DATA S H E E T HIGH POWER TRAVELING WAVE TUBE FOR COMMUNICATIONS LD7260 6 GHz, 2.25 kW CW, PPM FOCUSING, HIGH POWER GAIN GENERAL DESCRIPTION The NEC LD7260 is a PPM-focused traveling wave tube designed for use as final amplifiers in the earth-tosatellite communications transmitter. This is capable of delivering an output power of 2.25 kW over the range of 5.85 to 6.425 GHZ and provides a power gain of 44 dB at rated output power. This is equipped with dual-stage depressed collector for enhancing overall efficiency. Furthermore, this is of rugged and reliable design offering long-life service. FEATURES ™ Lightweight, Compact and Efficient The tube has 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 transmission systems. ™ 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) The information in this document is subject to change without notice. Document No. ET0478EJ1V0DS00 Date Published September 1999 M Printed in Japan © 1999 LD7260 GENERAL CHARACTERISTICS ELECTRICAL Frequency ……………………………………………… 5.850 to 6.425 GHz Output Power ………………………………………… 2.25 kW Heater Voltage ………………………………………… 6.3 V Heater Current ………………………………………… 1.5 A Type of Cathode ……………………………………… Indirectly heated, Impregnated Cathode Warm-up Time …………………………… 180 s MECHANICAL Dimensions …………………………………………… See Outline Weight ………………………………………………… 11 kg approx. Focusing ……………………………………………… Periodic Permanent Magnet Mounting Position …………………………………… Any Electrical Connections ……………………………… AMP LGH 1I Receptacle RF Connections Input ………………………………………………… Type SMA Female Output ……………………………………………… Mates with CPR-137F Flange Cooling ………………………………………………… Forced Air ABSOLUTE RATINGS (Note 1, 2 and 3 ) ELECTRICAL Heater Voltage ……………………………………… Heater Surge Current …………………………… Heater Current ……………………………………… Heater Warm-up Time …………………………… Helix Voltage ……………………………………… Helix Current ……………………………………… Collector-1 Voltage ………………………………… Collector-1 Current ………………………………… Collector-2 Voltage ………………………………… Collector-2 Current ………………………………… Cathode Current …………………………………… RF Drive Power …………………………………… Load VSWR ………………………………………… Min. 6.0 – – 180 12.0 – 9.0 – 4.0 – – – – Max. 6.6 5.0 5.0 – 16.0 25.0 11.0 600 6.0 925 1000 90 1.5 : 1 Unit V A A s kV mA kV mA kV mA mA mW – Min. –20 –62 Max. +52 +80 Unit ˚C ˚C ENVIRONMENTAL Operating Temperature …………………………… Storage Temperature ……………………………… 2 DATA SHEET ET0478EJ1V0DS00 LD7260 TYPICAL OPERATION (Note 2, 3, 4 and 5) Unit Frequency …………………………………………… 5.850–6.425 GHz Output Power ……………………………………… 2.25 W Heater Voltage (Note 4) …………………………… 6.3 V Heater Current ……………………………………… 1.5 A Helix Voltage ……………………………………… 15.0 kV Helix Current ……………………………………… 12 mA Collector-1 Voltage ………………………………… 9.75 kV Collector-1 Current ………………………………… 430 mA Collector-2 Voltage ………………………………… 5.25 kV Collector-2 Current ………………………………… 420 mA Cathode Current …………………………………… 862 mA Power Gain 54 dB at 225 W ……………………… at 2.25 kW …………………… 48 dB Gain Variation at 225 W ……………………… 0.7 dB Gain Slope At 225 W 0.01 dB/MHz at 225 W ……………………… 1.5 deg./dB at 2.25 kW …………………… 5.0 deg./dB 3rd Order Intermodulation ……………………… (two equal carries, 225 W total) –29 dBc …………………… AM-PM Conversion 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. DATA SHEET ET0478EJ1V0DS00 3 LD7260 LD7260 OUTLINE (Unit in mm) 50.8 ± 0.8 135.6±0.8 No.8-32 UNC-2B X 6.35 DEEP MIN. (4 PLACES-OPPOSITESIDE) 101.6 ± 0.5 No.8-32 UNC-2B X 7.6 DEEP MAX. (4 PLACES) 126.5±1 127 RF OUTPUT CPR-137F FLANGE WITH No.10-32 UNF-2B THREADED HOLES THERMAL SWITCH CONNECTOR DEUTCH DN9601-3P 50.8±0.8 101.6±0.5 24.1 MAX. 98.5±0.8 76.2 17.5±0.8 327.05 REF 31.8 ± 0.5 238.2 ± 1 12.7 ± 0.5 RF INPUT TYPE SMA FEMALE 66.5 ± 4 NO.6-32 UNC-2B X 6.9 DEEP MIN. (8 PLACE) HELIX (GROUND) M3 WITH NUTS 6.35±0.5 CAPTIVE FIXING SCREWS No.8-32 UNC-2A (7 PLACE) 5.6±0.8 18.3±0.8 18.3±0.8 69.1±0.5 4 H.V. CONNECTOR AMP LGH 1I RECEPTACLE FOR 22.4 (0.88) ENGAGEMENT COLLECTOR-2 87.4±0.8 106.6±1.5 COLLECTOR-1 HEATER CATHODE HEATER 122 4 DATA SHEET ET0478EJ1V0DS00 165.1 ± 1.5 139.7 ± 0.5 127 108± 0.5 19 508 ± 0.5 439 ± 3 416 ± 5 203.2 ± 0.5 560 MAX. 406.4 ± 0.5 185.6 ± 1.5 304.8 ± 0.5 176.3 76 ± 13 101.6 ± 0.5 19 HANDLE LD7260 DATA SHEET ET0478EJ1V0DS00 5 LD7260 No part of this document may be copied or reproduced in any form or by any means without the prior written consent of NEC Corporation. NEC Corporation assumes no responsibility for any errors which may appear in this document. NEC Corporation does not assume any liability for infringement of patents, copyrights or other intellectual property rights of third parties by or arising from use of a device described herein or any other liability arising from use of such device. No license, either express, implied or otherwise, is granted under any patents, copyrights or other intellectual property rights of NEC Corporation or others. While NEC Corporation has been making continuous effort to enhance the reliability of its electronic components, the possibility of defects cannot be eliminated entirely. To minimize risks of damage or injury to persons or property arising from a defect in an NEC electronic component, customers must incorporate sufficient safety measures in its design, such as redundancy, fire-containment, and anti-failure features. NEC devices are classified into the following three quality grades: “Standard”, “Special”, and “Specific”. The Specific quality grade applies only to devices developed based on a customer designated “quality assurance program” for a specific application. The recommended 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. Standard: Computers, office equipment, communications equipment, test and measurement equipment, audio and visual equipment, home electronic appliances, machine tools, personal electronic equipment and industrial robots Special: Transportation equipment (automobiles, trains, ships, etc.), traffic control systems, anti-disaster systems, anti-crime systems, safety equipment and medical equipment (not specifically designed for life support) Specific: Aircrafts, aerospace equipment, submersible repeaters, nuclear reactor control systems, life support systems or medical equipment for life support, etc. The quality grade of NEC devices is "Standard" unless otherwise specified in NEC's Data Sheets or Data Books. If customers intend to use NEC devices for applications other than those specified for Standard quality grade, they should contact an NEC sales representative in advance. Anti-radioactive design is not implemented in this product.