| 摘要 |
PURPOSE:To increase the number of combinations between signals I and Q to 55 from conventional 27, by dividing the signals I and Q of a single frequency and obtaining an IQ signal which contains no 2nd higher harmonic wave. CONSTITUTION:An input video signal (x) is supplied to a superposing circuit 1 which superposes signals I and Q as well as to a synchronism detector 3 in an I/Q signal generating circuit 2. The circuit 2 forms 11 types of combinations of single frequency signals (twice as much as the basic frequency of the original IQ signal) obtained from an IQ signal generator 6 and on the basis of the detected synchronizing signal. The output of combination is applied to a frequency divider 15. The division output of the divider 15 is set so as to be coincident with the basic frequency of the IQ signal. As a result, a waveform containing no 2nd higher harmonic wave is obtained. For the output of the divider 15, the 3rd and higher harmonic waves are suppressed to obtain an IQ signal with all higher harmonic waves eliminated. |
