Abstract: A mapping memory, for use with a transmitter, for mapping a first signal segment and a second signal segment of a packet so that each signal segment has the same average power level. Each signal segment is characterized by a different modulation format. The first signal segment might use BPSK, while the second signal segment might use QAM, having multiple amplitude levels.

Abstract: To provide a wireless communication device including a transmitting device for transmitting control signals or data signals without any need for a battery, which can be downsized by using electric power generated from natural energy only as well as which can reduce its power consumption by using very weak waves for which no license is required by the Radio Law in Japan.

Abstract: In a wireless communication device which performs a wireless communication on an internal power supply without use of a commercial power, the period of a disturbance electromagnetic wave from a microwave oven or the like is accurately detected to avoid any effect of the disturbance electromagnetic wave.

Abstract: A two-step automatic-gain-control (AGC) loop for use with a receiver. An AGC amplifier amplifies a received signal. From an output signal from the AGC amplifier, a received-signal-strength-indicator (RSSI) circuit generates an RSSI signal proportional to a received-signal-power level of the received signal. An RSSI-mapping circuit has an RSSI-mapping table. From the RSSI signal, the RSSI-mapping circuit, using the RSSI-mapping table, generates an AGC signal. An AGC-storing circuit stores the AGC signal. The AGC amplifier uses the stored-AGC signal to adjust the AGC gain. A converter circuit converts the output signal from the AGC amplifier to an in-phase component and a quadrature-phase component at a processing frequency. The error circuit determines an error signal from the in-phase component and the quadrature-phase component.

Abstract: The invention provides a small portable radio apparatus including a slot antenna member. The slot antenna member has an improved form disposed in a casing. The casing has a curvedly bulging side edge surface. Thus, there is no useless space in the casing reducing the size of the portable radio apparatus. The slot antenna member has first and second conductive plates which form a slot groove at an outer peripheral edge of the first and second conductive plates. A short-circuiting element short-circuits the conductive plates with each other over the slot groove. A tuning capacitor element is connected to the first and second conductive plates at a position opposite to a position where the short-circuiting element is provided. The radio apparatus casing has a side portion which curvedly bulges toward an outer periphery thereof. The first and second conductive plates have central portions with openings and side portions which bulge slantingly toward outer peripheral edges thereof.

Abstract: A miniaturized and thin slot antenna device maintains high transmitting and receiving performance by improving the configuration of an antenna body and a circuit substrate. The slot antenna device includes an antenna body made of an electrically conductive member having a slot into which the circuit substrate is placed. Alternatively, the slotted, electrically conductive member can be placed flat on a first surface of the circuit substrate, which can contain a reflector on its second, opposite surface. The slot antenna device also can be constructed from two parallel, opposed, electrically conductive members spaced apart by a gap so that a slot is defined by outer peripheries of the electrically conductive members. The electrically conductive members can be provided on opposite surfaces of a circuit substrate.

Abstract: A loop antenna device of the invention, when incorporated in a transceiver, stably a high level of sensitivity without being substantially influenced by the body, regardless of the posture or direction of the transceiver when the transceiver is mounted on or carried by the human body. The loop antenna device also provides, when the transceiver is not carried on a human body, a highly stable sensitivity characteristic even in such a condition that the polarization plane changes over time under the influence of multi-path strain or fading. The antenna circuit which provides these advantageous effects does not require any additional element for matching and contributes to reduction in the size of a transceiver.

Abstract: A portable radio communication device such as wristwatch receiver and/or transmitter is provided with an effective noise shielding structure. The portable radio communication device includes a high frequency analog circuitry for receiving and transmitting radio signals and further includes digital circuitry for data processing and display. The noise shielding structure protects high frequency noise from being transmitted to the analog circuitry from the digital circuitry and from other outside sources. The noise shielding structure is made of electrically conductive material. In another aspect of the invention, at least one circuit board constructed of a multi-layered construction having at least one inner printed wire pattern is provided. The inner printed wire pattern is set at ground potential with respect to the high frequency output from the analog circuitry. In this manner the inner printed wire pattern serves as a noise shielding member.

Abstract: A wrist-mounted-type portable radio apparatus includes a main body having a front surface that faces away from the user's wrist, a rear surface that faces the user's wrist when mounted around the user's wrist, a circuit board having electrical circuitry and arranged in the main body, and wrist bands connected to the main body for mounting the device around the user's wrist. The radio apparatus also includes an antenna assembly fixed in the main body and the wrist bands, and arranged in the main body so that it is positioned on a side of the circuit board facing the front surface of the main body. Because the circuit board is not disposed on the front surface side of the antenna assembly, a radiation wave generated by the antenna assembly is not disturbed. Therefore, the wrist-mounted-type antenna device has high directivity and sensitivity.

Abstract: An arm-attached band type radio apparatus capable of providing a stable antenna gain without being affected by the band size has an arm attaching band that is formed into a loop by way of a buckle 31 having an metallic electrode plate 32, first and second conductor plates 5L, 5R, shaped so as to form a slot antenna, to form a loop-like slot antenna. The distal end side of conductor plate 5L has an overlap capacitance changing portion 15 so that, when the connecting position of the band changes according to the thickness of the wearer's arm, the overlap capacitance between first conductor plate 5L and metallic electrode 32, is changed. The magnitude of the capacitance change corresponds to a change in the inductance of the antenna to compensate for a shift in the resonance frequency. The overlap capacitance can be changed by controlling the overlap area or the effective dielectric constant of the material separating conductor plate 5L from metallic electrode 32.

Abstract: The invention is directed to a wristwatch type paging device having a structure for preventing the intrusion of static electricity. The paging device is provided for receiving or transmitting signals. A pager circuit is provided for controlling and operating on the received or signals to be transmitted. A pager body, having a two part wrist band coupled thereto, houses the pager circuit. The body is formed with at least a conductive portion. The band fastens around the wrist of the user and carries antenna portions. A fastener mechanically couples the end portions and electronically couples the antenna portions. The conductive portion of the pager body is set to the AC ground potential (the potential of one of the positive or negative electrodes of the battery). A balanced varactor diode circuit is provided between the antenna portion ends defining an essentially neutral point coupled to one of its positive and negative electrodes.

Abstract: A portable radio communication device such as wristwatch receiver and/or transmitter is provided with an effective noise shielding structure. The portable radio communication device includes a high frequency analog circuitry for receiving and transmitting radio signals and further includes digital circuitry for data processing and display. The noise shielding structure protects high frequency noise from being transmitted to the analog circuitry from the digital circuitry and from other outside sources. The noise shielding structure is made of electrically conductive material. In another aspect of the invention, at least one circuit board constructed of a multi-layered construction having at least one inner printed wire pattern is provided. The inner printed wire pattern is set at ground potential with respect to the high frequency output from the analog circuitry. In this manner the inner printed wire pattern serves as a noise shielding member.

Abstract: The antenna circuit and wrist radio instrument of the present invention compensates for slippage in the resonance frequency of antenna circuits caused by such as the wrist thickness of the person wearing them, and by being worn on the wrist and then not worn, and can always tune to a set frequency. Accordingly, the present invention is one that can automatically receive a set frequency signal stably and with a set sensitivity, with no need for special adjustments.