A generic approach to the theory of superregenerative reception

The superregenerative receiver has been widely used for many decades in short-range wireless communications because of its relative simplicity, reduced cost, and low power consumption. However, the theory that describes the behavior of this type of receiver, which was mainly developed prior to 1950, is of limited scope, since it applies to particular implementations, usually operating under continuous-wave signal or narrow-band modulation. As a novelty, we present the theory of superregenerative reception from a generic point of view. We develop an analytic study based on a generic block diagram of the receiver and consider not only narrow-band, but a wider variety of input signals. The study allows general results and conclusions that can be easily particularized to specific implementations to be obtained. Starting from the proposed model, the differential equation that describes the operation of the receiver in the linear mode is deducted and solved. Normalized parameters and functions characterizing the performance of the receiver are presented, as well as the requirements for proper operation. Several characteristic phenomena, such as hangover and multiple resonance, are described. The nonlinear behavior of the active device is also modeled to obtain a solution of the differential equation in the logarithmic mode of operation. The study is completed with a practical example operating at 2.4 GHz and illustrating the typical performance of a superregenerative receiver.