Agilent 1955-10 free download

File name 1955-10.pdf

HEWLETT-PACKARD JOURNAL TECHNICAL INFORMATION FROM THE -hp- LABORATORIES SHED ALTO, CALIFORNIA HEWLETT-PACKARD COMPANY, 275 PAGE MILL ROAD, PALO ALTO, CALIFORNIA OCTOBER, 1955 High -Directivity Coaxial Directional Couplers and Reflectometers AiOUT a year ago -bp- announced a reflecto whose performance substantially surpasses any meter system for wave guide use. This heretofore known to be available has recently was a system that, like a slotted line measure been designed. The new couplers operate over ment, gave quantitative impedance mismatch 2.1:1 frequency bands in the 216-4,000 mega information but would give the information cycle range, have coupling ratios of 20 db, and for a whole wave guide range of frequencies in have directivities of at least 26 and 30 db, de about the same time that a slotted line measure pending on their particular frequency range ment could be made at only one frequency. The (see accompanying table). saving of time and effort offered by a system Coaxial couplers with these characteristics that automatically presents quantitative mis are obviously suited to forming accurate reflec- match information on a meter will be appreci tometers for coaxial systems, and the final de ated by anyone who has plotted VSWR meas sign of the couplers has been carried out with urements over wide frequency ranges with a a view toward reflectometer use. The couplers slotted line. have thus been designed as dual couplers: one The speed of measurement of the reflecto- coupler provides a sample of both an incident meter and the fact that it could be operated by and a reflected wave at separate terminals. non-technical personnel in production testing The schematic arrangement of the couplers have resulted in considerable demand for a is shown in Fig. 2. They consist basically of a similar system for coaxial devices. To this end main arm with two coupled auxiliary arms. All