Page 1
DATA SHEET
HIGH POWER TRAVELING WAVE TUBE
FOR COMMUNICATIONS
LD7260
6 GHz, 2.25 kW CW, PPM FOCUSING, HIGH POWER GAIN
GENERAL DESCRIPTION
The NEC LD7260 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 2.25 kW over the range of 5.85 to 6.425 GHZ and provides a
power gain of 44 dB at rated output power. This is equipped with dual-stage depressed collector for enhancing
overall efficiency.
Furthermore, this is of rugged and reliable design offering long-life service.
FEATURES
™ 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.
™ 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 optimum performance across a broad power range and is ideally suited for multi-carrier transmission systems.
™ Rugged Construction
The power gain is designed to be rugged, therefore it is suitable for transportable systems.
™ Long Life and High Stability
The tube employs an advanced impregnated cathode with a low operating temperature for long life.
™ 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.
For safe use of microwave tubes, refer to NEC document “Safety instructions to all personnel
handling electron tubes” (ET0048EJ∗V∗UM00)
Document No. ET0478EJ1V0DS00
Date Published September 1999 M
Printed in Japan
The information in this document is subject to change without notice.
©
1999
Page 2
GENERAL CHARACTERISTICS
ELECTRICAL
Frequency ……………………………………………… 5.850 to 6.425 GHz
Output Power ………………………………………… 2.25 kW
Heater Voltage ………………………………………… 6.3 V
Heater Current ………………………………………… 1.5 A
Type of Cathode ……………………………………… Indirectly heated, Impregnated
Cathode Warm-up Time …………………………… 180 s
MECHANICAL
Dimensions …………………………………………… See Outline
Weight ………………………………………………… 11 kg approx.
Focusing ………………………………………………Periodic Permanent Magnet
Mounting Position …………………………………… Any
Electrical Connections ……………………………… AMP LGH 1I Receptacle
RF Connections
Input ………………………………………………… Type SMA Female
Output ……………………………………………… Mates with CPR-137F Flange
Cooling ………………………………………………… Forced Air
LD7260
ABSOLUTE RATINGS (Note 1, 2 and 3 )
ELECTRICAL
Heater Voltage ……………………………………… 6.0 6.6 V
Heater Surge Current …………………………… – 5.0 A
Heater Current ……………………………………… – 5.0 A
Heater Warm-up Time …………………………… 180 – s
Helix Voltage ……………………………………… 12.0 16.0 kV
Helix Current ……………………………………… – 25.0 mA
Collector-1 Voltage ………………………………… 9.0 11.0 kV
Collector-1 Current ………………………………… – 600 mA
Collector-2 Voltage ………………………………… 4.0 6.0 kV
Collector-2 Current ………………………………… – 925 mA
Cathode Current …………………………………… – 1000 mA
RF Drive Power …………………………………… – 90 mW
Load VSWR ………………………………………… – 1.5 : 1 –
ENVIRONMENTAL
Operating Temperature …………………………… –20 +52 ˚C
Storage Temperature ……………………………… –62 +80 ˚C
Min. Max. Unit
Min. Max. Unit
2
DATA SHEET ET0478EJ1V0DS00
Page 3
TYPICAL OPERATION (Note 2, 3, 4 and 5)
Frequency …………………………………………… 5.850–6.425 GHz
Output Power ……………………………………… 2.25 W
Heater Voltage (Note 4)…………………………… 6.3 V
Heater Current ……………………………………… 1.5 A
Helix Voltage ……………………………………… 15.0 kV
Helix Current ……………………………………… 12 mA
Collector-1 Voltage ………………………………… 9.75 kV
Collector-1 Current ………………………………… 430 mA
Collector-2 Voltage ………………………………… 5.25 kV
Collector-2 Current ………………………………… 420 mA
Cathode Current …………………………………… 862 mA
Power Gain at 225 W ……………………… 54 dB
at 2.25 kW …………………… 48 dB
Gain Variation at 225 W ……………………… 0.7 dB
Gain Slope At 225 W …………………… 0.01 dB/MHz
AM-PM Conversion
at 225 W ……………………… 1.5 deg./dB
at 2.25 kW …………………… 5.0 deg./dB
3rd Order Intermodulation ……………………… –29 dBc
(two equal carries, 225 W total)
LD7260
Unit
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.
