Conference Paper

A 330W distortion-cancelled Doherty 28V GaAsHJFET amplifier with 42% efficiency for W-CDMA base stations

NEC Compound Semicond. Devices, Ltd., Shiga
DOI: 10.1109/MWSYM.2006.249498 Conference: Microwave Symposium Digest, 2006. IEEE MTT-S International
Source: IEEE Xplore

ABSTRACT An L/S-band 330W distortion-cancelled Doherty GaAs FET amplifier has been successfully developed optimizing the main and the peak amplifiers load impedance shift. The amplifier employed a pair of 28V operation 150W GaAs heterojunction FETs. It demonstrated low third order intermodulation of -37dBc with a drain efficiency of 42% at an output power of 49dBm around 6dB back-off level under the two-carrier W-CDMA signals of 2.135GHz and 2.145GHz. To our knowledge, these represent the best results ever reported among the simple high power FET amplifiers for W-CDMA base stations. Moreover, we proposed the evaluation techniques to obtain each AM-AM and AM-PM characteristics of the main and the peak amplifiers in an operating Doherty amplifier, and for the first time, experimentally proved the distortion cancellation effect in the GaAs FET Doherty amplifier

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    ABSTRACT: An L/S-band 330-W distortion-cancelled Doherty GaAs field-effect transistor (FET) amplifier has been successfully developed optimizing the main and peak amplifiers load impedance shift. The amplifier employed a pair of 28-V operation 150-W GaAs heterojunction FETs. It demonstrated low third-order intermodulation of -37 dBc with a drain efficiency of 42% at an output power of 49 dBm around 6-dB backoff level under the two-carrier wideband code-division multiple-access (W-CDMA) signals of 2.135 and 2.145 GHz. To our knowledge, these represent the best results ever reported among the simple high-power FET amplifiers for W-CDMA base stations. In addition, we proposed the evaluation techniques to obtain each AM-AM and AM-PM characteristics of the main and peak amplifiers in an operating Doherty amplifier, and have experimentally proven the distortion cancellation effect in the GaAs FET Doherty amplifier
    IEEE Transactions on Microwave Theory and Techniques 01/2007; DOI:10.1109/TMTT.2006.883606 · 2.94 Impact Factor
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