DATA S H E E T HIGH POWER TRAVELING WAVE TUBE FOR GROUND TERMINALS LD7249 SERIES 14 GHz, 350 W/400 W CW, CONDUCTION COOLING, HIGH POWER GAIN GENERAL DESCRIPTION NEC LD7249 series of PPM-focused traveling wave tube are designed for use as final amplifiers in the earth-tosatellite communications transmitter. Two models of the LD7249 series are capable of delivering an output power of 350 W and 400 W over the range of 13.75 to 14.5 GHz and provide a high power gain of more than 47 dB at the rated output power level. Furthermore, this is of rugged and reliable design offering long-life service. FEATURES ™ High Power Gain The power gain is typically 54 dB at the rated output power level. ™ Simple Cooling System The tube is conduction-cooled so that the cooling system is greatly simplified. ™ PPM Focusing The tube is PPM (Periodic Permanent Magnet) -focused, eliminating entirely the focusing power supplies and interlock circuits. ™ Rugged Construction The tube 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. ™ Microdischarge 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. ET0221EJ5V0DS00 (5th edition) Date Published August 1999 M Printed in Japan © 1997 LD7249 SERIES GENERAL CHARACTERISTICS ELECTRICAL Frequency ……………………………………………… 13.75 to 14.5 GHz Output Power LD7249 ……………………………………………… 350 W LD7249U …………………………………………… 400 W Heater Voltage ………………………………………… 6.3 V Heater Current ………………………………………… 1.2 A Type of Cathode ……………………………………… Indirectly heated, Impregnated Cathode Warm-up Time …………………………… 180 s MECHANICAL Dimensions …………………………………………… See outline Weight ………………………………………………… 4 kg approx. Focusing ……………………………………………… Periodic Permanent Magnet Mounting Position …………………………………… Any Electrical Connections ……………………………… Flying Leads Heater, Heater-Cathode, (Optionally, the HV lead out let position can be changeable) Helix, Collector-1, Collector-2 and Thermal Protection RF Connections Input ………………………………………………… Type SMA Female Output ……………………………………………… Mates with UBR-120 Flange, Waveguide : WR-75 Cooling ………………………………………………… Conduction ABSOLUTE RATINGS (Note 1, 2 and 3 ) ELECTRICAL Heater Voltage ……………………………………… Heater Surge Current …………………………… min. max. Unit 6.0 6.6 V – 3.0 A Heater Current ……………………………………… 1.0 2.0 A Heater Warm-up Time …………………………… 180 – s Helix Voltage ……………………………………… 8.0 9.2 kV Helix Current ……………………………………… 0 10 mA Collector-1 Voltage ………………………………… 4.0 4.6 kV Collector-1 Current ………………………………… – 180 mA Collector-2 Voltage ………………………………… 2.3 3.1 kV Collector-2 Current ………………………………… – 290 mA Cathode Current …………………………………… 200 290 mA RF Drive Power …………………………………… – 5 mW Load VSWR ………………………………………… – 1.5 : 1 Min. Max. Unit –40 +115 °C Min. Max. Unit MECHANICAL Heat Sink Temperature …………………………… ENVIRONMENTAL Ambient Temperature 2 Storage …………………………………………… –50 +90 ˚C Operating ………………………………………… –40 +100 ˚C DATA SHEET ET0221EJ5V0DS00 LD7249 SERIES TYPICAL OPERATION (Note 2, 3 and 5) LD7249 LD7249U Unit Frequency ……………………………………………… 14.25 14.25 GHz Output Power ………………………………………… 350 400 W Heater Voltage (Note 4) ……………………………… 6.3 6.3 V Heater Current ………………………………………… 1.2 1.2 A Helix Voltage …………………………………………… 8.6 8.8 kV Helix Current …………………………………………… 1.5 2.4 mA Collector-1 Voltage …………………………………… 4.3 4.4 kV Collector-1 Current …………………………………… 141 147 mA Collector-2 Voltage …………………………………… 2.7 2.8 kV Collector-2 Current …………………………………… 94 100 mA Cathode Current ……………………………………… 237 250 mA Power Gain at 20 W ……………………… 62 58 dB at 350 W ……………………… 58 54 dB Gain Variation at 20 W ……………………… 0.86 1.02 dB/750MHz Gain Slope at 40 W ……………………… 0.006 0.006 dB/MHz Less than 100 W …………………………… 0.3 0.3 deg./dB at 350 W ……………………………………… 2.5 2.5 deg./dB 3rd Order Intermodulation ………………………… –23 –24 dBc AM-PM ConversioN (two equal carriers, 100 W total) 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 ET0221EJ5V0DS00 3 LD7249 SERIES LD7249 OUTLINE (Unit in mm) 85 max. 77.2 ± 1.3 76 ± 1 RF OUTPUT UBR-120 FLANGE WITH No.6-32 UNC-2B THREADED HOLES 47.8 ± 0.2 43.5 ± 0.3 55.9 ± 1 175 ± 0.8 322.8 ± 1.5 39.9 ± 0.8 117.6 ± 0.2 162.1 ± 0.2 PARAMETER LEBEL 8 × φ 4.85 +0.1 – 0.0 THRU I D E N T I F I C AT I O N LEBEL 225.6 ± 0.2 289.1 ± 0.2 352.6 ± 0.2 416.1 ± 0.2 431.8 ± 0.8 60 ± 0.8 11.5 ± 1 73.2 ± 0.2 38 ± 0.8 22.4 ± 0.2 55.9 ± 0.8 127 ± 0.8 WITH 8. LENGTH 14 (8 SLOTS) 10 × φ 5 +0.1 – 0.0 THRU BeO CAUTION LEBEL No.6-32 UNC-2B × 9 DEEP BOTHSIDE RF INPUT SMA FEMALE 19 ± 0.3 6 ± 0.3 38 ± 0.3 45.5 ± 0.8 45.7 ± 0.3 54 ± 0.3 57 max. LEAD COLOR 4 LEAD CONECTIONS LENGTH BROWN HEATER 650 mm YELLOW HEATER-CATHODE 650 mm RED COLLECTOR-1 650 mm BLUE COLLECTOR-2 650 mm BLACK HILIX (GROUND) 650 mm BLUE (SLIM CABLE) THERMAL SWITCH-1 650 mm GREEN (SLIM CABLE) THERMAL SWITCH-2 650 mm DATA SHEET ET0221EJ5V0DS00 LD7249 SERIES DATA SHEET ET0221EJ5V0DS00 5 LD7249 SERIES 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 Conponents, 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 Conponents, 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: Aircrafis, 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.