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Design of Power Efficient Power Amplifier for B3G Base Stations.Hussaini, Abubakar S., Gwandu, B.A.L., Abd-Alhameed, Raed, Rodriguez, Jonathan 11 November 2010 (has links)
Yes / Fourth generation systems require the use of both
amplitude and phase modulation to efficiently utilize the
available spectrum and to obtain high data rates, hence imposing
stringent requirements on the power amplifier in terms of
efficiency and linearity and requires the power amplifier to
operate linearly and efficiently. The B3G base station transceiver
Doherty power amplifier was designed to operate over the
frequency range of 3.47GHz to 3.53GHz mobile WiMAX band
using Freescale¿s N-Channel Enhancement-Mode Lateral
MOSFET Transistor, MRF7S38010HR3; The performances of
the Doherty amplifier are compared with that of the conventional
Class AB amplifier. The results of 43 dBm output power and
66% power added efficiency are achieved.
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A 70-W Asymmetrical Doherty Power Amplifier for 5G Base StationsAbdulkhaleq, Ahmed M., Al-Yasir, Yasir I.A., Ojaroudi Parchin, Naser, Brunning, J., McEwan, N., Rayit, A., Abd-Alhameed, Raed, Noras, James M., AbdulJabbar, N. 22 August 2018 (has links)
Yes / Much attention has been paid to making 5G developments more en-ergy efficient, especially in view of the need for using high data rates with more complex modulation schemes within a limited bandwidth. The concept of the Doherty power amplifier for improving amplifier efficiency is explained in addi-tion to a case study of a 70W asymmetrical Doherty power Amplifier using two GaN HEMTs transistors with peak power ratings of 45W and 25W. The rationale for this choice of power ratio is discussed. The designed circuit works in the 3.4GHz frequency band with 200 MHz bandwidth. Rogers RO4350B substrate with dielectric constant εr=4.66 and thickness 0.035 mm is used. The perfor-mance analysis of the Doherty power amplifier is simulated using AWR MWO software. The simulated results showed that 54-64% drain efficiency has been achieved at 8 dB back-off within the specified bandwidth with an average gain of 10.7 dB.
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Adaptive Power Amplifiers for Modern Communication Systems with Diverse Operating ConditionsMahmoud Mohamed, Ahmed January 2014 (has links)
In this thesis, novel designs for adaptive power amplifiers, capable of maintaining excellent performance at dissimilar signal parameters, are presented. These designs result in electronically reconfigurable, single-ended and Doherty power amplifiers (DPA) that efficiently sustain functionality at different driving signal levels, highly varying time domain characteristics and wide-spread frequency bands. The foregoing three contexts represent those dictated by the diverse standards of modern communication systems.
Firstly, two prototypes for a harmonically-tuned reconfigurable matching network using discrete radio frequency (RF) microelectromechanical systems (MEMS) switches and semiconductor varactors will be introduced. Following that is an explanation of how the varactor-based matching network was used to develop a high performance reconfigurable Class F-1 power amplifier.
Afterwards, a systematic design procedure for realizing an electronically reconfigurable DPA capable of operating at arbitrary centre frequencies, average power levels and back-off efficiency enhancement power ranges is presented. Complete sets of closed-form equations are outlined which were used to build tunable matching networks that compensate for the deviation of the Doherty distributed elements under the desired deployment scenarios. Off-the-shelf RF MEMS switches are used to realize the reconfigurability of the adaptive Doherty amplifiers.
Finally, based on the derived closed-form equations, a tri-band, monolithically integrated DPA was realized using the Canadian Photonics Fabrication Centre (CPFC??) GaN500 monolithic microwave integrated circuit (MMIC) process. Successful integration of high power, high performance RF MEMS switches within the MMIC process paved the way for the realization of the frequency-agile, integrated version of the adaptive Doherty amplifier.
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Contributions to the Design of RF Power AmplifiersAcimovic, Igor 19 August 2013 (has links)
In this thesis we introduce a two-way Doherty amplifier architecture with multiple feedbacks for digital predistortion based on impedance-inverting directional coupler (transcoupler). The tunable two-way Doherty amplifier with a tuned circulator-based impedance inverter is presented. Compact N-way Doherty architectures that subsume impedance inverter and offset line functionality into output matching networks are derived. Comprehensive N-way Doherty amplifier design and analysis techniques based on load-pull characterization of active devices and impedance modulation effects are developed. These techniques were then applied to the design of a two-way Doherty amplifier and a three-way Doherty amplifier which were manufactured and their performance measured and compared to the amplifier performance specifications and simulated results.
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Doherty-Outphasing Power Amplifier Continuum TheoryLiang, Chenyu January 2020 (has links)
No description available.
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A Novel 3-Way Dual-Band Doherty Power AmplifierAlsulami, Ruwaybih R. 30 August 2022 (has links)
No description available.
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Negative Conductance Load Modulation RF Power AmplifierNeslen, Cody R 01 June 2010 (has links) (PDF)
The number of mobile wireless devices on the market has increased substantially over the last decade. The frequency spectrum has become crowded due to the number of devices demanding radio traffic and new modulation schemes have been developed to accommodate the number of users. These new modulation schemes have caused very poor efficiencies in power amplifiers for wireless transmission systems due to high peak-to-average power ratios (PAPR). This thesis first presents the issue with classical power amplifiers in modern modulation systems. A brief overview of current attempts to mitigate this issue is provided. A new RF power amplifier topology is then presented with supporting simulations.
