Our SAW filter is really useful for LoRa deployments in urban environments. Why? Because 4G cellular towers in Europe and the UK, operating on 4G Band 20, work on frequencies as high as 862MHz. A high-gain antenna in an urban environment is going to pick up a lot of this RF energy, which your 868MHz LoRa device will need to filter out.
This filter is based on the RFMi SF2137E-2 filter module (datasheet), which introduces <2.2dB of loss between 867.5MHz and 870.5MHz. Outside of this range, the loss is >35dB - effectively muting other transmitters.
We've carefully designed this filter ourselves so it's impedance-matched at 50 ohms, with impedance controlled PCB manufacturing and quality components. We manufacture the assemblies in our workshop in East London. As a result, it performs better than most of the generic brands available on eBay.
On Helium nodes using high-gain antennas in urban areas, this can improve performance by 20-30%.
A hotspot in central London with a high-gain omni antenna showed significant improvement with a SAW filter
However, they're not for everyone and in less congested areas may introduce more loss than benefit. If you have any questions - as always, get in touch: we're happy to help.
Package contains (SMA or RP-SMA type depending on selection above)
- 1x 868MHz SAW filter, female connections on both ends
- 1x male-male rigid adapter
The filter has a similar response in the forward and reverse direction.
| S21 gain 867.5MHz - 870Mhz | > -2.2dB |
| S21 gain <867.5MHz and >870MHz | < -35dB |
| SWR | < 1.3 |
| Maximum input power | 13 dBm |
| Dimensions | 67 x 23mm, 6g |
| Connectors | SMA or RP-SMA female-female, includes 1x male-male adapter |
| Made in the United Kingdom |