The Design Methodology And Optimization Of Varactors Based Tunable Matching Network For Power Amplifiers With Load Adaptation Technique
DOWNLOAD
Download The Design Methodology And Optimization Of Varactors Based Tunable Matching Network For Power Amplifiers With Load Adaptation Technique PDF/ePub or read online books in Mobi eBooks. Click Download or Read Online button to get The Design Methodology And Optimization Of Varactors Based Tunable Matching Network For Power Amplifiers With Load Adaptation Technique book now. This website allows unlimited access to, at the time of writing, more than 1.5 million titles, including hundreds of thousands of titles in various foreign languages. If the content not found or just blank you must refresh this page
The Design Methodology And Optimization Of Varactors Based Tunable Matching Network For Power Amplifiers With Load Adaptation Technique
DOWNLOAD
Author : Chun-Ju Yang
language : en
Publisher:
Release Date : 2011
The Design Methodology And Optimization Of Varactors Based Tunable Matching Network For Power Amplifiers With Load Adaptation Technique written by Chun-Ju Yang and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2011 with categories.
Abstract: This thesis presents two tunable matching network designs relying on varactors. The matching network should provide and instantaneous optimized impedance according to different power levels of the power amplifier. The matching networks are designed for an high efficiency class B power amplifier operating at 2 G Hz. Two topologies for the load matching network are considered in this thesis: the Pi network and the T network. The varactors are integrated as part of the load network. By changing the biasing voltages on the varactors, the value of capacitors can be varied and the output impedance modified. The design procedure followed consists in determining the design parameters yielding the maximum load impedance range that can be provided by the network. The major research steps followed include (1) the computational algorithm development, (2) ADS simulations, (3) circuit fabrication and (4) measurements.
Adaptive Rf Front Ends For Hand Held Applications
DOWNLOAD
Author : Andre van Bezooijen
language : en
Publisher: Springer Science & Business Media
Release Date : 2010-10-28
Adaptive Rf Front Ends For Hand Held Applications written by Andre van Bezooijen and has been published by Springer Science & Business Media this book supported file pdf, txt, epub, kindle and other format this book has been release on 2010-10-28 with Technology & Engineering categories.
The RF front-end – antenna combination is a vital part of a mobile phone because its performance is very relevant to the link quality between hand-set and cellular network base-stations. The RF front-end performance suffers from changes in operating environment, like hand-effects, that are often unpredictable. Adaptive RF Front-Ends for Hand-Held Applications presents an analysis on the impact of fluctuating environmental parameters. In order to overcome undesired behavior two different adaptive control methods are treated that make RF frond-ends more resilient: adaptive impedance control, and adaptive power control. Several adaptive impedance control techniques are discussed, using a priori knowledge on matching network properties, in order to simplify robust 2-dimensional control. A generic protection concept is presented, based on adaptive power control, which improves the ruggedness of a power amplifier or preserves its linearity under extremes. It comprises over-voltage, over-temperature, and under-voltage protection.
Two Port Network Theory Based Design Method Of Broadband Doherty Power Amplifier
DOWNLOAD
Author : Yue Li
language : en
Publisher:
Release Date : 2018
Two Port Network Theory Based Design Method Of Broadband Doherty Power Amplifier written by Yue Li and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2018 with Amplifiers, Radio frequency categories.
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.
On The Design Of High Efficiency Rf Doherty Power Amplifiers
DOWNLOAD
Author : Mehran Yahyavi
language : en
Publisher:
Release Date : 2016
On The Design Of High Efficiency Rf Doherty Power Amplifiers written by Mehran Yahyavi and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2016 with categories.
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.
Reconfigurable Impedance Matching Networks Based On Rf Mems And Cmos Mems Technologies
DOWNLOAD
Author : Siamak Fouladi Azarnaminy
language : en
Publisher:
Release Date : 2010
Reconfigurable Impedance Matching Networks Based On Rf Mems And Cmos Mems Technologies written by Siamak Fouladi Azarnaminy and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2010 with categories.
