Abstract: Disclosed herein are a clock driver circuit and a method of routing clock interconnect lines, which control the lengths of adjacent interconnect lines and ununiformity of conductive line capacitance due to the intersection of interlayer interconnect lines, thereby reducing clock skews.
Abstract: An optical switch circuit network includes r input optical switches 102a each having n input ports, m 1×r optical switches 125a, and an n×m optical switch for switching a path connecting the input ports and the 1×r optical switches, and r output optical switches 125 each having r×1 optical switches, n output ports, and an m×n optical switch for switching a path connecting the output ports and 1×r optical switches. The i-th 1×r optical switch of each input optical switch is connected to the i-th r×1 optical switch of each output optical switch.
Abstract: In a differential surface acoustic wave resonator, when an unbalanced electric signal is inputted between an input terminal 301 and an output terminal connected to a ground potential, this electric signal is inputted to two-terminal-pair surface acoustic wave resonators 351 and 352. The electric signal inputted to the two-terminal-pair surface acoustic wave resonator 351 is converted into a surface acoustic wave, and thereafter it is again converted into an electric signal to be outputted to a two-terminal-pair surface acoustic wave resonator 353. The electric signal inputted to the two-terminal-pair surface acoustic wave resonator 353 is converted into a surface acoustic wave, and thereafter it is again converted into an electric signal to be outputted from an output terminal 302 of the differential surface acoustic wave filter as a balanced signal.
Abstract: An alignment mark for use in electron beam lithography for manufacturing a fine semiconductor structure by repeating a regrowth of a compound semiconductor layer and a fine process including electron beam exposure. The alignment mark includes a lower protection layer made of tungsten formed on a compound semiconductor substrate, a mark main body made of gold, chromium or platinum shaped into a desired pattern having a sharp edge profile which generates a detection signal of a mark position having a large gain, and an upper protection layer covering the mark main body and made of silicon oxide which does not react significantly with substances constituting a compound semiconductor layer. The mark main body has a thickness which is not less than 100 nm.
Abstract: A transmission power controller includes a transmission amplifier located in a first station and having an adjustable gain. The transmission amplifier controls the power transmitted from the first station to a second station in accordance with a power control information signal transmitted from the second station. The transmission power controller comprises a power control information extracting circuit, and up/down decision circuit, and a filter interposed between the up/down decision circuit and the transmission amplifier. The filter extracts low frequency band components from sequential output signals of the up/down decision circuit, generates command signals, and applies the command signals to the transmission amplifier to control the gain of the transmission amplifier.
Abstract: An echo canceling apparatus has two microphones, both receiving an acoustic signal including a near-end speech component and an echo component. A first adaptive filter cancels the echo component in the output of the first microphone, obtaining a first residual signal. A second adaptive filter cancels the echo component in the output of the second microphone, obtaining a second residual signal. The two residual signals are added together with a timing delay compensating for the delay between their near-end speech components. In the resulting sum signal, the near-end speech component is enhanced, while the echo component, and a near-end background noise component, are relatively weakened.
Abstract: A hit-less cell switching device capable of switching ATM (Asynchronous Transfer Mode) cells between a system ZERO and a system ONE is disclosed. The system ZERO includes a first cell switch, a first input cell gate, a first output cell gate, and a first shaper. Likewise, the system ONE includes a second cell switch, a second input cell gate, a second output cell gate, and a second shaper. First, a controller opens the first and second input cell gates and first output cell gate, closes the second output cell gate, and puts the first and second cell switches and first and second shapers in a fully switched condition, thereby initializing the switching device. Subsequently, the controller closes the second input cell gate, evacuates queue buffers included in the second cell switch and second shaper, and opens the second output gate. After putting the two cell switches and two shapers in an in-switching state, the controller closes the first input cell gate and opens the second input cell gate simultaneously.
Abstract: A telephone communication method capable of promoting the efficient use of the limited number of IP (Internet Protocol) addresses is disclosed. When a call is originated on a first telephone terminal, a first gateway accommodating the terminal accesses a DNS (Domain Name System) server via a UDP (User Datagram Protocol) channel of Internet or Intranet. The first gateway inquires the DNS server of the IP address of a second gateway accommodating a telephone terminal to be called, using an office number assigned to the second telephone terminal as a host name. The DNS server returns the IP address of the second gateway to the first gateway via the UDP channel. In response, the first gateway selects its own IP address for speech transfer and sends a call connection request to the second gateway on a TCP (Transmission Control Protocol) channel of Internet.
Abstract: A mobile communication receiver generates an audio signal from a radio signal received on a communication channel, detects conditions on the communication channel, mutes the audio signal according to a first rule when the channel conditions are bad, and un-mutes the audio signal according to a second rule when the channel conditions are good. The first rule is more stringent than the second rule; as a result, sporadic muting and choppy muting are avoided.
Abstract: In one aspect of the invention, a light-emitting semiconductor device has a light-emitting layer with a certain bandgap energy, an upper cladding layer with a higher bandgap energy, a first diffusion area extending into the light-emitting layer, a second diffusion area extending only into the upper cladding layer, and an electrode making contact with the second diffusion area, without covering any part of the first diffusion area. The second diffusion area conducts current to the first diffusion area, where light is emitted from a pn junction in the light-emitting layer. In another aspect of the invention, a semiconductor contact layer is provided to assure ohmic contact with the electrode, and the semiconductor contact layer is removed from the light-emitting area, avoiding absorption of light.
