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A 1V power amplifier for 81-86 GHz E-band

Tired, Tobias LU ; Sjöland, Henrik LU ; Bryant, Carl LU and Törmänen, Markus LU (2014) In Analog Integrated Circuits and Signal Processing 80(3). p.335-348
Abstract
The design and layout of a two stage SiGe E-band power amplifier using a stacked transformer for output power combination is presented. In EM-simulations with ADS Momentum, at E-band frequencies, the power combiner consisting of two individual single turn transformers performs significantly better than a single 2:1 transformer with two turns on the secondary side. Imbalances in the stacked transformer structure are reduced with tuning capacitors for maximum gain and output power. At 84 GHz the simulated loss of the stacked transformer is as low as 1.35 dB, superseding the performance of an also presented alternative power combiner. The power combination allows for a low supply voltage of 1 V, which is beneficial since the supply can then... (More)
The design and layout of a two stage SiGe E-band power amplifier using a stacked transformer for output power combination is presented. In EM-simulations with ADS Momentum, at E-band frequencies, the power combiner consisting of two individual single turn transformers performs significantly better than a single 2:1 transformer with two turns on the secondary side. Imbalances in the stacked transformer structure are reduced with tuning capacitors for maximum gain and output power. At 84 GHz the simulated loss of the stacked transformer is as low as 1.35 dB, superseding the performance of an also presented alternative power combiner. The power combination allows for a low supply voltage of 1 V, which is beneficial since the supply can then be shared between the power amplifier and the transceiver, thereby eliminating the need of a separate voltage regulator. To improve the gain of the two-stage amplifier it employs a capacitive cross-coupling technique not yet seen in mm-wave SiGe PAs. Capacitive cross-coupling is an effective technique for gain enhancement but is also sensitive to process variations as shown by Monte Carlo simulations. To mitigate this two alternative designs are presented with the cross coupling capacitors implemented either with diode coupled transistors or with varactors. The PA is designed in a SiGe process with f T = 200 GHz and achieves a power gain of 12 dB, a saturated output power of 16 dBm and a 14 % peak PAE. Excluding decoupling capacitors it occupies a die area of 0.034 mm2. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Power amplifier, E-band, mm-wave, Transformers, EM-simulation, Capacitive cross coupling
in
Analog Integrated Circuits and Signal Processing
volume
80
issue
3
pages
335 - 348
publisher
Springer
external identifiers
  • wos:000342079400003
  • scopus:84906949543
ISSN
0925-1030
DOI
10.1007/s10470-014-0338-5
language
English
LU publication?
yes
id
1e244ab1-b800-41af-a734-4f179392c48c (old id 4588186)
date added to LUP
2014-08-19 11:55:03
date last changed
2017-07-09 03:55:08
@article{1e244ab1-b800-41af-a734-4f179392c48c,
  abstract     = {The design and layout of a two stage SiGe E-band power amplifier using a stacked transformer for output power combination is presented. In EM-simulations with ADS Momentum, at E-band frequencies, the power combiner consisting of two individual single turn transformers performs significantly better than a single 2:1 transformer with two turns on the secondary side. Imbalances in the stacked transformer structure are reduced with tuning capacitors for maximum gain and output power. At 84 GHz the simulated loss of the stacked transformer is as low as 1.35 dB, superseding the performance of an also presented alternative power combiner. The power combination allows for a low supply voltage of 1 V, which is beneficial since the supply can then be shared between the power amplifier and the transceiver, thereby eliminating the need of a separate voltage regulator. To improve the gain of the two-stage amplifier it employs a capacitive cross-coupling technique not yet seen in mm-wave SiGe PAs. Capacitive cross-coupling is an effective technique for gain enhancement but is also sensitive to process variations as shown by Monte Carlo simulations. To mitigate this two alternative designs are presented with the cross coupling capacitors implemented either with diode coupled transistors or with varactors. The PA is designed in a SiGe process with f T = 200 GHz and achieves a power gain of 12 dB, a saturated output power of 16 dBm and a 14 % peak PAE. Excluding decoupling capacitors it occupies a die area of 0.034 mm2.},
  author       = {Tired, Tobias and Sjöland, Henrik and Bryant, Carl and Törmänen, Markus},
  issn         = {0925-1030},
  keyword      = {Power amplifier,E-band,mm-wave,Transformers,EM-simulation,Capacitive cross coupling},
  language     = {eng},
  number       = {3},
  pages        = {335--348},
  publisher    = {Springer},
  series       = {Analog Integrated Circuits and Signal Processing},
  title        = {A 1V power amplifier for 81-86 GHz E-band},
  url          = {http://dx.doi.org/10.1007/s10470-014-0338-5},
  volume       = {80},
  year         = {2014},
}