Ferrites applied to carrier-frequency equipment

The properties of some ferrites and other magnetic materials in the carrier frequency range are compared and an indication is given of the field of application of ferrites. In transformer design, insertion loss and return loss are examined in relation to the reluctivity of core materials, and it is shown that ferrites have advantages in the frequency range above 30kc/s. Examples are given of a ferrite-cored transformer in the input network of a 0·3¿12Mc/s coaxial-line amplifier, a hybrid coil for the measurement of return loss in the range 1¿100Mc/s, and a 5kW transformer for 4¿28Mc/s. The design of inductors for carrier frequencies falls into three main classes. In one class very high stability may be obtained with high Q-factor. In the second class, very high Q-factor is combined with high stability. In the third class adequate performance is accompanied by very small size.