DATA S H E E T
Document No. ET0398EJ1V0DS00
Date Published August 1998 M
Printed in Japan
30 GHz, 100 W CW, CONDUCTION COOLING, HIGH POWER GAIN
HIGH POWER TRAVELING WAVE TUBE
FOR COMMUNICATIONS
LD7267 SERIES
The information in this document is subject to change without notice.
1998
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 LD7267 series of PPM-focused traveling wave tubes are designed for use as final amplifiers in the
earth-to-satellite communications transmitter, LMDS (Local Multipoint Distribution Service) and other advanced
communication systems.
Three models of the LD7267 series are capable of delivering an output power of 100 W over the range of 26.5
GHz to 31.1 GHz and provide a high power gain of 50 dB at 100 W output power. These are equipped with dual-
stage depressed collector for enhancing overall efficiency and a single collector.
Furthermore, they are of rugged and reliable design offering long-life service.
FEATURES
TM High Power Gain
The power gain is typically 50 dB at 100 W level.
TM Simple Cooling System
The tubes are conduction-cooled, so that the cooling systems are greatly simplified.
TM PPM Focusing
The tubes are PPM (Periodic Permanent Magnet) -focused, eliminating entirely the focusing power supplies
and interlock circuits.
TM Rugged Construction
The tubes are designed to be rugged, therefore they are suitable for transportable systems.
TM Long Life and High Stability
The tubes employ an advanced impregnated cathode with a low operating temperature for long life.
TM Microdischarge Free
The tubes are carefully designed to be free from microdischarge in the electron gun for long term operation,
therefore they are suitable for digital communication service.
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LD7267 SERIES
GENERAL CHARACTERISTICS
ELECTRICAL
Frequency ...................................................... 26.5 to 28.6 GHz
27.5 to 30.0 GHz
30.0 to 31.3 GHz
Output Power ................................................ 100 W
Heater Voltage ................................................ 6.3 V
Heater Current ................................................ 1.05 A
Type of Cathode ............................................. Indirectly heated, Impregnated
Cathode Warm-up Time
................................. 300 s
MECHANICAL
Dimensions ................................................... See Outline
Weight ......................................................... 3.5 kg approx.
Focusing
...................................................... Periodic Permanent Magnet
Mounting Position .......................................... Any
Electrical Connections .................................... Flying Leads
RF Connections
Input ......................................................... Mates with UG-599/U Flange
Output ...................................................... Mates with UG-599/U Flange
Cooling ......................................................... Conduction
ABSOLUTE RATINGS (Note 1, 2 and 3 )
ELECTRICAL
Min.
Max.
Unit
Heater Voltage .............................................
6.0
6.6
V
Heater Surge Current
.................................
1.6
A
Heater Current .............................................
1.5
A
Heater Warm-up Time .................................
300
s
Helix Voltage
.............................................
10.5
11.5
kV
Helix Current
.............................................
3.0
mA
5Isolated Anode Type
Anode Voltage .............................................
0
10.0
kV
Anode Current .............................................
0
1.0
mA
5Single Collector Type
Collector Voltage ..........................................
4.0
6.0
kV
Collector Current ..........................................
120
mA
5Dual-stage Collector Type
Collector Voltage-1 .......................................
4.0
6.0
kV
Collector Current-1 .......................................
80
mA
Collector Voltage-2 .......................................
1.8
2.5
kV
Collector Current-2 .......................................
120
mA
Cathode Current ..........................................
120
mA
RF Drive Power ..........................................
3.0
mW
Load VSWR ................................................
1.25 : 1
ENVIRONMENTAL
Min.
Max.
Unit
Heat Sink Temperature .................................
15
+110
C
Ambient Temperature
Storage ......................................................
55
+100
C
Operation ...................................................
30
+75
C
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LD7267 SERIES
TYPICAL OPERATION (Note 2, 3, 4 and 5)
Unit
Frequency ...................................................
30.0
GHz
Output Power .............................................
100
W
Heater Voltage ( Note 4 ) ..............................
6.3
V
Heater Current .............................................
1.05
A
Helix Voltage
.............................................
11.0
kV
Helix Current
.............................................
0.5
mA
5Isolated Anode Type
Anode Voltage .............................................
9.0
kV
Anode Current .............................................
0.01
mA
5Single Collector Type
Collector Voltage ..........................................
4.4
kV
Collector Current ..........................................
90
mA
5Dual-stage Collector Type
Collector Voltage-1 .......................................
4.4
kV
Collector Current-1 .......................................
40
mA
Collector Voltage-2 .......................................
2.2
kV
Collector Current-2 .......................................
50
mA
Cathode Current ..........................................
91
mA
Power Gain
at 10 W ...........................
57
dB
at 100 W ...........................
51
dB
Gain Variation
at 10 W ...........................
0.15
dB/60MHz
Gain Slope
at 10 W ...........................
0.005
dB/MHz
AM-PM Conversion
at 10 W ...........................
2.5
deg./dB
at 100 W ...........................
5.0
deg./dB
3rd Order Intermodulation ...........................
30
dBc
(two equal carriers, 10 W total)
(two equal carriers, 20 W total)
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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LD7267 SERIES
LD7267 SERIES OUTLINE (Unit in mm)
67
0.5
10
0.5
10.9
0.5
RF Output
UG-599/U
(No.4-40 UNC-2B
4 Threaded Holes)
RF Input
UG-599/U
(No.4-40 UNC-2B
4 Threaded Holes)
55
0.5
400
1
169
2
131
1
361
0.5
55
0.5
34
0.5
21
0.5
42
0.5
45
0.5
69
1
69.5
1
Flying Leads
8- 4.5 Thru
7
0.5
1 2
0.5
12
0.5
Lead Color
Lead Connections
Brown
Heater
Yellow
Heater-Cathode
Blue
Anode (
1)
Black
Helix
Red
Collector-1
White
Collector-2 (
2)
1. For the type without an isolated anode, the blue lead line will not
be provided.
2. For the single collector type, the white lead line will not be
provided.
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LD7267 SERIES
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