| 摘要 |
Disclosed herein is a frequency tunable balun circuit including: first and second balanced terminals having balanced signals outputted therefrom or inputted thereto, the balanced signals having the same magnitude and a predetermined phase difference; a first transmission line maintaining a predetermined phase difference between the first and second balanced terminals; a first inductor connected in series between the first transmission line and an unbalanced terminal having an unbalanced signal inputted thereto or outputted therefrom; a first tunable capacitive device connected in series between the unbalanced terminal and the second balanced terminal; a second transmission line connected between the first inductor and the first varacter diode; and a second tunable capacitive device connected in parallel with the second transmission line. The frequency tunable balun circuit may easily tune an operating frequency, while improving impedance matching characteristics, signal transmission loss characteristics, and signal isolation characteristics. |