Reconfigurable impedance matching networks are an integral part of multiband radio-frequency (RF) transceivers. They are used to compensate for the input/output impedance variations between the different blocks caused by switching the frequency band of operation or by adjusting the output power level. Various tuning techniques have been developed to construct tunable impedance matching networks employing solid-state p-i-n diodes and varactors. At millimeter-wave frequencies, the increased loss due to the low quality factor of the solid-state devices becomes an important issue. Another drawback of the solid-state tuning elements is the increased nonlinearity and noise at higher RF power levels. The objective of the research described in this thesis is to investigate the feasibility of using RF microelectromechanical systems (RF-MEMS) technology to develop reconfigurable impedance matching networks. Different types of tunable impedance matching networks with improved impedance tuning range, power handling capability, and lower insertion loss have been developed. Another objective is to investigate the realization of a fully integrated one-chip solution by integrating MEMS devices in standard processes used for RF integrated circuits (RFICs). A new CMOS-MEMS post-processing technique has been developed that allows the integration of tunable RF MEMS devices with vertical actuation within a CMOS chip. Various types of CMOS-MEMS components used as tuning elements in reconfigurable RF transceivers have been developed. These include tunable parallel-plate capacitors that outperform the available CMOS solid-state varactors in terms of quality factor and linearity. A tunable microwave band-pass filter has been demonstrated by employing the proposed RF MEMS tunable capacitors. For the first time, CMOS-MEMS capacitive type switches for microwave and millimeter-wave applications have been developed using TSMC 0.35-[mu]m CMOS process employing the proposed CMOS-MEMS integration technique. The switch demonstrates an excellent RF performance from 10-20 GHz. Novel MEMS-based reconfigurable impedance matching networks integrated in standard CMOS technologies are also presented. An 8-bit reconfigurable impedance matching network based on the distributed MEMS transmission line (DMTL) concept operating at 13-24 GHz is presented. The network is implemented using standard 0.35-[mu]m CMOS technology and employs a novel suspended slow-wave structure on a silicon substrate. To our knowledge, this is the first implementation of a DMTL tunable MEMS impedance matching network using a standard CMOS technology. A reconfigurable amplifier chip for WLAN applications operating at 5.2 GHz is also designed and implemented. The amplifier achieves maximum power gain under variable load and source impedance conditions by using the integrated RF-MEMS impedance matching networks. This is the first single-chip implementation of a reconfigurable amplifier using high-Q MEMS impedance matching networks. The monolithic CMOS implementation of the proposed RF MEMS impedance matching networks enables the development of future low-cost single-chip RF multiband transceivers with improved performance and functionality.
Design And Computer Aided Optimization Of Rf Cmos Power Amplifiers
DOWNLOAD
Author : Ravi Gupta
language : en
Publisher:
Release Date : 1998
Design And Computer Aided Optimization Of Rf Cmos Power Amplifiers written by Ravi Gupta and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 1998 with Integrated circuits categories.
In recent years, there has been an extensive effort to develop low-cost implementations of radio frequency integrated circuits for consumer applications. This thesis is a research effort in the design and implementation of integrated RF CMOS Power Amplifiers (PAs). A significant challenge in the implementation of RF CMOS ICs is the impact of device, package and passive element parasitics on circuit performance. Passive components are a critical part of any RF IC design, and a process optimized for digital circuits results in inductors and capacitors with very high parasitics. In this work, we have developed a compact model for inductors fabricated in a digital CMOS process. Measured results have been used to further refine the accuracy of the inductor model. This model has been used to predict the impact of inductor parasitics on the performance of RFICs, and is also simple enough to be included in a CAD tool for circuit optimization. We have also studied the operation of Class A, B and C power amplifiers and highlighted design issues which are specific to the implementation of integrated PAs. It is shown that inductor loss has the most critical impact on the performance of integrated PAs. A custom CAD tool, based on the simulated annealing algorithm, has been developed to optimize the performance of power amplifiers for maximum efficiency in the presence of package, device and passive element parasitics. This CAD tool simulates the process of load-pull to determine the optimum large-signal load impedance for the PA, and optimizes the matching network design based on the trade-off between the loss in the matching network and its impedance transformation properties. This trade-off is relevant in the case of high-loss matching networks only, as is the case in integrated RF CMOS ICs. This CAD tool has been used to optimize the efficiency of balanced 100mW CMOS PAs operating at 900MHz. Measured results validate the design and optimization process outlined in this work. It is demonstrated that in the design of RF CMOS ICs, significant benefits can be gained by incorporating parasitics into the design process by means of CAD optimization. The CAD tool developed is an effort towards achieving this goal. It is further proposed that CAD optimization is an essential part of the design of RF CMOS ICs in general, and with the development of improved package, device and passive element models, CAD optimization will replace the "tuning" of RF circuits and result in robust, fully-integrated implementations of RF circuits.
Design Of High Efficiency Broadband Adjusted Class Ab Power Amplifier
DOWNLOAD
Author : Aynaz Vatankhahghadim
language : en
Publisher:
Release Date : 2010
Design Of High Efficiency Broadband Adjusted Class Ab Power Amplifier written by Aynaz Vatankhahghadim and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2010 with categories.
