| 摘要 |
643,162. High - frequency transmission. WESTERN ELECTRIC CO., Inc. July 4, 1947, No. 17682. Convention date, Dec. 31, 1942. [Class 40 (iv)] [Also in Group XL (b)] A coupling arrangement for electrical wave transmission systems comprises a single closed loop of wave-guide to which four connections, each either a wave-guide or a coaxial line, are so connected as to provide electrical balance between certain of the circuits and electrical unbalance between others. In the arrangement shown the loop is one-and-a-half wavelengths long (1¢#). Four lines 1, 2, 3 and 4 are connected to the ring with spacings #/4 between each adjacent pair. A generator in branch 2 will transmit equally divided power to equal loads in branches 1 and 3 whereas branch 4 will receive no power. If the coupling arrangement is used in a duplex system the other generator will be in branch 1. It can also be calculated that if the impedances are as shown on the drawings impedance matching is accomplished whether the arrangement is driven from branch 1 or branch 2. In this arrangement all the branch guides make series connections with the loop. Similar arrangements can be produced by substituting shunt connections for any or all of the series connections. Alteration of the length of the loop is sometimes then required to maintain the matching quality. By a certain amount of reactance tuning in the branches balancing can be obtained over a broad band without excessive mismatch. The arrangement functions in a manner somewhat similar to hydrid coil in conventional telephone practice and can be used in the construction of a duplex transmission system, a duplex repeater or three arrangements can be combined to form a multiple duplex balancer. Specifications 491,359 and 643,163, [Group XL (b)], are 'referred to. The Specification as open to inspection under Sect. 91 comprises also constructions in which the wave-guide loop is replaced by a loop of coaxial line or Lecher pair. This subjectmatter does not appear in the Specification as accepted. |
