DATA S H E E T
Document No. ET0214EJ2V1DS00 (2nd edition)
Date Published August 1998 M
Printed in Japan
6 GHz, 3 kW CW, PPM FOCUSING, HIGH POWER GAIN
The information in this document is subject to change without notice.
1996
HIGH POWER TRAVELING WAVE TUBE
FOR GROUND TERMINALS
LD7215W
For safe use of microwave tubes, refer to NEC document "Safety instructions to all personnel
handling electron tubes" (ET0048EJ
V
UM00)
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
TM High Power Gain
The power gain is typically 42 dB minimum at 3 kW level.
TM Simple Cooling System
The tube is forced-air-cooled, so that the cooling systems are simplified.
TM PPM Focusing
The tube is PPM (Periodic Permanent Magnet) -focused, eliminating entirely the focusing power supplies and
interlock circuits.
TM Rugged Construction
The tube is designed to be rugged, therefore it is suitable for transportable systems.
TM Long Life and High Stability
The tube employs an advanced impregnated cathode with a low operating temperature for long life.
TM 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.
2
LD7215W
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
ABSOLUTE RATINGS (Note 1, 2 and 3 )
ELECTRICAL
Min.
Max.
Unit
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
Min.
Max.
Unit
Cooling Air Flow ..........................................
720
kg/hr
Operating temperature .................................
0
+45
C
Inlet air temperature ....................................
20
+45
C
Storage temperature ....................................
30
+70
C
3
LD7215W
TYPICAL OPERATION (Note 2, 3 and 5)
Unit
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
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.
4
LD7215W
LD7215W OUTLINE (Unit in mm)
q
w
e
RF OUTPUT
RF INPUT
HIGH VOLTAGE
CONNECTIONS
CPR-137 FLANGE
(NO. 10-32 UNF 2B THREADED HOLES)
FEMALE SMA CONNECTOR
FLYING LEADS WITH M6 TERMINALS
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)
,
,,
,,,
,,,
,
,
,
,,
,,,
,,,
,
,,
,,
,,
,
,
,
,,
,
,,,
,,
,
,,
,,
,
,
,,
,,,,,
,,,,,,,
,,,,,,,
,,,,,
,
,,
,,
,,
,,
12
1
3
1
35 Max.
97
1
5.5
1
198 Max.
No.1
No.4
No.5
No.6
No.3
No.2
235 Max.
12
0.5
Bearing Face
Bearing Face
116
1
320.8
3
15
1
M4
(8 Holes)
Air
Intake
230
2
100
1
35
1
30
1
105
1
266
2
630
10
178 Max.
130
1
14.5
2
20 Max.
195 Max.
20 Max.
210
130
1
800
50
535
822 Typ.
850 Max.
140
(6)
35
16
1
(2 Holes)
M4
(4 Holes)
M10
Rubber
Air
Exhaust
4 Spring Loaded
Captive Screws
160
1
M6 Terminal
3
2
1
(
)
155
1
83
1
83
1
LEAD CONNECTIONS
NOTE 1 : THE 3RD ANGLE ORTHOGRAPHIC
PROJECTION.
5
LD7215W
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