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
Flexible pouch
Tab visibility
RFID device using single antenna for multiple resonant frequency ranges
Electronic device
Recombinant vectors for use in position-independent transgene expression within chromatin
Smart television system having methods or means for accessing paid or subscribed digital content from the internet
Vehicle headlight
  Randomly Featured Patents
Optical pickup for enabling accurate measurement of various characteristics thereof without increasing the number or parts
Soft baby bottle
Console for vehicle
Automatic adjustment of logical channels in a fibre channel network
Processor, data processing system and method for synchronzing access to data in shared memory
Automatic segmentation of prostate, rectum and urethra in ultrasound imaging
Readhering and removable adhesive
Recording and/or reproducing apparatus displaying identification information
Integrated reactant and coolant fluid flow field layer for an electrochemical fuel cell