Flamingo+ FM - High Attenuation Broadcast FM Bandstop Filter v2 for Software Defined Radio (SDR) Applications

Flamingo+ FM (Flamingo FM v2) is a high-quality, high-attenuation bandstop filter designed for software defined radio (SDR) applications where broadcast FM transmissions are especially strong and/or problematic. This generally means urban areas, but can include rural areas where there are nearby high wattage FM transmitters. For other locations, we strongly recommend considering the original Flamingo FM v1, which has lower attenuation of the stopband but also lower attenuation of the nearby VHF airband (108-137MHz) and otherwise similar characteristics and out-of-band performance.

Broadcast FM signals can be particularly problematic compared to other signal types due to their amplitude (transmit power) and proximity to residential areas. These signals can overload the front end of an SDR, causing imaging and a number of other issues.

We designed Flamingo+ FM to provide sufficient attenuation for broadcast FM frequencies (>60dB typical average & >70dB typical maximum stopband attenuation) while ensuring adjacent bands, such as the important VHF airband (108-137MHz) are minimally affected. The -3dB rolloff of the filter is 75MHz and 120MHz, and -10dB rolloff of the filter is 80MHz and 116MHz.

This probably sounds more complicated than it actually is. For more information, and to determine whether it is suitable for your particular application, we'd highly recommend reviewing the full graphs and performance characteristics available in the downloads tab of the product page. It will be a lot easier to digest the information.

The minimal (<0.25dB) out-of-band insertion loss means the filter can stay in place for most any application. The maximum recommended signal level is +18dBm (5Vp-p), so there is no issue using the filter if you have higher power requirements than most do. As a true bandstop filter, you are able to pass-through DC (bias power) when it is required. DC current handling is 250mA (min).

Flamingo+ FM has its front end protected by an ESD diode meant for RF applications. Designed and manufactured by Nooelec in North America, with a full 2-year product warranty.