FM RECEIVER AND INTEGRATED CIRCUIT DEVICE FOR FM SIGNAL PROCESSING

摘要

PURPOSE:To simplify the circuit constitution, and to reduce the size and cost, by replacing the 2nd frequency converting stage into a frequency-division circuit with high speed and high frequency characteristics constituted with an ECL circuit system. CONSTITUTION:FM radio frequency signal electromagnetic waves of a specified high frequency band received at an antenna ANT are amplified at an RF amplifying stage 1 and transmitted to the 1st frequency converting stage at the next stage. The 1st frequency converting stage consists of a mixing circuit 3 frequency-mixing a local oscillating frequency signal formed with a local oscillation circuit 2 and an RF amplifying output signal, and the 1st intermediate frequency filter. An output IF1 of the mixing circuit 3 is inputted to a frequency division circuit 5 of the 2nd frequency converting stage through a limiter amplifier 4 and a frequency-division output IF2 is inputted to a quadrature FM detection stage 6 for detection.