuit enables it to provide high gain, for example 50 dB, while consuming low currents, for example, tens of microamperes. The circuit is especially suitable for use at intermediate frequencies in radio receivers such as mobile telephones.