TW201929424A - Improved radio frequency amplifier structure including a transistor, a transformer and a variable capacitor - Google Patents

Abstract

This invention provides an improved radio frequency amplifier structure. The structure includes a transistor, a transformer and a variable capacitor; the transistor is provided with an input end, an output end and a control end; the transformer is provided with 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; 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 variable capacitor is matched with the transformer, so that the aims of reducing noise and improving the output impedance are achieved.

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 container is connected in parallel with the second coil conductor to adjust the matching value between the variable container and the transformer, thereby reducing noise and improving output impedance.

100‧‧‧RF amplifier

M‧‧‧O crystal

C _tune ‧‧‧Variable Capacitor

C _pad ‧‧‧pad capacitance

C _bypass ‧‧‧Shut capacitor

V _in ‧‧‧ input

V _out ‧‧‧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.

1 is a schematic diagram of a structure of an RF amplifier. As shown, the RF amplifier 100 includes a transistor M, a transformer, and a variable capacitor C _tune including a first coil conductor N1 and a second coil. The conductor N2, the first coil conductor N1 and the second coil conductor N2 are magnetically connected. The RF amplifier 100 further includes a transistor M, an inductor L and a parallel capacitor C _bypass . The crystal M has an input terminal V _in and an output. Terminal V _out and a control terminal.

The transistor M has an input terminal V _in , an output terminal V _out and a control terminal. In a specific implementation, the transistor M is an MOS transistor, and a source capacitor (input terminal) V _{in is} connected to a pad capacitor ( Pad capacitance) C _pad , 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 perform the gain value. Adjusting, the magnetic flux of the integrated circuit is changed through the first coil conductor N1. Because the impedance and the magnetic flux change, the second coil conductor N2 changes, thereby achieving the purpose of adjusting the operating frequency and reducing noise.

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 (5)

An improved structure of a radio frequency amplifier, the structure comprising: a transistor having an input end, an output end and a control end; a transformer having a first coil conductor and a second coil conductor, the first coil The conductor is magnetically coupled to the second coil conductor, the second coil conductor is electrically connected to the control end, the first coil conductor is electrically connected to the input end, and a variable capacitor is connected in parallel with the second coil conductor. The improved structure of the radio frequency amplifier according to claim 1, wherein the signal output end and a signal input end are electrically connected to the input end of the transistor, and the signal output end is electrically Connect the output of the transistor. The improved RF amplifier structure as described in claim 2, further comprising: an inductor electrically connected to the signal input end and the transistor input end. The improved RF amplifier structure as described in claim 3, further comprising: a substrate capacitor electrically connected to the signal input end. The RF amplifier structure improvement according to claim 1, further comprising: a bypass capacitor electrically connected to the second coil conductor.