Abstract: A high-power amplifier changes matching conditions of an output matching circuit 5 connected between a final stage amplifying element 3 and an output terminal 8 in response to the output power of the amplifying element 3. Thus, the efficiency at low output power can be greatly improved without reducing the efficiency at the maximum output. Besides, since it is not necessary to load a DC-DC converter, an increase in size or cost can be prevented.

Abstract: A wide-angle shooting apparatus includes a convex surface structure which reflects light from outside, a concave surface structure having a first polarizing device which permits the light from outside to be transmitted and reflects the light reflected by the convex surface structure. The concave surface structure is positioned before the convex surface structure. The apparatus also includes a second polarizing device which permits the light reflected by the concave surface structure to be transmitted and shielding direct light beam transmitted through the concave surface structure. The second polarizing device is positioned at a part to which the light reflected by the concave surface structure is concentrated. The apparatus further includes image-shooting device which receives the light transmitted through the second polarizing device and shoots an image.

Abstract: A high-power amplifier changes matching conditions of an output matching circuit 5 connected between a final stage amplifying element 3 and an output terminal 8 in response to the output power of the amplifying element 3. Thus, the efficiency at low output power can be greatly improved without reducing the efficiency at the maximum output. Besides, since it is not necessary to load a DC-DC converter, an increase in size or cost can be prevented.

Abstract: A high frequency amplifier includes a constant voltage driven amplifier 1 using as its amplifying element a bipolar transistor 7 with its base biased by a constant voltage, and a constant current driven amplifier 2 using as its amplifying element a bipolar transistor 8 with its base biased by a constant current. The idle current of the constant current driven amplifier 2 is set at a low value. In accordance with the idle current, the idle current of the constant voltage driven amplifier 1 is adjusted, and the two amplifiers are combined in parallel.

Abstract: A high frequency amplifier includes a constant voltage driven amplifier 1 using as its amplifying element a bipolar transistor 7 with its base biased by a constant voltage, and a constant current driven amplifier 2 using as its amplifying element a bipolar transistor 8 with its base biased by a constant current. The idle current of the constant current driven amplifier 2 is set at a low value. In accordance with the idle current, the idle current of the constant voltage driven amplifier 1 is adjusted, and the two amplifiers are combined in parallel.

Abstract: An input device includes a magnet to be worn by a user on one fingertip of either a right hand or a left hand, a first magnetic sensor to be worn by the user on a wrist of either the right hand or the left hand to detect a magnetic field generated by the magnet at a corresponding position, a second magnetic sensor to be worn by the user on the same wrist on which the first magnetic sensor is worn and at a position that is farther from the magnet than the first magnetic sensor and eliminates effects of geomagnetism, and an output unit to output a difference between an output signal from the first magnetic sensor and an output signal from the second magnetic sensor.

Abstract: A wide-angle shooting apparatus includes a convex surface structure which reflects light from outside, a concave surface structure having a first polarizing device which permits the light from outside to be transmitted and reflects the light reflected by the convex surface structure. The concave surface structure is positioned before the convex surface structure. The apparatus also includes a second polarizing device which permits the light reflected by the concave surface structure to be transmitted and shielding direct light beam transmitted through the concave surface structure. The second polarizing device is positioned at a part to which the light reflected by the concave surface structure is concentrated. The apparatus further includes image-shooting device which receives the light transmitted through the second polarizing device and shoots an image.

Abstract: An input device includes a magnet to be worn by a user on one fingertip of either a right hand or a left hand, a first magnetic sensor to be worn by the user on a wrist of either the right hand or the left hand to detect a magnetic field generated by the magnet at a corresponding position, a second magnetic sensor to be worn by the user on the same wrist on which the first magnetic sensor is worn and at a position that is farther from the magnet than the first magnetic sensor and eliminates effects of geomagnetism, and an output unit to output a difference between an output signal from the first magnetic sensor and an output signal from the second magnetic sensor.

Abstract: A frequency divider circuit including a field effect transistor on a semi-insulating substrate including applying a voltage higher than the lowest of the power supply voltages of the frequency divider circuit to the semi-insulating substrate.