Abstract: One of objects of a wireless communication apparatus according to the present invention is to realize stable communication regardless of received signal strength indication and information amount. The wireless communication apparatus for communicating in an autonomous distributed wireless network includes a detection unit which generates a detection signal by detecting a first wireless signal from a first wireless apparatus; a wireless circuit which receives a second wireless signal relating to said first wireless signal, transmitted from a second wireless apparatus which received said first wireless signal; a signal estimation unit which estimates said detection signal and the received second wireless signal; a signal selector which selects either said detection signal or the received second wireless signal, based on an estimation result of said signal estimation unit; and a demodulator which demodulates the signal selected by said signal selector.

Abstract: A wireless communication system which transmits and receives a signal by using a plurality of wireless apparatuses, comprising: a first wireless apparatus group having a plurality of transmitting apparatuses, each transmitting a wireless signal based on a first control signal, said first wireless apparatus group forming a first ad-hoc network between said transmitting apparatuses; and a second wireless apparatus group having a plurality of destination apparatuses, each receiving the wireless signal transmitted from said first wireless apparatus group, said second wireless apparatus group transmitting and receiving the wireless signal received by said destination apparatuses based on a second control signal, and said second wireless apparatus group forming a second ad-hoc network between said destination apparatuses different from said first ad-hoc network.

Abstract: A storage device includes a recording medium having a user-area and a system-area. The storage device conducts a self-diagnostic test on a recording medium. When conducting the self-diagnostic test, a writing/reading unit performs writing of data in and reading of data from the system area at a user-area write/read frequency that is a frequency for writing of data in and reading of data from the user area.

Abstract: In an apparatus for recording and/or reproducing information, which reproduces servo information being recorded on a medium and conducts a tracking operation based on the servo information, a power save part conducts a power save operation by reducing an operation clock frequency in accordance with a predetermined process during a tracking operation, during a seek operation, and/or during spindle motor startup.

Abstract: In a radio apparatus, the band of a loop filter of a synthesizer in a blank channel searching state is narrower than the band in a communicating state. In addition, a radio wave environment is measured. A characteristic necessary for the radio apparatus is determined corresponding to the measured-radio wave environment. The power is controlled corresponding to the performance of the radio apparatus. Thus, the power consumption is decreased. In addition, the efficiency of the output power is improved. In the radio apparatus, the current consumption of a power amplifier PA is measured. A matching circuit (LNA or MIX) of the antenna is adjusted with the measured result so as to decrease an antenna loss. In the radio apparatus, a DC offset is removed from the transmitted power and the reflected wave. When the DC offset is removed using an AC coupling capacitor, the deterioration of the frequency characteristic of the receiving portion is compensated with a capacitor in a digital signal process.

Abstract: An object of the present invention is to provide a wireless communication system, a wireless communication system, comprising: one or more wireless base station; and a plurality of wireless terminals capable of communicating with said wireless base station by wireless, two or more of said wireless terminals capable of communicating with each other by wireless thereby forming a wireless terminal group; wherein said wireless base station has a representative determination unit configured to determine at least one wireless terminal belonging to said wireless terminal group as a representative terminal; and said representative terminal receives first frames transmitted from other wireless terminals belonging to said wireless terminal group, and transmits the received first frames to said wireless base station.

Abstract: In a radio apparatus, the band of a loop filter of a synthesizer in a blank channel searching state is narrower than the band in a communicating state. In addition, a radio wave environment is measured. A characteristic necessary for the radio apparatus is determined corresponding to the measured-radio wave environment. The power is controlled corresponding to the performance of the radio apparatus. Thus, the power consumption is decreased. In addition, the efficiency of the output power is improved. In the radio apparatus, the current consumption of a power amplifier PA is measured. A matching circuit (LNA or MIX) of the antenna is adjusted with the measured result so as to decrease an antenna loss. In the radio apparatus, a DC offset is removed from the transmitted power and the reflected wave. When the DC offset is removed using an AC coupling capacitor, the deterioration of the frequency characteristic of the receiving portion is compensated with a capacitor in a digital signal process.

Abstract: A library is referred to and thus facilities are executed when executing an application program for receiving and transmitting radio signals. That is, the library serving as programs depending on hardware converts commands based on the application program into signal to control the hardware. As a result, the application program is describable by a program independent of an analog device for receiving and transmitting the radio signal, and a common application program can be used even in case of different hardware.

Abstract: A tunable filter has a plurality of variable capacitors and a plurality of inductor elements, each being formed on a common substrate, a filter circuit formed by using at least a portion of the plurality of variable capacitors and a portion of the plurality of inductor elements, a monitor circuit formed by using at least a portion of the plurality of variable capacitors and a portion of the plurality of inductor elements, a detecting circuit which detects a prescribed circuit constant of the monitor circuit, a storage which stores information relating to a reference circuit constant of the monitor circuit, and a capacitance control circuit which controls capacitance of the variable capacitors in the monitor circuit and capacitance of the variable capacitors in the filter circuit, based on a result detected by the detecting circuit and information stored in the storage.

Abstract: A nonvolatile memory, storing a plurality of access programs for accessing a storage device by the storage device connectable depending on an adopted interface, is comprised in an information processor, when power is applied to the information processor, the types of the adopted interface and connected storage devices are determined, and access programs, except for an access program corresponding to the type specified by the determination, are cleared from the nonvolatile memory. Consequently, the nonvolatile memory can prepare the appropriate access program only.

