MY136667A - Receiving circuit - Google Patents

Abstract

A RECEIVING CIRCUIT MAINLY AVAILABLE IN A DIGITAL MODULATION TYPE COMMUNICATION SYSTEM HAVING A PLURALITY OF CHANNELS, WHICH IS CAPABLE OF REDUCING POWER IN A RECEIVING SYSTEM, SIMPLIFYING THE CIRCUIT AND REDUCING THE POWER CONSUMPTION. UPSIDE AND DOWNSIDE FREQUENCIES CORRESPONDING TO A CENTRAL VALUE BETWEEN CHANNELS ARE SEPARATELY SUPPLIED FROM A LOCAL FREQUENCY SIGNAL GENERATING CIRCUIT 4 TO FIRST AND SECOND FREQUENCY CONVERTING CIRCUITS 2, 3 SO THAT TWO OUTPUT SIGNALS ARE DEVELOPED WITH RESPECT TO ONE OF A DESIRED WAVE, UPSIDE CHANNEL AND DOWNSIDE CHANNEL. THE DESIRED WAVE PRESENT IN COMMON IN THE FIRST AND SECOND FREQUENCY CONVERTING CIRCUITS 2, 3 IS EXTRACTED IN A COMMON WAVE EXTRACTING CIRCUIT 5, AND A FREQUENCY OFFSET OF ?O EXISTING IN THE OUTPUT OF THE COMMON WAVE EXTRACTING CIRCUIT 5 IS REMOVED A FREQUENCY OFFSET CIRCUIT 6 AND FURTHER AN UNNECESSARY FREQUENCY COMPONENT IS FILTERED BY A FILTER 8. IN ADDITION, THE COMMON WAVE EXTRACTING CIRCUIT 5 HAS TRANSFORMERS AND, USING ITS INDUCTANCES, RAISES THE DIFFERENCE BETWEEN THE COMMON WAVE AND THE NON-COMMON WAVE WITHIN THE CIRCUIT TO MORE THAN TWO TIMES THAT OF A PRIOR ART.(FIG.1)