GB1111464A - Broadband rotary transformer - Google Patents

Abstract

1,111,464. Transformers. SANDERS ASSOCIATES Inc. 12 April, 1966 [26 April, 1965], No. 15948/66. Heading H1T. In a broadband rotary transformer (e.g. 30 to 1000 megacycles), annular primary and secondary conductors 24 and 32 (Fig. 1) are mounted for relative rotation about a common axis 14, the primary conductor 24 being either of tubular cross-section with a longitudinal slot or, as shown, channel section, and the secondary 32 being disposed in the primary 24 to reduce leakage inductance. The primary 24 is secured in an annular recess 22 in a base 20 of magnetic material (e.g. ferrite) which is secure by set-screws 17 to an outer tube 18 arrayed to be driven. The secondary 32 is mounted on an insulating annulus 30 secured to a ferrite base 28 secured to an inner, stationary tube 16. The primary 24 and secondary 32 are each radially cut to provide ends for connection to coaxial cables 26, 34 led from their respective conductors through holes in the respective bases 20, 28. The secondary may have a number of turns, and the recess 22 may face radially inwards or outwards. The coupling coefficient is stated to be relatively independent of the relative angular position of the primary and secondary provided the circumference of each is less than a wavelength at the frequency of the signals coupled.