This thesis starts with a discussion of different classes of operation of power amplifiers (PAs). Comparing advantages and disadvantages of these classes, class AB is chosen as the best initial candidate for the design of broadband PA. Different methods for design of matching networks are first discussed. Some of them fall into the group of narrowband matching networks, while others are suitable for a broadband context. Broadband design methodologies are categorized into two groups of real-to-real transformations and complex-to-real transformations. Complex-to-real transformations are the most useful methods for this project, since design of power amplifiers deals with complex loads rather than just real loads. The design of broadband matching networks exploiting filter theory is presented in this thesis for synthesizing broadband and highly efficient power amplifiers (PAs). Starting with sets of optimum impedances over the targeted frequency band, the matching networks are designed using a systematic approach. The effects of load termination at the 2nd and 3rd harmonic on the PA performance (efficiency) are studied. The significance of proper termination, especially at the 2nd harmonic, is highlighted. To prevent further complication of the design process, though, specific harmonic termination (stubs) is avoided and special arrangement of the matching network (position of the bias network) is preferred, as it is found to lead to acceptable efficiency. Two PA prototypes were designed with the proposed methodology using 25W GaN devices. The designs targeted two frequency bands: 1.8 to 2.2 GHz (20% BW) and 1.8 to 2.7 GHz (40% BW). For the former, drain efficiency (DE) of 70% (+/-5%) and output power of 45.5 dBm (+/- 1.0dB) was measured while the latter achieved very promising efficiency of about 60% over the entire bandwidth.
Design Techniques For Broadband Linear Power Amplifiers
DOWNLOAD
Author : Rong Wang
language : en
Publisher:
Release Date : 2009
Design Techniques For Broadband Linear Power Amplifiers written by Rong Wang and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2009 with categories.
In this dissertation, several crucial aspects concerning power amplifiers' performances on thermal management, linearity and bandwidth are discussed. We proposed and explored a novel ballast resistor network to alleviate the thermal issue exists in power amplifier cells. It shows that the novel network can achieve a more uniform temperature distribution than the conventional one. A power amplifier's linearity is improved by about 3dB using our programmable predistortion linearizer implemented as input stage. Then we discuss that RLC high frequency loss compensation network works as a bandwidth enhancement technique not only at small-signal but also at large signal condition. The RLC network is utilized on a cascode amplifier, saving design efforts for an extra linearizer stage. Explanation is given regarding why RLC can improve bandwidth and linearity. Volterra series method is used to demonstrate the RLC effects on nonlinear condition. Combining those previously discussed techniques, a broadband WiMAX linear power amplifier is designed. Some previous work used different power amplifier in one module to cover different WiMAX band with bias circuit toggling on and off. In contrast to it, the highlight of our design is that one power amplifier with one input/output matching networks shall be able to cover currently existing WiMAX bands from 2.5GHz to 5.8GHz. The power amplifier is composed of two cascode stages. The die size is 1.8mm & times 1.4mm. The gain is 29dB, output power is 30 dBm and PAE is 21% at P1dB. EVM is about 5% at output power level of 25dBm at 3.6GHz. To the best of our knowledge, this is the first time to use RLC network in a power amplifier design to improve bandwidth and linearity. Also, the broadband WiMAX linear power amplifier is a first demonstration to cover all three existing WiMAX bands in one power amplifier design.
Optimization Of The Interstage Matching Network Design In The Driver And Final Stage Of The Power Amplifier
DOWNLOAD
Author : Gurpreet K. Narula
language : en
Publisher:
Release Date : 2010
Optimization Of The Interstage Matching Network Design In The Driver And Final Stage Of The Power Amplifier written by Gurpreet K. Narula and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2010 with Amplifiers, Radio frequency categories.
Efficient Radio Frequency Power Generation And Impedance Matching
DOWNLOAD
Author : Anas Ibrahim Al Bastami
language : en
Publisher:
Release Date : 2020
Efficient Radio Frequency Power Generation And Impedance Matching written by Anas Ibrahim Al Bastami and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2020 with categories.
A wide range of applications require the efficient generation and delivery of radio-frequency (rf) power to do useful work. This is commonly achieved by utilizing an rf power amplifier or inverter that delivers the required amount of power to the load. In many applications, the load impedance varies widely due to changes in the operating conditions. A key challenge in these rf power delivery systems is attaining high efficiency and performance across all operating conditions, including accurate control of the delivered power, and achieving wide bandwidths with respect to power delivery and/or load variation. Typical rf amplifiers and inverters operate efficiently into a fixed load resistance, but their performance heavily degrades with variations in load impedance. This problem is often addressed through tunable matching networks (TMNs), which provide adaptive impedance transformation between the rf source and load. However, they become costly, bulky, and slow in response to load changes, especially at high power levels (hundreds to thousands of watts and above). This thesis develops solutions for efficient generation and delivery of rf power into dynamically-varying loads, with a focus on systems suitable for plasma generation at power levels from hundreds of watts to tens of kilowatts. It presents an efficient, low cost, and small size alternative to a TMN that achieves acceptable impedance matching for inductively-coupled rf plasma systems. It also develops techniques that enable the design of an efficient high power TMN capable of very fast modulation of impedance. In addition, this thesis explores different architectural implementations for complete rf generation and power delivery systems that are efficient, fast, and capable of driving a wide load range with accurate control of power, and identifies the most promising implementations. While the solutions in this thesis are demonstrated in the context of plasma generation systems, they can be applied to many other systems having dynamically-varying rf loads.