Design Of Dual-bands Harmonic Controlled Power Amplifier And Harmonic Controlled Power Combining Amplifier

With rapid development of wireless communication systems,traditional single band communication systems are unable to meet the growing demands of communications.Dual-bands and multi-bands communications already attract extensive attention.Power amplifiers,filters,power combiners and other devices are important parts of wireless communication systems.However,these devices are often designed separately,and then cascade to form wireless communication systems.This method will greatly increase the sizes of the systems and bring transmission losses,and,is not in line with the development trend of miniaturization,integration,low cost and high performance for wireless communication systems.In order to achieve high efficiency,save system sizes and cost,integrated designs of filtering power amplifier and filtering power combining amplifier become the focus of attention.In order to satisfy the demand of dual-bands communications,it is first designed that a harmonic controlled dual-bands filtering power amplifier,followed then by a harmonic controlled filtering and power combining amplifier in this dissertation.In the designs,the filters,the filtering power combiners and the amplifiers are designed coordinately,making the circuits high efficiency.Detailed introductions are as following:1.A dual-bands SLR suspended substrate strip-line filter is proposed.Firstly,the structure of the suspended microstrip line is introduced.It is low loss and is useful in wide-band filters.In order to adjust the bandwidths of two bands independently,we use an open branch loaded resonator and a short-circuit branch loaded resonator to form a dual-bands filter.The simulation analysis and verification are carried out.At the same time,the filter structure generates three transmission zeros on both sides of the two pass bands,which show the high selectivity of the filter.The-10d B impendence bandwidth of the low band is 2.223-2.626GHz?403MHz?,and the-10d B impendence bandwidth of the high band is 3.243-3.781GHz?538MHz?.At the low frequency of 2.4GHz,the return loss is 19.53d B and the insertion loss is 0.34d B.At the high frequency of 3.5GHz,the return loss is 27.91d B and the insertion loss is 0.26d B.This shows good matching and low insertion loss.2.A harmonic controlled filtering power amplifier is proposed.Based on the analysis of the dual-bands SLR suspended substrate strip-line filter,the filtering power amplifier uses microstrip structures and dual-bands filter to form its output network.The filter is used as a part of the output matching network and the harmonic control network.Its fundamental input impedance is adjusted to achieve the best matching with the best fundamental impedance of the transistor.Its phases of S₁₁ in the second harmonic and the third harmonic are far away from the low efficiency zones.In the way,the integrated design of the dual-bands filtering power amplifier is completed.From 2.3GHz to 2.5GHz,the output power is about 40d Bm,the output efficiency is more than 65%,and the maximum output efficiency is 69.382%.From 3.4GHz to3.6GHz,the output power is over 40d Bm,the output efficiency is over 60%,and the maximum output efficiency is 64.5%.The simulated results are in good agreement with the measured results,which show the high output efficiency of the integrated dual frequency filter power amplifier.3.A harmonic controlled filtering power combining amplifier is proposed.By the analysis of the principle of Wilkinson power divider and quarter wavelength resonator,the integrated design of filter and power divider is realized;in order to improve its filtering characteristics,the SIR Wilkinson power divider is used to achieve better dual-mode filtering characteristics;further,in order to improve its isolation and reduce the impact between the two transistors,an additional isolation unit is added.Finally,a filtering power combiner with low loss and wide bandwidth is completed.The filtering power combiner acts as the filter network,output impedance matching network and harmonic control network of the power amplifier at the same time.The optimal fundamental impedance of the power amplifier is taken as the input impedance of the filtering power combiner,and its phases in the second harmonic and the third harmonic are far away from the low efficiency zones.The filters,the filtering power combiners and the amplifiers are designed coordinately.Finally,the output power of the filtering power combining amplifier is over 42.5d Bm and the output efficiency is over 65%in the range of2.15-2.62GHz.The bandwidth of the filtering power combining amplifier,with the output efficiency of over 65%is 470MHz,of which the bandwidth of the output efficiency of over 70%is 335MHz,the maximum output efficiency is 73.92%and the maximum power is 44.6d Bm.The simulation results show the high output efficiency of the integrated filtering power combining amplifier.