Title :
Doherty Amplifier Using Load Modulation and Phase Compensation DGS Microstrip Line
Author :
Choi, Heung-Jae ; Lim, Jong-Sik ; Jeong, Yong-Chae ; Kim, Chul-Dong
Author_Institution :
Dept. of Inf. & Commun. Eng., Chonbuk Nat. Univ., Jeonju
Abstract :
In this paper, a new Doherty power amplifier having the ideal harmonic termination condition that has been usually ignored is proposed. A defected ground structure (DGS) is adopted on the ground pattern of the output lambda/4 impedance inverter of the carrier amplifier and output offset transmission line of the peaking amplifier that are essential for proper load modulation operation of a conventional Doherty amplifier. As a result of the second and third harmonic termination, excellent improvement in power added efficiency (PAE), gain, maximum output power as well as linearity is obtained. The acquired improvements in gain, maximum output power (P1dB), PAE and adjacent channel leakage ratio (ACLR) to WCDMA 2FA signal are 0.42dB, 0.33dB, 12.7%, and 5.1dB, respectively. Moreover, physical length of microstrip line is shortened fairly by DGS, therefore the whole amplifier circuit size is considerably reduced
Keywords :
differentiating circuits; microstrip lines; power amplifiers; DGS microstrip line; Doherty power amplifier; WCDMA 2FA signal; adjacent channel leakage ratio; carrier amplifier; defected ground structure; harmonic termination condition; impedance inverter; load modulation; output offset transmission line; phase compensation; power added efficiency; Impedance; Inverters; Linearity; Microstrip; Operational amplifiers; Phase modulation; Power amplifiers; Power generation; Power system harmonics; Power transmission lines; DGS; Doherty Amplifier; PAE; linearity;
Conference_Titel :
Microwave Conference, 2006. 36th European
Conference_Location :
Manchester
Print_ISBN :
2-9600551-6-0
DOI :
10.1109/EUMC.2006.281346
