The 7th National Radar Seminar and The 2ndInternational Conference on Radar, Antenna, Microwave, Electronics and Telecommunications (ICRAMET)
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RF Power amplifier Using LDMOS Transistors Technology Components for Digital TV Broadcasting Application Pamungkas Daud, Suhana Hermana, Dadin Mahmudin Electronics and Telecommunications Research Center (PPET)-LIPI LIPI Campus Gd. 20 Lt. 4 Jl. Sangkuriang Bandung - INDONESIA Tel. 022 2504660 Fax. 022 2504659 Email:
[email protected] Abstract--The paper reviews the technology cursory MOSFET, DMOS and LDMOS RF power amplifier for the application of digital TV transmitters. Comparison of DMOS and LDMOS structures reveals the fundamentals of RF MOSFET technology as a tool to improve the performance and reliability of RF components. Until now, research dominance MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) is focused on VLSI technology, which is driven by computer IC market pressures. VLSI devices using the physical structure similar to RF power MOSFETs, but the use of VLSI physical dimensions much smaller. Significant difference between RF MOSFETs and VLSI devices is the larger channel length, the larger depth of the connection lines and gate oxide thickness, where the conditions are necessary to obtain high power and mostly needed for RF applications. Currently Component for applications with high power RF circuits tend without supporting complex. RF market is being driven by the need for higher reliability, gain, linearity and output power requirements that will be constrained by the limitations of the DC power supply. Majority high power RF applications using DC supply voltage ranging from 20 to 50 volt. In this paper portion of the discussion will focus on the implementation, especially a transistor BLF888 UHF power LDMOS transistor as to be used in high power RF amplifier for digital TV transmitters. Keywords-Semiconductors, RF Power, MOSFET, VLSI
I. INTRODUCTION Linearity power amplifier radio frequency (RF) plays an important role in wireless communication systems [7]. However, the power amplifier itself has linear and nonlinear properties at once. The nature of nonlinear RF power amplifier output signals resulting experience intermodulation distortion and produce spurious responses. In dense multichannel communication systems, such as CDMA, intermodulation distortion or spurious signals may interfere with other transmissions on adjacent canal [4]. As a result, communication channels can deliver part of the canal so that the signal event of an irregular overlapping and therefore, the power amplifier, nonlinear properties are properties that are not desired
appearance. Two main structural categories of RF MOSFETs used at present, is the structure DMOS (double-diffused Metal-Oxide-Semiconductor) and LDMOS (lateral spread Metal-Oxide-emiconductor) [1]. In this paper will be shown to the implementation of the LDMOS module that is so, and we use it to design a RF Power Amplifier (PA) High power (the unit of Kilo Watt Power) that will be used for use in transmitter Digital TV standard DVB-T. II. DESIGN AND DEVELOPMENT Basic requirements of digital television transmitter Digital Video Broadcasting - Terrestrial Standard (DVB-T Standard) are: amplifier with high linearity, wide dynamic range that digital modulation signal peaks in the dynamic range of the transmitter still has good linearity, the frequency of the transmitter must be precise enough and high stability, low phase noise to ensure that the signal is transmitted at the lowest possible bit error ratio (BER) and modulation error ratio (MER) [5]. To meet the needs of an amplifier with gain high linearity, high power amplifier system design are used BLF888 transistor, which is UHF BLF888 LDMOS power transistors that can provide ± 180 Watt output power DVB-T wider frequency range [2.6]. Transistor BLV888 digital television transmitter also meets DVB-T standard specification: Ultra High Frequency (UHF) frequency ranges from 470-MHz to 860 MHz, amplified by a class AB amplification; 50Ω input impedance and output impedance 50Ω.Dalam this design, the power amplifier is used to amplify the output of the low-power amplifier, in which the input of a low power amplifier derived from digital television exciter. With - 3 dBm output level of the exciter, high power amplifier system consists of a power splitter, the power amplifier and the power combiner, can provide a power output 500 Watt-800 Watt DVB-T. This design can be applied to digital television transmitters DVB-T standard that operates in the UHF band. III. REALIZED AND MEASUREMENT Actual PA scale output can be determined by the configuration of the module UHF power LDMOS transistor is used, where 1 Pallet UHF LDMOS module 800 consists of 2 pieces of transistor BLF888, before the 2 pieces LDMOS UHF module to integrate into a 1KW PA. Characterization test performed as follows:
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The 7th National Radar Seminar and The 2ndInternational Conference on Radar, Antenna, Microwave, Electronics and Telecommunications (ICRAMET)
ICRAMET
Figure. 2 1KW PA Module
Figure. 1 Measurement Procedure PA Block Diagram
From the characterization results obtained that for the frequency range. 470 Mhz-840 Mhz frequency response. Vs. gain is nearly flat as shown in TABLE 1 TABLE 1 Freq. Input (MHz) 470 520 570 620 670 720 770 820 870
To drive PA 1 KW Power Supply is required specifications include: a stable voltage and low ripple [3], was used for switching PSU PS EATON APR48, SN 24423573, where the measurement procedure can be seen in Figure 3 and the results of the Test PSU can be seen in Table-3 and table-4.
