The power split is accomplished using a quadrature splitter: In order to achieve better flat gain profile with reference to power level, dividing loss should be compensated by high gain arising from load modulation Care is also required to ensure linearity over the whole of the operating range.
The modified DPA combining technique has provided potential economical solution by using low power LDMOS transistor with an advantage of high efficiency. While PA operates in the back-off region, it degrades the efficiency considerably. Basic 2-way DPA configuration consists of two amplifiers: Energy consumption can further decrease with the addition of small cell along with Doherty power amplifier thesis eNodeB.
GaN is a special material with high electron mobility, higher breakdown voltage and wide band gap which helps to improve the efficiency of the amplifier.
Apart from enhancing capacity and filing up the coverage holes, large number of Micro eNodeBs along with Macro eNodeBs decrease the overall energy consumptions of LTE access network significantly by shifting traffic from Macro to Micro eNodeBs.
One branch feeds power to the main amplifier and Doherty power amplifier thesis other two branches feed power to two peaking amplifiers. The main advantage of this design is that it uses 15 watt low power LDMOS transistor to achieve the desired target which was not achievable using 3 way conventional DPA.
But in this case a problem arises that the maximum amplitude of peaking current might not be reachable. Typically Doherty amplifier designs are limited in terms of their bandwidth.
Thus, it will provide the 0 0 uniform gain versus input power level The performance comparison among various PA configurations is discussed in Table 2. Signal processing, Communication and Networking, pp. In 3-stage DPA design, both peaking amplifiers are switched ON one by one and hence it will have peak efficiency at three different points as shown in Fig.
Due to more number of peak efficiency points, 3- stage DPA will provide better average efficiency in comparison of 3-way DPA.
The splitters and combiners are limited in their bandwidth, and outside this their phase shift varies significantly, impairing the performance of the overall amplifier design. Ensuring that the impedance of both amplifiers is sufficiently maintained over the operating range can present issues in some designs.
Beyond certain threshold, both peaking amplifiers will be switched on simultaneously. In the region of 0. A typical issue Doherty power amplifier thesis with the conventional 3-stage DPA is that the dynamic load modulation of the carrier amplifier stops at a certain power level, leaving the Main amplifier in deep saturation and leading to significant degradation of its linear performance Since different techniques have their pros and cons, appropriate design selection for the specific application is utmost important.
However amplifiers will introduce a phase shift and this may not be equally match as one is designed to handle the lower power levels and the other for the peaks. He has more than 10 years of experience in research and development for RF design. His areas of interest include Data Networking, Wireless and Telecommunication.
Although, percentage of saving in energy consumption depends on various factors like frequency band, transmit power, antenna parameters of Macro and Micro eNodeB, interference mitigation schemes, power saving features enabled in Macro and Micro eNodeB etc.
Tech from DDU, Nadiad. Nikhil J Kothari has received his Ph. Considering these 2 dB losses, the proposed design of power amplifier is made for 39 dBm average output power. This means that nonlinear analysis needs to be undertaken to complete the design.
The signal enters the overall Doherty power amplifier and is presented to a splitter. Events Doherty Power Amplifier Design Doherty amplifier design needs to ensure the performance of both amplifiers is optimised along with the biasing, splitter, feed, matching and combination to ensure the most efficiency operation Doherty Amplifier Includes: It also explains the advantage of the modified output combining techniques in a 3-stage Doherty power amplifier DPA.
Such heterogeneous network HetNet with a combination of a Macro, large number of Micro sites and small cells in common geographic areas increase individual user data throughput and overall capacity of the network.
Acknowledgements The authors would like to thank Mr.Abstract This thesis explores the feasibility of integrating the Doherty power amplifier (PA) technique at frequencies of 10 GHz and above.
Doherty circuits in two separate. Thesis submitted to the faculty of the EFFICIENCY ENHANCEMENT OF BASE STATION POWER AMPLIFIERS USING DOHERTY TECHNIQUE By Vani Viswanathan ABSTRACT The power amplifiers are typically the most power-consuming block in wireless communication systems.
Spectrum is expensive, and newer technologies demand transmission of maximum. Mitigation of Memory Effects in High Power Microwave Amplifiers by Nizar Messaoudi A thesis This thesis expounds on the application of Doherty Power Amplifiers (DPA) along with baseband Digital PreDistortion (DPD) techniques to tackle the antagonistic demands of high.
A GHz Doherty Power Amplifier with a 40 dBm Saturated Output Power using GaN on SiC HEMT Devices by Bryant Baker A thesis submitted in partial fulfilment of the. Thesis for The Degree of Licentiate of Engineering Theory and Design of Wideband Doherty Power Ampliﬁers David Gustafsson Microwave Electronics Laboratory.
Highly Integrated Wideband Doherty Power Amplifier. Sundas Sheikh. Raza Hussain. This thesis is presented as part of Degree of.
Master of Science in Electrical Engineering.Download