Phase study on broad band high power microwave amplifiers

With the advent of sophisticated pulse compression radars, the phase linearity of the various components has become of utmost importance. A phase measurement program was initiated to determine the phase linearity of broad band high power microwave tube. Swept frequency phase measurements were made on three types of pulsed C-band tubes. These tube types are: (1) 5-kw helix TWT; (2) 3-megawatt cloverleaf TWT; and (3) 3-megawatt cloverleaf Twystron® (klystron input section, cloverleaf output section). The 5-kw tube is used as a driver tube for the megawatt tubes. The deviation from linearity and the output power was measured for several beam voltages and rf drive powers for each of these tube types. Swept frequency measurements were made over a frequency range of 5.4 to 5.9 kmc. In addition, measurements were also made to determine the phase shift as a function of drive power at individual frequencies.