Regulated suppressed carrier modulation system
Microwave integrated circuit frequency converter
Frequency converter used for a receiver which receives signals of a UHF band or a microwave band Patent #: 4731875
ApplicationNo. 449616 filed on 05/24/1995
US Classes:455/302, Image frequency suppression455/285With image frequency suppression
ExaminersPrimary: Eisenzopf, Reinhard J.
Assistant: Nguyen, Lee
Attorney, Agent or Firm
Foreign Patent References
International ClassH04B 001/10
Foreign Application Priority Data1994-06-06 FR
AbstractIn a device for rejecting the image signal of a signal converted to a predetermined intermediate frequency, a local oscillator supplies a local signal at a frequency chosen according to the frequency of the signal and the intermediate frequency. A first phase-shifter has two passive phase-shifter cells including resistive and capacitive components and respectively connected to the output of the oscillator to supply two mixer signals in phase quadrature. Two mixers receive an input signal containing a signal and its image signal and a respective mixer signal and supply two intermediate signals at the intermediate frequency. A second phase-shifter comprises two passive phase-shifter cells comprising resistive and capacitive components and respectively connected to the outputs of the two mixers to introduce a further phase quadrature relationship between the two intermediate signals. A summing device connected to the outputs of the two passive phase-shifter cells of the second phase-shifter eliminates the image signal.