Abstract: Cavity resonators, preferably thermocompensated, with a straight-line frequency tuning, tuning elements of which move along a straight-line forced trajectory, and microwave circuits that contain such cavity resonators. At least one tuning element is connected to the cavity, made up of structural elements that are displaceable along a forced trajectory when the elements are in a forced coupling with a straight guide path formed on the structural element. The latter can be swung around an axis which is perpendicular to the direction of movement of the tuning element, the latter being provided with a roller that bears against the guide path. The cavity resonators are furthermore provided with frequency-linear adjusting members that can be displaced along the straight forced trajectory on the latter, also provided with a roller which bears against the guide path that is in a forced coupling with the structural element.