Nec Corporation

Yoshimasa Hosonuma

Masahiko Tanaka

A foldable portable radio terminal is disclosed which normally optimizes an antenna characteristic by an antenna matching circuit even if the body length of the foldable portable radio terminal varies. A folded state detection circuit sends a detection signal to a control section depending upon whether or not the foldable portable radio terminal is folded. An antenna matching circuit is determined so that the antenna characteristic of an antenna is optimized when the foldable portable radio terminal is in a folded state. When the foldable portable radio terminal is unfolded, the control section renders a matching characteristic changeover circuit operative to change over the matching characteristic of the antenna matching circuit so that, even when the foldable portable radio terminal is in an unfolded state, the antenna characteristic by the antenna matching circuit may be optimized.

Foldable portable radio terminal

There is provided a flexible board including (a) an internal layer, (b) a line formed in a first area of the internal layer, the line radiating unnecessary radiation, (c) a first ground layer formed on an upper surface of the internal layer, the first ground layer disallowing radiation to pass therethrough, and (d) a second ground layer formed a lower surface of the internal layer, the second ground layer disallowing radiation to pass therethrough. The flexible board prevents unnecessary radiation from outwardly radiating without an increase in a size thereof.

Flexible board and method of fabricating the same

In a movable radio terminal device, a switching circuit connects, in response to one of first and second matching switching control signals, an antenna,to one of first and second impedance matching circuits. The controlling unit produces and supplies, at every predetermined time interval, the first and second matching switching control signals to the switching circuit, respectively, to make a memory device memorize, as first and second level signals having first and second level values, detected level signals from a level detecting circuit when the switching circuit connects the antenna to the first and second impedance matching circuits, respectively, when the detected level value from the level detecting circuit is smaller than one of the first and second level values that corresponds to the second greatest level value in the first and second level values, and when the controlling unit is supplied with a human body contact discriminating signal from a human body contact discriminating circuit. The controlling unit selects, as a selected level value, one of the first and second level values that is greatest in the first and second level values. The controlling unit produces and supplies one of the first and second matching switching control signals that corresponds to the selected level value to the switching circuit.

Movable radio terminal device capable of precisely matching impedances

A communication apparatus of the present invention has a hands-free communication capability and is applicable to, but not limited to, a motor vehicle. Only if the apparatus is connected to, e.g., an on-board cigar-lighter, hands-free communication can be held. This eliminates the need for a hands-free unit, an outside microphone and other extra parts conventionally mounted on the vehicle to implement a hands-free feature.

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Tokyo, Japan

Yoshimasa Hosonuma