Abstract:
A combined linear and delta-modulated (DeltaM) switch-mode PA supply modulator for polar transmitters in wireless handsets is designed in a 0.25 mum CMOS process. The mod...Show MoreMetadata
Abstract:
A combined linear and delta-modulated (DeltaM) switch-mode PA supply modulator for polar transmitters in wireless handsets is designed in a 0.25 mum CMOS process. The modulator employs a DeltaM switch-mode DC-DC buck converter to enhance the efficiency of a linear regulator at backed-off supply voltages and powers. The delta-modulator's noise-shaping characteristic, linear regulator's power supply rejection, digital pre-emphasis of the input envelope, and a closed-loop amplitude path from the PA output are simultaneously used to achieve state-of-the-art modulator performance. The presented supply modulator follows the input signal's envelope with 20 dB output dynamic range, maximum efficiency of 75.5% at an output power of 30.8 dBm, and 75 dB SFDR for envelope signals up to 4 MHz occupied RF bandwidth. For a 1625 kb/s 8 PSK RF input signal at 900 MHz, polar modulation of a commercial low-power GSM-900 PA provides 10 dB ACPR improvement.
Published in: IEEE Journal of Solid-State Circuits ( Volume: 44, Issue: 2, February 2009)
Keywords assist with retrieval of results and provide a means to discovering other relevant content. Learn more.
- IEEE Keywords
- Index Terms
- Supply Module ,
- Output Power ,
- Input Signal ,
- Linear Mode ,
- Supply Voltage ,
- Instantaneous Amplitude ,
- CMOS Process ,
- Buck Converter ,
- RF Input ,
- Low-pass ,
- Maximum Yield ,
- Output Signal ,
- Power Conversion ,
- Phase Information ,
- System Input ,
- Power Devices ,
- Network Bandwidth ,
- Output Filter ,
- Signals In Order ,
- Frequency Conversion ,
- Converter Output ,
- Highest Noise ,
- Effective Bandwidth ,
- Converter Switching ,
- Path Delay ,
- Input Stage ,
- Clock Frequency ,
- Output Spectrum ,
- Dominant Pole ,
- Switching Network
- Author Keywords
Keywords assist with retrieval of results and provide a means to discovering other relevant content. Learn more.
- IEEE Keywords
- Index Terms
- Supply Module ,
- Output Power ,
- Input Signal ,
- Linear Mode ,
- Supply Voltage ,
- Instantaneous Amplitude ,
- CMOS Process ,
- Buck Converter ,
- RF Input ,
- Low-pass ,
- Maximum Yield ,
- Output Signal ,
- Power Conversion ,
- Phase Information ,
- System Input ,
- Power Devices ,
- Network Bandwidth ,
- Output Filter ,
- Signals In Order ,
- Frequency Conversion ,
- Converter Output ,
- Highest Noise ,
- Effective Bandwidth ,
- Converter Switching ,
- Path Delay ,
- Input Stage ,
- Clock Frequency ,
- Output Spectrum ,
- Dominant Pole ,
- Switching Network
- Author Keywords