AbstractsEngineering

The investigation of the Frequency Conversion Properties of Transistors at medium high radio frequencies has brought together the process of frequency conversion and the new electronic device known as the transistor. Frequency conversion is the term now given to the process of combining two frequencies, the signal and local oscillator frequencies, to produce a third called the intermediate frequency. It is a process of modulation that was originally called heterodyne detection and later first detection. If one tube combines the function of oscillator and modulator, then that tube may be logically termed a converter. If, however, separate tubes or other devices are used for the oscillator and modulator portions of the converter, the latter tube or device is called a modulator or mixer. This terminology will be applied throughout this paper. A short historical review of frequency conversion circuit development and transistor progress follows.[...]