u/Cute_Wallaby6361

Hi,

With regard to Meshtastic Receivers being used at 915MHz, I am aware that when being used close to Cell Towers in the USA, de-sensing of the receiver can become a regular occurrence. Usually,most Meshtastic receivers have a very wide rf front-end and it is relatively easy for unwanted 5G/LTE signals (or even WIFI,etc) to overdrive the Receiver LNA into compression such that gain drops,unwanted intermods and harmonics are generated and the receiver sensitivity at 915MHz can then reduce dramatically. This means that important data does not get received by the Meshtastic Receiver.

I have developed a 915MHz saw filter pcba,size 10mm by 12mm and 1.2mm high and the board includes the rf connectors (u.fl).This filter board works perfect up to a receiver input level of +10dbm with a zero-drift reliability.The performance of the rf bandpass filter with regard to In-Band Insertion Loss and Out-of-Band Rejection is exceptional.This filter will safely attenuate unwanted Blocking Signals due to 4G,5G,LTE,WIFI,Bluetooth,Amateur Radio,Pagers,Zigbee and Public Safety bands below and above 915MHz such that the LNA never becomes overloaded by unwanted blocking signals so the important Meshtastic Receive data always gets received correctly.This filter provides excellent rejection from 100MHz through to 6.1GHz such that all unwanted blocking signals at the input of the Receiver Antenna terminal are greatly attenuated.

If you are interested, I can provide photos of the pcba and VNA plots of the filter performance close in at 915MHz and also wider band over the range (100MHz-6.1GHz). I can also provide S2P files across the two bands mentioned such that you can look at the performance of the filter in RF Design Software such as ADS,Microwave Office or free software such as RFSIM99 or ATYUNE.

The main target of this rf bandpass filter was to provide a solution to Unwanted Receiver Blocking problems as a re-fit to a Meshtastic Receiver.The pcba weighs less than 1 gram (it was too light for my electronics scale to measure a value,just showed 0.00 grams!!!) and can easily fit inside most sort of enclosures.I would be interested to hear feedback regarding your point of view on whether lost receive data due to LTE/5G blocking or other blockers is a real problem and if yes do you think my hardware solution might help?

Hi,

With regard to Receivers on the RTL-SDR being used at 915MHz, I am aware that de-sensing of the receiver can become a regular occurrence especially when the RTL-SDR is used close to 5G/LTE Cell Towers in the USA. The RTL-SDR receiver has a very wide rf front-end and it is relatively easy for unwanted 5G/LTE signals to overdrive the Receiver LNA into compression such that gain drops,unwanted intermods and harmonics are generated and the receiver sensitivity at 915MHz can reduce dramatically. This means that important receive data does not get received by the RTL-SDR due to unwanted very large signal level blocking.

I have developed a 915MHz saw filter pcba,size 10mm by 12mm and 1.2mm high and the board includes the rf connectors (u.fl).This filter board works perfect up to a receiver input level of +10dbm with a zero-drift reliability.The performance of the rf bandpass filter with regard to In-Band Insertion Loss and Out-of-Band Rejection is exceptional.This filter will safely attenuate the 5G/LTE bands just below and above 915MHz such that the LNA never becomes overloaded so the important receive data always gets received correctly.This filter provides excellent rejection from 100MHz through to 6.1GHz such that all unwanted blocking signals at the input of the Receiver Antenna terminal are greatly attenuated.

If you are interested, I can provide photos of the pcba and VNA plots of the filter performance close in at 915MHz and also wider band over the range (100MHz-6.1GHz). I can also provide S2P files across the two bands mentioned such that you can look at the performance of the filter in RF Design Software such as ADS,Microwave Office or free software such as RFSIM99 or ATYUNE.

The main target of this rf bandpass filter was to provide a solution to Unwanted Receiver Blocking problems as a re-fit to the RTL-SDR.The pcba weighs less than 1 gram (it was too light for my electronics scale to measure a value,just showed 0.00 grams!!!) and can easily fit inside most sort of enclosures including the RTL-SDR enclosure.

