Gridded Pierce gun design and the PPM focussing of beams from gridded electron guns

A large fraction of linear beam microwave and millimeter wave tubes manufactured today include gridded electron guns and employ PPM fields for beam focussing. While techniques for the design of gridless guns and theories for the focussing of laminar beams are numerous, convenient methods for designing gridded guns and nonlaminar beam PPM focussing systems are scant. This paper outlines new numerical and experimental methods for the design and optimization of gridded Pierce guns. The paper also deals with the inseparable problem of gridded gun beam focussing and presents a new theoretical technique for the design of PPM focussing systems to control the nonlaminar beams originating from gridded guns.