TWI656727B - RF amplifier structure improvement - Google Patents

Abstract

The invention provides an improved structure of a radio frequency amplifier, the structure comprising a transistor, a transformer and a variable capacitor, the transistor having an input end, an output end and a control end, the transformer having a first coil conductor And a second coil conductor, the first coil conductor is magnetically coupled to the second coil conductor, the second coil conductor is electrically connected to the control end, and the first coil conductor is electrically connected to the input end, the variable container is The second coil conductors are connected in parallel, and the variable container is matched with the transformer to reduce noise and improve output impedance.

Description

RF amplifier structure improvement

The present invention relates to a radio frequency amplifier structure, and more particularly to a multi-frequency amplifier structure improvement.

The integrated circuit often uses a radio frequency cascode as the output or input of the integrated circuit. In the case of using a radio frequency stacked amplifier, the noise generated by the integrated circuit is increased, but If the integrated circuit does not use the RF stack amplifier, although the output value of the low noise can be obtained, the integrated circuit cannot obtain the desired gain effect, so it is common to reduce the noise generation and add a conventional RF. Amplifier, this kind of setting method can suppress the generation of noise, but the operating frequency that can be used in the integrated circuit is limited, so how to provide a radio frequency amplifier that can reduce the noise without affecting the operating frequency used, It is also a relatively important research goal.

In view of the above disadvantages of the prior art, it is a primary object of the present invention to provide an improved RF amplifier structure that reduces broadband amplifier noise and improves output gain.

Another object of the present invention is to provide a system that can be applied to different frequencies. The rate of RF amplifier structure is improved.

In order to achieve the above object, the present invention provides an improved RF amplifier structure, the structure comprising a transistor, a transformer and a variable capacitor, the transistor having an input end, an output end and a control end, the transformer having a first coil conductor and a second coil conductor, the first coil conductor is magnetically coupled to the second coil conductor, the second coil conductor is electrically connected to the control end, and the first coil conductor is electrically connected to the input end, The variable capacitor is connected in parallel with the second coil conductor, and the matching value between the variable capacitor and the transformer is adjusted, thereby reducing noise and improving output impedance.

100‧‧‧RF amplifier

M‧‧‧O crystal

C _tune ‧‧‧Variable Capacitor

C _pad ‧‧‧pad capacitor

C _bypass ‧‧‧bypass capacitor

V _in ‧‧‧ signal input

V _out ‧‧‧ signal output

R _out ‧‧‧Output resistance

N1‧‧‧First coil conductor

N2‧‧‧second coil conductor

L‧‧‧Inductance

Figure 1 is a schematic diagram showing the structure of a radio frequency amplifier of the present invention.

The embodiments of the present invention are described by way of specific examples, and those skilled in the art can understand the other advantages and advantages of the present invention from the disclosure of the present disclosure.

Please refer to FIG. 1 , which is a schematic diagram of a structure of a radio frequency amplifier. As shown in the figure, the RF amplifier structure is composed of a signal input end, a signal output end and an RF amplifier. The RF amplifier 100 includes a transistor M and a a transformer and a variable capacitor C _tune comprising a first coil conductor N1 and a second coil conductor N2, the first coil conductor N1 and the second coil conductor N2 being magnetically connected, and the first coil conductor N1 and the second coil conductor N2 magnetically coupled, one end of the second coil conductor N2 is electrically connected to the control end of the transistor M of the radio frequency amplifier 100, one end of the first coil conductor N1 is electrically connected to the input end of the transistor M, and the other end of the first coil conductor N1 The RF amplifier 100 further includes a transistor M, an inductor L and a _bypass capacitor C _bypass . The transistor M has an input end, an output end and a control end.

The transistor M has an input terminal, an output terminal and a control terminal. In the specific implementation, the transistor M is a MOS transistor, and the signal input terminal V _in is electrically connected to the ground via a pad capacitor (C _pad ). The input end of the transistor is electrically connected to the inductor, and the inductor is electrically connected to the signal input terminal V _in , and the variable capacitor (C _tune ) is connected in parallel with the second coil conductor. Wherein, in the integrated circuit using the RF amplifier, the output resistance R _{out is} often confused due to the gain variation of the leakage end (output), so the variable capacitor C _tune is added to adjust the gain value, and the first coil is transmitted through the first coil. The conductor N1 changes the magnetic flux of the integrated circuit, because the change of the impedance and the magnetic flux causes the second coil conductor N2 to change, thereby achieving the purpose of adjusting the operating frequency and reducing the noise; the RF amplifier structure is improved, wherein the complex includes a signal output end And a signal input end, and the signal input end is electrically connected to the input end of the transistor M, the signal output end is electrically connected to the output end of the transistor M; and the signal is electrically connected The input end and the inductor of the transistor input end; a substrate capacitor electrically connected to the signal input end; and the other end of the second coil conductor is electrically connected to the ground end via a bypass capacitor (C _bypass ).

The above-described embodiments are merely illustrative of the features and functions of the present invention, and are not intended to limit the scope of the technical scope of the present invention. Modifications and variations of the above-described embodiments can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention should be as set forth in the scope of the claims described below.

Claims (3)

An RF amplifier structure is composed of a signal input terminal, a signal output terminal and an RF amplifier. The RF amplifier comprises a transistor, a transformer and a variable capacitor (C _tune ), wherein the RF amplifier comprises a first coil conductor of the transformer is magnetically coupled to a second coil conductor, and one end of the second coil conductor is electrically connected to a control end of the transistor, and one end of the first coil conductor is electrically connected to an input of the transistor The other end of the first coil conductor is electrically connected to a ground end, and an output end of the transistor is electrically connected to the signal output end, and the input end is electrically connected to the signal input end, wherein the transistor The input terminal is electrically connected to an inductor, and the inductor is electrically connected to the signal input end, and the variable capacitor (C _tune ) is connected in parallel with the second coil conductor and transmits the variable capacitor (C _tune ) to adjust the matching value of the transformer. The RF amplifier structure as described in claim 1 is characterized in that the signal input terminal is electrically connected to the ground via a pad capacitor (C _pad ). The RF amplifier structure is improved as described in claim 1, wherein the other end of the second coil conductor is electrically connected to the ground via a _bypass capacitor (C _bypass ).