1 An InGaP–GaAs HBT MMIC Smart Power Amplifier for W-CDMA Mobile Handsets 指導老師 : 林志明...

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An InGaP–GaAs HBT MMIC Smart Power Amplifierfor W-CDMA Mobile Handsets

指導老師 :林志明學生 :黃政德系級 :積體所研一

IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 38, NO. 6, JUNE 2003

Joon Hyung Kim, Ji Hoon Kim, Youn Sub Noh, Student Member, IEEE, and Chul Soon Park, Member, IEEE

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Introduction 1

A conventional PA achieves its peak efficiency at the maximum output power.

As the output power level is reduced, the efficiency drastically drops.

New design for increasing the efficiency.

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Introduction 2

Bias current control

Bias voltage control

Dual-chain power amplifier: P1dB=16dBm , 28dBm

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Load line characteristics for the maximum output power

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Architecture of the dual-chain MMIC power amplifier

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Amplifier chain 1 is activated and chain 2 is disabled

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Proposed linearizer schematics using reverse diode capacitance

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Simulated gain compression and phase distortion of the power amplifier

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Schematic circuit of the dual-chain MMIC power amplifier

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Photograph of the dual-chain MMIC power amplifier

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Measured power gain and S11 of the dual-chain MMIC power amplifier

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Measured output power and dc average current

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Measured dc current and power added efficiency

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Measured gain and ACLR of the dual-chain MMIC power amplifier

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Conclusion

Propose a new structure of dual-chain power amplifier.

21% PAE and -33dBc ACLR at 16dBm output power (low).

40% PAE and -30dBc ACLR at 28dBm out power (high).

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REFERENCES

[1] T. Fowler, K. Burger, N.-S. Cheng, A. Samelis, E. Enobakhare, and S. Rohlfing, “Efficiency improvement techniques at low power levels for linear CDMA and WCDMA power amplifies,” in Proc. IEEE RFIC Symp., June 2002, pp. 41–44. [2] J. H. Kim, J. H. Kim, Y. S. Noh, and C. S. Park, “A bias controlled HBT MMIC power amplifier with improved PAE for PCS applications,” in Proc. 3rd Int. Conf. Microwave and Millimeter Wave Technology, Aug. 2002, pp. 725–728. [3] P. Asbeck, G. Hanington, P. F. Chen, and L. Larson, “Efficiency and linearity improvement in power amplifier for wireless communications,” in IEEE GaAs IC Symp. Tech. Dig., 1998, pp. 15–18. [4] G. Hanington, P. Chen, P. Asbeck, and L. Larson, “High-efficiency power amplifier using dynamic power supply voltage for CDMA application,” IEEE Trans. Microwave Theory Tech., vol. 47, pp. 1471–1476, Aug. 1999. [5] Y. S. Noh, T. W. Lee, and C. S. Park, “Linearized high efficient HBT power amplifier module for L-band application,” in IEEE GaAs IC Symp. Tech. Dig., 2001, pp. 197–200.