Patent ID: 6998783

Claim:
An amplifying apparatus, comprising: a broadband impedance transformer; an electron gun including a cathode, an anode spaced a distance therefrom, and a grid disposed between said cathode and anode, said cathode providing an electron beam that passes through said grid and said anode, said grid being coupled to an input radio frequency (RF) signal via said broadband impedance transformer, said RF signal density modulating said electron beam; a first polepiece comprising a first centered hole through which said electron beam passes; a second polepiece comprising a second centered hole through which said electron beam passes; a drift tube extended from and concentric with said electron gun and anode and surrounding said electron beam, said drift tube including a space defined between said first and second polepieces; and a collector extended from said second polepiece, said electron beam passing into said collector after transit across said space; wherein said broadband impedance transformer comprises a transmission line having one or more sections, each of said one or more sections having approximately one-quarter of a RF wavelength in length, each of said one or more sections further having a respective characteristic impedance intermediate in magnitude between impedance levels existing at each end of each corresponding one of said one or more sections.