Document
DATA S H E E T
TRAVELING WAVE TUBE AMPLIFIER FOR GROUND TERMINALS
LD79U12K
14 GHz, 123 W CW, LIGHT WEIGHT, COMPACT, EFFICIENT
GENERAL DESCRIPTION
NEC TWTA (Traveling Wave Tube Amplifier) LD79U12K delivers an output power of 123 W over the range of 13.75 to 14.5 GHz with a gain of 50 dB. The Traveling Wave Tube (TWT : LD7246A) in the LD79U12K has been designed and developed upon the NEC's advanced technology and enormous experience on a number of TWTs used in satellite ground terminals and terrestrial microwave links. The very small and light weight Electric Power Conditioners (EPC) designed with sophisticated and experienced circuit technology ensures higher reliability, reduced maintenance costs and improved technical performance. The LD79U12K is most suitable for a power amplifier in digital communication systems.
FEATURES
™ Light weight, Compact, and Efficient The TWT has a dual-depressed collector and is designed to operate at high efficiency across the power output range. The EPC features state-of-the-art techniques to optimize size and efficiency and the combination results in a unit significantly smaller and with less power consumption than a comparable solid state amplifier. ™ Low Distortion NEC has developed techniques for the correction of non-linear distortion of gain and phase generated in a TWT. As a result, the TWTA has optimum performance across a broad power range and is ideally suited for multicarrier transmission systems. ™ Long Life The TWT is designed to have a lifetime of 50,000 hours or more, which in actual usage. ™ Ideal for Digital Systems A mini-arcing in the electron gun have been eliminated in the TWT used in the TWTA. ™ Wide range of primary voltage
For safe use of microwave tubes, refer to NEC document “Safety instructions to all personnel handling electron tubes” (ET0048EJ∗V∗UM00)
The information in this document is subject to change without notice.
Document No. ET0224EJ2V0DS00 Date Published September 1998 M Printed in Japan
©
1996
LD79U12K
TYPICAL OPERATIONS
Frequency Range ………………………………………… 13.75 –14.5 GHz Power Output …………………………………………… 123 W minimum Instantaneous Bandwidth ……………………………… 750 MHz Gain Variation …………………………………………… 1.0 dB / 750 MHz Gain ……………………………………………………… 53 dB (at Po = 123 W) 60 dB (at small signal) Gain Stability …………………………………………… ± 0.25 dB / 24 h (25˚C ± 10˚C) Gain Slope ………………………………………………… 0.03 dB / MHz Harmonic Output ………………………………………… 10 dB below at rated output power Spurious Output ………………………………………… –70 dBW in any 4 kHz band in the 13.75 to 14.5 GHz AM to PM Conversion Group Delay Linear component …………………………………… 0.1 ns / MHz Parabolic component ………………………………… 0.01 ns / MHz2 Ripple component …………………………………… 1.0 ns (p-p) in any 40 MHz band RF Input Connector ……………………………………………… Mates with Type SMA Female VSWR …………………………………………………… 2.0 : 1 maximum Load VSWR …………………………………………… Operate into 1.5 : 1 maximum RF Output Waveguide …………………………………………… Mates with BRJ-120 Flange VSWR …………………………………………………… 2.0 : 1 maximum Load VSWR …………………………………………… Operate into 1.5 : 1 maximum Primary Power …………………………………………… 85 Vac-255 Vac (450 VA) Power Factor ……………………………………………… 0.9 minimum Electrical Connections AC IN …………………………………………………… JL04V-2E10SL-3PE-B Connector CONT & MON ………………………………………… DA-15P-N D-Sub Connector Dimensions ……………………………………………… TWT : 315 x 40 x 50 mm EPC : 350 x 220 x 75 mm Weight ……………………………………………………… TWT : 1.3 kg EPC : 5 kg ………………………………… 4˚ / dB maximum at rated power Intermodulation ………………………………………… 18 dB below each of two equal 45 dBm carriers
ENVIRONMENTAL CONDITIONS
™ Ambient Temperature 0˚C to +45˚C (operating) –30˚C to +70˚C (non operating, storage) ™ Relative Humidity 90% maximum (non dewing) ™ Base Plate Temperature of the TWT +90°C maximum
2
LD79U12K
Note 1 : These characteristics and operating values may be changed as a result of additional information or product improvement. NEC should be consulted before using this information for equipment design. This data sheet should not be referred to a contractual specification.
3
LD79U12K
LD79U12K OUTLINE (Unit in mm)
RF Output Mates with FURB-120 Flange 210 40 34
41.8 7
30 80
40
20
90
93 231.5
M A D E I N J A PA N
160
350
320
295
275
NEC Cor poration
220 200
18
10 - φ 4.5
7 75
35.4
9. HV ON CMD COM
1. HV ON CMD 2. HV ON RESP 3. Ihel ALM 4. Ihel MON 5. STAND BY AC C A B GND AC
50
HV/OUT
HV/ON
ACVIN
CONT
55
10. HV ON RESP. COM 11. Ihel ALM COM 12. Ihel MON COM 13. STAND BY COM
Pin Connection (D-sub. 15 pins) (Note 1-5)
Pin Connection (AC IN)
AC IN : MS3102A 14S-7P (3 pins) CONT : DA-15P-N D-Sub connector (15 pins)
Note 1. HV ON/OFF RESPONSE SIGNAL : Photocoupler Interface (No.2: Collector, No.10: Emitter) HV ON : No.2 and No.10 conduct 2. Ihel ALM Signal : Photocoupler Interface (No.3: Collector, No.11: Emitter) Ihel ALM Signal ON : No.3 and No.11 conduct 3. Ihel Monitor (No.4, No.12) : 1 V/mA 4. HV ON : When No.1 and No.9 conduct, TWT will be ready to amplify 5. STANDBY : .