Datasheet LD7713 Datasheet (NEC)

DATA SHEET

MIDIUM POWER TRAVELING WAVE TUBE

FOR COMMUNICATIONS

LD7713

30 GHz, 20 W CW, Conduction Cooling, Mimimum Size

GENERAL DESCRIPTION

The NEC LD7713 is a PPM-focused traveling wave tube designed for use as final amplifier in the earth-to­satellite communications transmitter, LMDS (Local Multipoint distribution service) and other advanced
communication systems.

This is capable of delivering an output power of 20 W over the range of 27.5 to 30.0 GHz and provides a power
gain of more than 40 dB at 20 W level.

Furthermore, it is of rugged and reliable design offering long-life service.

FEATURES

™ Lightweight, Compact and Efficient

The tube has a 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 trancmission systems.

™ Simple Cooling System

The tube is conduction cooled, so that the cooling system is simplified.

™ 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. ET0455EJ1V0DS00
Date Published August 1999 M
Printed in Japan

The information in this document is subject to change without notice.

©

1999

GENERAL CHARACTERISTICS

ELECTRICAL

Frequency ……………………………………………… 27.5 to 30 GHz
Output Power ………………………………………… 20 W
Heater Voltage ………………………………………… 6.3 V
Heater Current ………………………………………… 0.82 A
Heater Surge Current ……………………………… 2.5 A
Type of Cathode ……………………………………… Indirectly heated, Impregnated
Cathode Warm-up Time …………………………… 180 s

MECHANICAL

Dimensions …………………………………………… See Outline
Weight ………………………………………………… 700 g approx.
Focusing ……………………………………………… Periodic Permanent Magnet
Mounting Position ……………………………………Any
Electrical Connections ……………………………… Flying Leads
RF Connections

Input ………………………………………………… Mates with UG-599/U Flange or K connector Female
Output ……………………………………………… Mates with UG-599/U Flange

Cooling ………………………………………………… Conduction

LD7713

ABSOLUTE RATINGS (Note 1, 2 and 3 )

ELECTRICAL

Heater Voltage ……………………………………… 6.0 6.6 V
Heater Surge Current …………………………… – 2.5 A
Heater Current ……………………………………… – 1.2 A
Heater Warm-up Time …………………………… 180 – s
Helix Voltage ……………………………………… 5.8 6.4 kV
Helix Current ……………………………………… – 5.0 mA
Collector–1 Voltage ……………………………… 2.2 2.5 kV
Collector–1 Current ……………………………… – 30 mA
Collector–2 Voltage ……………………………… 1.1 1.3 kV
Collector–2 Current ……………………………… – 42 mA
RF Drive Power …………………………………… – 3 dBm
Load VSWR ………………………………………… – 1.5 : 1 –

ENVIRONMENTAL

Heat Sink Temperature –30 +90 ˚C
Storage Temperature –40 +90 ˚C

Min. Max. Unit

2 DATA SHEET ET0455EJ1V0DS00

TYPICAL OPERATION (Note 2, 3 and 5)

Frequency …………………………………………… 28.0 GHz
Output Power ……………………………………… 24.0 W
Heater Voltage (Note 4)…………………………… 6.3 V
Heater Current ……………………………………… 0.82 A
Collector–1 Voltage ……………………………… 2.2 kV
Collector–1 Current ……………………………… 22.0 mA
Collector–2 Voltage ……………………………… 1.1 kV
Collector–2 Current ……………………………… 14.5 mA
Cathode Current …………………………………… 38 mA
Helix Voltage ……………………………………… 6.0 kV
Helix Current ……………………………………… 1.5 mA
Power Gain (SSG) ………………………… 52 dB

(LSG) ………………………… 45 dB
Gain Variation at 2 W ………………………… 2.5 dB/2.5 GHz
Gain Slope at 2 W ………………………… 0.025 dB/MHz
AM-PM Conversion ……………………………… 3.5 deg./dB
3rd Order Intermodulation ……………………… –31 dBc

(two equal carriers, 2 W total)
Spurious …………………………………………… –60 dBc
Noise Figure………………………………………… 32.5 dB
Overall Efficiency ………………………………… 30.5 %

LD7713

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.

3DATA SHEET ET0455EJ1V0DS00

LD7713 OUTLINE (Unit in mm)

LD7713

38.3±0.5

100±0.3151±0.3

19 ±0.5

φ

6– 4.5

RF OUTPUT
UG-599/U FLANGE WITH

M3 THREADED HOLES

RF INPUT
TYPE K CONNECTOR FEMALE

19.3±0.5

183±182±1

260±2 5.5±0.5

265.5±2

70±1

24.5±0.3 21±1

30±127±1

36±1

LEAD COLOR LEAD CONNECTIONS LENGTH

BROWN HEATER 500 mm MIN.

YELLOW HEATER-CA THODE 500 mm MIN.

RED COLLECTOR-1 500 mm MIN.
GREEN COLLECTOR-2 500 mm MIN.
BLACK HELIX (GROUND) 500 mm MIN.

4 DATA SHEET ET0455EJ1V0DS00

LD7713

5DATA SHEET ET0455EJ1V0DS00

LD7713

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.