A class B totem pole power amplifier is presented. The amplifier has a small signal bandwidth of 23MHz and is capable of driving a 1MHz sinsuiodal signal into a 7.5Ω load resistance at an output power of 3.7W. When amplifying the AC envelope component of a 20MHz bandwidth 3GPP Long Term Evolution (LTE) signal, 2W is produced into the 7.5Ω load. By optimising the supply rails based on the characteristics of the envelope signal, an efficiency of 31% is achieved. When combined with a switched mode power supply, it forms an envelope modulator that can achieve 61.6% efficiency at 9.3W output power with an output peak-to-average power ratio of 8.5dB.

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Correspondence

This article has following corresponding article(s):

pushing the envelope

High bandwidth class B totem pole power amplifier for envelope modulators

References

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