DATA S H E E T
Document No. ET0479EJ1V0DS00
Date Published September 1999 M
Printed in Japan
14 GHz, 750 W CW, CONDUCTION COOLING, HIGH POWER GAIN
HIGH POWER TRAVELING WAVE TUBE
FOR COMMUNICATIONS
LD7263
The information in this document is subject to change without notice.
1999
For safe use of microwave tubes, refer to NEC document "Safety instructions to all personnel
handling electron tubes" (ET0048EJ
V
UM00)
GENERAL DESCRIPTION
The NEC LD7263 is a PPM-focused traveling wave tube designed for use as final amplifiers in the earth-to-
satellite communications transmitter.
This is capable of delivering an output power of 750 W over the range of 1 3.75 to 14.5 GHZ and provides a
power gain of more than 47 dB at 750 W Ievel.
Furthermore, this is of rugged and reliable design offering long-Iife service.
FEATURES
TM Lightweight, Compact and Efficient
The tube has dual-depressed collectors and designed to operate at high efficiency across the power output
range. It features state-of-the-art techniques to optimize size and efficiency.
TM Low Distortion
Distortion is a very important factor in multiplex digital signals transmission. NEC has developed techniques
for the correction of non-linear distortion and phase generated in a TWT. As a result, the TWT has an opti-
mum performance across a broad power range and is ideally suited for multi-carrier transmission systems.
TM Simple Cooling System
The tube is conduction cooled, so that the cooling system is simplified.
TM Rugged Construction
The power gain 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 Micro-discharge 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
LD7263
DATA SHEET ET0479EJ1V0DS00
GENERAL CHARACTERISTICS
ELECTRICAL
Frequency ...................................................... 13.75 to 14.5 GHz
Output Power ................................................ 750 W
Heater Voltage ................................................ 6.3 V
Heater Current ................................................ 1.4 A
Type of Cathode ............................................. Indirectly heated, Impregnated
Cathode Warm-up Time
................................. 180 s
MECHANICAL
Dimensions ................................................... See Outline
Weight ......................................................... 3.5 kg approx.
Focusing
...................................................... Periodic Permanent Magnet
Mounting Position .......................................... Any
Electrical Connections .................................... Flying Leads
RF Connections
Input ......................................................... Type SMA Female
Output ...................................................... WR75, UBR-120 Flange
Cooling ......................................................... Conduction
ABSOLUTE RATINGS (Note 1, 2 and 3 )
ELECTRICAL
Min.
Max.
Unit
Heater Voltage .............................................
6.0
6.6
V
Heater Surge Current
.................................
3.0
A
Heater Current .............................................
2.0
A
Heater Warm-up Time .................................
180
s
Helix Voltage
.............................................
10.2
11.7
kV
Helix Current
.............................................
15.0
mA
Collector-1 Voltage .......................................
5.3
6.8
kV
Collector-1 Current .......................................
320
mA
Collector-2 Voltage .......................................
2.3
3.4
kV
Collector-2 Current .......................................
450
mA
RF Drive Power ..........................................
15
dBm
Load VSWR ................................................
1.5 : 1
ENVIRONMENTAL
Min.
Max.
Unit
Base Plate Temperature
..............................
40
+105
C
Storage Temperature ....................................
50
+85
C
3
LD7263
DATA SHEET ET0479EJ1V0DS00
TYPICAL OPERATION (Note 2, 3, 4 and 5)
Unit
Frequency ...................................................
14.25
GHz
Output Power .............................................
780
W
Heater Voltage ( Note 4 ) ..............................
6.3
V
Heater Current .............................................
1.4
A
Collector Voltage-1 .......................................
6.0
kV
Collector Current-1 .......................................
275
mA
Collector Voltage-2 .......................................
2.9
kV
Collector Current-2 .......................................
132
mA
Cathode Current ..........................................
410
mA
Helix Voltage
.............................................
11.0
kV
Helix Current
.............................................
3.0
mA
Power Gain
(SSG) ..............................
58
dB
(LSG) ..............................
53
dB
Gain Variation
at 75 W ...........................
1.0
dB/60MHz
Gain Slope
at 75 W ...........................
0.01
dB/MHz
AM-PM Conversion
at 75 W ...........................
1.0
deg./dB
at 750 W ...........................
5.0
deg./dB
3rd Order Intermodulation ...........................
31
dBc
(two equal carriers, 75 W total)
Spurious
...................................................
60
dBc
Noise Figure ................................................
28
dB
Overall Efficiency
.......................................
37.6
%
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
LD7263
DATA SHEET ET0479EJ1V0DS00
LD7263 OUTLINE (Unit in mm)
LEAD COLOR
LEAD CONNECTIONS
LENGTH
BROWN
HEATER
500 mm MIN.
YELLOW
HEATER-CATHODE
500 mm MIN.
ORANGE
COLLECTOR-1
500 mm MIN.
BLUE
COLLECTOR-2
500 mm MIN.
GREEN
HELIX (GROUND)
500 mm MIN.
8 - 10
COUNTER BORING
RF OUTPUT
WR75. FLANGE UBR-120 WITH
No. 6-32 UNC-2B THREADED HOLES
RF INTPUT
TYPE SMA FEMALE
No.6-32 UNC-28
9 DP
NEAR AND FARSIDE
16 - 4.2
+ 0.4
96 MAX.
50.8
0.2
330.2
0.2
266.7
0.2
203.2
0.2
139.7
0.2
95.25
0.2
102.85
0.6
303.5
2.0
(127)
33
420 MAX.
150 NOM.
25.4
0.2
45.35
0.2
55.88
0.2
71
1.0
55 NOM.
12.7
38 MAX.
45 NOM.
6
0.3
55.5 MAX.
45.72
0.2
0
5
LD7263
DATA SHEET ET0479EJ1V0DS00
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