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DATA SHEET
HIGH POWER TRAVELING WAVE TUBE
FOR GROUND TERMINALS
LD7215W
6 GHz, 3 kW CW, PPM FOCUSING, HIGH POWER GAIN
GENERAL DESCRIPTION
NEC LD7215W is a PPM-focused traveling wave tube designed for use as final amplifier in the earth-to-satellite
communications transmitter.
This is capable of delivering an output power of 3 kW over the range of 5.85 to 6.65 GHz.
It provides a high power gain of 42 dB at a rated output power.
Furthermore, this is of rugged and reliable design offering long-life service.
FEATURES
™ High Power Gain
The power gain is typically 42 dB minimum at 3 kW level.
™ Simple Cooling System
The tube is forced-air-cooled, so that the cooling systems are simplified.
™ PPM Focusing
The tube is PPM (Periodic Permanent Magnet) -focused, eliminating entirely the focusing power supplies and
interlock circuits.
™ Rugged Construction
The tube is designed to be rugged, therefore it is suitable for transportable systems.
™ Long Life and High Stability
The tube employs an advanced impregnated cathode with a low operating temperature for long life.
™ Microdischarge Free
The tube is carefully designed to be free from microdischarge in the electron gun for long term operation,
therefore it is suitable for digital communication service.
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. ET0214EJ2V1DS00 (2nd edition)
Date Published August 1998 M
Printed in Japan
©
1996
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GENERAL CHARACTERISTICS
ELECTRICAL
Frequency ……………………………………………… 5.85 to 6.65 GHz
Output Power ………………………………………… 3 kW
Heater Voltage…………………………………………6.3 V
Heater Current ………………………………………… 4.5 A
Type of Cathode ……………………………………… Indirectly heated, Impregnated
Cathode Warm-up Time …………………………… 300 s
MECHANICAL
Dimensions …………………………………………… See outline
Weight ………………………………………………… 30 kg approx.
Focusing ………………………………………………Periodic Permanent Magnet
Mounting Position …………………………………… Any
Electrical Connections ……………………………… Flying Leads
Heater, Heater-Cathode,
Helix, Anode, Collector
and Thermal Protection
RF Connections
Input ………………………………………………… Type SMA Female
Output ……………………………………………… Mates with CPR-137F Flange
Cooling ………………………………………………… Forced Air
LD7215W
ABSOLUTE RATINGS (Note 1, 2 and 3 )
ELECTRICAL
Heater Voltage……………………………………… 6.0 6.6 V
Heater Surge Current …………………………… – 8.0 A
Heater Current ……………………………………… 3.0 5.0 A
Heater Warm-up Time …………………………… 300 – s
Helix Voltage ……………………………………… 12.5 13.7 kV
Helix Current ……………………………………… – 25 mA
Anode Voltage……………………………………… 10.0 13.0 kV
Anode Current ……………………………………… –0.5 0.5 mA
Collector Voltage …………………………………… 8.0 9.5 kV
Cathode Current …………………………………… – 1.5 mA
Drive Power ………………………………………… – 24 mW
Load VSWR ………………………………………… – 1.15 : 1
MECHANICAL
Cooling Air Flow …………………………………… 720 – kg/ hr
Operating temperature …………………………… 0 +45 ˚C
Inlet air temperature ……………………………… –20 +45 ˚C
Storage temperature ……………………………… –30 +70 ˚C
Min. Max. Unit
Min. Max. Unit
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TYPICAL OPERATION (Note 2, 3 and 5)
Frequency ……………………………………………… 5.85 to 6.65 GHz
Heater Voltage (Note 4) ……………………………… 6.3 V
Heater Current ………………………………………… 4.5 A
Helix Voltage…………………………………………… 13.5 kV
Helix Current …………………………………………… 10.0 mA
Anode Voltage ………………………………………… 11.8 kV
Anode Current ………………………………………… 0.01 mA
Collector Voltage ……………………………………… 8.25 kV
Cathode Current ……………………………………… 1.4 mA
Saturated Output Power …………………………… 3.3 kW
Power Gain at 500 W ……………………… 51 dB
at 3 kW ……………………… 45 dB
Gain Variation at 500 W……………………… 1.5 dB/800 MHz
Gain Slope at 500 W ……………………… 0.02 dB/MHz
AM-PM Conversion
at 500 W ……………………………………… 1.7 deg./dB
at 3 kW………………………………………… 3.0 deg./dB
3rd Order Intermodulation
(two equal carriers, 300 W total) …………………… –31.5 dBc
Air Flow ………………………………………………… 720 kg/ hr
Air Pressure Drop …………………………………… 882.6 Pa
LD7215W
Unit
Note 1 : Absolute rating should not be exceeded under continuous or transient conditions. A single absolute
rating may be the limitation and simultaneous operation at more than one absolute rating may not be
possible.
Note 2 : The tube body is at ground potential in operation.
Note 3 : All voltages are referred to the cathode potential except the heater voltage.
Note 4 : The optimum operating parameters are shown on a test performance sheet for each tube.
Note 5 : 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.
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LD7215W OUTLINE (Unit in mm)
,
,
,
,,
LD7215W
822 Typ.
850 Max.
535
210
195 Max.
20 Max.
2
14.5±2
1
800±50
3
M6 Terminal
198 Max.
97±1
No.1
No.2
No.4
No.5
No.6
No.3
3±1
116±1 320.8±3
12±0.5
Bearing Face
235 Max.
5.5±1
35±130±1
100±1
230±2
266±2
Bearing Face
105±1
Air
Intake
155±1
83±183±1
630±10
15±1
M4
(8 Holes)
(6)
M10 Rubber
4 Spring Loaded
()
Captive Screws
q
RF OUTPUT
w
RF INPUT
HIGH VOLTAGE
e
CONNECTIONS
20 Max.
φ
160±1
M4
(4 Holes)
130±1
CPR-137 FLANGE
(NO. 10-32 UNF 2B THREADED HOLES)
FEMALE SMA CONNECTOR
FLYING LEADS WITH M6 TERMINALS
35 Max.
178 Max.
12±1
Air
Exhaust
130±1
140
35
φ
16±1
(2 Holes)
LEAD CONNECTIONS
LEAD NO.
1
2
3
4
5
6
LEAD NAME (COLOR)
HEATER (–) (BROWN)
HEATER (+), CATHODE (YELLOW)
ANODE (BLUE)
COLLECTOR (RED)
HELIX (GROUND) (BLACK)
THERMAL PROTECTION SWITCH (GRAY)
NOTE 1 : THE 3RD ANGLE ORTHOGRAPHIC
PROJECTION.
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LD7215W
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LD7215W
NEC Corporation does not assume any liability for infringement of patents, copyrights or other intellectual
property rights of third parties by or arising from use of a device described herein or any other liability arising
from use of such device. No license, either express, implied or otherwise, is granted under any patents, copyrights or other intellectual property rights of NEC Corporation or others.
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