KU-BAND DUAL LINEARIZED CHANNEL AMPLIFIER FOR COMMERCIAL SATELLITE TRANSPONDERS

The design and test results of a space qualified dual linearized chann el amplifier (DLCAMP) developed for Ku-band TWTA commercial satellite applications are presented in this paper. The unit consists of two ind ependent identical linearized channel amplifiers and therefore offers redundant configurations. The linearizer utilizes a diode bridge and c an be switched off electronically so that the LCAMP offers also the fu nctions of a conventional channel amplifier. Electronically switching on of the linearizer improves, in addition, the gain compression of th e connected TWTA at saturation by at least 2 dB, reduces its phase shi ft to less than +/- 10 degrees and considerably reduces its intermodul ation products. The LCAMP has a gain of 65 dB, 31 dB gain setting, 15 dB ALC setting range with 0.5 dB/step and additional 8 dB output power setting range with 0.5 dB/step in both cases for linearizer active or inactive. The DLCAMP is a part of the electronic power conditioner (E PC) of the travelling wave tube improving the EMC and reducing the mou nting area. The TWTs may be connected to the LCAMPs either directly or via a hybrid network for redundant or combined mode configurations.