A device for solving the problem of solid-state power amplifier power traction caused by a coupled detection circuit

Abstract

An embodiment of the present invention provides a device for solving the problem of solid-state amplifier power traction caused by a coupled detection circuit, which is characterized by comprising: a first shielding cover, a second shielding cover, a printed circuit board, and a box body; wherein, the printed circuit board is placed in the box body; the second shielding cover covers the box body for shielding the printed circuit board; the printed circuit board includes a first area and a second area, and the first shielding cover is installed on the first area for shielding the circuit structure in the first area.

Description

Technical Field

[0001] The present invention belongs to the technical field of microwave radio frequency communication, and relates to a device for solving the problem of solid-state amplifier power traction caused by a coupling detection circuit. Background Art

[0002] In an automatic gain control circuit, the coupling detection circuit and the power amplifier circuit are naturally adjacent to each other in the circuit spatial layout. However, their respective attributes belong to small-signal and large-signal circuits, and also belong to low-frequency detection signals and microwave radio frequency signals, with large spatial radiation. Especially at some discontinuities of electromagnetic wave boundaries in the component cavity, high-order modes are easily excited. These interferences and crosstalk are superimposed on the detection voltage, resulting in unstable power output. The design requires sufficient spatial isolation between the two. In particular, the coupling detection circuit needs to be specially shielded, and at the same time, absorbing materials are used at sensitive parts to reduce the degree of electromagnetic interference.

[0003] The microwave power amplifier component is an important part of the radio frequency front-end circuit and plays a key role in medium- and long-distance wireless communication. The quality of its performance indicators directly affects the technical level of the communication system. At present, microwave power amplifiers are developing towards high speed, high linearity, high power, and high efficiency, which deteriorates the stability of the solid-state amplifier output power and the in-band fluctuation index. Designers have introduced an automatic gain control loop in the circuit design to meet the requirements. In this negative feedback circuit, the coupling detection circuit is a key link, which can accurately reflect the change of the output power, minimize the disturbance of external electromagnetic signals as much as possible, and determines the automatic adjustment sensitivity of the loop gain, power change, in-band fluctuation, etc. within a certain bandwidth. Therefore, the layout and structure optimization of the circuit in this area are important design links in the development of solid-state amplifiers and need to be considered key points. Summary of the Invention

[0004] In order to achieve the above object, the present invention provides a device for solving the problem of solid-state amplifier power traction caused by a coupling detection circuit. The device is characterized by including: a first shielding cover, a second shielding cover, a printed circuit board, and a box body; wherein, the printed circuit board is placed in the box body; the second shielding cover covers the box body for shielding the printed circuit board; the printed circuit board includes a first area and a second area, and the first shielding cover is installed on the first area for shielding the circuit structure in the first area.

[0005] The object of the present invention is to provide a device for solving the problem of solid-state amplifier power traction caused by a coupling detection circuit, which is characterized by including: a first shielding cover, a second shielding cover, a printed circuit board, and a box body; wherein, the printed circuit board is placed in the box body; the second shielding cover covers the box body for shielding the printed circuit board; the printed circuit board includes a first area and a second area, and the first shielding cover is installed on the first area for shielding the circuit structure in the first area.

[0006] Preferably, the first region is a coupling and detection circuit part, including a coupling sub-circuit, a detection sub-circuit, and a proportional amplification and operation sub-circuit, which realizes the conversion of radio frequency power into a continuously variable analog quantity for reflecting the magnitude of the output power.

[0007] Preferably, the distribution structures of the coupling sub-circuit, the detection sub-circuit, and the proportional amplification and operation sub-circuit are as follows: the coupling sub-circuit should arrange the line spacing according to the microstrip coupling simulation results, the detection elements in the detection sub-circuit are symmetrically and linearly distributed, and the proportional amplification and operation sub-circuit is compactly arranged immediately afterwards.

[0008] Preferably, the second region includes a first fixed amplifier module, a second fixed amplifier module, and a bridge circuit; wherein, the first fixed amplifier module and the second fixed amplifier module are vertically distributed in the left region of the bridge circuit.

[0009] Preferably, the first fixed amplifier module and the second fixed amplifier module are shielded by physical isolation.

[0010] Preferably, the first shielding cover is provided with a raised plate corresponding to the upper part of the bridge circuit in the second region for shielding the first fixed amplifier module and the second fixed amplifier module.

[0011] Preferably, the horizontal net distance between the box body and the first shielding cover and the internal and external components is kept at 1.6 mm or more, and the spatial distance from the surface of the printed circuit board is 0.2 mm, controlling this distance to be much less than one-twentieth of the electromagnetic wavelength length to ensure the convergence of the electromagnetic field.

[0012] Preferably, the materials of the first shielding cover and the second shielding cover are selected as brass, with a thickness of 0.3 mm and a height of 2.2 mm.

[0013] Advantages of the present invention:

[0014] 1) The S parameters of the 3 dB bridge after simulating the closing of the cover are not affected in performance. See Figure 1 as shown.

[0015] 2) After the whole machine works, by using a vector signal analyzer to analyze the output power spectrum quality of the fixed amplifier, it can be seen that the EVM value of the spectrum signal is 4.7%, within the specified technical indicators, the power level value is 40.3 dBm, better than the index requirements, and the output is stable. Description of the Drawings

[0016] Figure 1 It is a schematic diagram of the S parameters of the 3 dB bridge in HFSS after simulating the closing of the cover in the embodiment of the present invention;

[0017] Figure 2 It is a layout diagram of the printed circuit board in the embodiment of the present invention, including a first region I and a second region II;

[0018] Figure 3 This is the first shielding cover of the embodiment of the present invention;

[0019] Figure 4 This is the second shielding cover of the embodiment of the present invention;

[0020] Figure 5 This is the installation schematic diagram of the first shielding cover of the embodiment of the present invention;

[0021] Figure 6 This is the installation schematic diagram of the second shielding cover of the embodiment of the present invention. Detailed implementation manners

[0022] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific implementation manners.

