Download or read book Design of a Broadband Doherty Power Amplifier with a Graphical User Interface Tool written by Pingzhu Gong and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A novel broadband Doherty Power Amplifier (DPA) design for 4G applications is presented with the aid of a modified version of DPA Graphical User Interface (GUI) Tool. Compared to the previous version, the new GUI uses Output Back-Off (OBO) as the input instead of the peak power ratio of the DPA Main and auxiliary PAs. Furthermore, the load impedance seen by the Main PA (MPA) at 2nd harmonic and 3rd harmonic can be directly controlled from the GUI. In this design, Main PA is operated under class F mode and the auxiliary PA is operated under Class C mode. The main PA is biased at -3.2 V at the gate (lower than typical values: -2.7 V ~ -3 V) to boost the efficiency. A new parasitic network with simple structure is extracted using OSU Embedding Model. Design procedures are stated as follows. Fundamental load impedances seen by both PAs are generated by GUI at Current source Reference Plane (CRP). Then, the Output Matching Network (OMN) is synthesized at CRP for both PAs separately. At last, the input matching network and the equal split Wilkinson power divider are designed to realize the broadband DPA. Electromagnetic (EM) Co-simulation result shows the DPA achieves 59.4-62.2% drain efficiency at 8-dB OBO at 1.5-2.2GHz with a gain of 10-13dB. The peak power range is between 43.7 dBm and 44.5 dBm. The THD and IM3 is around -15dB at back off power. The performance of the proposed DPA iii design is shown to be comparable to state-of-the-art designs, which indicates our DPA has a good performance.

Download or read book Bandwidth and Efficiency Enhancement in Radio Frequency Power Amplifiers for Wireless Transmitters written by Karun Rawat and published by Springer Nature. This book was released on 2020-03-05 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on broadband power amplifier design for wireless communication. Nonlinear model embedding is described as a powerful tool for designing broadband continuous Class-J and continuous class F power amplifiers. The authors also discuss various techniques for extending bandwidth of load modulation based power amplifiers, such as Doherty power amplifier and Chireix outphasing amplifiers. The book also covers recent trends on digital as well as analog techniques to enhance bandwidth and linearity in wireless transmitters. Presents latest trends in designing broadband power amplifiers; Covers latest techniques for using nonlinear model embedding in designing power amplifiers based on waveform engineering; Describes the latest techniques for extending bandwidth of load modulation based power amplifiers such as Doherty power amplifier and Chireix outphasing amplifiers; Includes coverage of hybrid analog/digital predistortion as wideband solution for wireless transmitters; Discusses recent trends on on-chip power amplifier design with GaN /GaAs MMICs for high frequency applications.

Download or read book Design and Optimization of the Doherty Power Amplifier for Broadband Applications written by Guolin Sun and published by . This book was released on 2012 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Doherty Power Amplifiers written by Bumman Kim and published by Academic Press. This book was released on 2018-03-28 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: Doherty Power Amplifiers: From Fundamentals to Advanced Design Methods is a great resource for both RF and microwave engineers and graduate students who want to understand and implement the technology into future base station and mobile handset systems. The book introduces the very basic operational principles of the Doherty Amplifier and its non-ideal behaviors. The different transconductance requirements for carrier and peaking amplifiers, reactive element effect, and knee voltage effect are described. In addition, several methods to correct imperfections are introduced, such as uneven input drive, gate bias adaptation, dual input drive and the offset line technique. Advanced design methods of Doherty Amplifiers are also explained, including multistage/multiway Doherty power amplifiers which can enhance the efficiency of the amplification of a highly-modulated signal. Other covered topics include signal tracking operation which increases the dynamic range, highly efficient saturated amplifiers, and broadband amplifiers, amongst other comprehensive, related topics. Specifically written on the Doherty Power Amplifier by the world’s leading expert, providing an in-depth presentation of principles and design techniques Includes detailed analysis on correcting non-ideal behaviors of Doherty Power Amplifiers Presents advanced Doherty Power Amplifier architectures

