A compact magnet system for use in a high-power microwave tube includes an electromagnetic coil surrounded on three sides by permanent magnets. More particularly, constituent components include a first tubular retaining member; the electromagnetic coil that fits within the first tubular retaining member and that has a central cavity; first permanent magnets positioned to extend radially from the central cavity so that like poles of the first permanent magnets wrap around the central cavity along a first side of the solenoid coil; and second permanent magnets positioned to extend radially from the central cavity so that opposite poles to the first permanent magnets wrap around the central axis along the second side of the solenoid coil. Optional added components include two sets of permanent magnets, one set on each side of the coil and a pole piece located adjacent to an end of the first tubular retaining member.