NEC LD79U12K Datasheet

DATA SHEET

TRAVELING WAVE TUBE AMPLIFIER

FOR GROUND TERMINALS

LD79U12K

14 GHz, 123 W CW, LIGHT WEIGHT, COMPACT, EFFICIENT

GENERAL DESCRIPTION

NEC TW TA (Traveling Wave Tube Amplifier) LD79U12K delivers an output power of 123 W over the range of

13.75 to 14.5 GHz with a gain of 50 dB.
The Traveling Wave Tube (TWT : LD7246A) in the LD79U12K has been designed and developed upon the NEC's

advanced technology and enormous experience on a number of TW Ts used in satellite ground terminals and ter­restrial microwave links.

The very small and light weight Electric Power Conditioners (EPC) designed with sophisticated and experienced

circuit technology ensures higher reliability, reduced maintenance costs and improved technical perform­ance.

The LD79U12K is most suitable for a power amplifier in digital communication systems.

FEATURES

™ Light weight, Compact, and Efficient

The TWT has a dual-depressed collector and is designed to operate at high efficiency across the power output
range. The EPC features state-of-the-art techniques to optimize size and efficiency and the combination results
in a unit significantly smaller and with less power consumption than a comparable solid state amplifier.

™ Low Distortion

NEC has developed techniques for the correction of non-linear distortion of gain and phase generated in a TWT.
As a result, the TW TA has optimum performance across a broad power range and is ideally suited for multi­carrier transmission systems.

™ Long Life

The TWT is designed to have a lifetime of 50,000 hours or more, which in actual usage.

™ Ideal for Digital Systems

A mini-arcing in the electron gun have been eliminated in the TWT used in the TWTA.

™ Wide range of primary voltage

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. ET0224EJ2V0DS00
Date Published September 1998 M
Printed in Japan

©

1996

TYPICAL OPERATIONS

Frequency Range …………………………………………13.75–14.5 GHz
Power Output …………………………………………… 123 W minimum
Instantaneous Bandwidth ……………………………… 750 MHz
Gain Variation …………………………………………… 1.0 dB / 750 MHz
Gain ……………………………………………………… 53 dB (at Po = 123 W)

60 dB (at small signal)

Gain Stability …………………………………………… ±0.25 dB / 24 h (25˚C±10˚C)
Gain Slope …………………………………………………0.03 dB / MHz
Harmonic Output ………………………………………… 10 dB below at rated output power
Spurious Output …………………………………………–70 dBW in any 4 kHz band

in the 13.75 to 14.5 GHz
AM to PM Conversion …………………………………4˚ / dB maximum at rated power
Intermodulation …………………………………………18 dB below each of two equal 45 dBm carriers
Group Delay

Linear component …………………………………… 0.1 ns / MHz
Parabolic component………………………………… 0.01 ns / MHz
Ripple component ……………………………………1.0 ns (p-p) in any 40 MHz band

RF Input

Connector ……………………………………………… Mates with Type SMA Female
VSWR …………………………………………………… 2.0 : 1 maximum
Load VSWR …………………………………………… Operate into 1.5 : 1 maximum

RF Output

Waveguide …………………………………………… Mates with BRJ-120 Flange
VSWR …………………………………………………… 2.0 : 1 maximum
Load VSWR …………………………………………… Operate into 1.5 : 1 maximum

Primary Power …………………………………………… 85 Vac-255 Vac

(450 VA)
Power Factor ……………………………………………… 0.9 minimum
Electrical Connections

AC IN …………………………………………………… JL04V-2E10SL-3PE-B Connector
CONT & MON ………………………………………… DA-15P-N D-Sub Connector

Dimensions ………………………………………………TWT : 315 x 40 x 50 mm

EPC : 350 x 220 x 75 mm
Weight ……………………………………………………… TWT : 1.3 kg

EPC : 5 kg

2

LD79U12K

ENVIRONMENTAL CONDITIONS

™ Ambient Temperature

0˚C to +45˚C (operating)
–30˚C to +70˚C (non operating, storage)

™ Relative Humidity

90% maximum (non dewing)

™ Base Plate Temperature of the TWT

+90°C maximum

2