The Radio Receiver Characteristics Related to the Side-Band Coefficient of the Resonance Circuit

In the investigation of the over-all sensitivity, fidelity, and selectivity of radio receivers, it is necessary to consider not only the performance of the detector and amplifier, but also the modulated current in the resonant circuits. The general statement that the side bands of the modulated current are cut off in resonant circuits is not sufficient for a complete description of the over-all performance of the system. In this paper a theoretical treatment of the modulated current in resonant circuits is given. A factor called the side-band coefficient is introduced and its utility in the calculation of output response, selectivity, and fidelity is illustrated. A comparison of the side-band coefficient and the resonance curves is made, and experimental data showing various applications are given.