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.
By series-to-parallel transformation as shown in From Fig.3,
The total of the circuit is given by
At resonant frequency, and . Therefore,
This equation can be used as a sanity check for the calculated T-matching network element values.
- Find using Eq.(6) from given , and .
- Calculate and using Eq.(5)
- Find and using Eq.(1)
- Find and using Eq.(2)