DATA S H E E T
HIGH POWER TRAVELING WAVE TUBE
FOR GROUND TERMINALS
LD7202 SERIES
14 GHz, 600 W CW, PPM FOCUSING, HIGH POWER GAIN
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
™
High Power Gain
The power gain is typically 52 dB at 600 W level.
™
Simple Cooling System
The tubes are forced-air-cooled, so that the cooling systems are greatly simplified.
™
PPM Focusing
All the tubes are PPM (Periodic Permanent Magnet)-focused, eliminating entirely the focusing power supplies
and interlock circuits.
™
Rugged Construction
The tubes are designed to be rugged, therefore they are suitable for transportable systems.
™
Long Life and High Stability
The tubes employ an advanced impregnated cathode with a low operating temperature for long life.
™
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.
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. ET0141EJ2V1DS00 (2nd edition)
Date Published August 1998 M
Printed in Japan
©
1989(1995)
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
2
LD7202 SERIES
ABSOLUTE RATINGS
ELECTRICAL
Min.
Heater Voltage ..................................................................
Heater Surge Current ......................................................
Heater Current ..................................................................
Heater Warm-up Time .....................................................
Collector Voltage
∗
............................................................
Collector Current ..............................................................
Helix Voltage ....................................................................
Helix Current ....................................................................
Anode Voltage ..................................................................
Anode Current ..................................................................
Collector Dissipation .......................................................
RF Drive Power ................................................................
Output Power ...................................................................
Load VSWR
∗∗
...................................................................
5.5
–
–
300
4.75
–
10.25
–
5.5
–
–
–
–
–
Max.
6.5
4.5
3
–
6.2
425
10.75
12
6.5
0.5
2.4
20
670
1.15:1
Unit
V
A
A
s
kV
mA
kV
mA
kV
mA
kW
mW
W
(Note 2, 3 and 4)
∗
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.
Air Flow of Collector ........................................................
Ambient Temperature (Operation) .................................
Storage Temperature .......................................................
252
–10
–40
Max.
–
+50
+80
Unit
kg/hr
˚C
˚C
3
LD7202 SERIES
TYPICAL OPERATION
(Note 4 and 5)
Unit
Frequency
LD7202/A/B ..........................................................
LD7202L ...............................................................
LD7202W .............................................................
Output Power ...............................................................
Heater Voltage
(Note 5)
..................................................
Heater Current .............................................................
Helix Voltage ................................................................
Helix Current ................................................................
Collector Voltage .........................................................
Collector Current .........................................................
Anode Voltage .............................................................
Anode Current .............................................................
Power Gain
at 70 W .................................................................
at 600 W ...............................................................
Gain Variation (at Po=70 W)
LD7202/A/B ..........................................................
LD7202L ...............................................................
LD7202W (12.75 to 13.25 GHz) .........................
(13.75 to 14.5 GHz) ...........................
Gain Slope ...................................................................
AM-PM Conversion
at 70 W .................................................................
at 600 W ...............................................................
3rd Order Intermodulation .........................................
(two equal carriers, 70 W total)
Cooling Air Flow ..........................................................
Pressure Drop ..............................................................
252
588
kg/hr
Pa
1.5
5
-28
deg./dB
deg./dB
dBc
2
2.4
2
2.4
0.01
dB/500MHz
dB/750MHz
dB/500MHz
dB/750MHz
dB/MHz
58
52
dB
dB
14.0 to14.5
13.75 to14.5
12.75 to13.25, 13.75 to14.5
600
6.3
1.4
10.5
3
5.4
360
5.9
0.1
GHz
GHz
GHz
W
V
A
kV
mA
kV
mA
kV
mA
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.
4
LD7202 SERIES
LD7202, LD7202L, LD7202W OUTLINE DRAWING
(Unit in mm)
TERMINALS FOR M3
450 + 70
–
85 MAX.
RF INPUT
AIR INLET
170 MAX.
4-M4
6
10-
φ
6
110 MAX.
55
111
127 MAX.
166
RF OUTPUT
175
MATES WITH
UBR-120
FLANGE
100
4-M3
66
86
φ
83
Note. The thermal switch contacts are normally closed.
87 MAX.
AIR OUTLET
19
101
101
101
157
TYPE SMA
FEMALE
72
5
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