Ka-band low noise amplifier sub-system module for communication satellite payload

This paper describes the design and implementation of a Ka-Band Low Noise Amplifier (LNA) Sub-System Module for communication satellite payload. A Ka-Band monolithic low noise amplifier has been designed using a metamorphic HEMT with the gate length of 0.13um. A key challenge for Ka-Band LNA design is low noise figure with the high gain. This module contains the LNA MMIC, BPF, WA MMIC and MPA MMIC. All the MMIC are dropped into a hermetic box which has been used as a drop-in type. The MPA MMIC is used for the high P1dB requirement. This paper describes the LNA MMIC design, Mechanical box design and the in-line waveguide to microstrip Transition design. The box design is very critical in ka-Band and the cavity mode-suppression technique is used for the feedback rejection and suppression of cavity resonance. 2.8 dB noise figure and more than 40-dB associated gain have been achieved at 29.5-30.0 GHz Ka-Band frequency. This measurement result includes the input connector loss which is 0.4dB.