FREQUENCY RESPONSE. VS. GAIN
RF Out. (Watt) rms 50 100 150 200 250 300 350 500 800
Power Gain (dB) 55 55.7 54.26 55.51 55.3 55.17 55.74 57.5 59.8
DC Arus Maks. (Amp.) 13 17 20 24 27 29 31 33 35
Temp. °C
40° C 40° C 40° C 40° C 40° C 40° C 44° C 44° C 44° C
Arus PA Driver (Amp.) 3 3 3 3 3 3 3 3 3
For the response to the RF input power gain can be seen in Table-2
Figure.3
Measurement PSU Block Diagram
Input Voltage PLN 200 Volt Set UP to 220V by using a Variac
TABLE 2 RF INPUT POWER GAIN RF Input (dBm) -8.6 -5.7 -3.94 -2.79 -1.85 -1.03 0.36 1.25 3.2 4.2
RF Out. (Watt) rms 50 100 150 200 250 300 350 500 800 1000
Power Gain (dB) 55 55.7 54.26 55.51 55.3 55.17 55.74 57.5 59.8 61.2
DC Arus Maks. (Amp.) 13 17 20 24 27 29 31 33 35 38
Temp. °C
40° C 40° C 40° C 40° C 40° C 40° C 44° C 44° C 44° C 44° C
Arus PA Driver (Amp.) 3 3 3 3 3 3 3 3 3 3
TABLE -3. THE PSU MEASUREMENT RESULTS AC Inp. Volt
Iac Am p
Daya Inp. AC Watt
Idc Out Am p
Vdc Out Volt
V rippl mVo l
220 220 220 220 220 220 220 220 220
1.4 2.7 5.4 6.9 8.5 8.5 9.7 10 10
308 594 1188 1518 1870 1870 2134 2200 2200
5 10 15 20 25 30 35 40 41.7
54.20 54.10 54.10 54.10 54.00 54.00 53.90 49.50 48.50
6 8 8 8 10 10 12,5 10 10
Configuration and Layout of PA 1KW which is composed of 2 modules Pallet LDMOS UHF module 800 and 1 1 Splitter and Combiner Modules are shown pd figure 2.
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Fakt . Ripp l (%) 0.11 0.14 0.14 0.14 0.18 0.18 0.23 0.18 0.18
Daya Out. dc Watt 271 541 810 1078 1345 1611 1876 2140 2403
The 7th National Radar Seminar and The 2ndInternational Conference on Radar, Antenna, Microwave, Electronics and Telecommunications (ICRAMET)
ICRAMET
TABLE-4. THE PSU MEASUREMENT RESULTS AC Min Inp. Volt 195 190 180 170 160 150 125
Ia c A m p 8.6 8.8 9.3 9.9 10. 5 11. 4 11. 8
Digital television can provide more programs than traditional analog television over any transmission medium.
Day a Inp. AC Watt 1870 1677 1672 1674
Idc Out Amp
Vdc Out Volt
V rippl mVo l
Fakt rippl (%)
30 30 30 30
54 54 54 54
10 10 10 10
0.18 0.18 0.18 0.18
Day a Out dc Watt 1620 1620 1620 1620
1683
30
54
10
0.18
1620
1680
30
54
10
0.18
1620
[1]
1710
30
54
15
0.18
1620
[2]
From the results of Test Characteristics Module Power Supply PSU PA and the results can be seen from each of the tables that have been there, it turns out that the specification of the PA will be made appropriate and suitable, so for the early stages of the design and integration of modules that can be well characterized combined to produce a Power Amplifier as required.
V. ACKNOWLEDGMENTS THANKS The research activity is made possible through the Ministry of Research and Technology Incentives SINAS and Technology. For that we say thank you profusely for Research and Technology and LIPI also have to manage the administration of this study. REFERENCES
[3] [4]
[5]
IV. CONCLUSIONS Module UHF 800Watt LDMOS power transistor with BLV888 is suitable for the PA to use for a standard digital TV transmitters DVB-T, DVB-T2, DVB-H and TV to any standard analog television. Module types of solid state power amplifier is the latest LDMOS technology and theoretically have an infinite life time. Demands power amplifier with high power (order Kilo Watt) compact becomes a necessity where high power Power amplifier can be formed from the smaller power amplifier modules , thus simplifying operation and maintenance.
[6]
[7]
Philips Semiconductors, RF transmitting transistor and power amplifier fundamentals, March 1998 30 kVA LF/VLF power amplifier module Williford, J.G.; DuBose, J.T.;Rockwell Int. Corp.Military Communications Conference, 1995. MILCOM '95, Conference Record, IEEE Issue Power Amplifiers``, IEEE Transactions on Microwave Theory and Techniques, vol. 47, pp.2364-2378, 1999. P. Perugupalli, Y. Xu, and K. Shenai, “Measurement of thermal and packaging limitations in LDMOSFET’s for RFIC application,” in Proc. IEEE Instrum. Meas. Technol. Conf., vol. 1,1998, pp. 160–164 Titov, A.A.; Ilyushenko, V.N.; Avdochenko, B.I.; Obikhvostov, V.D.; Tomsk State Univ.” The power amplifier for TV transmitter” Electronic Instrument Engineering Proceedings, 1998. APEIE-98. Volume 1. 4th International Conference on Actual Problems of Electronic Instrument Engineering Proceedings, 1998. APEIE-98 Motorola’s Electro Thermal LDMOS Model, http://ewww.motorola.com/collateral /MET_LDMOS_MODEL_DOCUMENT_0502.pdf. J. Vuolevi and T. Rahkonen, “Third-order intermodulation distortion caused by thermal power feedback,” in Proc. Norchip’99, Oslo, Norway, pp. 121–125.
DISSCUSSION No question from participant
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