Abstract:
The rotor of the joint includes two rectangular waveguide ports, carrying two separate signals. The stator has two corresponding rectangular waveguide ports. The ports are coupled with a circular waveguide, which comprises two relatively rotatable stub-cylinders, disposed co-axially in-line on the axis of rotation. Signal A is transmitted through the circular waveguide, across the joint, in the TM01 propagation mode, while signal B is transmitted across the joint in the TE01 mode. These circular-symmetrical modes, with mutually orthogonal field distribution, are able to cut cross-talk interference, since the mode transducers of these modes maintain good mutual isolation, even though the signals are present together in the circular waveguide, and at the same or similar frequency. The TM01 mode (signal A) is excited, and received, by means of slots formed in the end wall of the circular waveguide stubs. The port for signal A communicates with the circular waveguide through the two slots. The TE01 mode (signal B) is excited, and received, by means of four axial slots formed in the cylindrical wall of the circular waveguide. The transducer for signal B is disposed in a wrap-around relationship with the circular waveguide, and is in communication with the circular waveguide through the four slots. An E-plane junctional continuation communicates the port for signal B, via two slots, with the transducer for signal B.
Abstract:
A transition device achieves transformation of the signal carrier mode of a continuous wave guide, into the hybrid mode, the corresponding mode for carrying signals in corrugated structures, by employing a tapered waveguide transition of circular cross-section having dual-depth circumferential slots in the interior boundary surface thereof. The transition device utilizes a mutual resonance property of the slots at the port which connects to a continuous waveguide to achieve satisfactory operation in two frequency bands. At the port which is connected to a corrugated horn, the quarter wavelength self resonance of the individual slots provides the desired hybrid mode under balanced hybrid condition in these two bands. A gradual transition of the electrical characteristics is achieved along the length of the transition device through an adjustment of slot dimensions. Excitation of higher order spurious modes is maintained at a low level when properly chosen cross-sectional dimensions are considered along the length of the transition device.
Abstract:
Systems and methods for hardware-accelerated key color extraction are disclosed. An update corresponding to a portion of a digital representation of a display screen is received. Key color information for locations within the update is identified. A data structure code associated with the portion of the digital representation of the display screen is determined based on the identification of the key color information. The data structure code is provided to a data structure. During a scan of the frame buffer for display, the frame buffer is capable of being read according to the data structure.
Abstract:
The video output system in a computer system reads pixel information from a frame buffer to generate a video output signal. In addition, full-motion video may also be displayed in a window defined in the frame buffer. If the native resolution of the full-motion video is larger than the window defined in said frame buffer then valuable memory space and memory bandwidth is being wasted by writing said larger full-motion video in a memory system (and later reading it back) when some data from the full-motion video will be discarded. Thus, a video pre-processor is disclosed to reduce the size of the full-motion video before that full-motion video is written into a memory system. The video pre-processor will scale the full-motion video down to a size no larger than the window defined in the frame buffer.
Abstract:
Thin-client terminal systems allow computer systems to be shared by multiple computer users. With modern technology, the cost of implementing a thin-client terminal system can be very low. To improve thin-client terminal systems, a thin-client terminal system accepts user input data in a first serial interface format and transcodes the user input data into a second serial interface format for transmission to a server.
Abstract:
A device and a method of authenticating an electronic device are described. The method may comprise transmitting a token value and a parameter value to the electronic device and selecting a private key within the electronic device using the parameter value. The token value may be processed with a method selected by the parameter value to generate a processed token. The processed token may be compared with an expected processed token and the electronic device may be authenticated if the processed token compares favorably with said expected processed token.
Abstract:
In a system and method for a thin-client terminal system having a local screen buffer using a serial bus, a serial bus interface device receives encoded data from a thin-client server system. The serial bus interface device decodes the encoded data according to a serial bus data format and provides the decoded data to a thin-client control system. The thin-client control system distributes the decoded data for processing to a video processing system, an audio processing system, and an input/output control system. The thin-client control system also receives input data from input devices connected to the thin-client terminal system. The input data is processed and encoded according to the serial bus data format for transmission to the thin-client server system.
Abstract:
Graphics display adapters for driving multiple display monitors have become very popular. Graphics display adapters that drive multiple monitors can be used to provide terminal services to multiple independent terminals or be used to provide multiple displays to a single user. Generating video signals for multiple display systems puts a heavy burden on the video memory system since multiple different video signal generators may read from associated frame buffers in a shared video memory system. In one disclosed embodiment, a plurality of video memory read triggers are provided wherein at least two of which are staggered to reduce the load on the video memory system. In response to each read trigger, display data is read from a frame buffer to an associated video signal generation circuit. Each video signal generation circuit then provides a display signal to an associated display screen in a multi-screen environment.
Abstract:
The video output system in a computer system reads pixel information from a frame buffer to generate a video output signal. In addition, a full-motion video may also be displayed. Reading from both the frame buffer and the full-motion video buffer when displaying the full-motion video window wastes valuable memory bandwidth. Thus, the disclosed system provides a system and methods for identifying where the video output system must read from the frame buffer and where it must read from the full-motion video buffer while minimizing the amount of area it reads from both the frame buffer and the full-motion video buffer.
Abstract:
When a PCI-bus controller receives a request from a PCI-bus master to transfer data with an address in secondary memory, the controller performs an initial inquire cycle and withholds TRDY# to the PCI-bus master until any write-back cycle completes. The controller then allows the burst access to take place between secondary memory and the PCI-bus master, and simultaneously and predictively, performs an inquire cycle of the L1 cache for the next cache line. In this manner, if the PCI burst continues past the cache line boundary, the new inquire cycle will already have taken place, or will already be in progress, thereby allowing the burst to proceed with, at most, a short delay. Predictive snoop cycles are not performed if the first transfer of a PCI-bus master access would be the last transfer before a cache line boundary is reached.