Patent ID: 6252460
Filing Date: 2001-06-26
Classification: H03F

Abstract:
An FET balun transformer for converting a single-ended signal received at an input terminal into differential signals and then outputting the differential signals through first and second output terminals, respectively, the transformer comprising:a first FET, the drain of which is connected to a positive power supply and the first output terminal, and the gate of which is connected to the input terminal;a second FET, the drain of which is connected to the positive power supply and the second output terminal;an AC grounded capacitor, one terminal of which is connected to the gate of the second FET and the other terminal of which is grounded;a third FET, the drain of which is connected to the sources of the first and second FETs and the gate of which is grounded; anda series-resonant circuit, which is disposed between the first and second output terminals and causes a series resonance at a frequency twice higher than that of the single-ended signal received at the input terminal.