NEC LD7267 Datasheet
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
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