Resources Contact Us Home
Polarization direction synchronization detecting circuit and receiving apparatus

Image Number 7 for United States Patent #8131160.

A switch is to be inputted a modulation signal including the synchronization signal extracted from a received communication signal as a control signal, is to be inputted a detection signal detected by a photodetector that receives a polarization modulation signal adjusted to a polarization direction of a quantum cipher signal, and selectively switches and outputs one of the detection signal and an inverted signal of the detection signal according to the control signal. A low-pass filter outputs the output signal of the switch, whereby a plus level signal is outputted when a relative angle difference .DELTA..theta. between polarization axes on a transmission side and a reception side is larger than a predetermined polarization angle, a 0 level signal is outputted when .DELTA..theta. is equal to the predetermined polarization angle, and a minus level signal is outputted when .DELTA..theta. is in a range of the predetermined polarization angle from 0 degree.

  Recently Added Patents
Subpixel-based image down-sampling
Vehicle drive control system
Anthranilic diamide compositions for propagle coating
Methods, systems, and computer program product for virtually modifying surface region curvature to detect protrusions
Phosphor adhesive sheet, light emitting diode element including phosphor layer, light emitting diode device, and producing methods thereof
Methods and systems providing desktop search capability to software application
Label printer
  Randomly Featured Patents
Method of molding a polymer composition containing a tetraalkenyl orthosilicate
Novel-17-spirosultines their corresponding hydroxy acids and compositions thereof
Teddy bear calendar
Magnetic disk drive with a filter assembly capable of removing dust and toxic gases
Lock-In Training system
Gas spring end member
Method and apparatus for monitoring molecular contamination of critical surfaces using coated SAWS
Method of preventing adhesions with absorbable polyoxaesters
Sampling/quantization converters
Freight containers