The application provides a high-balance active
balun circuit, which comprises an RF
signal input port, a
signal input matching stage, a single-end to differential circuit and an output load stage, wherein the
signal input matching stage comprises a first
transistor, a second
transistor, an input
resistor and an input
inductor, and the single-end to differential circuit comprises a third
transistor, a fourth transistor, a fifth transistor and a
capacitor. The application does not need to waste
chip area to make a complex matching circuit. When the circuit is connected in the front stage, the circuit will not cause the problem that power cannot be transmitted due to high-frequency reflection. The phase adjusting
inductor is introduced into the circuit, and the frequency phase characteristics of the
inductor are used to compensate the
phase imbalance of the differential output. The
bandwidth extension technology is used in the load, so that the phase shifter maintains the flatness of the
gain in a wide frequency. Meanwhile, the two-stage
cascade transistor is used to realize the single-end input to differential output
gain stage architecture, which is more suitable for low-
voltage application.