THE JOURNAL OF KOREAN INSTITUTE OF ELECTROMAGNETIC ENGINEERING AND SCIENCE. 2015 Mar.; 26(3), 276 282. http://dx.doi.org/10.5515/kjkiees.2015.26.3.276 ISSN 1226-3133 (Print) ISSN 2288-226X (Online) RRH Class-J An Analysis of Wideband and High Efficiency Class-J Power Amplifier for Multiband RRH 최상일 이상록 이영철 Sang-Il Choi Sang-Rok Lee* Young-Chul Rhee 요약 LDMOS AB- 60 MHz 55 %, RRH 100 MHz 60 %, GaN 2, J-., W-CDMA 1.6 2.3 GHz 60 75 % 45 W J-. Abstract Until recently, power amplifiers using LDMOS were Class-AB and Doherty type, and showed 55 % efficiency for narrowband of 60 MHz bandwidth. However, owing to the RRH application of base stations power amplifier module, a bandwidth expansion of at least 100 MHz and high efficiency power amplifiers of at least 60 % power efficiency are required. In this study, a Class-J power amplifier was designed by optimizing an output matching circuit so that the second harmonic load will contain a pure reactance element only and have broadband characteristics by using GaN HEMT. The measurements showed that a 45 W Class-J power amplifier with a power added efficiency of 60 75 % was achieved when continuous wave signals were input at 1.6 2.3 GHz, including W-CDMA application. Key words: Class-J Power Amplifier, GaN, Load-Pull, Wideband. 서론, LTE(Long Term Evolution) [1].. 3G/4G, LDMOS, (Department of Information & Communication Engineering, Kyung-nam University) *( ) (Korea Telecommunication Component) Manuscript received January 6, 2015 ; Revised February 5, 2015 ; Accepted February 13, 2015. (ID No. 20150106-08S) Corresponding Author: Sang-Il Choi (e-mail: sichoi@integral-lab.com ) 276 c Copyright The Korean Institute of Electromagnetic Engineering and Science. All Rights Reserved.
RRH Class-J 5G [2].,. LTE 3G [3]. RRH, W-CDMA(Wideband Code Division Multiple Access), 3G, LTE. RRH RF, RF. 1 RRH, CPRI(Common Public Radio Interface) W- CDMA 1.2288 Gbps LTE 2.4576 Gbps [1]. RRH LDMOS GaN GaN HEMT,,,, GaN [4].,. DPD(Digital Pre-Distortion), D, E, F [4] [6]. 100 %., 100 %, [7].,, 2 J-. J-, AB, B [8]. LTE 1.8 GHz, 2.1 GHz, WCDMA, GaN HEMT - (source pull)/ - (load pull) / J- 2, Q J- RRH.. J- 급전력증폭기동작특성분석 그림 1. RRH Fig. 1. Block diagram of RRH. J- 2. J- DC,, 2 (1) [7]. 277
THE JOURNAL OF KOREAN INSTITUTE OF ELECTROMAGNETIC ENGINEERING AND SCIENCE. vol. 26, no. 3, Mar. 2015. sec sin cos (1) 180. DC, 2. 2. 2 2 90, 90. 2 45. (2). sin (2), 2. 2 2 2. ± sin (3) J- 78.5 %, B- [8]. J- (6),. 2 2 90 2 (7). sec cos (7) 2 45 (8). sin (8) 2 2 45. J- 2,, 2. J-,,, sin (4) 0 (4) (5). (5),,, (6). m ax, m in (6) 그림 2. Fig. 2. Drain voltage wavform and drain current waveform. 278
