A Phase-Locked AM Radio Receiver

The problems in the microminiaturization of frequency selective circuits have shown the lack of adaptability of the presently used superheterodyne system, particularly in the lower frequency band, to the integrated radio receiver. By using phase-lock technique, the incoming signal can be converted to baseband directly, eliminating the need for intermediate frequency tuned circuits. A preliminary study has been made of the feasibility and the practicality of using phase-lock technique in the consumer AM Tadio receiver. A two-channel, phase-locked receiver is discussed in this paper. It is shown that this system offers not only the advantages of microminiaturization, but in many aspects, better performance as well.