[0023] The present invention provides a device for solving the problem of solid-state amplifier power traction caused by a coupling detection circuit. Specifically, through local circuit layout and structure optimization, it avoids fluctuations in component technical indicators caused by the mutual coupling of high-frequency electromagnetic wave radiation and sensitive circuits. As Figures 1-6 shown, the device includes:

[0024] A first shielding cover, a second shielding cover, a printed circuit board, and a box body; among them,

[0025] The printed circuit board is placed in the box body;

[0026] The second shielding cover covers the box body and is used to shield the printed circuit board;

[0027] The printed circuit board includes a first area and a second area. The first shielding cover is installed on the first area to shield the circuit structure in the first area.

[0028] According to an embodiment of the present invention, the first area is the coupling detection circuit part, which includes a coupling sub-circuit, a detection sub-circuit, and a proportional amplification operation sub-circuit, and is used to convert radio frequency power into a continuously variable analog quantity to reflect the magnitude of the output power.

[0029] According to an embodiment of the present invention, the distribution structure of the coupling sub-circuit, the detection sub-circuit, and the proportional amplification operation sub-circuit is as follows: the coupling sub-circuit should arrange the line spacing according to the microstrip coupling simulation results, the detection elements in the detection sub-circuit are symmetrically and linearly distributed, and the proportional amplification operation sub-circuit is arranged compactly immediately after.

[0030] According to an embodiment of the present invention, the second area includes a first solid-state amplifier module, a second solid-state amplifier module, and a bridge circuit; among them, the first solid-state amplifier module and the second solid-state amplifier module are distributed on both sides of the bridge circuit.

[0031] According to an embodiment of the present invention, the first fixed amplifier module and the second fixed amplifier module are shielded by physical isolation.

[0032] According to an embodiment of the present invention, a raised plate is provided on the upper part of the bridge circuit corresponding to the second region of the second shielding cover for shielding the first fixed amplifier module and the second fixed amplifier module.

[0033] For example, the second shielding cover uses a cross-shaped cavity pattern to partition and isolate the first fixed amplifier module and the second fixed amplifier module, while avoiding the circuit layout wiring pattern. The first region and the second region are arranged as neatly as possible, and there are relatively regular interfaces between the fixed amplifier modules and the 3dB bridge.

[0034] According to an embodiment of the present invention, the horizontal net distance between the box body and the first shielding cover and the internal and external components is maintained at 1.6 mm or more, and the spatial distance from the surface of the printed circuit board is 0.2 mm. This distance is controlled to be much less than one-twentieth of the electromagnetic wavelength to ensure the convergence of the electromagnetic field.

[0035] According to an embodiment of the present invention, the materials of the first shielding cover and the second shielding cover are selected as brass, with a thickness of 0.3 mm and a height of 2.2 mm.

[0036] According to an embodiment of the present invention, the external dimensions of the shielding cavity formed by the box body and the second shielding cover have no practical engineering impact on the coupling degree and standing wave of the coupling detection circuit, and have no practical engineering impact on the self-resonant frequency of the fixed amplifier cavity.

[0037] Obviously, those skilled in the art can make various changes and modifications to the invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these changes and modifications.

Claims

1. A device for solving the problem of solid-state amplifier power traction caused by a coupled detection circuit, characterized in that, Including: A first shielding cover, a second shielding cover, a printed circuit board, and a box body; wherein, The printed circuit board is placed in the box body; The second shielding cover covers the box body and is used to shield the printed circuit board; The printed circuit board includes a first area and a second area. The first shielding cover is installed on the first area and is used to shield the circuit structure in the first area; The first area is a coupled detection circuit part, which includes a coupling sub-circuit, a detection sub-circuit, and a proportional amplification operation sub-circuit, and is used to convert the radio frequency power into a continuously variable analog quantity to reflect the magnitude of the output power; The distribution structure of the coupling sub-circuit, the detection sub-circuit, and the proportional amplification operation sub-circuit is as follows: the coupling sub-circuit should arrange the line spacing according to the microstrip coupling simulation results, the detection elements in the detection sub-circuit are symmetrically linearly distributed, and the proportional amplification operation sub-circuit is closely arranged behind it; The second area includes a first fixed amplifier module, a second fixed amplifier module, and a bridge circuit; wherein, the first fixed amplifier module and the second fixed amplifier module are vertically distributed in the left area of the bridge circuit; The first fixed amplifier module and the second fixed amplifier module are shielded by physical isolation; The second shielding cover is provided with a raised plate corresponding to the upper part of the bridge circuit in the second area and is used to shield the first fixed amplifier module and the second fixed amplifier module; The horizontal distance between the box body and the first shielding cover and the internal and external components is kept at 1.6 mm or more, and the space distance from the surface of the printed circuit board is 0.2 mm. This distance is controlled to be much less than one-twentieth of the electromagnetic wavelength to ensure the convergence of the electromagnetic field; The materials of the first shielding cover and the second shielding cover are selected as brass, with a thickness of 0.3 mm and a height of 2.2 mm.

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