# Tapped Inductor Matching 1 comment

## Tapped Inductor Matching

The impedance transformation ratio and Q-factor/matching bandwidth of the circuit can be set independently. A tapped inductor matching circuit is shown in Fig.1

Fig.1 Tapped inductor matching circuit

From Fig.1, Q-factor of branch is given by,

(1)

At resonant frequency the circuit is redrawn, by parallel-to-series transformation, as shown in Fig.1(b).

(2)

(3)

(4)

(5)

From Eq.(5) and Eq(1)

(6)

If ,

(7)

Fig.1(c) illustrates the parallel R-L-C resonant circuit form of tapped inductor matching circuit.

(8)

(9)

When and , using Eq.(7)

(10)

When Q-factors are large, from Eq.(7), we can conclude that the impedance transformation ratio is a function of inductors tap ratio. Hence the name tapped inductor matching for this matching circuit.

## Design Procedure

1. Calculate the value of using Eq.(9).

2. Calculate using Eq.(1)

3. Find the value of C using Eq.(8)

4. Calculate using Eq.(6)

This site uses Akismet to reduce spam. Learn how your comment data is processed.