Abstract: An RF envelope detection circuit that operations at low currents, high sensitivity, and high dynamic range. The circuit receives an AC signal at its input terminal and applies a signal on its output terminal that is a function of the envelope magnitude of the AC signal. To do so, a current source provides a current with an AC signal being superimposed thereon. A rectification circuit rectifies the AC component of this current. A voltage amplifier then amplifies the voltage for providing on the output terminal of the detection circuit. A current sink draws a current from the output terminal that has approximately the same magnitude as the current provided by the current source. A capacitor is coupled to the output terminal of the rectifier so as to store excess charge provided by the rectifier that is in excess of the magnitude of the current provided by the current source.

Abstract: In a portable telephone, a display device, a telephone receiver, a ten-numeral entry key, a telephone transmitter, and the like are mounted on surface sides of a first housing (1) and a second housing (2), which are located on inner sides thereof when the first housing and the second housing are closed, both the first housing and the second housing being hinged to each other via a hinge portion in a freely openable/closable manner; and a speaker for producing at least a telephone call-receiving sound is provided on the surface side of any one of the first housing, the second housing, and the hinge portion. Also, a sound projection portion (12) for projecting the telephone call-receiving sound produced from the speaker is formed in a side of the portion where the speaker is provided even under such a condition that the first housing and the second housing are closed.

Abstract: A personal communication system has first and second portable communication devices, each device including a display, a wireless transceiver, a memory having a plurality of stored audio files, a means to select one of the audio files, the audio file selection means being operable to permit a user to select one of the audio files, and an audio speaker. The wireless transceiver of the first device is operable to transmit a signal identifying an audio file selected by the user and the wireless transceiver of the second device is operable to receive the signal, and, upon receipt of the signal, to play the selected audio file on the audio speaker of the second device. The memory includes one or more attributes for each stored audio file, the attributes comprising a sequence attribute, a message type attribute or a target gender attribute.

Abstract: An earphone antenna includes an audio signal transmission path formed by connecting a first shield wire of a coaxial cable to a ground, connecting a central conductor of the coaxial cable to a pair of first signal lines of an earphone cable via a capacitor which exhibits high impedance in a frequency range of audio signals and low impedance in a frequency range of high frequency signals, and connecting a second signal line and a grounding wire, respectively, to the pair of first signal lines via a high frequency choke which exhibits low impedance in the frequency range of audio signals and high impedance in the frequency range of high frequency signals. Connecting the second shield wire to the ground causes formation of a sleeve antenna by the earphone cable and the second shield wire.

Abstract: A radio communication terminal disposed in close proximity to or built in electronic equipment is provided with a receiver connected to a receiving antenna and an interference canceller for removing from a received signal a radiated noise component from the electronic equipment received by the receiving antenna. The interference canceller includes a radiated noise predictor which predicts the radiated noise component in the received signal based on the radiated noise from the electronic equipment and generates a pseudo interference signal accordingly, and an adder which cancels the radiated noise component in the received signal by the pseudo interference signal.

Abstract: A radio receiver having multiple AM/FM tuners. A first tuner and a second tuner may be connected with an antenna for generating a first and second composite audio output signal. A dual input digital signal processor may be connected with the first tuner and the second tuner. The first and second composite audio output signals are processed by the dual input digital signal processor to generate a first audio output signal and a second audio output signal. A first audio power amplifier may be connected with the dual input digital signal processor for receiving the first audio output signal and a second audio power amplifier may be connected with the dual input digital signal processor for receiving the second audio output signal.

Abstract: A radio transceiver includes circuitry that enables received RF signals to be down-converted to baseband frequencies and baseband signals to be up-converted to RF signals prior to transmission without requiring conversion to an intermediate frequency. The circuitry includes a temperature sensing module that produces accurate voltage level readings that may be mapped into corresponding temperature values. A processor, among other actions, adjusts gain level settings based upon detected temperature values. One aspect of the present invention further includes repetitively inverting voltage signals across a pair of semiconductor devices being used as temperature sensors to remove a common mode signal to produce an actual temperature-voltage curve. In one embodiment of the invention, the circuitry further includes a pair of amplifiers to facilitate setting a slope of the voltage-temperature curve.

Abstract: The radio network controller estimates respective attenuation ratios of radio signals received by a terminal from transmitters of an active set. It commands at least some of the transmitters of the active set to transmit to the terminal with respective powers such that the difference pi-pj between the respective transmission powers pi and pj of two transmitters i and j is substantially proportional to 1 L j - 1 L i , where Li and Lj designate the attenuation ratios estimated for the transmitters i and j, respectively.

Abstract: A high-frequency module includes a switching circuit having a phase-shift circuit. The phase-shift circuit matches only PCS/DCS reception signals so as to be passed therethrough by setting a control-voltage input terminal to a Low level when receiving PCS/DCS signals, and attenuates PCS/DCS transmission signals to the PCS/DCS reception circuit side by setting the control-voltage input terminal to a Hi level when transmitting PCS/DCS signals. Also, another phase-shift circuit, which further attenuates the PCS transmission signal when transmitting the PCS signal, is provided in the DCS Rx terminal side of the phase-shift circuit.

Abstract: An improved directional coupler that significantly reduces the signal degradation problems associated with distortion caused by circuit elements used to measure the transmitted power. In a selected embodiment, the directional coupler of the present invention comprises a plurality of active elements, such as capacitors, that have values selected to ensure that the distortion created by circuit elements used to measure forward transmitted power. In an embodiment of the invention, capacitors have values selected to minimize in-band distortion signals at the fundamental carrier frequency of the transmitted signal and also at the second and third harmonics of the fundamental carrier frequency.

