Etude de Cavités Electromagnétiques Perturbées par un Diélectrique : Application aux Masers

Abstract

In certain types of masers it is common to use storage quartz bulbs in microwave cavities. We describe the effects of such bulbs on the field components, the frequency, the quality factor, and the filling factor. Two different methods are used to solve the problem: one of these methods is classical and exact and is based on the continuity of the field components and on the equations of separation; the other method used is the so called "method of moments". The two methods give essentially the same results. Experiments have been performed to verify the theoretical results. We have observed that the quartz storage bulb produces a slight negative frequency shift, a notable lowering of the quality factor and a very slight change in the filling factor; the perturbed mode appears as a superposition of other modes. It is concluded that to reduce the perturbation we must use extremely thin bulbs with walls very close to the cavity walls.