An eight per cent bandwidth, 100 kW, L-band klystron amplifier

The PT6006 is a resonant coupled cavity klystron operating in L-band. It gives a peak output power of 100 kW across an eight percent 1.5 dB bandwidth with an efficiency of 25%. The PT6006 has an overall length of 1.3 m, a diameter of 300 mm, and a weight of 65 kg. The tube gives a large signal gain of at least 25 dB. The two-cavity resonant coupled cavity output (RCCO) has two gaps which double the R/Q and can therefore be used to double the bandwidth; it also has two resonantly-coupled cavities which increase the output bandwidth further. These two effects provide the RCCO with up to 3.5 times the bandwidth of a standard klystron output at the same efficiency level. The PT6006 also requires eight buncher cavities to provide the specified gain and bandwidth; with this arrangement it is possible to remove all zeros from the required band. The two-cavity RCCO is a stable broadband, high efficiency output circuit, which has the potential to be extended for increasing the output and achieving a higher efficiency.