Abstract: Disclosed is a surface acoustic wave filter having a first serial-arm SAW resonator coupled to an input terminal and a first dual-mode SAW resonator coupled between the first serial-arm SAW resonator and an output terminal, wherein the first dual-mode SAW resonator includes first to third comb-shaped interdigital transducers, the second comb-shaped interdigital transducer is arranged between the first and third comb-shaped interdigital transducers and also coupled between the first serial-arm SAW resonator and the ground potential, and each of the first and third comb-shaped interdigital transducers is coupled between the ground potential and the output terminal. Also disclosed is a branching filter utilizing the surface acoustic wave filter.
Abstract: A spreading code synchronization circuit in a RAKE receiver in a spread-spectrum mobile communication system reassigns receiver fingers that are tracking substantially the same synchronization positions as other fingers, as well as reassigning fingers that are tracking synchronization positions with low correlation power. Under adverse multipath reception conditions, receiver fingers are quickly released from weak signal components and reassigned to stronger signal components, while maximum path diversity is maintained.
Abstract: A semiconductor device according to the invention of the present application comprises a first semiconductor layer, a first insulating layer formed over the first semiconductor layer, a second semiconductor layer formed over the insulating layer, a protective element formed over the second semiconductor layer, an electrode pad, and a plurality of series-connected through holes for connecting the electrode pad and the protective element. Thus, a surge voltage applied across a diffused resistor can be lightened and hence an oxide film placed below the diffused resistor can be prevented from destruction.
Abstract: A surface-acoustic-wave filter has a pair of series-arm surface-acoustic-wave resonators and a shunt-arm surface-acoustic-wave resonator coupled in a T configuration. An additional bridging surface-acoustic-wave resonator is coupled between the input and output terminals, in parallel with the series arm. The bridging surface-acoustic-wave resonator provides enhanced attenuation of spurious signals at multiples of the passband frequency.
Abstract: A non-impact printer has a print data correction circuit for providing a print data correction processing for video signals transmitted from a printing control unit to produce correction output data or patterns for printing on basic raster lines and other correction output data or patterns for printing on sub-raster lines. Those correction output data or patterns are supplied to the print head in the form of a real printing data signal.
Abstract: A branching filter includes a transmitting filter and a receiving filter, both of the SAW-resonator type. The transmitting filter and receiving filter are housed in separate packages. The packages also include coupling circuitry and other necessary circuit elements such as inductor-capacitor chips. Accommodation of the SAW-resonator-type filters and other circuit elements in two separate packages leads to improved performance characteristics.
Abstract: A solid state disk system having an electrically erasable and programmable read only memory is disclosed. The solid state disk system comprises a host interface for inputting data from and outputting data to a host computer located outside of said solid state disk system, a buffer memory coupled to the host interface for temporally storing data, an EEPROM coupled to the buffer memory, a micro-controller coupled to the host interface and buffer memory for controlling a replacement procedure. The EEPROM has a memory region divided into a plurality of blocks each of which is erased at the same time. The memory region has a user block region storing data accessed from the host computer, a spare block region storing data from the outside for replacing any defective block within the user block region, and a replacement information region storing information about an address of a spare block corresponding to the defective block.
Abstract: An automatic verification apparatus and method for communication software can automatically verify the result of a regression test without manually operating a terminal for the regression test, which results in the improved efficiency of the test operation. An automatic verification apparatus for communication software comprises a virtual terminal manager for performing a pseudo-operation of a terminal connector, one or more virtual terminals, each performing a pseudo-operation of a terminal, a scenario recording unit for recording the pseudo-operation performed by each virtual terminal as a scenario, a scenario executing unit for automatically executing the recorded pseudo-operation of the terminal, and a scenario verification unit for automatically verifying if the result of the automatic execution is correct whenever the recorded pseudo-operation of the terminal is automatically executed.
Abstract: A sequence controller includes a sequencer to which a basic clock is applied. The sequencer sequentially generates at a period of 125 &mgr;sec address signals for reading statements to be executed at a period of 125 &mgr;sec and one block of statements to be executed at a period of 10 msec or one block of statements to be executed at a period of 100 msec. A memory stores the above statements beforehand. The statements are selectively read out of the memory in accordance with the address signals and fed to a decoder. The decoder decodes the statements and generates control signals respectively corresponding to the statements and feeds the control signals to a switch. The switch controls each of a plurality of function registers on the basis of the respective control signal.
Abstract: An M-sequence generator has a linear feedback shift register, a mask table, a masked operation circuit, and a control unit. The mask table stores mask data corresponding to different phase shifts. The masked operation circuit performs logic operations on the mask data and the contents of the linear feedback shift register to obtain shifted register state data. The control unit selects the mask data, and loads the shifted register state data into the linear feedback shift register. An arbitrary phase shift is produced as a sum of phase shifts for which mask data are stored in the mask table.