Frontier's LSQ2929A series of SMD Square Air Wound Coils come tape and reeled and facilitate placement by pick and place machines.
There are three main advantages to using a square air coil over a round air coil:
1) Overall length of a square coil will be shorter than that of a round coil, all other things being equal.
The radius of a round coil should equal 1/2 of the square coil’s side length to achieve the same inductance value. The inner section area of the square coil is
larger than that of the round coil, so the square coil’s number of turns (N) would be less than the round coil's for both coils to have the same inductance value.
2) A square coil’s C (capacitance) is lower than the C of a comparable round coil
3) The SRF value for a Square Coil is higher than a comparable round coil’s.
These factors make our LSQ Square Coil series ideal for high frequency operation when board real-estate is a concern.