Abstract: In an apparatus for measuring absorbed power including an electromagnetic field probe 1 fixedly mounted within a head simulation phantom 2 which simulates the configuration and the electromagnetic characteristics of a head of a human body, and wherein the strength of an electric field or a magnetic field of a radio wave externally irradiated upon the head simulation phantom 2 is measured by the electromagnetic field probe 1, and the power of the radio wave absorbed by the head is estimated on the basis of measured values, the head simulation phantom 2 comprises a solid dielectric 10? which simulates the configuration and the electromagnetic characteristics of a head of a human body or a liquid dielectric 10 which simulates the electromagnetic characteristics of a head of a human body and which is filled in an enclosed vessel 10 which simulates the configuration of a head of a human body. The volume of the solid dielectric 10? or the volume of the enclosed vessel 11 is equal to or less than 5×105 mm3.

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: The invention relates to a high sensitivity receiver installed outdoors which may be used in a base station of a mobile communication system, for example. A received radio frequency signal is converted into a signal in a desired frequency band by a reception bandpass filter RXF3, is subject to a low noise amplification to a desired level by a low noise reception amplifier LNA4, and the amplified signal is converted into an optical signal by a laser diode LD5. RXF3, LNA4 and LD5 are confined in a heat shielding box. LD5 is cooled by cooling means to the order of critical temperature where RXF3, for example, assumes a superconducting state, whereby the dynamic range is increased and stabilized.

Abstract: In an apparatus for measuring absorbed power including an electromagnetic field probe 1 fixedly mounted within a head simulation phantom 2 which simulates the configuration and the electromagnetic characteristics of a head of a human body, and wherein the strength of an electric field or a magnetic field of a radio wave externally irradiated upon the head simulation phantom 2 is measured by the electromagnetic field probe 1, and the power of the radio wave absorbed by the head is estimated on the basis of measured values, the head simulation phantom 2 comprises a solid dielectric 10? which simulates the configuration and the electromagnetic characteristics of a head of a human body or a liquid dielectric 10 which simulates the electromagnetic characteristics of a head of a human body and which is filled in an enclosed vessel 10 which simulates the configuration of a head of a human body. The volume of the solid dielectric 10? or the volume of the enclosed vessel 11 is equal to or less than 5×105 mm3.

Abstract: In an apparatus for measuring absorbed power including an electromagnetic field probe 1 fixedly mounted within a head simulation phantom 2 which simulates the configuration and the electromagnetic characteristics of a head of a human body, and wherein the strength of an electric field or a magnetic field of a radio wave externally irradiated upon the head simulation phantom 2 is measured by the electromagnetic field probe 1, and the power of the radio wave absorbed by the head is estimated on the basis of measured values, the head simulation phantom 2 comprises a solid dielectric 10? which simulates the configuration and the electromagnetic characteristics of a head of a human body or a liquid dielectric 10 which simulates the electromagnetic characteristics of a head of a human body and which is filled in an enclosed vessel 10 which simulates the configuration of a head of a human body. The volume of the solid dielectric 10? or the volume of the enclosed vessel 11 is equal to or less than 5×105 mm3.

Abstract: A system for measuring the position of an in vivo radio device is disclosed. The system comprises the in vivo radio device administered into a living organism, a plurality of ex vivo radio devices disposed outside of the living organism, and a position measuring device. The in vivo radio device includes a transmitter for transmitting a vital information signal or a position measuring signal. Each of the ex vivo radio devices includes a receiver for receiving the vital information signal or the position measuring signal. The position measuring device includes a position measuring unit for measuring the position of the in vivo radio device based on receiving characteristics of the vital information signal or the position measuring signal received by the ex vivo radio devices.

Abstract: A divider/combiner unit combines RF signals, then converts the combined signal into an optical signal and sends it over an optical fiber. N radio access units each convert the optical signal received from the optical fiber into an RF signal and transmits it from an antenna, and each radio access unit converts an RF signal received by the antenna into an optical signal and sends it over an optical fiber to the divider/combiner unit. The divider/combiner unit converts the received optical signal into RF signals and outputs them. This system is operated as plurality of communication systems in common to them in correspondence to a plurality of input/output terminals of the divider/combiner unit.

Abstract: A system for measuring the position of an in vivo radio device is disclosed. The system comprises the in vivo radio device administered into a living organism, a plurality of ex vivo radio devices disposed outside of the living organism, and a position measuring device. The in vivo radio device includes a transmitter for transmitting a vital information signal or a position measuring signal. Each of the ex vivo radio devices includes a receiver for receiving the vital information signal or the position measuring signal. The position measuring device includes a position measuring unit for measuring the position of the in vivo radio device based on receiving characteristics of the vital information signal or the position measuring signal received by the ex vivo radio devices.

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: The invention relates to a high sensitivity receiver installed outdoors which may be used in a base station of a mobile communication system, for example. A received radio frequency signal is converted into a signal in a desired frequency band by a reception bandpass filter RXF3, is subject to a low noise amplification to a desired level by a low noise reception amplifier LNA4, and the amplified signal is converted into an optical signal by a laser diode LD5. RXF3, LNA4 and LD5 are confined in a heat shielding box. LD5 is cooled by cooling means to the order of critical temperature where RXF3, for example, assumes a superconducting state, whereby the dynamic range is increased and stabilized.

