Linearity Optimisation for Multi-Bit Digital Power Amplifier

Ma, Jiteng; Nair, Manish; Watkins, Gareth; Morris, Kevin; Beach, M.A.

doi:10.1109/pawr53092.2022.9719716

“…In this way, optimal power levels are elaborately selected to minimize the EVM. If an uniform quantization was selected, the EVM would be 3 dB lower on average [30]. With the presented algorithm, the resulting codebook and input signal partition for an eight-level DPA is reported in Table I.…”

Section: B Dpa Control Strategymentioning

confidence: 99%

Highly Efficient 3-Bit Digital Power Amplifier for OFDM Waveform Amplification

Ma

¹

,

Jindal

²

,

Nair

³

et al. 2023

IEEE Trans. Microwave Theory Techn.

4

0

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In this work, we present a digital power amplifier (DPA) and a signal-optimized control technique suitable for the amplification of orthogonal frequency division multiplexing (OFDM). OFDM is a high peak-to-average power ratio (PAPR) signal that is naturally arising from high spectrum efficiency modulations. A three-bit DPA is implemented with three powerscaled transistors which are turned on and off based on the signal amplitude, while phase modulation is restored using the RF input signal. The unavoidable non-linearities at the DPA output due to the PA switching are minimized by accounting for the OFDM signal probability density function (PDF). This PDF is a priori knowledge to design an optimal quantizer that minimizes distortion by distributing the DPA power levels where the signal amplitude is more similar to the original one. Back-off efficiency within 2 3 = 8 possible states is then optimized by implementing a load-modulating power combiner. Theory and an example design of the combiner network are provided and demonstrated for this DPA. The reported DPA prototype operates at 1.5 GHz with a three-bit control and achieves a maximum power-added efficiency (PAE) of 64.3% and maintains a drain efficiency greater than 47% over the output power range from 36.6 to 45.2 dBm (8.6 dB range).

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“…In this way, optimal power levels are elaborately selected to minimize the EVM. If an uniform quantization was selected, the EVM would be 3 dB lower on average [29]. With the presented algorithm, the resulting codebook and input signal partition for an eight-level DPA are reported in Table I.…”

mentioning

confidence: 99%

Highly Efficient 3-Bit Digital Power Amplifier for OFDM Waveform Amplification

Ma¹,

Jindal²,

Nair³

et al. 2022

Preprint

0

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<p>In this work, we present a digital power amplifier (DPA) and a signal-optimized control technique suitable for the amplification of orthogonal frequency division multiplexing (OFDM). OFDM is a high peak-to-average power ratio (PAPR) signal that is naturally arising from high spectrum efficiency modulations. A 3-bit DPA is implemented with three power-scaled transistors which are turned on and off based on the signal amplitude, while phase modulation is restored using the RF input signal. The unavoidable non-linearities at the DPA output due to the PA switching are minimized by accounting for the OFDM signal probability density function (PDF). This PDF is a priori knowledge to design an optimal quantizer that minimizes distortion by distributing the DPA power levels where the signal amplitude is more similar to the original one. Back-off efficiency within 2^3=8 possible states is then optimized by implementing a load-modulating power combiner. Theory and an example design of the combiner network are provided and demonstrated for this DPA. The reported DPA prototype operates at 1.5 GHz with a 3-bit control and achieves a maximum power-added efficiency (PAE) of 64.3% and maintains a drain efficiency greater than 47% over the output power range from 36.6 to 45.2dBm (8.6dB range).</p>

show abstract

Highly Efficient 3-Bit Digital Power Amplifier for OFDM Waveform Amplification

Ma¹,

Jindal²,

Nair³

et al. 2022

Preprint

Self Cite

0

View full text Add to dashboard Cite

<p>In this work, we present a digital power amplifier (DPA) and a signal-optimized control technique suitable for the amplification of orthogonal frequency division multiplexing (OFDM). OFDM is a high peak-to-average power ratio (PAPR) signal that is naturally arising from high spectrum efficiency modulations. A 3-bit DPA is implemented with three power-scaled transistors which are turned on and off based on the signal amplitude, while phase modulation is restored using the RF input signal. The unavoidable non-linearities at the DPA output due to the PA switching are minimized by accounting for the OFDM signal probability density function (PDF). This PDF is a priori knowledge to design an optimal quantizer that minimizes distortion by distributing the DPA power levels where the signal amplitude is more similar to the original one. Back-off efficiency within 2^3=8 possible states is then optimized by implementing a load-modulating power combiner. Theory and an example design of the combiner network are provided and demonstrated for this DPA. The reported DPA prototype operates at 1.5 GHz with a 3-bit control and achieves a maximum power-added efficiency (PAE) of 64.3% and maintains a drain efficiency greater than 47% over the output power range from 36.6 to 45.2dBm (8.6dB range).</p>

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Linearity Optimisation for Multi-Bit Digital Power Amplifier

Cited by 3 publications

References 8 publications

Highly Efficient 3-Bit Digital Power Amplifier for OFDM Waveform Amplification

Highly Efficient 3-Bit Digital Power Amplifier for OFDM Waveform Amplification

Highly Efficient 3-Bit Digital Power Amplifier for OFDM Waveform Amplification

Highly Efficient 3-Bit Digital Power Amplifier for OFDM Waveform Amplification

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