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
Liquid-level sensor
Method for fabricating a nitrided silicon-oxide gate dielectric
Near-field optical disk having surface plasmon amplification by stimulated emission of radiation
Intermediate film for laminated glasses, and laminated glass
Device and implantation system for electrical stimulation of biological systems
Macrocyclic cysteine protease inhibitors and compositions thereof
Data processing circuit with arbitration between a plurality of queues
  Randomly Featured Patents
Pyrido[1',2':4,5][1,4]oxazino[2,3-b]quinoxalines and pyrrolo[1',2':4,5][1,4]oxazino[2,3-b]quinoxalines
Deflection structure
Method of forming high temperature thermistors
Apparatus for the centrifugal separation of at least two liquid phases and one sedimentary phase of a mixture
Current steering variable gain amplifier with linearizer
Adapter skirt for static aerator mixer
Method for performing access procedure of mobile communication terminal in data communication system, and mobile communication terminal using the same
Surface pattern for a paper product
Method for providing fault tolerance to multiple servers
Common-gate transimpedance amplifier with dynamically controlled input impedance