Hi,
I've started a new project involving some 2.4Ghz transcievers I got as samples a few years ago - P/N: ML2724. I have a few nordic transcievers, but this is more a project of learning rather than practicality/cost.
The thing that makes these transcievers interesting/difficult is, they have a balanced RF TX, and a single ended RX side, both with odd impedances. The Tx has two pins, each at 12+j0, open collector outputs. The RX has 2.6-j2.6 input (that seems awfully low to me).
Thankfully I have two reference designs to help me work out whats going on, and whether I can trust the impedance figures given in the datasheet, both designs have full schematics, BOM and gerbers - which I guess I need to look out for transmission lines. As for the Tx, I'm just going straight off the ref design (I can actually get hold of the parts) with matching network -> balun (balanced to unbalanced) then into an antenna switch, no PA, just for short range testing.
But...can anyone help me with an impedance matching circuit for the RX side? The LNA they use is discontinued, and I would like to have a half decent match from a standard 50ohm input (which is what most modern LNA's are internally matched to) to the odd 2.6-J2.6. I realise impedance matching isn't as crucial as many think, but considering I have NO RF testing equipment, I cannot effectively measure what I have made - so I'm trying to get it right first time. This is NOT for 'perfection', purely to increases the chances of it actually working to some degree.
I've been up to my eyeballs in smith charts for the past few days, and despite lots of handy software tools avaliable, experience counts far more Frankly, I am out of my depth.
Blueteeth
I've started a new project involving some 2.4Ghz transcievers I got as samples a few years ago - P/N: ML2724. I have a few nordic transcievers, but this is more a project of learning rather than practicality/cost.
The thing that makes these transcievers interesting/difficult is, they have a balanced RF TX, and a single ended RX side, both with odd impedances. The Tx has two pins, each at 12+j0, open collector outputs. The RX has 2.6-j2.6 input (that seems awfully low to me).
Thankfully I have two reference designs to help me work out whats going on, and whether I can trust the impedance figures given in the datasheet, both designs have full schematics, BOM and gerbers - which I guess I need to look out for transmission lines. As for the Tx, I'm just going straight off the ref design (I can actually get hold of the parts) with matching network -> balun (balanced to unbalanced) then into an antenna switch, no PA, just for short range testing.
But...can anyone help me with an impedance matching circuit for the RX side? The LNA they use is discontinued, and I would like to have a half decent match from a standard 50ohm input (which is what most modern LNA's are internally matched to) to the odd 2.6-J2.6. I realise impedance matching isn't as crucial as many think, but considering I have NO RF testing equipment, I cannot effectively measure what I have made - so I'm trying to get it right first time. This is NOT for 'perfection', purely to increases the chances of it actually working to some degree.
I've been up to my eyeballs in smith charts for the past few days, and despite lots of handy software tools avaliable, experience counts far more Frankly, I am out of my depth.
Blueteeth
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