NEC LD79U04K Datasheet

DATA SHEET

MICROWAVE POWER MODULE

FOR GROUND TERMINALS

LD79U04K

14 GHz, 40 W CW, LIGHT WEIGHT, COMPACT, EFFICIENT

GENERAL DESCRIPTION

NEC Microwave Power Module (MPM) LD79U04K is a microwave power device in which a traveling wave tube
(TWT) and an electric power conditioner (EPC) are combined, so that both components can accomplish each full
performance.

LD79U04K delivers an output power of 40 W over the range of 13.75 to 14.5 GHz with a gain of 25 dB.

The TWT in the LD79U04K has been designed and developed upon the NEC's advanced technology and enor­mous experience on a number of TWTs used in satellite ground terminals and terrestrial microwave links.

The very small and light weight EPC designed with sophisticated and experienced circuit technology ensures
higher reliability, reduced maintenance costs and improved technical performance.

The LD79U04K is most suitable for a power amplifier in digital communication systems.

A configuration of separated TWT and EPC can offer superior flexibility of design for high power section of
transmitters.

FEATURES

™ Light weight, Compact, and Efficient

The TW T 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 MPM has optimum performance across a broad power range and is ideally suited for multi­carrier transmission systems.

™ Long Life

The TWT in NEC's MPM is designed to have a lifetime of 100,000 hours or more, which is comparable to that of
a solid state amplifier in actual usage.

™ Ideal for Digital Systems

A mini-arcing in the electron gun have been eliminated in the TW T used in the MPM.

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. ET0225EJ2V0DS00
Date Published September 1998 M
Printed in Japan

©

1996

TYPICAL OPERATIONS

Frequency Range …………………………………………13.75– 14.5 GHz
Power Output …………………………………………… 40 W minimum
Instantaneous Bandwidth ……………………………… 750 MHz
Gain Variation …………………………………………… 2.0 dB / 750 MHz
Gain ……………………………………………………… 25 dB (at Po = 40 W)

35 dB (at small signal)

Gain Stability …………………………………………… ±0.25 dB / 24 h (25˚C±10˚C)
Gain Slope …………………………………………………0.02 dB / MHz
Harmonic Output ………………………………………… 15 dB below at rated output power
Spurious Output …………………………………………–90 dBW in any 4 kHz band

in the 13.75 to 14.5 GHz
AM to PM Conversion …………………………………4.5˚/ dB at rated power
Intermodulation …………………………………………28 dB below each of two equal carriers

(total 8 W)
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

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

Primary Power …………………………………………… –48 V± 10%
Power Consumption …………………………………… 163 W
Electrical Connection …………………………………… DA-9-N D-Sub Connector
Dimensions

TWT ……………………………………………………178 × 33 × 25 mm
EPC ……………………………………………………… 220 × 140 × 47 mm

Weight ……………………………………………………… 2.5 kg

(both TWT and EPC)

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LD79U04K

ENVIRONMENTAL CONDITIONS

™ Ambient Temperature

–15˚C to +50˚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

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