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.

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 wireless transmitting apparatus according to the present invention, comprising: N (N is two or more integer) pieces of antennas capable of transmitting a wireless signal; and a selector which selects L (L is one or more integer, and L≦N) pieces of antennas from said N pieces of antennas and selects the types of signals to be transmitted from the selected L pieces of antennas.

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: 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: 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: 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.

Abstract: An object of the present invention is to prevent congestion of networks and to effectively use a plurality of autonomous distributed wireless networks.

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: 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: A receiver having a function of a direct current offset, and including a receiving section for receiving a radio frequency signal, an analog signal processing section for amplifying, band-converting and frequency-converting an analog signal inputted from the receiving section, and an AD converting section for converting an output of the analog signal processing section from an analog signal to a digital signal. Also included is a digital signal processing section for processing the digital signal converted by the DC converting section.

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: A radio-frequency signal receive section, including an antenna, collectively receives radio-frequency signals on a plurality of channels each of which is modulated with data and outputs a received signal. In a quadrature demodulator, the received signal is multiplied by each of first quadrature local signals to produce quadrature baseband signals. In two low-pass filters, low-frequency component signals are extracted from the quadrature baseband signals. In a quadrature modulator, the low-frequency component signals are multiplied by second quadrature local signals and thereby converted into quadrature intermediate-frequency signals, which are in turn combined into an output signal. After converted into a digital signal, the output signal of the quadrature modulator is inputted to a digital signal processing unit where a signal on at least one channel is selected and the selected signal is processed to recover the original data.

Abstract: A magnetic disk apparatus includes at least two systems, each system having at least one power unit and at least one battery unit ancillary to the power unit. The disk apparatus also includes at least one common power unit having a pluralities of batteries attached thereto connected in common with the two systems. Patrol control means (PC) is operatively connected to a power control unit (0) of one system and a power control unit (1) of another system for giving a control signal during a battery monitoring operation and a priority order to the battery monitoring operation. The patrol control means monitors the function of the common batteries attached to the common power unit and, further, when the common batteries are incorporated in the magnetic disk apparatus, controls the simultaneous monitoring of the common batteries and the time of incorporation of the common batteries into the magnetic disk apparatus.

Abstract: A magnetic disk apparatus which is used as a subsystem of a computer system, in particular a medium-sized computer system which uses commercial power and does not have its own backup power, provided with a plurality of directors (118), a plurality of magnetic disk modules (148) commonly accessed from the plurality of directors, a plurality of director batteries (114-m) for supplying power individually to the plurality of directors, magnetic disk module batteries (114-n) for supplying power to the magnetic disk modules, and a power controller (110) for independently controlling the supply of power from the plurality of director batteries and magnetic disk module batteries in accordance with the operating state of the plurality of directors and magnetic disk modules. (FIG. 1).

Abstract: A high-density disk unit and disk medium are disclosed. Track ID information is not placed in a servo area, or if some track ID information is placed therein, a necessary minimum is placed. The servo area is thus reduced in order to improve formatting efficiency.A data side of a disk medium is divided into a servo area and a data area in units of a sector. A track ID area in which track information is recorded is defined at the start position of the data area immediately following the servo area. A formatter circuit allows a write data modulation circuit to write track information in the track ID area during track formatting. For writing in the data area, the formatter circuit allows a read data demodulation circuit to read data from the track ID area. Track information is thus detected, and writing tracking is assured.

Abstract: A variable-gain amplifier circuit has an offset correcting function by which the fluctuation of offset due to the switching of a gain is decreased. In an offset detection mode, an input offset voltage of the variable-gain amplifier circuit is inputted to an offset retaining section, and in a signal amplifying mode, the offset is corrected by subtracting the output of the offset retaining section from an input signal by means of an input section of the variable-gain amplifier circuit. In addition, the variable-gain amplifier circuit can be applied to a radio receiver. The offset produced in a baseband section of a receiver is corrected by the offset correcting function of the variable-gain amplifier circuit, so as to prevent the quality of communication from being deteriorated.

Abstract: A magnetic disk apparatus which is used as a subsystem of a computer system, in particular a medium-sized computer system which uses commercial power and does not have its own backup power, provided with a plurality of directors (118), a plurality of magnetic disk modules (148) commonly accessed from the plurality of directors, a plurality of director batteries (114-m) for supplying power individually to the plurality of directors, magnetic disk module batteries (114-n) for supplying power to the magnetic disk modules, and a power controller (110) for independently controlling the supply of power from the plurality of director batteries and magnetic disk module batteries in accordance with the operating state of the plurality of directors and magnetic disk modules. (FIG. 1).