NETWORK-THEORETICAL APPROACH TO OROTRON ANALYSIS

For the use of oscillators in microwave networks, the knowledge of the behavior of the isolated oscillator is not sufficient. Of major interest is the interaction of the device with the external circuit, where questions about stability, modulation, injection locking, noise, etc. arise. If it is possible to describe the behavior of the active element in the frequency domain, the answers to the above mentioned questions can be found utilizing the standard methods of network theory. Recently the gyrotron oscillator has been described successfully in the frequency domain [1]. In this report such an approach is developed for the orotron [2]. The calculations yield a nonlinear device admittance which describes the behavior of the electron beam and is represented by its locus in the complex plane. On the other hand a linear load admittance can be derived from Maxwell's equations, describing the behavior of the cavity and the external circuit. Connecting the two admittances, one arrives at an equivalent circuit for the orotron which can be analyzed with the help of network theory [3], [4]. To point out the usefulness and feasibility of this model, the stability of the orotron is investigated as an example.