Key Technologies Research Of Millimeter-wave Digital Power Amplifier In InP DHBT

With the need of high-data-rate stardand and the development of multiband services,there appears more and more difficulties for the trantional transmitter architures to meet the next generation.In recent years,the wireless commucation system develops towards the direction of digital,high data rate and multi-band.So the research turn to the digital field to meet the challenge of millimeter and submillimeter wave.Based on the characteristics of InP DHBT devices compatible with high-speed digital and RF power circuits,this paper develops and verifies the millimeter wave digital power amplifier unit based on the common emitter-common base)(CE-CB)structure,and verifies the digitiation method of power amplifier.On this basis,the design scheme of a digital power amplifier(DPA)with a bus-bar based output power synthesis structure is proposed,which is the first K-band DPA in InP DHBT.To improve the output power and efficiency of the circuit,it is advanced to propose a digital power amplifier based on distributed structure output power synthesis,which verifies the correctness of the method to improves the circuit efficiency?The large signal and dynamic characteristics of the DPA cell circuit is analysed.The DPA adopts a coding method that combines binary weighted coding and thermometer code coding.The output of the power amplifier unit with different weights passes through the bus bar structure with the lower metal ground as a ground plane for power synthesis,which effectively adjusts the impedance of the transmission line and the coupling of the signal,conducive to the synthesis of output power.When the digital power amplifier chip works at 20 GHz,it achieves saturated output power of 27 dBm with peak PAE of 21%,and the mean square error of the normalized output voltage is 0.0315,showing good circuit linearity with the chip size of 2.4 mm*2 mm.On the basis of the fuctional verification of DPA,the method of distributed structure output power synthesis is first applied to improve the impedance matching.The microstrip line is combined with the parasitic parameters of the input and output of the DPA unit circuit,which is conducive to good power and efficiency design.And four DPA cell with binary weights are used to verify.When the digital power amplifier chip works at 20 GHz,the drain efficiency after improved matching reaches 34%.The chip effectively improves efficiency of the digital power amplifier?...