• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.159-160
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• 2007

Two analog predsitorters (PDs) using the mixing operation are proposed to compensate for the memory effects of the power amplifier and then significantly cancel IM3 components with the independent control of IM3 terms. In the first PD, IM3 terms are generated by using mixing operation of low frequency terms. In the second PD, the double mixing operation of the fundamental components is used. For a two-tone signal with 20-MHz tone spacing, the notable IM3 suppression is achieved over a whole output power range.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.10
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• pp.41-49
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• 2004

Nonlinear distortion introduced by the optical transmitter using a direct modulation of laser diode(LD) and an indirect modulation of optical modulator can limit considerably the performance of analog optical link system such as subcarrier multiplexing system. In this paper, we have compensated the nonlinear distortion of LD and optical modulator using electrical predistorter. In the case of LD, two-tone experiments using 877.5 MHz and 882.5 MHz have shown reduction of 19 dB in third-order intermodulation product(IMP$_3$). And in the case of optical modulator, we have achieved nearly 21 dB reduction in IMP3 through two-tone experiments using 1.8975 GHz and 1.9025 GHz. The spurious free dynamic ranges of LD and optical modulator are also improved by 5 dB/Hz$^{2}$ 3/ and 7 dB/Hz$^{2}$ 3/, respectively.