Hello Everyone!

Thanks to all who have been interested in our project. It is important for us to see people’s attention and feedfback. There is a motivation for further development.

Now we have RF SAW-filter in signal chain. But it does not cover the entire band of all GNSS systems. Current frequency response is below.

Not only the quality of the product, but also the possibility of reducing per unit costs has importance for us. Our goal is to replace expensive components and improve technical characteristics.

To date, we have been able to develop a passive filter to replace the SAW-filter in the input circuit.

We have tested the filter and obtained the following measurement:

• Bandwidth 1107 - 1388 MHz
• SWR across the bandwidth does not exceed 2
• Passband loss – 2.5 dB.

The filter is designed on passive components. This way the total cost of the filter is reduced greatly and the characteristics fully conform to the requirements for the tract.

The graphs show that the filter we designed provides lower passband losses. The SAW-filter provides a loss in passband of 3.5-4.5 dB. The parameter of the new filter does not exceed 2.5 dB.

The initial modeling has been carried out in the AWR program. The developed topology has been transferred to the PCB board and additional configuration has been performed to improve the capability. The next step is trace of the filter on the NUT2NT + on PCB board.

The new revision of NUT2NT+ board will cover full RNSS band and particularly GALILEO E6 band and will improve system Noise Floor at cost of slightly wider passband width.

Daria Ianovskaia

Amungo Navigation