The objective of the activity is to design, manufacture and test a Ka-band Gallium Nitride (GaN) Low Noise Amplifier suitable for integration in large feed arrays.
Targeted Improvements: Overall 1 dB improvement of the noise figure in comparison to the state of the art; Extension of the operating temperature range by at least 10 degrees Celsius.
In conventional Ka-band payloads, the low noise amplifier (LNA) is located at a distance from the antenna feed which translates into distribution network lossesthat degrade the overall noise figure of the receiver. Additionally, a bandpass filter has to be added in front of the LNAto protect it from unwanted signals.With the advent of gallium nitride (GaN) it is possible to design more robust LNA Monolithic Microwave Integrated Circuits (MMICs) which do not require a bandpass filter at the input, or require a less demanding input bandpassfilter, hence improving the noise figure of the receiver.
The filtering is then implemented later in the payload chain where it hasa limited effect on the noise figure. Furthermore, the use of GaN increases the resilience to strong interference.Additionally, the GaN MMIC is able to operate over a wider temperature range than current gallium arsenide (GaAs) based products. This helps tolocate the LNA closer to the antenna feed, hence further reducing the overall noise figure of the receiver. Mass saving can be achieved as waveguideruns can be replaced by coaxial cable after low noise amplification.
This activity will study and develop a Ka-band GaNlow noise amplifier (LNA) for use in telecommunication payloads. A reduced Engineering Model containing the following critical functions shall be manufactured and tested:
- Low noise amplifier block and substrates;
- Radio frequency package and transition;
- Supply and control board