Impedance matching by using RF transistors
I am trying to design a matching circuit that shows (1600+500j) ohm impedance from one of its port and 50 ohm impedance from the other port of it. I plan to use transistor in common collector configuration.But it seems difficult to have an impedance of such high value after 1 MHz. Has anyone designed such a matching network that uses transistors? The matching will be in the range of DC to 1 GHz.
Thnk you very much...
The question sounds confused. No real device has a frequency independent impedance of "1600+500j" over a range of "DC to 1 GHz".
Hi FvM,
you are actually right. The corrected question might be a matching circuit that shows on the order of 1K ohm real impedance and on the order of 100 ohm reactance from one of its port and 50 ohm impedance from the other port of it. I plan to use transistor in common collector configuration.But it seems difficult to have an impedance of such high value after 1 MHz.
A short comment on the problem formulation first.
The term impedance matching is usually referring to passive circuits. A transistor can act as a buffer amplifier with high (ideally infinite) input impedance.
While an impedance matching circuit tries to transform an available signal energy to a different impedance level with low loss, an ideal high input impedance amplifier tries to absorb as little signal energy as possible.
To allow a better understanding of the problem, can you describe the nature of the high source impedance?
Hi FvM,
I have a diode that has a big input impedance on the order of 1K real part and on the order of 100 ohm imaginary part. I want to make complex conjugate matching from the diode part and on the other part i want to have a 50 ohm impedance to connect baseband circuitry.I should desing a matching network that matches complex conjugately from the diode side and on the other side the circuit must show 50 ohm.Thats why i think of us,ng a transistor.Thnx in advance...