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