Download or read book Two Port Network Theory Based Design Method of Broadband Doherty Power Amplifier written by Yue Li and published by . This book was released on 2018 with total page 55 pages. Available in PDF, EPUB and Kindle. Book excerpt: LTE-Advanced (LTE-A) is a widely used communication standard and it mainly features Carrier aggregation (CA). CA increases the user data rate and efficiently exploits the fragmented spectrum by combining various carrier frequencies. The intrinsic multi-band and multi-standard of CA, along with the existing high peak-to-average power ratio (PAPR), brings the challenges of broadband requirement and back-off (BO) efficiency enhancement when designing radio frequency power amplifiers (PA). The above two challenges inspire research interest in designing of broadband Doherty power amplifiers (DPAs), which maintain the high efficiency at BO power level and perform constantly versus frequency. In this work, the continuous design space was discussed. Output combining and matching network (OCMN) and its impact on the impedances shown to the two transistors were analyzed based on two port network theory. ABCD parameters of matching networks was formulated to accommodate continuous class-B (class-J) operation to DPAs. Second harmonic was terminated to avoid clipping and efficiency degradation. By enlarging design space, the bandwidth was substantially expanded. The proposed design methodology allowed the adsorption of parasitics which was the one of the bandwidth limiting factor. To validate the proposed methodology, an 8 Watts DPA was simulated to operate from 3 GHz to 5 GHz using Cree Gallium nitride (GaN) High-electron-mobility transistors (HEMTs). And simulation results showed that the 6dB BO efficiency was above 40% and Peak-envelope-power (PEP) of 50% over the frequency range of 3GHz to 5GHz. The Doherty power amplifier prototype is fabricated on substrate of Rogers4003C and assembled in house. Continuous wave measurement showed that the PA could provide 8.2 - 10.6 dB gain in the frequency band of 2.7 to 4.3 GHz. The 6 dB back off efficiency was 40% to 43%. And at peak power, the drain efficiency reached 48% to 60%. 80 MHz inter-band modulated signal and 15MHz dual band signal measurement were carried out to investigate the linearizability. In the inter-band measurement, average power around 33dBm and average drain efficiency of 46% was obtained with PAPR of 6.4 dB. ACLR above 48.7 dBc after DPD verified the easiness of linearization for this PA. Dual band measurement using two carriers at 2.8 and 3.2 GHz showed even when the PAPR of two band were 7.6 and 8.0 dB separately, average power of 32.3 dBm power can still be extracted with average efficiency of 40.5%. ACLR of 49.5 and 46.7 dBc of those two bands were good endorsement of the capability of inter-band concurrent amplification.

Download or read book High Efficiency Load Modulation Power Amplifiers for Wireless Communications written by Zhancang Wang and published by Artech House. This book was released on 2017-06-30 with total page 389 pages. Available in PDF, EPUB and Kindle. Book excerpt: This cutting-edge resource presents a complete and systematic overview of the practical design considerations of radio frequency (RF) high efficiency load modulation power amplifiers (PA) for modern wireless communications for 4G and beyond. It provides comprehensive insight into all aspects of load modulation PA design and optimization not only covering design approaches specifically for passive and active load modulation operation but also hybrid with dynamic supply modulation and digital signal processing algorithms required for performance enhancement. Passive load impedance tuner design, dynamic load modulation PA, active load modulation PA and Doherty PA design for efficiently enhancement are explained. Readers find practical guidance into load modulation PA design for bandwidth extension, including video bandwidth enhancement techniques, broadband dynamic load amplifiers, topology selection, design procedures, and network output. This book presents the evolution and integration of classical load modulation PA topologies in order to meet new challenges in the field.

Download or read book A Doherty Power Amplifier with Extended Bandwidth and Reconfigurable Back off Level written by Yu-Ting David Wu and published by . This book was released on 2013 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Emerging wireless standards are designed to be spectrally efficient to address the high cost of licensing wireless spectra. Unfortunately, the resulting signals have a high peak-to-average ratio that reduces the base station power amplifier efficiency at the back-off power level. The wasted energy is converted to heat that degrades the device reliability and increases the base-station's carbon footprint and cooling requirements. In addition, these new standards place stringent requirements on the amplifier output power, linearity, efficiency, and bandwidth. To improve the back-off efficiency, a Doherty amplifier, which uses two device in parallel for back-off efficiency enhancement, is deployed in a typical base station. Unfortunately, the conventional Doherty amplifier is narrowband and thus cannot satisfy the bandwidth requirement of the modern base station that needs to support multiple standards and backward compatibility. In this thesis, we begin by studying the class F/F-1 high efficiency mode of operation. To this end, we designed a narrowband, harmonically-tuned 3.3 GHz, 10 W GaN high efficiency amplifier. Next, we investigate how to simultaneously achieve high efficiency and broad bandwidth by harnessing the simplified real frequency technique for the broadband matching network design. A 2 to 3 GHz, 45 W GaN amplifier and a 650 to 1050 MHz, 45 W LDMOS amplifier were designed. Finally, we analyze the conventional Doherty amplifier to determine the cause of its narrow bandwidth. We find that the narrow bandwidth can be attributed to the band-limited quarter-wave transformer as well as the widely adopted traditional design technique. As an original contribution to knowledge, we propose a novel Doherty amplifier configuration with intrinsically broadband characteristics by analyzing the load modulation concept and the conventional Doherty amplifier. The proposed amplifier uses asymmetrical drain voltage biases and symmetrical devices and it does not require a complex mixed-signal setup. To demonstrate the proposed concept in practice, we designed a 700 to 1000 MHz, 90 W GaN broadband Doherty amplifier. Moreover, to show that the proposed concept is applicable to high power designs, we designed a 200 W GaN broadband Doherty amplifier in the same band. In addition, to show that the technique is independent of the device technology, we designed a 700 to 900 MHz, 60 W LDMOS broadband Doherty amplifier. Using digital pre-distortion, the three prototypes were shown to be highly linearizable when driven with wideband 20 MHz LTE and WCDMA modulated signals and achieved excellent back-off efficiency. Lastly, using the insights from the previous analyses, we propose a novel mixed-technology Doherty amplifier with an extended and reconfigurable back-off level as well as an improved power utilization factor. The reconfigurability of the proposed amplifier makes it possible to customize the back-off level to achieve the highest average efficiency for a given modulated signal without redesigning the matching networks. A 790 to 960 MHz, 180 W LDMOS/GaN Doherty amplifier demonstrated the extended bandwidth and reconfigurability of the back-off level. The proposed amplifier addresses the shortcomings of the conventional Doherty amplifier and satisfies the many requirements of a modern base station power amplifier.

