GB827024A - Uhf impedance matching means - Google Patents

Abstract

827,024. Impedance matching. COLLINS RADIO CO. June 6, 1957, No. 18057/57. Class 40 (8). [Also in Group XL (c)] Impedance matching means for connecting a first coaxial line with waveguiding means, such as a second coaxial line or a waveguide, having a greater area of crosssection, has the first line terminated within the wider waveguiding means with the terminated outer and inner conductors slidably connected to different parts of the waveguiding means. The first coaxial line passes through a shorting plunger slidably positioned in the waveguiding means and axial positioning of the plunger and the terminations of the first line controls the impedance match between said line and the waveguiding means. A first coaxial line 20 having inner and outer conductors 22, 21 is slidably terminated in a larger coaxial line 10 with inner and outer conductors 12, 11 by means of a plunger 13 having a dielectric annulus 14 which supports inner and outer conducting annuli 17, 16, respectively. Inner conductor 22 is attached to annulus 17 which carries a contact member 19 which bears on conductor 12, and outer conductor 21 is rigidly secured to annulus 16 which carries a contact member 18 bearing on the inner wall of conductor 11 so that the termination may be axially positioned by movement of rigid line 20. A slidable shorting plunger 26 connected by slidable contacts 31, 32 to line 10 may be separately axially positioned by rod 33 to terminate said line and has an opening 27 therein with sliding contacts 28 through which line 20 passes. The larger coaxial line may be replaced by a rectangular or circular waveguide (Figs. 8 and 6, not shown) in which the plungers are rotatable to compensate for any variation in the orientation of the field polarization. In Fig. 3 (not shown) the invention is embodied in a tunable U.H.F. amplifier (see Group XL (c)).