Abstract: A cellular phone includes upper casing 2 having a front surface with LCD panel 21 disposed thereon, lower casing 3 having a front surface with key pad 22 disposed thereon, and an antenna, upper and lower casings 2, 3 being openably and closably coupled to each other. First control plate 10 for reflecting electromagnetic waves is disposed in upper casing 2, and second control panel 11 for reflecting electromagnetic waves is disposed in lower casing 3. First control plate 10 and second control plate 11 comprise separate members which are independent of each other. When the cellular phone is in an unfolded state in which the angle formed between the front surface of upper casing 2 and the front surface of the lower casing 3 is maximum, first control plate 10 and second control plate 11 have a maximum projected area on the surfaces of upper and lower casings 2, 3.

Abstract: The characteristics of an object are measured using an electrical characteristics measurement device in which a probe includes a signal terminal, a ground terminal, and a variable resistance element is connected via a coaxial cable to a measuring instrument. The calibration of the probe entails adjusting the resistance value of the variable resistance element, setting the impedance of the distal end vicinity of the probe essentially to zero, and establishing a match with the coaxial cable and measuring instrument. When the electrical characteristics of the object are measured, the resistance value of the variable resistance element is varied in accordance with the impedance created by the side of the circuit containing the measurement object as viewed from the contact between the object and the signal terminal and ground terminal, and the input impedance of the probe is set to a value that does not affect the operation of the object.

Abstract: A battery pack has a case for storing a battery can, and a metal plane made of a conductive material and connected to the battery can in high frequency is provided on the outer circumference plane of the case. A mounting recessed part for removably mounting the battery pack is provided, and a printed circuit board is provided inside. In the mounting recessed part, a plurality of grounding terminals are electrically connected to a grounding layer of the printed circuit board, on an inner plane to which the metal plane of the battery pack abuts. When the battery pack is mounted in the mounting recessed part, electricity is carried between the metal plane and the grounding terminals, and the metal plane and the battery can are grounded to the grounding layer of the printed circuit board in high frequency.

Abstract: The electrical characteristics of a measurement object 8 are measured using an electrical characteristics measurement device in which a probe 1 comprising a signal terminal 2, a ground terminal 3, and a variable resistance element 4 is connected via a coaxial cable 5 to a measuring instrument 6. The calibration of the probe 1 in such a configuration entails adjusting the resistance value of the variable resistance element, setting the impedance of the distal end vicinity of the probe 1 essentially to 0, and establishing a match with the coaxial cable 5 and measuring instrument 6.

Abstract: A current restriction structure for restricting a higher-harmonic-wave current generated in a digital circuit block from entering a radio circuit block and/or a radio-frequency current generated in the radio circuit block from entering the digital circuit block is disposed between the radio circuit block and the digital circuit block. The current restriction structure is formed by one or two of equivalent rectangular cylindrical metallic tube including metallic planes overlying/underlying the ground layer and a narrow-pitch via-hole array, which are disposed to enclose the subject current to be restricted and have a short-circuited distal end. The distance between the open plane of the equivalent rectangular cylindrical metallic tube and the short-circuiting plate is set at ¼ of the wavelength of the subject current to be restricted.

Abstract: A mobile phone has an upper antenna at the top of a casing constituting a body and a lower antenna at the bottom of the casing. The mobile phone includes an influence-on-antenna evaluation unit for evaluating the influence of the ambient environment on each of the antennas by determining an input impedance (Z) of each antenna at predetermined time intervals during connection and by comparing the determined input impedance with a predetermined input-impedance reference value (Z0). Transmission power corresponding to the amount of radio waves radiated is supplied to the antenna that is less affected by the ambient environment and transmission power is not supplied to the antenna that is more affected by the ambient environment.

Abstract: A low-profile cellular phone has improved radiation efficiency during a call for higher communication quality, and is of a structure allowing the cellular phone to be of a lower profile than heretofore with the magnetic plate and awkward structures such as its fixing jigs being not disposed in a gap within an outer case of the cellular phone. A cellular phone includes at least an antenna for mainly sending and receiving radio waves for communication with a base-station, a printed-circuit board having a metal surface as a board ground layer for the antenna and electronic components mounted thereon, a feeder for supplying electric power to the antenna and the metal surface, a magnetic plate made of a magnetic material housed in an outer case for intensifying a radio wave in a free space during a talk, and an outer case housing therein the printed-circuit board, the feeder, and the magnetic plate.

Abstract: A portable phone comprises an upper casing 11 provided with a speaker 14 and a display screen 15, a lower casing 12 on which a keyboard is disposed 18, and an antenna 16 mounted on an upper end of the upper casing 11 or a lower end of the lower casing 12. A dielectric member 17 with a predetermined dielectric constant and little loss is mounted on a back side or a front side of the antenna 16. The dielectric member 17 may have a curved surface on a side opposite to the antenna 16.

Abstract: A compact cellular phone with a foldable configuration and two planar antennas having outward directivities are provided inside the compact cellular phone in the foldable configuration. An interval between the two planar antennas provided to a pair of housings is equal to or wider than a width of a human palm in a state in which the compact cellular phone is open. The two planar antennas are planar inverse F-type antennas or patch antennas and impedance around each of the two planar antennas is measured. Then, one of the two planar antennas, which has a preferred transmission characteristic, is selected and used.

