| 摘要 |
601,575. Impedance networks. MAR CONI'S WIRELESS TELEGRAPH CO., Ltd. Dec. 28, 1945, No. 35132. Convention date, Dec. 30, 1944. [Class 40 (viii)] [Also in Group XL (c)] In a radio frequency network including two input points which are to be isolated from each other and two output points, each of which is to be supplied simultaneously with energy from both input points, the two output points are supplied in phase by two branch lines connected to one of the input points and out of phase by two further branch lines connected to the other of the input points. As described, the power from a television transmitter in coaxial feeder 31, and from a sound transmitter in coaxial feeder 37 are both fed to the two dipole pairs N, Sand E, W of a turnstile aerial. The points 21, 21<1> are fed in phase from feeder 31 through parallel quarter-wave line sections 27, 27<1>, and in phase opposition from feeder 37 through series line sections 33, 33<1>, coupled to the feeder through a line balance converter 35 which produces a balanced output from the asymmetric output of feeder 37. From each of the points 21, 21<1> run a pair of paralleled sections 11, 13 and 11<1>, 13<1> respectively which feed line balance, converters 9, 9<1> respectively, the outputs from which are fed to the dipole pairs N, Sand E, W respectively. The pairs of feeders from converters 9, 9<1> differ in length by a. quarter-wavelength so that the mutually perpendicular aerials are excited in quadrature. The line -balance converters 9, 9<1> comprise parts of the line sections 11, 13. and a cylindrical conductor 15, the outers of the line sections and conductor 15 being connected together by a conductive plate 17 which closes a shield 19 surrounding the converter. The plate 17 is a quarter-wavelength from the upper ends of sections 11, 13 and the conductor 15 is a quarter-wavelength. The upper end of shield 19 is closed by a plate 23 into which the aerial feed lines 1, 3 extend. The inner conductor of line 1 is connected to the free end of conductor 15 and the inner conductor of line 3 to the free end of the outer of line section 11. The inner of section 11 is connected to the free end of the outer of section 13 and the inner of section 13 to the free end of conductor 15. The conditions necessary for compensating the reactances of the converter over a wide frequency band are developed in the Specification. The line balance converter 35 comprises a cylindrical conductor 39, into the closed end of which the feeder 33 extends for a quarter-wavelength. Feeder 33<1> terminates at the other closed end of conductor 39 and the inner conductors of 33, 33<1> are connected together. The transmitter feeder outer conductor terminates on conductor 39 and its inner conductor is connected to the end of the outer of feeder 33. |