DATA SHEET ET0478EJ1V0DS00
3
Page 4
LD7260 OUTLINE (Unit in mm)
No.8-32 UNC-2B X 6.35 DEEP MIN.
(4 PLACES-OPPOSITESIDE)
THERMAL SWITCH CONNECTOR
DEUTCH DN9601-3P
HANDLE
19
101.6±0.5
No.8-32 UNC-2B X 7.6 DEEP MAX.
(4 PLACES)
RF OUTPUT
CPR-137F FLANGE WITH
No.10-32 UNF-2B
THREADED HOLES
135.6 ±0.8
126.5±1
98.5±0.8
24.1 MAX.
50.8±0.8
50.8±0.8
101.6±0.5
76.2
17.5±0.8
LD7260
101.6±0.5
127
304.8±0.5
560 MAX.
176.3
185.6±1.5
203.2±0.5
416±5
406.4±0.5
RF INPUT
TYPE SMA FEMALE
CAPTIVE FIXING SCREWS
No.8-32 UNC-2A (7 PLACE)
18.3±0.8
439±3
508±0.5
76±13
19
238.2±1
327.05 REF
12.7±0.5
31.8±0.5
127
NO.6-32 UNC-2B
X 6.9 DEEP MIN.
(8 PLACE)
HELIX (GROUND)
66.5±4
M3 WITH NUTS
6.35±0.5
5.6±0.8
18.3±0.8
108±0.5
139.7±0.5
165.1±1.5
4
COLLECTOR-2
COLLECTOR-1
HEATER CATHODE
4 H.V. CONNECTOR
AMP LGH 1I RECEPTACLE
FOR 22.4 (0.88) ENGAGEMENT
HEATER
DATA SHEET ET0478EJ1V0DS00
69.1±0.5
87.4±0.8
106.6±1.5
122
Page 5
LD7260
DATA SHEET ET0478EJ1V0DS00
5
Page 6
LD7260
No part of this document may be copied or reproduced in any form or by any means without the prior
written consent of NEC Corporation. NEC Corporation assumes no responsibility for any errors which may
appear in this document.
NEC Corporation does not assume any liability for infringement of patents, copyrights or other intellectual
property rights of third parties by or arising from use of a device described herein or any other liability arising
from use of such device. No license, either express, implied or otherwise, is granted under any patents,
copyrights or other intellectual property rights of NEC Corporation or others.
While NEC Corporation has been making continuous effort to enhance the reliability of its electronic
components, the possibility of defects cannot be eliminated entirely. To minimize risks of damage or injury
to persons or property arising from a defect in an NEC electronic component, customers must incorporate
sufficient safety measures in its design, such as redundancy, fire-containment, and anti-failure features.
NEC devices are classified into the following three quality grades:
“Standard”, “Special”, and “Specific”. The Specific quality grade applies only to devices developed based
on a customer designated “quality assurance program” for a specific application. The recommended
applications of a device depend on its quality grade, as indicated below. Customers must check the quality
grade of each device before using it in a particular application.
Standard: Computers, office equipment, communications equipment, test and measurement equipment,
audio and visual equipment, home electronic appliances, machine tools, personal electronic equipment and
industrial robots
Special: Transportation equipment (automobiles, trains, ships, etc.), traffic control systems, anti-disaster
systems, anti-crime systems, safety equipment and medical equipment (not specifically designed for life
support)
Specific: Aircrafts, aerospace equipment, submersible repeaters, nuclear reactor control systems, life support
systems or medical equipment for life support, etc.
The quality grade of NEC devices is "Standard" unless otherwise specified in NEC's Data Sheets or Data
Books.
If customers intend to use NEC devices for applications other than those specified for Standard quality
grade, they should contact an NEC sales representative in advance.
Anti-radioactive design is not implemented in this product.
Loading...