DATA S H E E T HIGH POWER TRAVELING WAVE TUBE FOR GROUND TERMINALS LD7215W 6 GHz, 3 kW CW, PPM FOCUSING, HIGH POWER GAIN GENERAL DESCRIPTION NEC LD7215W is a PPM-focused traveling wave tube designed for use as final amplifier in the earth-to-satellite communications transmitter. This is capable of delivering an output power of 3 kW over the range of 5.85 to 6.65 GHz. It provides a high power gain of 42 dB at a rated output power. Furthermore, this is of rugged and reliable design offering long-life service. FEATURES ™ High Power Gain The power gain is typically 42 dB minimum at 3 kW level. ™ Simple Cooling System The tube is forced-air-cooled, so that the cooling systems are 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. ET0214EJ2V1DS00 (2nd edition) Date Published August 1998 M Printed in Japan © 1996 LD7215W GENERAL CHARACTERISTICS ELECTRICAL Frequency ……………………………………………… 5.85 to 6.65 GHz Output Power ………………………………………… 3 kW Heater Voltage ………………………………………… 6.3 V Heater Current ………………………………………… 4.5 A Type of Cathode ……………………………………… Indirectly heated, Impregnated Cathode Warm-up Time …………………………… 300 s MECHANICAL Dimensions …………………………………………… See outline Weight ………………………………………………… 30 kg approx. Focusing ……………………………………………… Periodic Permanent Magnet Mounting Position …………………………………… Any Electrical Connections ……………………………… Flying Leads Heater, Heater-Cathode, Helix, Anode, Collector and Thermal Protection RF Connections Input ………………………………………………… Type SMA Female Output ……………………………………………… Mates with CPR-137F Flange Cooling ………………………………………………… Forced Air ABSOLUTE RATINGS (Note 1, 2 and 3 ) ELECTRICAL Min. Heater Voltage ……………………………………… Max. Unit 6.0 6.6 V – 8.0 A Heater Current ……………………………………… 3.0 5.0 A Heater Warm-up Time …………………………… 300 – s Helix Voltage ……………………………………… 12.5 13.7 kV Helix Current ……………………………………… – 25 mA Anode Voltage ……………………………………… 10.0 13.0 kV Anode Current ……………………………………… –0.5 0.5 mA Collector Voltage …………………………………… 8.0 9.5 kV Cathode Current …………………………………… – 1.5 mA Drive Power ………………………………………… – 24 mW Load VSWR ………………………………………… – 1.15 : 1 Min. Max. Unit 720 – kg/hr Operating temperature …………………………… 0 +45 ˚C Inlet air temperature ……………………………… –20 +45 ˚C Storage temperature ……………………………… –30 +70 ˚C Heater Surge Current …………………………… MECHANICAL Cooling Air Flow …………………………………… 2 LD7215W TYPICAL OPERATION (Note 2, 3 and 5) Unit Frequency ……………………………………………… 5.85 to 6.65 GHz Heater Voltage (Note 4) ……………………………… 6.3 V Heater Current ………………………………………… 4.5 A Helix Voltage …………………………………………… 13.5 kV Helix Current …………………………………………… 10.0 mA Anode Voltage ………………………………………… 11.8 kV Anode Current ………………………………………… 0.01 mA Collector Voltage ……………………………………… 8.25 kV Cathode Current ……………………………………… 1.4 mA Saturated Output Power …………………………… 3.3 kW Power Gain at 500 W ……………………… 51 dB at 3 kW ……………………… 45 dB Gain Variation at 500 W ……………………… 1.5 dB/800 MHz Gain Slope at 500 W ……………………… 0.02 dB/MHz at 500 W ……………………………………… 1.7 deg./dB at 3 kW ………………………………………… 3.0 deg./dB (two equal carriers, 300 W total) …………………… –31.5 dBc Air Flow ………………………………………………… 720 kg/hr Air Pressure Drop 882.6 Pa AM-PM Conversion 3rd Order Intermodulation …………………………………… 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 LD7215W LD7215W OUTLINE (Unit in mm) 210 No.1 No.2 No.4 195 Max. 235 Max. No.5 198 Max. No.6 5.5 ±1 266±2 116±1 12±0.5 Bearing Face M6 Terminal 1 14.5 ±2 15±1 M4 (8 Holes) Air Intake 105±1 30±1 3±1 97 ±1 155 ±1 83 ±1 83 ±1 Bearing Face 320.8 ±3 822 Typ. 850 Max. 3 630±10 230±2 2 535 20 Max. ,, ,, 100±1 800±50 35±1 No.3 ,, ,, ,, ,,,,,,,,,,, ,,,,,,,, ,,,,,,,, ,,,, Rubber 12±1 ) Air Exhaust 140 M4 (4 Holes) φ 16±1 (2 Holes) 35 φ 160 ±1 130±1 ( M10 4 Spring Loaded Captive Screws ,,,, ,,, ,,, ,,, (6) , , ,,, ,,, ,,, , 20 Max. , , ,,, ,,, ,,, ,,, 178 Max. 35 Max. 130 ±1 LEAD CONNECTIONS RF OUTPUT CPR-137 FLANGE (NO. 10-32 UNF 2B THREADED HOLES) w RF INPUT FEMALE SMA CONNECTOR e HIGH VOLTAGE CONNECTIONS q FLYING LEADS WITH M6 TERMINALS LEAD NO. LEAD NAME HEATER (–) 2 HEATER (+), CATHODE (YELLOW) 3 ANODE (BLUE) 4 COLLECTOR (RED) 5 HELIX (GROUND) (BLACK) 6 THERMAL PROTECTION SWITCH (GRAY) NOTE 1 : THE 3RD ANGLE ORTHOGRAPHIC PROJECTION. 4 (COLOR) 1 (BROWN) LD7215W 5 LD7215W 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.