GB460096A - Improvements in frequency changers - Google Patents

Abstract

460,096. Generating oscillations. SIEMENS & HALSKE AKT.-GES. July 20, 1935, No. 20705. Convention date, July 20, 1934. [Class 40 (v)] Relates to frequency multipliers or dividers of the kind in which an original frequency is changed by a process of multiple reactive modulation. Specifications 216,132, [Class 40 (v)], and 421,129 are referred to. According to the invention, passive modulators such as the bridge of copper-oxide rectifiers 25, 26, 27, 28 shown in Fig. 3 are used instead of valves, and are separated from their associated amplifiers. In the arrangement of Fig. 1, an original frequency f1 is applied to the terminal 7 of the modulator M1 and also to the terminal 8 of modulator M2. Another frequency f2, which may or may not be an harmonic, is produced as the result of some initial instability at the terminal 9. The resulting sum or difference frequency f3 passes from the terminal 11 through an amplifier 5 and filter 3 tuned to it, and through the second modulator M2, where it combines with the original frequency f1. The resulting frequency f2 passes through a tuned amplifier 6 and filter 4 back to the modulator M1. Or it can be drawn off at 14. Similarly the frequency f3 can be drawn off at 13. In Fig. 2 only one modulator M is used, and the currents pass through it twice, the filters 3, 4 accepting the sum and difference frequencies respectively.