The presented amplifier topology utilizes the concept of negative conductance and load modulation. The amplifier operates in two stages, a low power stage and a high power stage. A negative conductance amplifier is utilized during peak power transmission to modulate the load presented to the input amplifier. This topology is shown to greatly improve the power added efficiency of power amplifiers in systems with high PAPR.
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Energy efficient radio frequency system design for mobile WiMax applications. Modelling, optimisation and measurement of radio frequency power amplifier covering WiMax bandwidth based on the combination of class AB, class B, and C operations.Hussaini, Abubakar S. January 2012 (has links)
In today's digital world, information and communication technology accounts for 3%
and 2% of the global power consumption and CO2 emissions respectively. This
alarming figure is on an upward trend, as future telecommunications systems and
handsets will become even more power hungry since new services with higher
bandwidth requirements emerge as part of the so called ¿future internet¿ paradigm. In
addition, the mobile handset industry is tightly coupled to the consumer need for more
sophisticated handsets with greater battery lifetime. If we cannot make any significant
step to reducing the energy gap between the power hungry requirements of future
handsets, and what battery technology can deliver, then market penetration for 4G
handsets can be at risk. Therefore, energy conservation must be a design objective at the
forefront of any system design from the network layer, to the physical and the
microelectronic counterparts. In fact, the energy distribution of a handset device is
dominated by the energy consumption of the RF hardware, and in particular the power
amplifier design. Power amplifier design is a traditional topic that addresses the design
challenge of how to obtain a trade-off between linearity and efficiency in order to avoid
the introduction of signal distortion, whilst making best use of the available power
resources for amplification. However, the present work goes beyond this by
investigating a new line of amplifiers that address the green initiatives, namely green
power amplifiers. This research work explores how to use the Doherty technique to
promote efficiency enhancement and thus energy saving. Five different topologies of
RF power amplifiers have been designed with custom-made signal splitters. The design
core of the Doherty technique is based on the combination of a class B, class AB and a
class C power amplifier working in synergy; which includes 90-degree 2-way power
splitter at the input, quarter wavelength transformer at the output, and a new output
power combiner. The frequency range for the amplifiers was designed to operate in the
3.4 - 3.6 GHz frequency band of Europe mobile WiMAX. The experimental results
show that 30dBm output power can be achieved with 67% power added efficiency
(PAE) for the user terminal, and 45dBm with 66% power added efficiency (PAE) for
base stations which marks a 14% and 11% respective improvement over current stateof-
the-art, while meeting the power output requirements for mobile WiMAX
applications.
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Investigation and Design of New, Efficient and Compact Load Modulation Amplifiers for 5G Base Stations. Design, Simulation, Implementation and Measurements of Radio Frequency Power Amplifiers Using Active Load Modulation Technique for More Compact and Efficient 5G Base Stations AmplifiersAbdulkhaleq, Ahmed M. January 2020 (has links)
High efficiency is an essential requirement for any system, where the energy
can be saved with full retention of system performance. The power amplifier in
modern mobile communications system consumes most of the supplied power
through the dissipated power and the required cooling systems. However, as
new services were added as features for the developed mobile generations, the
required data rate has increased to fulfil the new requirements. In this case, the
data should be sent with the allocated bandwidth, so complex modulation
schemes are used to utilise the available bandwidth efficiently. Nevertheless,
the modulated signal will have a Peak to Average Power Ratio (PAPR) which
increases as the modulation complexity is increasing. In this case, the power
amplifier should be backed off and designed to provide good linearity and
efficiency over high PAPR.
Among the efficiency enhancement techniques, the Doherty technique (Load
modulation technique) is the simplest one, where no additional circuity nor
signal processing is required. In this work, the theory of load modulation
amplifiers is investigated through two asymmetrical Doherty Power Amplifiers
(DPA) targeting 3.3-3.5 GHz were designed and fabricated using two transistors
(25 W and 45 W). In addition, more compact load modulation amplifiers
targeting sub 6-GHz bandwidth of 5G specifically 3.4-3.8 GHz is discussed
including the theory of implementing these amplifiers, where different amplifier
capabilities are explored. Each amplifier design was discussed in detail, in
which the input and output matching networks were designed and tested in
addition to the design of the stability circuit to make sure that the amplifier is
stable and working according to the specified requirements. The fabricated
circuits were evaluated practically using the available instrument test, whereas
Microwave Office software was used for the simulation purpose, each amplifier
was designed separately, where all the designed amplifiers were able to provide
the targeted efficiency at different back-off power points. Besides, some
additional factors that affect the designed load modulation amplifiers such as
the effect of the harmonics at the back-off and mismatching the amplifier is
discussed. / European Union’s Horizon 2020 research and innovation programme (SECRET)
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NONLINEAR EMBEDDING FOR HIGH EFFICIENCY RF POWER AMPLIFIER DESIGN AND APPLICATION TO GENERALIZED ASYMMETRIC DOHERTY AMPLIFIERSJang, Haedong 04 November 2014 (has links)
No description available.
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