| 摘要 |
991,152. Impedance matching; negative impedance circuits. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. June 14, 1963 [June 19, 1962], No. 23784/63. Headings H3U and H4R. The known circuit of Fig. 1 (in which Z 1 and Z 2 represent impedances having a negative resistance part) is adapted for connection between unequal impedances (e.g. transmission lines) by dividing the primary of series transformer T 1 into two windings 12, 13 and connecting the end of one of the windings to a tapping 11 on shunt transformer T 2 . In order to obtain frequency-independent transformation, the transformation ratio between the total winding T 2 and the part between terminals 2, 11 is made equal to the ratio between windings 12 and 13. In the variable circuit of Fig. 4, the transformation ratio may be chosen by connecting terminals 27, 21 and 22, 28 or terminals 26, 22 and 23, 29. The number of turns between terminals 1 and 26 is made equal to the number of turns between terminals 7 and 28. Denoting windings by their terminals, the following transformation ratios obtain:-1,27/1,26 = 21,2/22,2 and 22,2/23,2 = 28,7/29,7. The last two ratios are made equal to the square of the first two. A balanced version of the circuit of Fig. 4 is shown. |
