Sevotharte
Newbie level 1
Hello,
I have a problem with design antenna to rfid tag used in ID-1 card. I design a rectangular coil for Mifare Classic. I need a information where i can find a resistance of Mifare chip?
I took to my calculation a Resistance a chip: 300 ohm, but i dont know if this is a true value. This is a calue that I received for my coil:
Rectangular coil:
- 4 turn,
- space between path: 0.5 mm,
- width of path: 0.5 mm,
- width of coil: 38mm,
- length: 72 mm,
- resistance of chip: 300 Ohm,
- voltage of chip: 5V (is this ok? )
- capacitance of chip: 17 pF,
Results for copper coil:
- Inductance: 1,673 uH,
- Capacitance (resonance) - 82,342 pF,
- Resistance of antenna: 4,076 Ohm,
- Q - 34,955 ,
- Minimal electromagnetic field strength: 1,425 A/m
I have internal capacitance of chip: 17pF. My resonance capacitance is 82.342 pF. What should I do? Fix a geometry of chip to get a capacitance near 17pF? What about a parasitic capacitance of coil? How can i calculate this?
And what about impedance? I think that should be a 50 Ohm. How can i tune to this impedance?
Sorry for my question but I am a newbie. Someone has a tutorial to design this antenna in sonnet? I think that will help me to improve design process.
Thank for your advice
W.A.
I have a problem with design antenna to rfid tag used in ID-1 card. I design a rectangular coil for Mifare Classic. I need a information where i can find a resistance of Mifare chip?
I took to my calculation a Resistance a chip: 300 ohm, but i dont know if this is a true value. This is a calue that I received for my coil:
Rectangular coil:
- 4 turn,
- space between path: 0.5 mm,
- width of path: 0.5 mm,
- width of coil: 38mm,
- length: 72 mm,
- resistance of chip: 300 Ohm,
- voltage of chip: 5V (is this ok? )
- capacitance of chip: 17 pF,
Results for copper coil:
- Inductance: 1,673 uH,
- Capacitance (resonance) - 82,342 pF,
- Resistance of antenna: 4,076 Ohm,
- Q - 34,955 ,
- Minimal electromagnetic field strength: 1,425 A/m
I have internal capacitance of chip: 17pF. My resonance capacitance is 82.342 pF. What should I do? Fix a geometry of chip to get a capacitance near 17pF? What about a parasitic capacitance of coil? How can i calculate this?
And what about impedance? I think that should be a 50 Ohm. How can i tune to this impedance?
Sorry for my question but I am a newbie. Someone has a tutorial to design this antenna in sonnet? I think that will help me to improve design process.
Thank for your advice
W.A.