DATA S H E E T HIGH POWER TRAVELING WAVE TUBE FOR GROUND TERMINALS LD7215, LD7215C, LD7215D 6 GHz, 3 kW, HELIX TYPE, PPM FOCUSING, HIGH POWER GAIN, FLAT GAIN VARIATION GENERAL DESCRIPTION The NEC LD7215, LD7215C and LD7215D are PPM-focused traveling wave tubes designed for use as the final amplifiers in the earth-to-satellite communications transmitter. These are capable of delivering an output of 3 kW over the range of 5.85 to 6.425 GHz. They provide a high power gain of 46 dB at an output power of 3 kW, and flat gain variation of 2.5 dB by LD7215, 1.0 dB by LD7215C and LD7215D at small signal level in the full frequency range. Furthermore, they are of rugged and reliable design offering long-life service. Both LD7215 and LD7215D are fully compatible with TH3640. FEATURES ™ High Power Gain The power gain is typically 52 dB at small signal level and 46 dB at 3 kW Ievel. ™ Simple Cooling System All the tubes are forced-air-cooled, so that the cooling system is greatly simplified. ™ PPM Focusing The tubes are PPM (Periodic Permanent Magnet) focused, and eliminate entirely the requirement for focusing power supplies and interlock circuits. ™ Long Life and High Stability The tubes employ 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 use in 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. ET0139EJ5V0DS00 (5th edition) Date Published August 1998 M Printed in Japan © 1991 LD7215, LD7215C, LD7215D GENERAL CHARACTERISTICS ELECTRICAL Frequency ……………………………………………… 5.85 to 6.425 GHz Cathode ………………………………………………… Indirectly heated, Impregnated Heater Voltage …………………………………… 6.3 V Heater Current …………………………………… 3.9 A MECHANICAL Dimensions …………………………………………… See Outline Focusing ……………………………………………… Periodic Permanent Magnet Electrical Connections ……………………………… Flying Leads (LD7215, LD7215D) AMP LGH 863023 Plug (LD7215C) RF Connectors Input ………………………………………………… Type SMA Female Output ……………………………………………… Mates with CPR 137 Flange Mounting Position …………………………………… Vertical (cathode down) or Horizontal Weight ………………………………………………… 30 kg approx. Cooling ………………………………………………… Forced Air ABSOLUTE RATINGS (Note 1, 2, 3 and 4 ) ELECTRICAL Min. Max. Heater Voltage ……………………………………… 6.0 6.6 V Heater Surge Current ……………………………… – 8 A 3 5 A 300 – s Heater Current ……………………………………… HeaterWarm-up Time …………………………… Collector Voltage …………………………………… 8.0 9.5 kV ……………………………………… 12.5 13.7 kV Accelerating Anode Voltage ……………………… 10.0 13.0 kV Collector Current …………………………………… – 1.5 A Helix Voltage Helix Current ……………………………………… Accelerating Anode Current …………………… – 30 mA –0.5 1.0 mA Collector Dissipation ……………………………… – 13.3 kW Helix Dissipation …………………………………… – 400 W Reflected Power …………………………………… – 100 W Load VSWR ………………………………………… – 1.5:1 Collector Temperature …………………………… Cooling Air Temperature (Inlet) ………………… – –20 300 45 °C °C Cooling Air Flow …………………………………… 720 – kg/hr MECHANICAL 2 LD7215, LD7215C, LD7215D TYPICAL OPERATION (Note 1, 3 and 4) Frequency ……………………………………………… 6.175 GHz Heater Voltage (Note 5) ……………………………… 6.3 V Heater Current ………………………………………… 3.9 A Coilector Voltage ……………………………………… 8.25 kV Helix Voltage …………………………………………… 13.5 kV Accelerating Anode Voltage ………………………… 11.5 kV Collector Current ……………………………………… 1.35 A Helix Current …………………………………………… 5 mA Accelerating Anode Current ………………………… 0.02 mA dB Power Gain at Small Signal …………………………………… 52 at 3 kW Output …………………………………… 46 Gain Variation (at Small Signal) …………………… 2.5/1.0 Gain Slope (at Small Signal) ……………………… dB dB (LD7215/LD7215C, LD7215D) 0.02 dB/MHz AM-PM Conversion 2 °/dB …………………………………… 3.5 °/dB 3rd Order Intermodulation ………………………… –27 dBc 720 kg/hr 882.6 Pa at less than 500 W ………………………………… at 3 kW Output (Two equal carriers, 250 W total) Cooling Air Flow ……………………………………… Air Pressure Drop …………………………………… 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 LD7215, LD7215C, LD7215D LD7215, LD7215C* and LD7215D OUTLINE (Unit in mm) 5.5 ±1 178 MAX. 12 ± 0.5 116 ± 1 (6) ( ) 14.5 ±2 3 535 2 TYP.822 97 ±1 3±1 850 MAX. TERMINAL φ6 20 MAX. 800 ± 50 15 ± 1 , 20 MAX. M10 4 SPRING LOADED CAPTIVE SCREWS RUBBER 35 MAX. 630 ± 20 320.8 ± 3 AOR INTAKE 30 ± 1 BEARING 266 ± 2 FACE 155 ±1 M4 (8 HOLES) 100 ± 1 150 ± 1 230 ± 2 83 ±1 , M4 (4 HOLES) φ 160 ±1 1 35 ± 1 83 ±1 12 ±1 ,, ,,, BEARING FACE , φ 16 ±1 (2 HOLES) 130 ± 1 140 35 , , , ,, 130 ±1 No.6 No.5 No.4 No.3 No.2 No.1 230 MAX. 193 MAX. 195 MAX. 210 LEAD CONNECTIONS LEAD NO. ELEMENT (COLOR) q RF OUTPUT CPR-137 FLANGE (NO. 10-32 UNF 2B THREADED HOLES) (YELLOW) w RF INPUT TYPE SMA FEMALE ANODE (BLUE) e FLYING LEADS WITH φ 6 TERMINALS 4 COLLECTOR (RED) HIGH VOLTAGE CONNECTIONS 5 HELIC (GROUND) (BLACK) 6 THERMALPROTECTION (GLAY) 1 HEATER (–) (BROWN) 2 HEATER (+), CATHODE 3 * LD7215C is electrically connected by AMP LGH 863023 Plug. No part of this document may be copied in any form or by any means without the prior written consent of NEC Corporation. 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 of others.