Agilent 1954-11 free download

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HEWLETT-PACKARD m f T E C H N I C A L JOURNAL I N F O R M A T I O N F R O M T H E - h p - L A B O R A T O R I E S Vol. 6 No. 3-4 [BUSHED BY THE HEWLETT-PACKARD COMPANY, 275 PAGE MILL ROAD, PALO ALTO, CALIFORNIA NOV.-DEC, 1954 New Broadband Microwave Power Amplifiers Using Helix- Coupled TWTS ' I ^HE Hewlett-Packard laboratories have watts, respectively, into 50 ohms and have J- developed several new broadband mi gains of 30 and 35 db. They can thus be op crowave power amplifiers which promise to erated directly from the 1 milliwatt drive be extremely important in furthering high- available from the -hp- Model 6l6A 1.8-4 frequency development work of many kinds. kmc signal generator to provide high level The importance of these am signal sources. plifiers lies in the fact that The 1-watt amplifier is designed as an un they provide high gains, modulated amplifier, while the 10-milliwatt high power output, and very unit is designed to be amplitude-modulated wide 2:1 bandwidths in the microwave re if desired. For modulating purposes very gion. The development of amplifiers with short pulses of about 25 millimicroseconds such characteristics at once solves several duration can be used. Both amplifiers will problems prevalent in high-frequency work. amplify even shorter r-f pulses of the order These problems include the need for signal of 1 millimicrosecond in duration. powers much higher than those available A third amplifier, soon to be in produc from signal generators and the need for the tion, has been designed to operate from 4-8 wide-band amplification device necessary to kmc and provide an output of 10 milliwatts. development work in any frequency range. Meantime, design work is progressing on Two of the amplifiers, those in production, higher frequency amplifiers. operate from 2 to 4 kilomegacycles, provide Eng