An IF Communication Circuit Tutorial

mm Freescale Semiconductor, Inc. Order this documentSEMICONDUCTOR APPLICATION NOTE by AN1539/D Prepared by: Albert FranceschinoField Applications EngineerMotorola Semiconductor Product Sectorcorresponds to a park time of 0.4 seconds/channel. ThisABSTRACTscheme reduces the likelihood of co–channel interference byThis article is intended to be a tutorial on the use of IF intentionally limiting the amount of continuous time a carriercommunication integrated circuits. The ISM band channel remains on channel. The spectral power density (SPD)bandwidths and the Motorola MC13156 are used within this measurement criteria for either scheme is the same —article as a platform for discussion. An examination of the 8.0 dBm/3.0 kHz bandwidth. This is computed as follows:devices topology is provided along with a discussion of theclassical parameters critical to the proper operation of any (1 Watt) (3 kHz)SPD 10 log (dBm)typical IF device. The parameters reviewed are impedance (500 kHz) (1 mWatt)matching the mixer, selecting the quad tank and filters andIntuitively it may be obvious that spread spectrum systemsconcluding with a overview of bit error rate testing for digitalwould exhibit a better signal to noise ratio than theirapplications. Upon completion, the reader will have a betternon–spread counterparts. This improvement in S/N ratio isunderstanding of IF communications basics and will be abletermed ...