High-frequency tuning device

Abstract

Abstract 1,077,629. Tuned transmission lines. AGA A.B. Oct. 26, 1966 [Nov. 23, 1964], No. 45245/65. Headng H1W. A tuner for the 20-400 MHz range comprises a capacitor and a number of electrically parallel conductors rotatable about a common axis towards and away from a ground plane, the arrangement being such that the conductors approach each other as they are rotated away from the ground plane. The two conductors 3, 4 shown in Fig. 7, are of U-shape and are rotatable about an axis 6 passing through the limbs of the U's. The position of the conductors determines the characteristic impedance and hence the resonant frequency of the arrangement, the impedance being at a maximum when the conductors are closest together and farthest away from the ground plane (position indicated by broken, line). Although a simple flat ground-plane may be used, the one illustrated consists of two troughs respectively formed by members 18, 19 and 20, 21. Trimming may be accomplished by bending the sides of the troughs, as shown. The electrical length of the arrangement may be increased by capacitative loading. two systems may be connected in tandem, the second system being rendered inoperative by a short-circuiting switch at the connecting point. The Specification describes a modification using three U- shaped conductors.

Inventors

• 👤 Carl-Erik Granqvist

Bibliographic Details