ANALOG FRONT PART FILTER STRUCTURE FOR TRANSMITTING AND RECEIVING AN OKK AND FSK DUAL MODE, CAPABLE OF REDUCING MANUFACTURING COSTS BY USING ONE DEMODULATION MODULE

摘要

PURPOSE: An analog front part filter structure for transmitting and receiving an OKK and FSK dual mode is provided to remove a harmonic signal of an OKK modulation signal and an FSK modulation signal by adding a low pass filter.;CONSTITUTION: A band pass filter(410) comprises a first band pass filter and a second band pass filter. A modulation and demodulation circuit unit includes a first modulation module(420), a second modulation module(430), and a dual mode demodulation module(440). A switching unit switches the signal between the band pass filter and the modulation and demodulation circuit unit. The band pass filter includes a third filter which blocks harmonic signals of the signal generated in the first modulation and demodulation module. The third filter blocks the harmonic signals inputted to the second band pass filter. A third filter blocks the harmonic signals of the signal generated in the first demodulation module, which is inputted to the first band pass filter.;COPYRIGHT KIPO 2011