Transformer Coupling Circuits for High-Frequency Amplifiers
A. J. Christopher · Bell System Technical Journal · 1932
This article deals with the use of transformer type of coupling circuits in high-frequency amplifiers to transmit efficiently voltages or currents between certain limiting frequencies while attenuating those above and below the limiting frequencies. The similarity of these coupling circuits to band-pass filters is shown and the conditions to be satisfied in order that they may act as such are covered. Means of obtaining uniformly high amplification over relatively wide frequency bands are explained. Typical conditions under which these coupling circuits have been employed and factors affecting their performance are discussed.