mike_bihan
Full Member level 3
In recent research or application, a lot of RF works had been done in CMOS Logic process.
It is really cool to enjoy the low cost of fabrication. However, some obstacles seemed to be unable to overcome.
1. how to fab accurate 50 ohm matching resistor in amplifier ?
Since every RF system had to be matched to each other, the accurate resistor will be necessary. Also, the resistor load of the amplifier, such as limiting amplifier, will have to be accurate to obtain stable DC operation point.
But the process tolerance is too large.( >15% ) How to resolve this problem ? My personal idea will be use multi-parallel resistors to reduce the interface resistor and make the ultimate resistor value more controllable.
2. when there is no 'clean' ground in the circuit, how can we improve it?
My personal idea will be add more substrate tap to make the voltage potential on the whole chip to be closer. However, this will inject more noise into the substrate, does any people
had better idea?
best regards.
Bi Han
It is really cool to enjoy the low cost of fabrication. However, some obstacles seemed to be unable to overcome.
1. how to fab accurate 50 ohm matching resistor in amplifier ?
Since every RF system had to be matched to each other, the accurate resistor will be necessary. Also, the resistor load of the amplifier, such as limiting amplifier, will have to be accurate to obtain stable DC operation point.
But the process tolerance is too large.( >15% ) How to resolve this problem ? My personal idea will be use multi-parallel resistors to reduce the interface resistor and make the ultimate resistor value more controllable.
2. when there is no 'clean' ground in the circuit, how can we improve it?
My personal idea will be add more substrate tap to make the voltage potential on the whole chip to be closer. However, this will inject more noise into the substrate, does any people
had better idea?
best regards.
Bi Han