Abstract: In an apparatus for measuring absorbed power including an electromagnetic field probe 1 fixedly mounted within a head simulation phantom 2 which simulates the configuration and the electromagnetic characteristics of a head of a human body, and wherein the strength of an electric field or a magnetic field of a radio wave externally irradiated upon the head simulation phantom 2 is measured by the electromagnetic field probe 1, and the power of the radio wave absorbed by the head is estimated on the basis of measured values, the head simulation phantom 2 comprises a solid dielectric 10′ which simulates the configuration and the electromagnetic characteristics of a head of a human body or a liquid dielectric 10 which simulates the electromagnetic characteristics of a head of a human body and which is filled in an enclosed vessel 10 which simulates the configuration of a head of a human body.

Abstract: A divider/combiner unit combines RF signals, then converts the combined signal into an optical signal and sends it over an optical fiber. N radio access units each convert the optical signal received from the optical fiber into an RF signal and transmits it from an antenna, and each radio access unit converts an RF signal received by the antenna into an optical signal and sends it over an optical fiber to the divider/combiner unit. The divider/combiner unit converts the received optical signal into RF signals and outputs them. This system is operated as plurality of communication systems in common to them in correspondence to a plurality of input/output terminals of the divider/combiner unit.

Abstract: In a fiber optics transmission system in which a plurality of access units are cascade-connected via up-link and down-link optical fiber lines and connected to a base unit, the base unit has a beat noise detector and a noise information generator and, upon detection of beat noise, noise information is sent to each access unit over the optical fiber lines. Each access unit has a random signal generator for generating a random value in response to the noise information and a wavelength control circuit for randomly selecting and controlling the oscillation wavelength of a laser diode, and each access unit repeats random wavelength selection until the noise information is reduced.

Abstract: The frequencies of input modulated signals fed via ports 11.sub.1 to 11.sub.n are converted by frequency converting parts 12.sub.1 to 12.sub.n to different bands, and the converted outputs are applied to power combining part 24 decides if 16 via variable attenuators 21.sub.1 to 21.sub.n, respectively, and provided therefrom as a multiplexed output a portion of which is branched. The envelope power level L is detected by level detecting part 23. Control with the detected level L exceeds a level L.sub.s that is k times the average power of the multiplexed signal k being about 4 to 5, and controls the attenuators 21.sub.1 to 21.sub.n to attenuate the average power of the modulated signal by k/n-fold or less for about 1/.DELTA.F.sub.0 (sec), where (.DELTA.F.sub.0 ?Hz! is the frequency bandwidth of the multiplexed signal.

Abstract: Band-pass filters BPF1, BPF2, and BPF3 correspond to the reception frequency band for FDD, the transmission band for FDD, and the band for TDD, respectively. An antenna A1 is used in common for transmission and reception in the FDD and TDD systems. Another antenna A2 is used for diversity reception in the FDD system. A controller 20 controls switches SW1 through SW4. When the FDD system is selected, the reception signal is sent from the antenna A1 or A2 through the filter BPF1 to a reception amplifier RA, and the transmission signal is sent from the transmission amplifier TA through the filter BPF2 to the antenna A1. When the TDD system is selected, the reception signal is sent from the antenna A1 through the filter BPF3 to the reception amplifier RA, and the transmission signal is sent from the transmission amplifier TA through the filter BPF3 to the antenna A1.

Abstract: A modulus counter counts first clock pulses to modulus M and outputs the count value as an m-bit reference signal, M being an integer. A latch circuit samples and holds the reference signal in response to a trigger signal generated by a trigger signal generator in synchronism with an input signal. A high-speed counter is supplied with second clock pulses of a frequency higher than that of the first clock pulses and starts counting the second clock pulses in response to the trigger signal and stops the counting in response to a first one of the first clock pulses immediately thereafter. A data processor converts the n-bit count value of the high-speed counter to n-bit data corresponding to a phase fraction of a phase quantization step in the latch, combines the n-bit data as low-order bits with m-bit data from the latch and outputs the combined data as phase difference data.

Abstract: In radio communication equipment for use in a mobile station, provision is made for selectively applying either one of the oscillation outputs of first and second local oscillators to a transmitting part and a receiving part by first and second RF switches, respectively. In a traffic channel hand-off system for a mobile communication system in which each time the mobile station moves from a certain zone to another, its traffic channel is switched to another traffic channel of a different frequency, a control part responds to a traffic channel assigning signal from the current base station to allot an idle one of the local oscillators to the assigned channel, set the allotted local oscillator to an oscillation frequency corresponding to the assigned channel, and control the second RF switch, in an idle time of the receiving part in the current communication, to set the receiving part to the assigned channel for receiving a down link hand-off preparatory signal from a new base station.

Abstract: A frequency division scheme which offsets for a phase lag produced on initial power-on is described. A division ratio of a programmable counter is initially set at a first division ratio at the time of releasing the programmable counter from its reset state. When the first division cycle is complete, the division ratio is reset to its steady state value. Thus, a delay equivalent to the phase lag is produced. A frequency synthesizer is also proposed where the division ratio is set, and a phase difference is detected. Reset signals are continually set while the phase difference is changed. This cycle is continued until the phase difference is reduced to one cycle of the input signals or less.

Abstract: In a phase locked loop frequency synthesizer, the frequency of a VCO is switched by changing the division ratio of a variable ratio frequency divider in the feedback path of the loop. At the time of switching, a prepositioning voltage is applied to the VCO to realize fast frequency switching. To correct for nonlinear response of the VCO, the prepositioning voltage is adjusted according to information received from a voltage measuring circuit connected to the VCO control circuit.