Design and investigation of 12–50 Ohm tunable microstrip impedance transforming filter

In practical applications, compensating the changes in transistors input and output impedances due to environmental and thermal effects requires tunable matching networks. Having tunability property is critical in manufacturing as well, since manufacturing errors may be compensated by post-production tuning. In this paper, a 12–50 Ω impedance transforming filter over 800–2200 MHz frequency band is chosen and a broadband tunable matching network has been designed using Real Frequency Direct Computational Technique.