# T Matching

Fig.1. T-match circuit

A T-matching circuit can be used either for upward or downward matching. It is a dual of -match circuit. A basic T-match circuit is shown in Fig.1. Like in -match, T-match also allows to set impedance transformation ratio and Q-factor/matching BW of circuit independently.

(1)

By series-to-parallel transformation as shown in From Fig.3,

(2)

Fig.2. T-match circuit decomposed to two L-match circuits

(3)

(4)

Fig.3. T-match circuit after series to parallel transformation

Rearranging Eq.(3)

(5)

The total of the circuit is given by

(6)

At resonant frequency, and . Therefore,

(7)

This equation can be used as a sanity check for the calculated T-matching network element values.

DESIGN PROCEDURE

1. Find using Eq.(6) from given , and .
2. Calculate and using Eq.(5)
3. Find and using Eq.(1)
4. Find and using Eq.(2)