Equivalent inlay circuit

AN2866

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Equivalent inlay circuit

The schematic shown in Figure 3 is but a first approach to the problem because it does not

take into account the connection between the chip and the antenna. The assembly phase of

the chip onto the antenna may lead to the introduction of parasitic elements. These parasitic

elements are symbolized by two resistances and a capacitance as shown in Figure 4 and

Figure 5.

The equivalent circuit of the antenna may include either a series (see Figure 4) or a parallel

(see Figure 5) resistance.

Figure 4.

Equivalent circuit of a chip, its antenna (modeled with a series

resistance) and connections

Figure 5.

Equivalent circuit of a chip, its antenna (modeled with a parallel

resistance) and connections

The symbols in Figure 4 and Figure 5 correspond to:

the antenna

the antenna

Antenna coil inductance

ai15805

A

B

Chip

Antenna

Connection

ai15841

A

B

Chip

Antenna

Connection