A High Efficiency High Power Transmitter Architecture

Wireless communication has gone through half a century of development,and the communication rate has continued to increase,from the Kbps level at the beginning to the current fifth-generation communication of several hundred Mbps.The development of many new technologies,such as VR,AI,and the Internet of Things,are based on more demanding communication systems.E-band,as a kind of millimeter wave,has natural advantages.Many countries have opened up the E-band spectrum,but most of the research is still in the experimental stage.With the rigid growth in demand for communication rates,E-band wireless communication with higher bandwidth and faster rate has great use and commercial value.The main purpose of this research is to explore a new transmitter architecture mechanism suitable for millimeter wave communication links.In traditional transmitters,baseband modulation is mostly realized by digital signal processing,and radio frequency modulation is realized by analog circuits,connected by digital-to-analog converters,to complete signal modulation to transmission.This research opens up a relatively different idea,that is,the coordinated processing of the digital domain and the analog domain is combined,and modulation and transmission are completed at the same time.It has the advantages of simple architecture,high power,and high efficiency.The main research content includes the theoretical analysis and structural improvement of the new transmitter architecture,as well as the theoretical analysis and design of the devices of the transmitter architecture,including balun,Lange coupler,Wilkinson power splitter,single pole double throw switch,distributed Amplifier.In 70-76 GHz,the insertion loss of the power splitter is about 3.3d B,and the amplitude and phase difference is equal to zero;the Lange coupler insertion loss is about 3.4d B,the difference between the maximum insertion loss of the two channels is 0.3d B,and the phase difference is90±0.8°;The insertion loss of the balun is about 3.5d B,the maximum insertion loss difference is0.4d B,and the phase difference is 180± 0.5°;the insertion loss of the single-pole double-throw switch is 4d B,and the isolation is greater than 24 d B;the amplifier gain is 8d B,the gain flatness is± 1.5d B,the input 1d Bm power compression point is-1d Bm at 72 GHz,and the output 1d B compression point is 7d Bm.Further using these devices to design and simulate two QPSK transmitter architectures,the switch-based transmitter architecture obtains an EVM of 11%,and the amplifierbased large design architecture obtains an EVM of 7%,and while the final amplifier can achieve saturation amplification,the modulation quality has not significantly deteriorated.Finally,use the four-channel QPSK transmitter structure to combine and integrate the control signals to build a16 QAM transmitter structure and simulate a 16 QAM constellation diagram.