Abstract: A handheld electronic device having a slidable display is provided. A display unit is slidably connected to a body unit at two (or more) sliding joints. A mechanical linkage constrains motion at all of the sliding joints to be substantially equal. In this manner, binding of the slidable display is avoided, since binding occurs as a result of unequal motion at sliding joints. In one embodiment, the linkage includes a gear-axle-gear assembly disposed in a recess in the body unit and constrained to rotate as a unit about the axis of the axle. The gears of this assembly are engaged with linear gear racks on the display unit.

Abstract: A Method and System for Optimizing Decibel Data Conversion. This invention provides an ability to convert linear signals into decibel units via digital logic circuitry. The resultant system can present information to users in real-time. This is made possible by performing an approximation function that is simple enough to be implemented directly in digital hardware, rather than through software executed by massive computing resources. An exemplary application for this technology is as a component of a surgical reactive electronic jamming system. This invention allows a surgical reactive jammer to determine precisely the correct jamming thresholds to apply in real-time. It allows signal surveillance equipment to survey the spectrum and display those results in dBm with far more efficiency than before. Finally, it enables a whole industry of communications related devices that need to do real time decibel conversion.

Abstract: A radio frequency output power control system for use in communication systems is disclosed. The power control system is used for a modulation scheme having a non-constant amplitude envelope and comprises a power amplifier having a power amplifier input for receiving an input signal with a non-constant amplitude envelope, a power control input for receiving a power control input, and a power amplifier output for providing an amplified output signal. The power control system also includes a track and hold circuit for tracking a measured reference power signal that is representative of a modulation of the input signal, and subtraction means for subtracting an output of the track and hold circuit from the measured reference power signal to provide a difference signal that is coupled to the power control input.

Abstract: A circuit arrangement for transmitting and receiving radio signals includes an amplification device with an output for transmitting signals, an input for receiving signals and a supply line, and an antenna for transmitting and receiving signals. The antenna is connected to the output of the amplification device. The output of the amplification device is an input for signals received via the antenna, and the supply line is an output for received signals that are converted to the supply line by the amplification device.

Abstract: A digital signal transceiver includes a frequency modulator for outputting a high-frequency signal frequency-modulated with a digital signal input thereto, a power amplifier, an antenna terminal, and an antenna switch. The antenna switch includes a first branch port for receiving a signal output from the power amplifier, a common port connected to the antenna terminal, said common port being connected to the first branch port in the transmitting mode, and a second branch port connected to the common port in the receiving mode. The transceiver further includes a filter having an input port thereof connected to the second branch port of the antenna switch, a high-frequency amplifier having an input port thereof connected to an output port of the filter, and a mixer for mixing a signal output from the high-frequency amplifier with the signal output from the frequency modulator.

Abstract: A method for the verification of anti-jamming in a communications system comprises several sensors or adaptive antennas, comprising at least the following steps: estimating the mean power ?;^y of the output of the communications system, estimating the respective power values Pu or P?u, of a station u, the antenna noise Pa or P?a, the thermal noise PT, or P?T, estimating at least one of the following ratios: J tot ? / ? S tot = ( ? p = 1 P ? P p ) ? / ? ( ? u = 1 U ? P u ) J tot ? / ? S u = ( ? p = 1 P ? P p ) ? / ? P u J u ? / ? S u = ( ? p = 1 P ? P pu ) ? / ? P u comparing at least one of the three ratios with a threshold value.

Abstract: Methods and apparatus are provided for RF switches (504, 612) integrated in a monolithic RF transceiver IC (500) and switched gain amplifier (600). Multi-gate n-channel enhancement mode FETs (50, 112, 114, Q1-3, Q4-6) are used with single gate FETs (150), resistors (Rb, Rg, Re, R1-R17) and capacitors (C1-C3) formed by the same manufacturing process. The multiple gates (68) of the FETs (50, 112, 114, Q1-3, Q4-6) are parallel coupled, spaced-apart and serially arranged between source (72) and drain (76). When used in pairs (112, 114) to form a switch (504) for a transceiver (500) each FET has its source (74) coupled to an antenna RF I/O port (116, 501) and drains coupled respectively to second and third RF I/O ports (118, 120; 507, 521) leading to the receiver side (530) or transmitter side (532) of the transceiver (500). The gates (136, 138) are coupled to control ports (122, 124; 503, 505; 606, 608).

Abstract: There is a need for an inexpensive, high-performance, fully-integrable, multi-standard transceiver, which suppresses spurious noise signals. The invention provides a topology that satisfies this need, using a first signal generator which produces an oscillator signal f1 and a second signal generator which produces a mono-tonal mixing signal ?2, where f1 is a multiple of the frequency of ?2; and a logic circuit for generating a multi-tonal mixing signal ?1, where ?1*?2 has significant power at the frequency of said local oscillator signal being emulated, neither of said cp1 nor said ?2 having significant power at the carrier frequency of said input signal x(t) or said LO signal being emulated.

Abstract: An Ultra Wide Band (UWB) transmitting and receiving device that includes a Digital Signal Processor (DSP) for implementing a DC offset cancellation algorithm, an adder for adding a baseband transmission signal from the transmitter and a calibration signal produced by the algorithm of the DSP, a modulator for modulating the signal from the adder, a transmitter amplifier for amplifying the modulated signal, a coupler for applying the output of the transmitter to the receiver, and a switch for selectively connecting the output of the coupler to the input of the receiver.

Abstract: The present invention discloses a method for RF output power control of a wireless communication device by switching the wireless communication device between different modes according to a state parameter corresponding to a received beacon. These modes include a normal power mode for outputting a normal RF output power and a reduced-power mode for outputting a reduced RF output power. The reduced RF output power is less than the normal RF output power.