Download or read book Broadband Doherty Power Amplifier Using Symmetrical GaN Transistors written by Aneta Wyrzykowska and published by . This book was released on 2014 with total page 55 pages. Available in PDF, EPUB and Kindle. Book excerpt: The wireless industry has seen a tremendous growth in its users over the last decade. This has led the industry to adapt a number of new standards allowing for better use of the scarce and often very fragmented frequency spectrum. [1] The new standards have brought with them the use of OFDM signaling to allow for higher data rates and better robustness against frequency selective channel interference. The OFDM protocols combined with multi-standard radios however have provided many challenges to the radio frequency, RF, industry with the largest challenge presented to the power amplifier design. The OFDM signals are well known for their high peak to average power ratio which forces the RF equipment to work at significant back-off compared to peak power. This unfortunately leads to rather low system efficiencies. To address the problem the Doherty power amplifier has been brought back into the design community as it directly solves the issues related to average power efficiency. To date however many of the Doherty designs have focused on the narrowband application of the power amplifier often targeting a single standard with bandwidths directly tied to the operational band which at best is usually only couple hundred MHz wide. With the recent changes in the standards and the ever growing desire to provide several standards on one radio the Doherty has to be redesigned to allow for broadband communications. This thesis examines the major sources of bandwidth limitation in the Doherty power amplifier and provides a review of the current approaches to solving the problem. It then goes on to propose several changes in the Doherty architecture to allow for the use of complex impedance to provide both higher efficiency at back-off and wider operational bandwidth. The proposed technique was then used to design a symmetrical Doherty power amplifier targeted to operate in the 1.8 - 2.8 GHz frequency range with 42 dBm of output power and back-off efficiency above 50%.

Download or read book Broadband Microwave Amplifiers written by Bal S. Virdee and published by Artech House. This book was released on 2004 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This authoritative resource offers a complete understanding of state-of-the-art and cutting-edge techniques for designing and fabricating broadband microwave amplifiers. The book covers the complete design cycle, detailing each stage in a practical, hands-on manner." "This comprehensive reference illustrates the formulation of small- and large-signal device models to help professionals accurately simulate amplifier performance, and covers all the practical aspects and circuit components used in fabrication. Engineers find design examples of various types of amplifiers that are applicable in broadband systems such as optical communications, satellite communications, spread-spectrum communications, wireless local area networks, electronic warfare, instrumentation, and phased array radar. The book also provides an in-depth treatment of ultra-broadband microwave amplifiers." --Book Jacket.

Download or read book Broadband Power Amplifier Design with High Power High Efficiency and Large Back off Range written by Yuchen Cao and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: As modern communication system technology develops, the demand for devices with smaller size, higher efficiency, and larger bandwidth has increased dramatically. To achieve this purpose, a novel architecture of load modulated balanced amplifier (LMBA) with a unique load-modulation characteristic different from any existing LMBAs and Doherty power amplifiers (DPAs) was presented, which is named as Pseudo-Doherty LMBA (PD-LMBA). Based on a special combination of control amplifier (carrier) and balanced amplifier (peaking) together with proper phase and amplitude controls, an optimal load-modulation behavior can be achieved for PD-LMBA leading to maximized efficiency over extended power back-off range. More importantly, the efficiency optimization can be achieved with only a static setting of phase offset at a given frequency, which greatly simplifies the complexity for phase control. Furthermore, the co-operations of the carrier and peaking amplifiers in PD-LMBA are fully de-coupled, thus lifting the fundamental bandwidth barrier imposed on Doherty-based active load modulation.

