Polar Transmitter Incorporates 2.4-GHz PA

Oct. 20, 2011
SWITCHING POWER amplifiers (PAs) boast higher efficiency compared to linear PAs. Yet they cannot be directly applied in systems employing spectrally efficient modulation. One solution proposed to "break" this tradeoff is polar modulation. ...

SWITCHING POWER amplifiers (PAs) boast higher efficiency compared to linear PAs. Yet they cannot be directly applied in systems employing spectrally efficient modulation. One solution proposed to "break" this tradeoff is polar modulation. At the University of California, a 2.4-GHz mixed-signal, polar-modulated PA in 65-nm CMOS has been demonstrated by Debopriyo Chowdhury, Lu Ye, Elad Alon, and Ali M. Niknejad.

Their digitally modulated polar transmitter houses a 2.4-GHz switching, Inverse Class D PA. When operating from a 1-V supply, that PA delivers +21.8 dBm peak output power with 44% efficiency. The transmitter also integrates the local-oscillator (LO) distribution network and digital drivers. To aid in the removal of spectral images for improved coexistence, this solution relies on low-power digital filtering on the amplitude path.

Thanks to simple static predistortion, the transmitter meets error-vector-magnitude (EVM) and mask requirements of IEEE 802.11g WLAN data with 18% average efficiency at +14 dBm output power. At this performance level, the transmitter consumes an average of 150 mW. See "An Efficient Mixed-Signal 2.4-GHz Polar Power Amplifier in 65-nm CMOS Technology," IEEE Journal Of Solid-State Circuits, Aug. 2011, p. 1796.

Sponsored Recommendations

Wideband MMIC LNA with Bypass

June 6, 2024
Mini-Circuits’ TSY-83LN+ wideband, MMIC LNA incorporates a bypass mode feature to extend system dynamic range. This model operates from 0.4 to 8 GHz and achieves an industry leading...

Expanded Thin-Film Filter Selection

June 6, 2024
Mini-Circuits has expanded our line of thin-film filter topologies to address a wider variety of applications and requirements. Low pass and band pass architectures are available...

Mini-Circuits CEO Jin Bains Presents: The RF Engine of the 21st Century

June 6, 2024
In case you missed Jin Bains' inspiring keynote talk at the inaugural IEEE MTT-S World Microwave Congress last week, be sure to check out the session recording, now available ...

Selecting VCOs for Clock Timing Circuits A System Perspective

May 9, 2024
Clock Timing, Phase Noise and Bit Error Rate (BER) Timing is critical in digital systems, especially in electronic systems that feature high-speed data converters and high-resolution...