• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.12A
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• pp.1242-1250
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• 2008

In this paper, we predicted the radiation field strength from the low power radio devices to force the radio interference on the AMPS receiver. The predicted value of 79.13[$dB{\mu}V/m$] is the upper value of radiation against the intermodulation interference emanated from the low power radio devices. To show the validity of the suggested values theoretical analysis on intermodulation and modeling of the AMPS receiver are performed, and also measurements on the AMPS receiver IC are carried out. The resultant numerals show the good match between them within the allowable tolerances.

• Proceedings of the IEEK Conference
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• 2004.06a
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• pp.201-204
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• 2004

In this paper, a down-converter that can work for L-band RF front-end of DMB receiver is designed. Since DRK-02, a reference for our work, had been designed for a stationary receiver, not for mobile one, the supply voltage is set relatively high of 8.5V. We improve it with 3.3V and save design space and cost by employing only one Mixer and IF_Amp comparing to the reference one in which two Mixers and two IF_Amps are used.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2006.05a
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• pp.302-305
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• 2006

A problem that arises in most communication receivers concerns the wide variation in power level of the signals received at the antenna. These variations cause serious problems which can usually be solved in receiver design by using Automatic Gain Control (AGC). AGC is achieved by using an amplifier whose gain can be controlled by external current or voltage. However, the AGC circuit does not respond to rapid changes in the amplitude of input. If input changes instantaneously, then even if op-amps could follow the change, the envelope detector capacitor could not, since the capacitor's voltage could not change instantaneously. To alleviate this deficiency, we present Improved Automatic Gain Control Circuit (IAGCC) replacing AGC circuit to FLC.