NEC LD7713 Datasheet

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