Download or read book The Doherty amplifier and beyond written by Luca Piazzon and published by Luca Piazzon. This book was released on 2011-04-11 with total page 199 pages. Available in PDF, EPUB and Kindle. Book excerpt: What's a Doherty power amplifier? What's the practical design flow to develop a DPA? May I estimate the achievable performance? May I get more efficiency, gain, back-off and frequencies from my DPA? Whether you have a FAQ or a rare question, inside you'll probably find the answer. This book is a real design manual, which can help the designer to identify, starting from the desired requirements, the best approach to use, simultaneously highlighting the advantages as well as disadvantages that occurs with its adoption.

Download or read book Partitioning Design Approach for the Reliable Design of Highly Efficient RF Power Amplifiers written by Roshanak Lehna and published by kassel university press GmbH. This book was released on 2017-11-13 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: The modern wireless communication systems require modulated signals with wide modulation bandwidth. This, in turns, requires signals with very high dynamic range and peak-to-average power ratio (PAPR). This means that the amplifier in the base-station has to work at a power back-off as large as the dynamic range of the signal, so that the amplifier has a high linearity in this region. For the standard single-stage amplifiers, this large power back-off reduces the efficiency dramatically. In this work, a three-way Doherty power amplifier (DPA) aiming at high power efficiency within a dynamic range of 9.5 dB, is designed and fabricated using partitioning design approach. The partitioning design approach decomposes a complex design task into small-sized, well-controllable, and verifiable subcircuits. This advanced straight forward method has shown very promising results. Using this design approach, a three-way DPA has been designed to demonstrate the advantages of this reliable design technique as well. Based on the design of a single-stage power amplifier and proposing a novel output power combiner, a 6 W three-way DPA has been designed which allows the mandatory load modulation principle in three-way DPA structures to be realized with simpler elements, whereas the design of a standard Doherty combiner would have been very challenging and not practical due to the extremely small value of its characteristic line impedance. The proposed combiner is calculated for a three-way DPA with 2-mm AlGaN/GaN-HEMTs. The simulation result shows a very good load modulation for the amplifier, which confirms the theoretical expectation for a three-way DPA. The efficiency of the designed 6 W three-way DPA at large back-off shows very promising values compared to recently reported amplifiers. The measured IMD3 products confirm the good linearity of the amplifier as well. Accordingly, the proposed power combiner and the design strategy are recommended to be used as the preferred option for designing three-way DPA structures with very high output power.

Download or read book Development of High Efficiency Power Amplifiers for Emerging Wireless Applications written by Jeffery Alan Curtis and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this Ph.D. research, several Ka-Band power amplifiers are designed and built for use in next generation mobile broadband communication systems. The Doherty power amplifier architecture is demonstrated as a possible solution to improving the back-off efficiency of millimeter-wave power amplifiers, since many mobile broadband communication systems employ modulation formats with large peak-to-average power ratios. This research also demonstrates some novel techniques to improve upon the Doherty architecture for millimeter-wave power amplifier design. Two fully integrated Ka-Band Doherty power amplifiers are designed and developed using a 0.15-[mu]m GaAs pseudomorphic high electron mobility transistor (pHEMT) process. The first uses the classic Doherty configuration with some previously developed modifications to resolve some practical issues and achieves a measured small signal gain of 10.3 dB, measured output power at 1-dB compression point (P1dB) of 25.1 dBm, measured peak power added efficiency (PAE) of 38%, and measured PAE of 27% at 6-dB back-off power. The bias network of this same Doherty was then modified by short circuiting some resistors in the gate bias path and it then achieves a measured small signal gain of 10.5 dB, measured output power at 1-dB compression point (P1dB) of 26.9 dBm, measured peak power added efficiency of 42%, and measured PAE of 32% at 6-dB back-off power. The second Doherty amplifier uses a novel load-pull based Doherty technique accounting for nonideal back-off impedance in millimeter-wave power amplifiers and achieves a measured small signal gain of 9 dB, simulated output power at 1-dB compression point (P1dB) of 29 dBm, simulated peak power added efficiency of 46%, and simulated PAE of 35% at 6-dB back-off power. The performance achieved with these power amplifiers makes them a promising candidate for use in next generation mobile broadband communication systems.

