GB1152453A - Circuit Arrangement For Feeding A Common Load From Two High-Frequency Current Sources - Google Patents

Abstract

1,152,453. R.F. couplings. TELEFUNKEN PATENTVERWERTUNGS G.m.b.H. 20 May, 1966 [20 May, 1965], No. 22457/66. Heading H4A. Relates to a known circuit arrangement (Fig. 1, not shown), for feeding a common load (e.g. an aerial) from two radio-frequency generators having the same frequency, a terminal of each generator is connected together directly and to one connection of a circuit containing a first resistance R, the other two generator terminals are connected by two coils of equal inductance tightly coupled together and the coils are bridged by a circuit incorporating a capacitor and a second resistance 4R, as disclosed in Electronic Engineering, December, 1952, pages 550 to 552. The generators may be equal in phase-case (a)-or opposite in phase-case (b)-and according to the invention in case (a) the first resistance is the load and the second resistance the load equalization which has no current passing through it in normal operation, in case (b) the first resistance is the load equalization having no current passing through it in normal operation and the second resistance is the load and in both eases compensating circuits are provided in the form of a filter matched to the load resistance. The filter in case (a) may be an L or IT band-pass or low-pass network and in case (b) may be a IT band-pass network. In one arrangement, Fig. 2, in which generators G1, G2 are in antiphase, R1 is the load equalization, R2 is the load, coils LH are the coils of equal inductance and a band-pass filter incorporates sections II, III and IV; by this means the generators are effectively decoupled. In another arrangement a further filter network is included in the path to resistance R1, and inductor L2 of Fig. 2 is an auto-transformer for tapping thereon of resistance R2, Fig. 4 (not shown). A frequency range of 3À5 : 1 is quoted over which mismatch is small in the medium and long wave-bands.