DATA S H E E T
Document No. ET0141EJ2V1DS00 (2nd edition)
Date Published August 1998 M
Printed in Japan
14 GHz, 600 W CW, PPM FOCUSING, HIGH POWER GAIN
The information in this document is subject to change without notice.
1989(1995)
HIGH POWER TRAVELING WAVE TUBE
FOR GROUND TERMINALS
LD7202 SERIES
For safe use of microwave tubes, refer to NEC document "Safety instructions to all personnel
handling electron tubes" (ET0048EJ
V
UM00)
GENERAL DESCRIPTION
NEC LD7202 series of PPM-focused traveling wave tubes are designed for use as final amplifiers tube in the
earth-to-satellite communications transmitter.
These are capable of delivering an output power of 600W over the range of 12.75 to 14.5 GHz and provide a high
power gain of 52 dB at 600 W output power.
Furthermore, they are of rugged and reliable design offering long-life service.
The LD7202 is fully compatible with TH3591B.
FEATURES
TM High Power Gain
The power gain is typically 52 dB at 600 W level.
TM Simple Cooling System
The tubes are forced-air-cooled, so that the cooling systems are greatly simplified.
TM PPM Focusing
All 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 use in digital communication service.
2
LD7202 SERIES
GENERAL CHARACTERISTICS
ELECTRICAL
Frequency
LD7202, LD7202A, LD7202B ............................................. 14.0 to 14.5 GHz
LD7202L ............................................................................. 13.75 to 14.5 GHz
LD7202W ............................................................................ 12.75 to 13.25 GHz, 13.75 to 14.5 GHz
Output Power ............................................................................ 600 W
Heater Voltage ........................................................................... 6.3 V
Heater Current ........................................................................... 1.4 A
Type of Cathode ........................................................................ Indirectly heated, Impregnated
Cathode Warm-up Time ........................................................... 300 s
MECHANICAL
Dimensions ................................................................................ See Outline
Weight ........................................................................................ 6.0 kg approx.
Focusing .................................................................................... Periodic Permanent Magnet
Mounting Position .................................................................... Any
Electrical Connections .............................................................. See Outline Drawing
RF Connections
Input ................................................................................... SMA-Female
Output ................................................................................ Mates with UBR-120 Flange
Thermal Switch Connections ................................................... See Outline Drawing
Cooling ....................................................................................... Forced Air
3
LD7202 SERIES
ABSOLUTE RATINGS
(Note 2, 3 and 4)
ELECTRICAL
Min.
Max.
Unit
Heater Voltage ..................................................................
5.5
6.5
V
Heater Surge Current ......................................................
4.5
A
Heater Current ..................................................................
3
A
Heater Warm-up Time .....................................................
300
s
Collector Voltage
............................................................
4.75
6.2
kV
Collector Current ..............................................................
425
mA
Helix Voltage ....................................................................
10.25
10.75
kV
Helix Current ....................................................................
12
mA
Anode Voltage ..................................................................
5.5
6.5
kV
Anode Current ..................................................................
0.5
mA
Collector Dissipation .......................................................
2.4
kW
RF Drive Power ................................................................
20
mW
Output Power ...................................................................
670
W
Load VSWR
...................................................................
1.15:1
The voltage between a helix and a collector must not exceed 8 kV.
Load VSWR must be met as follows.
In Band ..........................................................
1.15 : 1 max.
13.5 to 15.0 GHz ............................................
1.5 : 1 max. (LD7202, LD7202A, LD7202B)
13.25 to 15.0 GHz ..........................................
1.5 : 1 max. (LD7202L)
12.25 to 15.0 GHz ..........................................
1.5 : 1 max. (LD7202W)
15.0 to 16.0 GHz ............................................
1.8 : 1 max.
16.0 to 17.0 GHz ............................................
2.2 : 1 max.
MECHANICAL
Min.
Max.
Unit
Air Flow of Collector ........................................................
252
kg/hr
Ambient Temperature (Operation) .................................
10
+50
C
Storage Temperature .......................................................
40
+80
C
4
LD7202 SERIES
TYPICAL OPERATION
(Note 4 and 5)
Unit
Frequency
LD7202/A/B ..........................................................
14.0 to14.5
GHz
LD7202L ...............................................................
13.75 to14.5
GHz
LD7202W .............................................................
12.75 to13.25, 13.75 to14.5
GHz
Output Power ...............................................................
600
W
Heater Voltage
(Note 5)
..................................................
6.3
V
Heater Current .............................................................
1.4
A
Helix Voltage ................................................................
10.5
kV
Helix Current ................................................................
3
mA
Collector Voltage .........................................................
5.4
kV
Collector Current .........................................................
360
mA
Anode Voltage .............................................................
5.9
kV
Anode Current .............................................................
0.1
mA
Power Gain
at 70 W .................................................................
58
dB
at 600 W ...............................................................
52
dB
Gain Variation (at Po=70 W)
LD7202/A/B ..........................................................
2
dB/500MHz
LD7202L ...............................................................
2.4
dB/750MHz
LD7202W (12.75 to 13.25 GHz) .........................
2
dB/500MHz
(13.75 to 14.5 GHz) ...........................
2.4
dB/750MHz
Gain Slope ...................................................................
0.01
dB/MHz
AM-PM Conversion
at 70 W .................................................................
1.5
deg./dB
at 600 W ...............................................................
5
deg./dB
3rd Order Intermodulation .........................................
-28
dBc
(two equal carriers, 70 W total)
Cooling Air Flow ..........................................................
252
kg/hr
Pressure Drop ..............................................................
588
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 helix is at the ground potential in operation.
Note 3 : All voltages except heater voltage 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 prod-
uct improvement. NEC should be consulted before using this information for equipment design.
This data sheet should not be referred to a contractual specification.
5
LD7202 SERIES
LD7202, LD7202L, LD7202W OUTLINE DRAWING (Unit in mm)
4-M4
10- 6
6
AIR INLET
RF INPUT
TYPE SMA
FEMALE
RF OUTPUT
MATES WITH
UBR-120
FLANGE
110 MAX.
55
111
127 MAX.
83
AIR OUTLET
4-M3
85 MAX.
166
175
72
170 MAX.
157
101
101
101
19
TERMINALS FOR M3
450 70
+
100
66
87 MAX.
86
Note. The thermal switch contacts are normally closed.
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