Research On Multimode And Multiband Power Amplifiers  Posted on:20161126  Degree:Doctor  Type:Dissertation  Country:China  Candidate:P Chen  Full Text:PDF  GTID:1108330473456111  Subject:Circuits and Systems  Abstract/Summary:  PDF Full Text Request  With the rapid development of diverse wireless communication standards, all components of the radio frequency(RF) transmitter are required to deal with different modes and bands signals. As one indispensable component of the RF transmitter, power amplifier, which is responsible for transforming small power signal to a large one, is also demanded to deal with different modes and bands signals as its characteristics are related to the working frequency. The multimode and multiband power amplifier is designed to concurrently amplify multimode and multiband signals. According to the signals distribution, the multimode and multiband power amplifier can be divided into two categories: the broadband power amplifier and the multiband power amplifier. The broadband power amplifier is a better choice when the signals are distributed in one octave and the multiband power amplifier is preferred when the signals are distributed beyond one octave. The main concerns and innovations of this thesis are these two kinds of power amplifiers and organized as following four parts.1. Analysis of the inverse classE power amplifier at subnominal condition. The load impedance of the inverse classE power amplifier will change over a certain range in practical applications. On this situation, the inverse classE power amplifier works with only the zero current switching(ZCS) condition. In order to distinguish the conventional inverse classE power amplifier, which works with both ZCS and zero current derivative switching(ZCDS) conditions, the inverse classE power amplifier with only the ZCS condition is termed as the inverse classE power amplifier at subnominal condition. The performance of the inverse classE power amplifier at subnominal condition is analyzed in this thesis and the result shows that the inverse classE power amplifier at subnominal condition is still with 100% theoretical drain efficiency. As the ZCDS condition has been removed, the inverse classE power amplifier releases a new design parameter, which increases the design freedom. Considering that the duty ratio will affect the performance of inverse classE power amplifier, the inverse classE power amplifier at subnominal condition for any duty ratio is investigated to understand its mechanism. The analysis results show that the theoretical drain efficiency of the inverse classE power amplifier is100%. In order to verify the proposed power amplifier, an inverse classE power amplifier at subnominal condition for 0.4 duty ratio is designed in the Win Semiconductor 0.1 m GaAs pHEMT substrate. The simulation results agree with the theoretical results. And the accuracy of the proposed inverse classE power amplifier at subnominal condition is verified.2. Design procedure of the continuous classE power amplifier at subnominal condition. It is proofed that the drain current falling time at the switch ontooff instant will affect the drain efficiency of the classE power amplifier. In order to reduce the effect of the drain current falling time at the switch ontooff instant to the classE power amplifier,the continuous classE power amplifier at subnominal condition is investigated and presented. The continuous classE power amplifier at subnominal condition, which means it only work with zero voltage switching condition, can deliver 100% theoretical drain efficiency over a broad bandwidth by adjusting the fundamental and second harmonic impedances. Comparing with the traditional broadband classE power amplifier which is based on the admittance compensation technology, the continuous classE power amplifier at subnominal condition has more design freedom.3. Broadband power amplifier. When all the concerned signals distributions are in one octave, the broadband power amplifier is a better choice. Firstly the bandwidth of the inverse classE power amplifier is broadened by reactance compensation technology.Considering that the broadband inverse classE power amplifier is most likely used in integrated circuit, two kinds of power amplifier for basestation are also introduced: the extended continuous classF power amplifier and the leastlosses Chebyshev broadband power amplifier. The current and voltage waveforms of the continuous classF power amplifier are investigated at the transistor’s currentgenerated plane. It is discovered that the continuous classF power amplifier can only maintain highefficiency in oneoctave.An improving bandwidth method for continuous classF power amplifier is proposed.And a 0.42.3 GHz broadband and highefficiency power amplifier is designed and measured to verify the proposed design methodology. Also, a novel broadband impedance matching technology based on the leastlosses Chebyshev matching is introduced. The application of the traditional leastlosses Chebyshev broadband matching is limited as the using of the Norton transformer, which will bring in the unrealistic negative capacitor. The presented method avoids this disadvantage and broadens the application range of the leastlosses Chebyshev broadband matching technology. The gain ripple of the power amplifier based on this method is in 1 dB.4. Concurrent dualband and triband power amplifier. When all the concerned signals distributions are beyond one octave, the concurrent multiband power amplifier is preferred. A Πtype dualband impedance transformer is introduced to transfer two irrelevant complex sources impedances to two irrelevant complex loads impedances at two arbitrary frequencies. Traditional dualband impedance transformer with similar function needs to solve a quartic equation and manually select the proper solutions, which is not suitable for CAD design. The proposed Πtype dualband impedance transformer overcomes this drawback. Also, an optimization approach based on the transducer power gain function for multiimpedances matching technology is introduced and finished by the improved particle swarm optimization(PSO) algorithm. Both the matching network of the dualband and triband power amplifier are designed by this optimization approach. The dualband power amplifier is designed with harmonic impedance controlling technology and the triband power amplifier is based on the continuous classE power amplifier. The measurement results show that both the dualband and triband power amplifier can work with high drain efficiency.  Keywords/Search Tags:  multimode and multiband, power amplifier, highefficiency, subnominal condition, impedance matching  PDF Full Text Request  Related items 
 
