Frequency shifting circuit

Abstract

Abstract PURPOSE:To obtain phase information from a synchronizing signal which comes up to the current standards, and simplify the constitution of a frequency shifting circuit by providing a means of frequency conversion by amplitude modulation and controlling the phase of a carrier signal for frequency conversion to a specified value at fixed period. CONSTITUTION:The highly defined signal component of a luminance signal Y sampled at each sampling point in each line on a transmission side is extracted through a BPF6 and inputted to one terminal of a multiplier 8. A coefficient generating circuit 7 generates carrier signal values corresponding to the respective sampling points on the basis of the start of a horizontal synchronizing signal HD and applies them to the other terminal of the multiplier 8, and a BPF9 extracts the signal component in a frequency-shifted area according to the multiplication result. A multiplier 11 on a reception side multiplies the frequency-shifted highly defined signal by a carrier frequency corresponding to each sampling point which is generated by a circuit 10 to apply the multiplication result to a BPF12, which extracts the desired high defined signal, thereby simplifying the constitution of the frequency shifting circuit.

Inventors

• 👤 Yasuhiro Hirano
• 👤 裕弘 平野
• 👤 Hiroshi Yoshiki
• 👤 宏 吉木
• 👤 Norihiko Fukinuki
• 👤 吹抜　敬彦

Bibliographic Details