TẦNG SỐ SÓNG MANG THAY ĐỔI - 7 ppt

/4 8 9/12/2010 9/12/2010 43 43 Direct PM modulators Direct PM modulators • • Transistor direct PM modulator Transistor direct PM modulator /4 8 9/12/2010 9/12/2010 44 44 Frequency up Frequency up - - conversion conversion • • Heterodyning process Heterodyning process • • Frequency multiplication Frequency multiplication /4 8 9/12/2010 9/12/2010 45 45 Heterodyning process Heterodyning process /4 8 9/12/2010 9/12/2010 46 46 Multiplication method Multiplication method . modulator Transistor direct PM modulator /4 8 9/12/2010 9/12/2010 44 44 Frequency up Frequency up - - conversion conversion • • Heterodyning process Heterodyning process • • Frequency multiplication Frequency