What is a 455 kHz QUAD coil?
what is 455khz QUAD COIL in FM receiver design with ICs like as MC13135?
Do you have any datasheet link from TOKO or others?
It is a quadrature coil, meaning : this coild produces a phase shift of 90 degrees at the specified frequency.
Check the datasheet of the IC. Similar ICs are T7088 etc.
how at 455khz a coil can produce 90 degree phase shift?
can we use normal smd inductor instead of them?
why they are high Q(50 ,60)?
The phase shift is produced by the reactive load on the coil (RC network). This is the usual way FM was demodulated before PLL ICs became available. The quad coil did not work as well as the PLL at low SNRs.
You can use any coil of suitable inductance and required Q. The Inductance (along with other reactive elements, like capacitances in the transistor, though marginal at 455 KHz) decides the phase shift and Q decides the slope.
Like earlier stated by flautulent, this is one way to demodulate FM.
Suggest search for "FM demodulation" quadrature on Google.