Datasheet LD7267 Datasheet (NEC)

DATA SHEET

HIGH POWER TRAVELING WAVE TUBE

FOR COMMUNICATIONS

LD7267 SERIES

30 GHz, 100 W CW, CONDUCTION COOLING, HIGH POWER GAIN

GENERAL DESCRIPTION

The NEC LD7267 series of PPM-focused traveling wave tubes are designed for use as final amplifiers in the
earth-to-satellite communications transmitter , LMDS (Local Multipoint Distribution Service) and other advanced
communication systems.

Three models of the LD7267 series are capable of delivering an output power of 100 W over the range of 26.5
GHz to 31.1 GHz and provide a high power gain of 50 dB at 100 W output power . These are equipped with dual­stage depressed collector for enhancing overall efficiency and a single collector.

Furthermore, they are of rugged and reliable design offering long-life service.

FEATURES

™ High Power Gain

The power gain is typically 50 dB at 100 W level.

™ Simple Cooling System

The tubes are conduction-cooled, so that the cooling systems are greatly simplified.

™ PPM Focusing

The tubes are PPM (Periodic Permanent Magnet) -focused, eliminating entirely the focusing power supplies
and interlock circuits.

™ Rugged Construction

The tubes are designed to be rugged, therefore they are suitable for transportable systems.

™ Long Life and High Stability

The tubes employ an advanced impregnated cathode with a low operating temperature for long life.

™ Microdischarge Free

The tubes are carefully designed to be free from microdischarge in the electron gun for long term operation,
therefore they are 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. ET0398EJ1V0DS00
Date Published August 1998 M
Printed in Japan

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

©

1998

GENERAL CHARACTERISTICS

ELECTRICAL

Frequency ……………………………………………… 26.5 to 28.6 GHz

Output Power ………………………………………… 100 W
Heater Voltage ………………………………………… 6.3 V
Heater Current ………………………………………… 1.05 A
Type of Cathode ……………………………………… Indirectly heated, Impregnated
Cathode Warm-up Time …………………………… 300 s

MECHANICAL

Dimensions …………………………………………… See Outline
Weight ………………………………………………… 3.5 kg approx.
Focusing ………………………………………………Periodic Permanent Magnet
Mounting Position …………………………………… Any
Electrical Connections ……………………………… Flying Leads
RF Connections

Input ………………………………………………… Mates with UG-599/U Flange
Output ……………………………………………… Mates with UG-599/U Flange

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

LD7267 SERIES

27.5 to 30.0 GHz

30.0 to 31.3 GHz

ABSOLUTE RATINGS (Note 1, 2 and 3 )

ELECTRICAL

Heater Voltage ……………………………………… 6.0 6.6 V
Heater Surge Current …………………………… – 1.6 A
Heater Current ……………………………………… – 1.5 A
Heater Warm-up Time …………………………… 300 – s
Helix Voltage ……………………………………… 10.5 11.5 kV
Helix Current ……………………………………… – 3.0 mA

★Isolated Anode Type

Anode Voltage ……………………………………… 0 10.0 kV
Anode Current ……………………………………… 0 1.0 mA

★Single Collector Type

Collector Voltage …………………………………… 4.0 6.0 kV
Collector Current…………………………………… – 120 mA

★Dual-stage Collector Type

Collector Voltage-1………………………………… 4.0 6.0 kV
Collector Current-1 ………………………………… – 80 mA
Collector Voltage-2………………………………… 1.8 2.5 kV
Collector Current-2 ………………………………… – 120 mA
Cathode Current …………………………………… – 120 mA
RF Drive Power …………………………………… – 3.0 mW
Load VSWR ………………………………………… – 1.25 : 1 –

Min. Max. Unit

ENVIRONMENTAL

Min. Max. Unit
Heat Sink Temperature …………………………… –15 +110 ˚C
Ambient Temperature
Storage ……………………………………………… –55 +100 ˚C
Operation …………………………………………… –30 +75 ˚C

2

TYPICAL OPERATION (Note 2, 3, 4 and 5)

Frequency …………………………………………… 30.0 GHz
Output Power ……………………………………… 100 W
Heater Voltage ( Note 4 ) ………………………… 6.3 V
Heater Current ……………………………………… 1.05 A
Helix Voltage ……………………………………… 11.0 kV
Helix Current ……………………………………… 0.5 mA

★Isolated Anode Type

Anode Voltage ……………………………………… 9.0 kV
Anode Current ……………………………………… 0.01 mA

★Single Collector Type

Collector Voltage …………………………………… 4.4 kV
Collector Current…………………………………… 90 mA

★Dual-stage Collector Type

Collector Voltage-1………………………………… 4.4 kV
Collector Current-1 ………………………………… 40 mA
Collector Voltage-2………………………………… 2.2 kV
Collector Current-2 ………………………………… 50 mA
Cathode Current …………………………………… 91 mA
Power Gain at 10 W ……………………… 57 dB

at 100 W ……………………… 51 dB
Gain Variation at 10 W ……………………… 0.15 dB/60MHz
Gain Slope at 10 W ……………………… 0.005 dB/MHz
AM-PM Conversion

at 10 W ……………………… 2.5 deg./dB

at 100 W ……………………… 5.0 deg./dB
3rd Order Intermodulation ……………………… –30 dBc
(two equal carriers, 10 W total)
(two equal carriers, 20 W total)

LD7267 SERIES

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.

3

LD7267 SERIES OUTLINE (Unit in mm)

67 ±0.5
55±0.5
45±0.5

RF Input
UG-599/U

(No.4-40 UNC-2B
4 Threaded Holes)

10±0.5

Flying Leads

LD7267 SERIES

69±1

7±0.5

69.5±1

400±1

361±0.5

RF Output
UG-599/U

(No.4-40 UNC-2B
4 Threaded Holes)

10.9±0.5

42±0.5

21±0.5

34±0.5

55±0.5

169±2131±1

φ

8- 4.5 Thru

12±0.5

12±0.5

Lead Color Lead Connections

Brown Heater
Yellow Heater-Cathode
Blue Anode (∗1)
Black Helix
Red Collector-1
White Collector-2 (∗2)

4

∗

1. For the type without an isolated anode, the blue lead line will not
be provided.

∗

2. For the single collector type, the white lead line will not be
provided.

LD7267 SERIES

5

LD7267 SERIES

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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.
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audio and visual equipment, home electronic appliances, machine tools, personal electronic equipment and
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systems, anti-crime systems, safety equipment and medical equipment (not specifically designed for life
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Anti-radioactive design is not implemented in this product.

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