Hi-With regard to Drone Receivers being used at 915MHz, I am aware that when flying, de-sensing of the receiver can become a regular occurrence especially when Drone devices are flying close to 5G/LTE Cell Towers. Usually,most receivers have a very wide rf front-end and it is relatively easy for unwanted 5G/LTE signals to overdrive the receiver LNA into compression such that gain drops,unwanted intermods and harmonics are generated and the receiver sensitivity at 915MHz can reduce dramatically. This means that important data does not get received by the Drone,meaning you have lost control of the Drone.

I have developed a 915MHz saw filter pcba,size 10mm by 12mm and 1.2mm high and the board includes the rf connectors (u.fl).This filter board works perfect up to an receiver input level of +10dbm with a zero-drift reliability.The performance of the rf bandpass filter with regard to In-Band Insertion Loss and Out-of-Band Rejection is exceptional.This filter will safely attenuate the 5G/LTE bands just below and above 915MHz such that the LNA never becomes overloaded so the important control data always gets received correctly.This filter provides excellent rejection from 100MHz through to 6.1GHz such that all unwanted blocking signals at the input of the Receiver Antenna terminal are greatly attenuated.

If anyone is interested, I can provide photos of the pcba and VNA plots of the filter performance close in at 915MHz and also wider band over the range (100MHz-6.1GHz). I can also provide S2P files across the two bands mentioned such that you can look at the performance of the filter in RF Design Software such as ADS,Microwave Office or free software such as RFSIM99 or ATYUNE.

The main target of this rf bandpass filter was to provide a solution to Unwanted Receiver Blocking problems as a re-fit to the Receiver channel.The pcba weighs less than 1 gram (it was too light for my electronics scale to measure a value,just showed 0.00 grams!!!) and can easily fit inside most sort of enclosures.I would be interested to hear feedback regarding everyone's point of view on whether lost control of a Drone due to LTE/5G blocking is a real problem and if yes do you think my hardware solution might help?

UK

Hi-With regard to Drone Receivers being used at 915MHz, I am aware that when flying, de-sensing of the receiver can become a regular occurrence especially when Drone devices are flying close to 5G/LTE Cell Towers. Usually,most receivers have a very wide rf front-end and it is relatively easy for unwanted 5G/LTE signals to overdrive the receiver LNA into compression such that gain drops,unwanted intermods and harmonics are generated and the receiver sensitivity at 915MHz can reduce dramatically. This means that important data does not get received by the Drone,meaning you have lost control of the Drone.

I have developed a 915MHz saw filter pcba,size 10mm by 12mm and 1.2mm high and the board includes the rf connectors (u.fl).This filter board works perfect up to an receiver input level of +10dbm with a zero-drift reliability.The performance of the rf bandpass filter with regard to In-Band Insertion Loss and Out-of-Band Rejection is exceptional.This filter will safely attenuate the 5G/LTE bands just below and above 915MHz such that the LNA never becomes overloaded so the important control data always gets received correctly.This filter provides excellent rejection from 100MHz through to 6.1GHz such that all unwanted blocking signals at the input of the Receiver Antenna terminal are greatly attenuated.

If anyone is interested, I can provide photos of the pcba and VNA plots of the filter performance close in at 915MHz and also wider band over the range (100MHz-6.1GHz). I can also provide S2P files across the two bands mentioned such that you can look at the performance of the filter in RF Design Software such as ADS,Microwave Office or free software such as RFSIM99 or ATYUNE.

The main target of this rf bandpass filter was to provide a solution to Drone Unwanted Receiver Blocking problems as a re-fit to the Receiver channel.The pcba weighs less than 1 gram (it was too light for my electronics scale to measure a value,just showed 0.00 grams!!!) and can easily fit inside most sort of enclosures.I would be interested to hear feedback regarding everyone's point of view on whether lost control of a Drone due to LTE/5G blocking is a real problem and if yes do you think my hardware solution might help?