A LOW POWER HEATER-CATHODE SYSTEM FOR HIGH FREQUENCY SPACE COMMUNICATIONS

BECAUSE OF NEW TECHNOLOGY, IT IS NOW POSSIBLE TO OFFER HIGHER ELECTRON-BEAM DENSITIES AND LONGER CATHODE LIFE AT LOWER HEATER POWERS THEN EVER BEFORE. THIS IS A SIGNIFICANT DEVELOPMENT FOR HIGH-FREQUENCY SPACE COMMUNICATIONS, KA BAND AND ABOVE; IN THIS AREA, THE LIMITING FACTOR ON MICROWAVE POWER AND EFFICIENCY HAS BEEN THE CATHODE LOADING AND SIZE. A VERY SMALL, RUGGED, HEATER-CATHODE SYSTEM THAT WILL EXPLOIT THESE NEW TECHNOLOGIES WILL BE DEVELOPED. IT WILL PRODUCE UP TO 2 AMPS PER SQUARE CENTIMETER OF CURRENT DENSITY, LIVE FOR AT LEAST 30,000 HOURS, AND CONSUME LESS THAN 1/2 W OF HEATER POWER. THE DEVICE WILL EMPLOY THE NEW SCANDATE OXIDE CATHODE, AS WELL AS A CATHOPHORETICALLY COATED AND DARKENED HEATER THAT IS NOW AVAILABLE IN VERY SMALL SIZES. THE ABILITY TO EXTRUDE SEAMLESS TUBING AT WALL THICKNESS NOT PREVIOUSLY AVAILABLE WILL PROVIDE MAXIMUM THERMAL ISOLATION OF THE CATHODE-SUPPORT STRUCTURE. BECAUSE OF NEW TECHNOLOGY, IT IS NOW POSSIBLE TO OFFER HIGHER ELECTRON-BEAM DENSITIES AND LONGER CATHODE LIFE AT LOWER HEATER POWERS THEN EVER BEFORE. THIS IS A SIGNIFICANT DEVELOPMENT FOR HIGH-FREQUENCY SPACE COMMUNICATIONS, KA BAND AND ABOVE; IN THIS AREA, THE LIMITING FACTOR ON MICROWAVE POWER AND EFFICIENCY HAS BEEN THE CATHODE LOADING AND SIZE. A VERY SMALL, RUGGED, HEATER-CATHODE SYSTEM THAT WILL EXPLOIT THESE NEW TECHNOLOGIES WILL BE DEVELOPED. IT WILL PRODUCE UP TO 2 AMPS PER SQUARE CENTIMETER OF CURRENT DENSITY, LIVE FOR AT LEAST 30,000 HOURS, AND CONSUME LESS THAN 1/2 W OF HEATER POWER. THE DEVICE WILL EMPLOY THE NEW SCANDATE OXIDE CATHODE, AS WELL AS A CATHOPHORETICALLY COATED AND DARKENED HEATER THAT IS NOW AVAILABLE IN VERY SMALL SIZES. THE ABILITY TO EXTRUDE SEAMLESS TUBING AT WALL THICKNESS NOT PREVIOUSLY AVAILABLE WILL PROVIDE MAXIMUM THERMAL ISOLATION OF THE CATHODE-SUPPORT STRUCTURE.