Digitally enhanced CMOS RF transmitter with integrated power amplifier

Kwon, Dae Hyun

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https://hdl.handle.net/2142/15601 Copy

Description

Title

Digitally enhanced CMOS RF transmitter with integrated power amplifier

Author(s)

Kwon, Dae Hyun

Issue Date

2010-05-14T20:52:05Z

Director of Research (if dissertation) or Advisor (if thesis)

Chiu, Yun

Doctoral Committee Chair(s)

Chiu, Yun

Committee Member(s)

• Feng, Milton
• Rosenbaum, Elyse
• Schutt-Ainé, José E.

Department of Study

Electrical & Computer Eng

Discipline

Electrical & Computer Engr

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• Adaptive equalizer
• AM-AM
• AM-PM
• Class-B power amplifier
• Complementary metal-oxide semiconductor radio frequency (CMOS RF) transmitter
• digital equalization
• drain efficiency
• error-vector magnitude
• look-up table
• memoryless nonlinearities
• orthogonal frequency-division multiplexing (OFDM)
• peak-to-average power ratio
• power-added efficiency
• power amplifier
• predistortion
• Complementary metal–oxide–semiconductor (CMOS)
• Radio frequency (RF)

Abstract

An energy-efficient, 3.5 GHz, direct-conversion RF transmitter with integrated 23 dBm, Class-B power amplifier (PA) is fabricated in a 0.13 μm CMOS process. The TX chip is packaged using a low-cost chip-on-board (COB) technique. When 20-MHz bandwidth OFDM signals are transmitted, a high TX average power efficiency is achieved exploiting the dynamic current biasing of the Class-B PA and a low-loss output matching network using high-Q bondwire inductances in the package. Assisted by an integrated feedback path, a two-dimensional, digital look-up table (2-D LUT) adapted by complex gradient-descent algorithms compensates the I/Q mismatch and memoryless nonlinearities of the whole transmit path, including the severe amplitude and phase distortions of the on-chip PA. Fifth-order Butterworth transmit filters with 34 MHz cutoff frequency sufficiently attenuate the aliases of the 80 MS/s digital-to-analog converters (DACs), while retaining high in-band fidelity without corrupting the predistorted signal. When a 20 MHz, 64-QAM OFDM signal with 9.6 dB peak-to-average power ratio (PAPR) was transmitted, the measured average drain efficiency (DE) of the PA was 12.5% at 9.6 dB back-off and 17.5% at 7 dB back-off, and the corresponding error-vector magnitude (EVM) was measured −29.6 dB and −26.3 dB with equalization, respectively. Peak DE of 55% and 25 dBm saturated output power were also measured for the same PA in a stand-alone package.

Graduation Semester

2010-5

Permalink

http://hdl.handle.net/2142/15601

Copyright and License Information

Copyright 2010 Dae Hyun Kwon

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