GB959017A - Improvements in or relating to devices for use with coaxial lines - Google Patents

Abstract

959,017. High-frequency impedance networks. PHILIPS ELECTRICAL INDUSTRIES Ltd. May 30, 1960 [June 2, 1959], No. 19043/60. Heading H1W. The inner or outer conductor of a coaxial line is provided with helical or spiral portions whereby an axial magnetic field is generated. As shown in Fig. 1, the outer conductor 1 of a co al line 1, 2 is slotted to provide a number of parallel conductor portions 11, 12 &c., each of length equal to one quarter wavelength (#/4) at the signal frequency. The ends of the portions 11 are connected to the inner conductor 2 by means of portions 11<SP>1</SP>, 12<SP>1</SP> &c. which follow a spiral path in a radial plane. The rotational component of the current in the portions 11<SP>1</SP> produce an axial magnetic field which may be linked with a winding 19 forming the termination of a symmetrical transmission line. Alternatively, the coaxial cable 1, 2 may be coupled to a further coaxial cable which is terminated in the same manner as the cable 1, 2, the cables being arranged coaxially with their ends near each other. In a modification (Fig. 2), the second coaxial cable 30, 31 is terminated by a Hall disc 20 of e.g. indium antimonide. This is arranged in a radial plane between electrodes formed by the inner conductor 31 and parallel portions 22<SP>1</SP>, 23<SP>1</SP> &c. of the outer conductor 30 each of length #/4. If the plate is arranged in the alternating field of the device of Fig. 1 and a magnetic field applied at rightangles to the plate, a Hall voltage is produced between the electrodes. In a modification (Fig. 4), a Hall cylinder 50 is arranged between the ends of radial portions 62<SP>1</SP> of an inner conductor 61 and parallel axial portions 52 of an outer conductor 51. A radial magnetic field is applied to the cylinder. The device of Fig. 1 may be modified by imparting a helical formation to the ends of the conductor portions 11 and forming the radial portions 11<SP>1</SP> as straightsided segments (Fig. 3, not shown). As shown in Fig. 5, the inner conductor 2 of line 1, 2 is directly connected to the inner conductor of a further line, and the outer conductors are connected by parallel conductor portions 71 having an intermediate part of helical formation. The straight parts of conductors 71 have a length equal to #/4. The axial field produced by the helix is linked with the terminal winding of a symmetrical two-conductor line 40. The inner conductors may be provided with helical portions instead of the outer conductors. In this case, the coupling winding is situated between the inner and the outer conductors. Where both conductors have helical portions, these have different senses of rotation. In all the modifications the spiral or helical parts of the line may be used to provide local inductance, terminal or otherwise. Specification 953,331 is referred to.