Hughes Aircraft Company

Other

Kim V Gould

Victor S Reinhardt

Charles R Abraham

Kevin M McNab

George S Des Brisay, Jr

Michael H Porte

Michael D Elliott

A 'video fax' system electronically delivers a non-real time, full-motion, sub-broadcast quality facsimile of relatively short segments of video material from an originating location to a receiving location in a short period of time, utilizing selected widely available commercial telephone switched networks. At the originating location, analog source material is digitized, compressed, prepared for transmission and stored temporarily. Digital source material is handled by bypassing the digitization step and part of the compression step, and performing the necessary file conversion. The sending location dials up the receiving location, and a connection is established. The digital file is transmitted over the network. When finished, the connection is terminated. At the receiving location, the material is received, decompressed and converted back to either analog form or digital form, depending on the recipient's preference. Compression and decompression are each performed in two stages, with a real-time component performed at full-frame rate, and an offline secondary reduced frame-rate component. Alternatively, the compression is performed entirely at the reduced frame rate, which involves undoing of the compression component performed in real-time. The corresponding decompression involves decompressing entirely at a reduced frame rate, followed by recompressing in preparation for full-frame rate real-time decompression. Transmission over the telephone network is performed concurrently with the reduced frame rate compression, resulting in an overall faster transfer.

System and method for transmitting video material

A sine output or phase interpolation direct digital synthesizer for use in satellite programs having a random or pseudorandom code generator for summing a random digital word whose value ranges from zero to just under the least significant bit of a digital-to-analog converter with the current register value normally sent to the converter for reducing the spurious sidebands associated with the finite resolution of the converter within the synthesizer, the sum being truncated to the resolution of the converter and for controlling the converter, the spurious sidebands being reduced by randomization of the periodic behavior associated with the truncation process while lowering the total phase noise.

Randomized digital/analog converter direct digital synthesizer

A phase lock loop frequency synthesizer for providing a synthesized frequency signal employing a modified adaptive loop construction having parallel feedback paths about a loop amplifier. A normal feedback path having a narrow bandwidth characteristic includes a feedback capacitor having one end connected to electrical ground via a controlled switch and a second feedback path having a wide bandwidth characteristic with a capacitor also connected across the amplifier. Upon the variation of an incoming reference signal, the controlled switch connects the normal feedback capacitor to ground permitting the wide bandwidth feedback path to rapidly settle the loop while charging the feedback capacitor of the normal feedback path. Upon opening the controlled switch, the narrow bandwidth feedback path completes the charging of the feedback capacitor of the normal feedback loop settling the loop to the steady state condition while enhancing the settling time.

Fast settling phase lock loop

Growing community of inventors

Hermosa Beach, CA, United States of America

Kim V Gould