Countries around the globe are implementing a more accurate way of tracking aircraft using the Automatic Dependent Surveillance-Broadcast (ADS-B) and eventually replacing radar as a primary surveillance method for Air Traffic Control (ATC). High performance, improved safety, reduced radio frequency (RF) pollution, cost-efficient are some of its notable features. The MAX2691 low-noise amplifier (LNA) can be a good fit for ADS-B application. The device achieves high gain, sub 1dB noise, and excellent linearity. This application note provides details on adapting it for use at 1090MHz.
The MAX2691 LNA is designed for GPS L2 (1227.6MHz) applications. However, the MAX2691 LNA can also be tuned to 1090MHz by changing external matching components. This application note provides details for those external matching components and the performance of the tuned circuit.
Why Use the MAX2691?
Over time, communication standards change, and frequency spectrum is reallocated. However, many existing ICs can be adapted to evolve with these changes. The advantages include the following:
- Time to production is reduced since you are using existing components requiring no supplier development time.
- Cost is lower since currently mass-produced items are used.
- Quality is improved since products are used that have a proven track record.
|RF Input Return Loss||13.80dB|
|RF Output Return Loss||12.20dB|
|Reference Designator||On Board||New Value|
|L1||8.2nH Inductor||12nH Inductor|
|C13||100pF Capacitor||8.2nH Inductor|
|*Cut RF trace between RFOUT SMA and C8 and place 100pF|