Abstract: A current restriction structure for restricting a higher-harmonic-wave current generated in a digital circuit block from entering a radio circuit block and/or a radio-frequency current generated in the radio circuit block from entering the digital circuit block is disposed between the radio circuit block and the digital circuit block. The current restriction structure is formed by one or two of equivalent rectangular cylindrical metallic tube including metallic planes overlying/underlying the ground layer and a narrow-pitch via-hole array, which are disposed to enclose the subject current to be restricted and have a short-circuited distal end. The distance between the open plane of the equivalent rectangular cylindrical metallic tube and the short-circuiting plate is set at ¼ of the wavelength of the subject current to be restricted.

Abstract: The portable telephone includes an antenna and a metallic cabinet operating as main radiation sources of electromagnetic waves, a feeding point for supplying said antenna and said metallic cabinet with electric power, an outer packaging formed of such a material as plastics or resin, and a reflecting plate for reflecting the electromagnetic waves radiated from said radiation sources, the reflecting plate being provided for increasing the amount of the electromagnetic waves radiated into a free space when the portable telephone is in use, being selectively arranged at a position where an electric field component or a magnetic field component of the electromagnetic waves radiated from said radiation sources is dominant, and having an electric constant which enables effective reflection of said magnetic field component or said electric field component and causes little electric power absorption.

Abstract: A low-profile cellular phone has improved radiation efficiency during a call for higher communication quality, and is of a structure allowing the cellular phone to be of a lower profile than heretofore with the magnetic plate and awkward structures such as its fixing jigs being not disposed in a gap within an outer case of the cellular phone.

Abstract: A mobile phone has an upper antenna at the top of a casing constituting a body and a lower antenna at the bottom of the casing. The mobile phone includes an influence-on-antenna evaluation unit for evaluating the influence of the ambient environment on each of the antennas by determining an input impedance (Z) of each antenna at predetermined time intervals during connection and by comparing the determined input impedance with a predetermined input-impedance reference value (Z0). Transmission power corresponding to the amount of radio waves radiated is supplied to the antenna that is less affected by the ambient environment and transmission power is not supplied to the antenna that is more affected by the ambient environment.

Abstract: In a portable telephone having a rechargeable battery, an electrically conductive outer cover of the rechargeable battery is connected at a plurality of locations to a ground layer of a circuit board provided within the portable telephone.

Abstract: A PCB (Printed Circuit Board) design support system and a PCB design method reduce radiation of electromagnetic waves by optimizing layout of a substrate while following a conventional method for designing a PCB and maintaining a conventional structure. The PCB design support system includes an input information section for a ground plane structure, power plane structure and layout of a PCB, a circuit model section for calculating voltages between the ground plane and power plane and distribution of currents flowing on the ground plane and power plane using input information, a frequency selection section and a section to display obtained voltage and current distribution in a form of two-dimensional voltage and current distribution maps corresponding to shapes of the PCB. The PCB design support system enables a via-hole disposed between planes and/or wiring installed between planes causing variations in voltages to be specified in a precautionary manner from a PCB design stage.

Abstract: A linear antenna capable of adjusting directivity and impedance matching comprises: a common dipole in which two cylindrical conductors each having a length of &lgr;/4 of the transmission frequency are provided linearly (thus having a total length of &lgr;/2); a plurality of linear parasitic elements that are provided at positions separated by a distance D2 from the axis of the common dipole so as to surround the common dipole; and a U-shaped parasitic element for realizing impedance matching that is arranged in proximity to one end of the common dipole. Each of the linear parasitic elements are arranged parallel to the common dipole and have a length of one half-wavelength of a desired transmission frequency.

Abstract: A compact cellular phone with a foldable configuration and two planar antennas having outward directivities are provided inside the compact cellular phone in the foldable configuration. An interval between the two planar antennas provided to a pair of housings is equal to or wider than a width of a human palm in a state in which the compact cellular phone is open. The two planar antennas are planar inverse F-type antennas or patch antennas and impedance around each of the two planar antennas is measured. Then, one of the two planar antennas, which has a preferred transmission characteristic, is selected and used.

Abstract: A linear antenna capable of adjusting directivity and impedance matching comprises: a common dipole in which two cylindrical conductors each having a length of &lgr;/4 of the transmission frequency are provided linearly (thus having a total length of &lgr;/2); a plurality of linear parasitic elements that are provided at positions separated by a distance D2 from the axis of the common dipole so as to surround the common dipole; and a U-shaped parasitic element for realizing impedance matching that is arranged in proximity to one end of the common dipole. Each of the linear parasitic elements are arranged parallel to the common dipole and have a length of one half-wavelength of a desired transmission frequency.

Abstract: A measuring method of the SAR is provided, which makes it possible to measure the SAR on the surface of a human body with high accuracy when the human body is approached to an antenna. After a probe for receiving at least one of two orthogonally-intersecting magnetic fields is prepared, a simulated biological body having approximately the same dielectric constant and approximately the same permeability as those of a human body is placed at a wanted point. A first magnetic field radiated from an antenna and a second magnetic field generated by reflection of the first magnetic field on the surface of the simulated biological body are separately measured at different measuring points by using the probe. A compensated magnetic field is calculated using the measured values of the first and second magnetic fields. A current distribution of the antenna is calculated by using the calculated values of the compensated magnetic field.

Abstract: The device disclosed is for measuring a Specific Absorption Rate (SAR) in a human body exposed to electromagnetic fields radiating from an antenna, and is constituted by a phantom (a model of the human body) and a probe structure. The phantom has equivalent electric constant of permittivity and permeability as those of a human body. The probe structure has a combination of first and second loop probes orthogonal to each other, and is arranged such that the second loop probe receives only a magnetic field that has been reflected from a surface of the phantom. Thus, the magnetic field radiating from the antenna and the magnetic field reflected from a surface of the phantom are distinguished from each other. The reflected magnetic field is corrected and the SAR can be accurately measured.