RRH Class-J. ( ).,.. GaN HEMT, 2.3 2.6 pf.,. 2 3 pole,,.. 고효율, 광대역을위한임피던스정합과 J- 급전력증폭기설계및제작 GaN 45 W, GaN - -. 3 -. 28 V AB- 3.05 V. 1.6 2.3 GHz GaN, 60 % 47 dbm /, - 그림 3. - Fig. 3. Load-pull simulation result.. J- 2 2. (open stub) 2. 2 45., 2, 2, J-., 1.6 2.3 GHz 45 46 dbm, 63 70 %. 4 5. 6 2 J-, 3.5 PCB. 7, 8., 1.6 2.3 GHz 46 dbm(45 W) 60 75 %. 279
THE JOURNAL OF KOREAN INSTITUTE OF ELECTROMAGNETIC ENGINEERING AND SCIENCE. vol. 26, no. 3, Mar. 2015. 그림 4. Fig. 4. Frequency-dependent output power. 그림 7. P in /P out Fig. 7. VS test result. 그림 5. Fig. 5. Frequency-dependent gain and power added efficiency. 그림 6. J- Fig. 6. Class-J power amplifier of implementation. 그림 8.,, Fig. 8. Frequency-dependent P out, gain, power added efficiency., 45 W., 1.6 GHz, 2 1.6 GHz 75 %. J- 1. D, E, F-, [5] 79 %,. GaN HEMT 280
RRH Class-J 표 1. Table 1. Power amplifier performance analysis. [MHz] BW [MHz] P out [W] PAE [%] HEMT type Ref. [4] 800 60 5.2 59 GaN Ref. [5] 1,950-0.1 79 E-pHEMT Ref. [6] 3,500-47 56.6 GaN This work 1,950 700 45 60 75 GaN J- 700 MHz.,,.. 결론 45 W GaN J-. J- E, F-,. J-, 1.6 2.3 GHz 45 W 60 %, AB LTE WCDMA., 2 2. J- RRH, 5G. References [1] Y. Kumagai, Y. Funyu, and H. Maeda, "High-efficiency power amplifier for LTE/W-CDMA system", FUSITSU Sci. Tech. Journal, vol. 48, no. 1, pp. 33-39, Jan. 2012. [2] L. Xichun, R. Salleh, A. Aani, and O. Zakaria, "Multinetwork data path for 5G mobile multimedia", ICCSN 09, pp. 583-587, Feb. 2009. [3] Y. Shimazu et al., "RRE shared between W-CDMA and LTE systems", NTT DOCOMO Tech. Journal, vol. 12, no. 1 pp. 29-33, 2010. [4] A. Wentzel, W. Heinrich, "A GaN voltage-mode class-d MMIC with improved overall efficiency for future RRH applications", 2013 EuMC, pp. 549-552, Oct. 2013. [5] H. R. Bae, S. S. Cho, and J. W. Lee, "Efficiency enhanced class-e power amplifier using the second harmonic injection at the feedback loop", 2010 European Microwave Conf., pp. 1042-1045, Sep. 2010. [6] J. H. Kim, S. J. Lee, B. H. Park, S. H. Jang, J. H. Jung, and C. S. Park, "Analysis of high-efficiency power amplifier using second harmonic manipulation : Inverse class-f/j amplifiers", IEEE Trans. on Microwave Theory and Techniques, vol. 59, pp. 2024-2036, Aug. 2011. [7] N. Tuffy, A. Zhu, and T. J. Brazil, "Class-J RF power amplifier with wideband harmonic suppression", 2011 IEEE-S Int. Microwave Symp. Digest, Jun. 2011. [8] P. Wright, J. Lees, J. Benedikt, P. J. Tasker, and S. C. Cripps, "A methodology for realizing high efficiency class-j in a linear and broadband PA", IEEE Trans. on Microwave Theory and Techniques, vol. 57, pp. 31. 281
THE JOURNAL OF KOREAN INSTITUTE OF ELECTROMAGNETIC ENGINEERING AND SCIENCE. vol. 26, no. 3, Mar. 2015. 2013 2 : ( ) 2013 3 : 2007 : ( ) [ 주관심분야 ], RF Power Amplifier 1981 : [ 주관심분야 ],, RF Power Amplifier 2011 2 : ( ) 2013 3 : 2011 : ( ) [ 주관심분야 ],, SSPA 282