Communities

Writing
Writing
Codidact Meta
Codidact Meta
The Great Outdoors
The Great Outdoors
Photography & Video
Photography & Video
Scientific Speculation
Scientific Speculation
Cooking
Cooking
Electrical Engineering
Electrical Engineering
Judaism
Judaism
Languages & Linguistics
Languages & Linguistics
Software Development
Software Development
Mathematics
Mathematics
Christianity
Christianity
Code Golf
Code Golf
Music
Music
Physics
Physics
Linux Systems
Linux Systems
Power Users
Power Users
Tabletop RPGs
Tabletop RPGs
Community Proposals
Community Proposals
tag:snake search within a tag
answers:0 unanswered questions
user:xxxx search by author id
score:0.5 posts with 0.5+ score
"snake oil" exact phrase
votes:4 posts with 4+ votes
created:<1w created < 1 week ago
post_type:xxxx type of post
Search help
Notifications
Mark all as read See all your notifications »
Q&A

Post History

71%
+3 −0
Q&A Power amplifier for remote controller

#1 before anything else is to do your homework. The Nordic semi web site says: "nRF24 Series Not recommended for new designs". That means forget about using this part! They are phasing it out of pr...

posted 1y ago by Lundin‭  ·  edited 1y ago by Lundin‭

Answer
#2: Post edited by user avatar Lundin‭ · 2022-09-07T07:28:03Z (over 1 year ago)
  • #1 before anything else is to do your homework. The Nordic semi [web site](https://www.nordicsemi.com/products/nrf24-series) says: "nRF24 Series Not recommended for new designs". That means **_forget about using this part!_** They are phasing it out of production and it will probably go EOL within a couple of years. Also be careful not to use some silicon vendor who has a habit to discontinue their whole product line every second year; I have never used Nordic so I have no experience about them in that regard.
  • Modern RFIC always come with an internal PA and it's common that the same manufacturer has a line of similar products but with a different PA. Some parts with +4dBm and some with +8dBm, so that's a different internal PA. And yes the whole point of having that is to drive the antenna without an external PA.
  • You will have to match this internal PA with passives as per the manufacturer's recommendation. How to do that depends on a lot of things: is it just Tx, just Rx or semi duplex? Will there be a "direct tie" to the antenna or will there be an antenna switch between Tx and Rx paths? Will you use a SAW bandpass filter for Rx? Lowpass "Pi" filters are also common. And so on.
  • 50Ω is by far the most common industry standard.
  • How to calculate your expected range is no trivial thing. The most important aspects tend to be receiver selectivity and sensitivity. And of course Tx output power, which depends on the PA + matching, how much losses you have in the Tx path and how well the antenna works. But also about regulations on the band you intend to use. The 2.4GHz is pretty much the Wild West so you probably don't have to worry too much about that. You have to be very concerned about other interfering radios however. Also there are product standards for Bluetooth, Zigbee etc that will state output powers.
  • 20 meters open sight might be possible even at 0 dBm, though it would take a good design to keep up 20 meters reliably. And just don't expect 2.4GHz technology to work well through walls and similar.
  • #1 before anything else is to do your homework. The Nordic semi [web site](https://www.nordicsemi.com/products/nrf24-series) says: "nRF24 Series Not recommended for new designs". That means **_forget about using this part!_** They are phasing it out of production and it will probably go EOL within a couple of years. Also be careful not to use some silicon vendor who has a habit to discontinue their whole product line every second year; I have never used Nordic so I have no experience about them in that regard.
  • Also in general don't do electronics projects by first picking a part and then try to figure out what to use it for. Write a specification then after that track down suitable candidate parts that fulfil it. That way you automatically don't end up with something obsolete or otherwise unsuitable. Also in these days of massive logistics incompetence among the silicon vendors, it is very important to check that the part can actually be purchased in the real world as well. Even previously reliable vendors fail to deliver right now.
  • Modern RFIC always come with an internal PA and it's common that the same manufacturer has a line of similar products but with a different PA. Some parts with +4dBm and some with +8dBm, so that's a different internal PA. And yes the whole point of having that is to drive the antenna without an external PA.
  • You will have to match this internal PA with passives as per the manufacturer's recommendation. How to do that depends on a lot of things: is it just Tx, just Rx or semi duplex? Will there be a "direct tie" to the antenna or will there be an antenna switch between Tx and Rx paths? Will you use a SAW bandpass filter for Rx? Lowpass "Pi" filters are also common. And so on.
  • 50Ω is by far the most common industry standard.
  • How to calculate your expected range is no trivial thing. The most important aspects tend to be receiver selectivity and sensitivity. And of course Tx output power, which depends on the PA + matching, how much losses you have in the Tx path and how well the antenna works. But also about regulations on the band you intend to use. The 2.4GHz is pretty much the Wild West so you probably don't have to worry too much about that. You have to be very concerned about other interfering radios however. Also there are product standards for Bluetooth, Zigbee etc that will state output powers.
  • 20 meters open sight might be possible even at 0 dBm, though it would take a good design to keep up 20 meters reliably. And just don't expect 2.4GHz technology to work well through walls and similar.
#1: Initial revision by user avatar Lundin‭ · 2022-09-07T07:11:11Z (over 1 year ago)
#1 before anything else is to do your homework. The Nordic semi [web site](https://www.nordicsemi.com/products/nrf24-series) says: "nRF24 Series Not recommended for new designs". That means **_forget about using this part!_** They are phasing it out of production and it will probably go EOL within a couple of years. Also be careful not to use some silicon vendor who has a habit to discontinue their whole product line every second year; I have never used Nordic so I have no experience about them in that regard.

Modern RFIC always come with an internal PA and it's common that the same manufacturer has a line of similar products but with a different PA. Some parts with +4dBm and some with +8dBm, so that's a different internal PA. And yes the whole point of having that is to drive the antenna without an external PA. 

You will have to match this internal PA with passives as per the manufacturer's recommendation. How to do that depends on a lot of things: is it just Tx, just Rx or semi duplex? Will there be a "direct tie" to the antenna or will there be an antenna switch between Tx and Rx paths? Will you use a SAW bandpass filter for Rx? Lowpass "Pi" filters are also common. And so on.

50Ω is by far the most common industry standard.

How to calculate your expected range is no trivial thing. The most important aspects tend to be receiver selectivity and sensitivity. And of course Tx output power, which depends on the PA + matching, how much losses you have in the Tx path and how well the antenna works. But also about regulations on the band you intend to use. The 2.4GHz is pretty much the Wild West so you probably don't have to worry too much about that. You have to be very concerned about other interfering radios however. Also there are product standards for Bluetooth, Zigbee etc that will state output powers.

20 meters open sight might be possible even at 0 dBm, though it would take a good design to keep up 20 meters reliably. And just don't expect 2.4GHz technology to work well through walls and similar.