315MHz + 433MHz Dual band RF receiver circuit

Thread Starter

ehabawni

Joined Dec 7, 2011
8
Hey,,
I need a chip or circuit that can be work with 315Mhz and 433Mhz bands at the sametime, all the chips that i have found so far can be only configured with one band (e.g. 315Mhz , ..etc). in my application i need to be able to communicate with some sensors that work in one of the mentioned bands.
  • is there any chip available which works on both bands ?
  • is it possible to have two receivers/ transmitters with different bands on the same circuit board? if yes, how to make the proper layout?
    if No, Any suggestions ?
 

Papabravo

Joined Feb 24, 2006
18,804
Hey,,
I need a chip or circuit that can be work with 315Mhz and 433Mhz bands at the sametime, all the chips that i have found so far can be only configured with one band (e.g. 315Mhz , ..etc). in my application i need to be able to communicate with some sensors that work in one of the mentioned bands.
  • is there any chip available which works on both bands ?
  • is it possible to have two receivers/ transmitters with different bands on the same circuit board? if yes, how to make the proper layout?
    if No, Any suggestions ?
I don't know about individual chips, but it is possible to have transmitters and receivers on the same board. There are some basic ground rules you have to observe, which may or may not affect the usability of the device:
  1. You cannot have both transmitters on at the same time.
  2. Both receivers must be disconnected, if either transmitter is on.
  3. Each channel must have a bandpass filter for it's frequency and a notch filter for the other frequency.
  4. RF layout techniques are nearly impossible for amateurs to learn and apply.
  5. The test equipment for checking such things out costs more than the average house.
My advice to you is to hire somebody who knows what they are doing (RF layout) in this regard. I'm retired -- so it won't be me.
 
Last edited:

sghioto

Joined Dec 31, 2017
3,315
I don't see a problem using two receiver modules on the same PC board. The frequency difference should allow both transmitters to be on at the same time if need be. Assuming you are talking about using those inexpensive RX/TX modules like the HC-12 or similar.
SG
 

Papabravo

Joined Feb 24, 2006
18,804
I don't see a problem using two receiver modules on the same PC board. The frequency difference should allow both transmitters to be on at the same time if need be. Assuming you are talking about using those inexpensive RX/TX modules like the HC-12 or similar.
SG
A nearby RF source does not need to be close to a receivers design frequency to desensitize that receiver, rendering it essentially deaf.
 

sghioto

Joined Dec 31, 2017
3,315
It will depend on the Tx power, distance between modules and the selectivity of the Rx modules in general. In this situation I believe the sensors /Tx modules will located remotely. I have a system that receives on 418mhz and had no issues with a 433 mhz Tx module 15 feet away at 50mw. Specifically my receiver used the Linx RMX-418-LR chip.
SG
 
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