Download or read book Broadband Doherty Power Amplifiers with Enhanced Linearity for Emerging Radio Transmitters written by Hamed Golestaneh and published by . This book was released on 2016 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ever-increasing demand for utilizing wireless spectra has led to development of spectrally efficient radio systems. While these systems offer much higher data throughput, they employ more sophisticated modulation schemes, which result in wideband signals with high peak-to-average power ratios. These signal characteristics significantly complicate the design of RF transmitters, particularly power amplifiers, in terms of power efficiency and linearity requirements. Furthermore, upcoming wireless standards, such as long term evolution advanced (LTE-A) require adoption of carrier aggregation which incorporates multiple component carriers to yield aggregated channels of larger bandwidth (up to 100 MHz). On the other hand, the emerging systems are expected to support legacy standards with minimum area, cost, and power overhead, and thus call for highly-efficient linear broadband power amplifiers capable of efficiently amplifying concurrent modulated signals located over a broad carrier frequency range. This thesis focuses on Doherty power amplifiers (DPAs) with extended high-efficiency range, enhanced bandwidth and improved linearity as a solution for high-efficiency multi-band multi-standard transmitters. It addresses three major concerns associated with DPAs, namely, back-off efficiency, bandwidth, and linearity.

Download or read book The Design of a Modified Doherty Power Amplifier for Wideband Code Division Multiple Access Basestations written by David Beishline and published by . This book was released on 2004 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book On the Design of High efficiency RF Doherty Power Amplifiers written by Mehran Yahyavi and published by . This book was released on 2016 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: Power amplifiers (PAs) are one of the most crucial elements in wireless standards becasue they are the most power hungry subsystems. These elements have to face an important issue, which is the power efficiency, a fact related with the output back-off (OBO). But the OBO depends on the kind of modulated signal, in proportion to the modulated signal peak-to-average power ratio (PAPR). The higuer is the data rate, the higer is the OBO, and consequently the lower is the efficiency. A low efficiency of PAs causes the waste of energy as heat. Furthermore, the trade-off between linearity and efficiency in PAs is another major issue. To cope with the undesired circumstances producing efficiency degradation, the Doherty power amplifier (DPA) is one of the useful techniques which provide high efficiency for high PAPR of modern communication signals. Nevertheless, the limited bandwidth (BW) of this kind of PAs (about 10% of fractional bandwidth) and its importance (in modern wireless systems such as LTE, WiMAX, Wi-Fi and satellite systems) have encouraged the researchers to improve this drawback in recent years. Some typical BW limiting factors effect on the performance of DPAs: i) quarter-wave length transformers, ii) phase compensation networks in/output matching circuits, iii) offset lines and device non-idealities; The quarter-wave length transformers performs as an inverter impedance in the load modulation technique of DPAs. The future objective in designing DPAs is to decrease the impact of these issues. In this context, this PhD-thesis is focused on improving fractional bandwidth of DPAs using the new methods that are related to impedance transformers instead of impedance inverters in the load modulation technique. This study is twofold. First, it is presented a novel DPA where a wideband GaN DPA in the 2.5 GHz band with an asymmetrical Wilkinson splitter. The impedance transformer of the proposed architecture is based on a matching network including a tapered line with multi-section transformer in the main stage. The BW of this DPA has ranged from 1.8 to 2.7 GHz. Plus, the obtained power efficiency (drain) is higher than 33% in the whole BW at both maximum and OBO power levels. Second, based on the benefits of the Klopfenstein taper, a promising DPA design is proposed where a Klopfenstein taper replaces the tapered line. In fact, this substitution results on reducing the reflection coefficient of the transformer. From a practical prototype realization of this novel Doherty-like PA in the 2.25 GHz band, this modification has demonstrated that the resulting DPA BW is increased in comparison to the conventional topology while keeping the efficiency figures. Moreover, this study also shows that the Klopfenstein taper based design allows an easy tuning of the group delay through the output reactance of the taper, resulting in a more straightforward adjustments than other recently published designs where the quarter-wave transformer is replaced by multi-section transmission lines (hybrid or similar). Experimental results have shown 43-54% of drain efficiency at 42 dBm output power, in the range of 1.7 to 2.75 GHz. Concretely, the results presented in this novel Doherty-like PA implies an specific load modulation technique that uses the mixed Klopfenstein tapered line together with a multi-section transformer in order to obtain high bandwidth with the usual efficiency in DPAs.

Download or read book Advanced Doherty Power Amplifier Design for Modern Communication Systems written by Syalwani Kamarudin and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: