Provided is a radio frequency (RF) amplifier. The RF amplifier includes an amplification circuit amplifying an RF signal, a bias voltage generation circuit supplying a bias voltage of the amplification circuit, and a first bias resistor connected between the amplification circuit ad the bias voltage generation circuit, and having a predetermined resistance allowing the bias voltage to be affected by the RF signal.
1. A radio frequency (RF) amplifier, comprising:
an amplification circuit amplifying an RF signal;
a bias voltage generation circuit supplying a bias voltage of the amplification circuit;
a first bias resistor connected between the amplification circuit and the bias voltage generation circuit, and having a predetermined resistance allowing the bias voltage to be affected by the RF signal,
wherein the bias voltage generation circuit comprises:
a first bias transistor comprising a drain and a gate commonly connected to one end of the first bias resistor, and a source connected to a ground terminal;
a second bias transistor comprising a drain connected to a reference voltage terminal, and a source connected to the one end of the first bias resistor; and
a load connected between a gate of the second bias transistor and the ground terminal.
2. The RF amplifier of claim 1 , wherein the load comprises:
a third bias transistor comprising a drain and a gate commonly connected to the gate of the second bias transistor;
a fourth bias transistor comprising a drain and a gate commonly connected to a source of the third bias transistor, and a source connected to the ground terminal; and
a second bias resistor connected between the reference voltage terminal and the drain of the third bias transistor.
3. The RF amplifier of claim 2 , wherein the load is connected between the gate of the second bias transistor and the ground terminal, and further comprises a bias capacitor functioning to reduce impedance at a corresponding frequency.
4. A radio frequency (RF) amplifier, comprising:
an amplification circuit amplifying an RF signal, the amplification circuit including:
a first transistor comprising a gate configured to receive the bias voltage and the RF signal, and a source connected to a ground terminal, and
a second transistor comprising a drain connected to a power supply voltage terminal, a gate configured to receive a gate voltage, and a source connected to a drain of the first transistor;
a bias voltage generation circuit supplying a bias voltage of the amplification circuit, the bias voltage generation circuit including:
a first bias transistor comprising a drain and a gate commonly connected to one end of a bias resistor, and a source connected to a ground terminal,
a second bias transistor comprising a drain connected to a reference voltage terminal, and a source connected to the one end of the bias resistor, and
a load connected between a gate of the second bias transistor and the ground terminal; and
wherein the bias resistor is connected between the amplification circuit and the bias voltage generation circuit, and having a predetermined resistance allowing the bias voltage to be affected by the RF signal,
wherein the bias voltage allows the first transistor to operate in a saturation region, and the gate voltage allows the second transistor to operate in a saturation region.
5. The RF amplifier of claim 4 , wherein the load is connected between the gate of the second bias transistor and the ground terminal, and further comprises a bias capacitor functioning to reduce impedance at a corresponding frequency.