Abstract: An orthogonal demodulating section converts the frequency of received signals to the lower range after rejecting an image band thereof by an RE filter. An image rejecting section rejects the image band of the orthogonally converted output. It allows enough of an image rejecting degree to be obtained. An A/D converter section converts the whole range into a digital signal and an orthogonal demodulating section demodulates a desirable channel by means of digital processing. Then, a channel selecting section selects and outputs the desirable channel.

Abstract: In a disk storage a command controller issues a seek command and transmits it to a seek command manager. A head position controller performs a seek operation. If the head position controller is not busy with the seek operation, the seek command manager transmits the seek command to the head position controller. If the head position controller is busy with the seek operation, the seek command manager queues the seek command in a memory and transmits the seek command to the head position controller after the head position controller has finished the seek operation.

Abstract: A filter control apparatus which controls a frequency variable filter capable of changing a transmission band width by controlling a capacitance of at least a portion of a plurality of voltage variable capacitors connected in series and parallel to a resonator has an input unit, and a filter control circuit. The input unit inputs a reference signal with a predetermined reference frequency to the frequency variable filter. The filter control circuit controls a center frequency and the transmission band width of the frequency variable filter by detecting a phase change generated when the reference signal passes through the frequency variable filter and by variably controlling the capacitance of at least a portion of the voltage variable capacitor by using a direct voltage in proportion to the phase change.

Abstract: A tunable filter has a plurality of variable capacitors and a plurality of inductor elements, each being formed on a common substrate, a filter circuit formed by using at least a portion of the plurality of variable capacitors and a portion of the plurality of inductor elements, a monitor circuit formed by using at least a portion of the plurality of variable capacitors and a portion of the plurality of inductor elements, a detecting circuit which detects a prescribed circuit constant of the monitor circuit, a storage which stores information relating to a reference circuit constant of the monitor circuit, and a capacitance control circuit which controls capacitance of the variable capacitors in the monitor circuit and capacitance of the variable capacitors in the filter circuit, based on a result detected by the detecting circuit and information stored in the storage.

Abstract: A high frequency filter comprises thin film piezoelectric resonators connected in series between the input/output nodes, thin film piezoelectric resonators connected in parallel between the input/output nodes and a variable voltage circuit adapted to change the voltage applied to at least either the thin film piezoelectric resonators connected in series or the thin film piezoelectric resonators connected in parallel. The resonance characteristic of at least either the thin film piezoelectric resonators connected in series or the thin film piezoelectric resonator connected in parallel is shifted by changing the voltage applied by the variable voltage circuit to change the pass characteristic of the filter.

Abstract: In a radio apparatus, the band of a loop filter of a synthesizer in a blank channel searching state is narrower than the band in a communicating state. In addition, a radio wave environment is measured. A characteristic necessary for the radio apparatus is determined corresponding to the measured-radio wave environment. The power is controlled corresponding to the performance of the radio apparatus. Thus, the power consumption is decreased. In addition, the efficiency of the output power is improved. In the radio apparatus, the current consumption of a power amplifier PA is measured. A matching circuit (LNA or MIX) of the antenna is adjusted with the measured result so as to decrease an antenna loss. In the radio apparatus, a DC offset is removed from the transmitted power and the reflected wave. When the DC offset is removed using an AC coupling capacitor, the deterioration of the frequency characteristic of the receiving portion is compensated with a capacitor in a digital signal process.

Abstract: In a radio apparatus, the band of a loop filter of a synthesizer in a blank channel searching state is narrower than the band in a communicating state. In addition, a radio wave environment is measured. A characteristic necessary for the radio apparatus is determined corresponding to the measured radio wave environment. The power is controlled corresponding to the performance of the radio apparatus. Thus, the power consumption is decreased. In addition, the efficiency of the output power is improved. In the radio apparatus, the current consumption of a power amplifier PA is measured. A matching circuit (LNA or MIX) of the antenna is adjusted with the measured result so as to decrease an antenna loss. In the radio apparatus, a DC offset is removed from the transmitted power and the reflected wave. When the DC offset is removed using an AC coupling capacitor, the deterioration of the frequency characteristic of the receiving portion is compensated with a capacitor in a digital signal process.

Abstract: To provide a miniaturized voltage controlled oscillator which can oscillate simultaneously a plurality of frequencies and has high stability of frequency, an excellent low phase noise, small variation per hour, and a wide frequency variable range. A thin film bulk acoustic wave resonator using single crystal ferroelectric material equal to or smaller than 10 &mgr;m in thickness whose direction of polarization is aligned to the direction of thickness is utilized as the piezoelectric member. The voltage controlled oscillator having large changing rate of the oscillation frequency of 0.01%/V or more and an extremely small phase noise is provided by changing the voltage applied to the electrodes.

Abstract: A library is referred to and thus facilities are executed when executing an application program for receiving and transmitting radio signals. That is, the library serving as programs depending on hardware converts commands based on the application program into signal to control the hardware. As a result, the application program is describable by a program independent of an analog device for receiving and transmitting the radio signal, and a common application program can be used even in case of different hardware.

Abstract: An orthogonal demodulating section converts the frequency of received signals to the lower range in batch after rejecting an image band thereof by an RF filter. An image rejecting section rejects the image band of the orthogonally converted output. It allows an enough image rejecting degree to be obtained. An A/D converter section converts the whole range into a digital signal and an orthogonal demodulating section demodulates a desirable channel by means of digital processing. Then, a channel selecting section selects and outputs the desirable channel. It then allows wide-bands to be received in batch, flexible processing to be achieved by the digital processing and an enough image rejecting degree to be obtained.