Circuit structure of ultra-wideband bias-t

Abstract

The application discloses a kind of circuit structures of ultra-wideband Bias-T, including Bias-T circuit, Bias-T circuit is fixed in metal shell, and the three terminals of the metal shell are RF terminal interface, RF+DC terminal interface and DC terminal interface respectively corresponding to the three terminals of Bias-T circuit in T-shaped structure, RF terminal interface is directly opposite RF+DC terminal interface, low-frequency cavity and high-frequency cavity are respectively arranged in metal shell, low-frequency cavity is communicated with DC connection port, and microwave transmission straight conductor and series capacitor C are fixed on insulating support frame in high-frequency cavity, ground end plate is respectively arranged at both ends of insulating support frame, and the microwave transmission straight conductor of both ends of series capacitor C is spaced apart from the ground end plate of both ends, and it is 90 degrees perpendicular state to form the edge line transmission state between Bias-T circuit RF connection port and RF+DC connection port.

Description

Technical Field

[0001] This invention relates to a circuit structure for ultra-wideband bias-T, which is an ultra-wideband bias-T from DC to 67 GHz implemented using edge line transmission lines. It is an ultra-wideband bias-T from DC to 67 GHz implemented using unconventional microwave transmission line methods. Background Technology

[0002] The traditional method for T-type bias circuits (Bias-T) uses microstrip lines or striplines for transmission. These transmission lines have high losses and severe dispersion at high frequencies (≥50GHz), leading to performance degradation and unusability. Summary of the Invention

[0003] The purpose of this invention is to provide a circuit structure for ultra-wideband Bias-T.

[0004] To achieve the above objectives, the solution of the present invention is as follows:

[0005] An ultra-wideband bias-T circuit structure includes a bias-T circuit. The RF terminal and RF+DC terminal of the bias-T circuit are connected in series with capacitors C via microwave transmission straight conductors. The DC bias terminal of the bias-T circuit is connected to a conductor on the RF+DC side via an inductor L. The bias-T circuit is fixed in a metal housing with a T-shaped structure. The three terminals of the T-shaped structure correspond to the three terminals of the bias-T circuit: the RF terminal interface, the RF+DC terminal interface, and the DC terminal interface. The RF terminal interface is directly connected to the RF+DC terminal interface. A low-frequency cavity and a high-frequency cavity are respectively set inside the metal housing. The low-frequency cavity is connected to the DC connection port, and the high-frequency cavity is set between the RF connection port and the RF+DC connection port. In the high-frequency cavity, the microwave transmission linear conductor and the series capacitor C are fixed on the insulating support frame. Grounding end plates are set at both ends of the insulating support frame. The grounding end plates at both ends and the microwave transmission linear conductors at both ends of the series capacitor C are spaced apart and perpendicular to each other at 90 degrees to form the edge line transmission state between the Bias-T circuit RF connection port and the RF+DC connection port.

[0006] A further aspect of the solution is that a PCB board is installed in the low-frequency cavity, and a bias power supply is connected to the copper foil surface of the PCB board through a DC connection port. The inductor is connected to the copper foil surface of the PCB board in the high-frequency cavity.

[0007] The solution further involves: the grounding end plates at both ends are spaced apart from the microwave transmission straight conductor and are perpendicular to each other at 90 degrees to form the edge line transmission state between the Bias-T circuit RF connection port and the RF+DC connection port, thereby realizing ultra-wideband microwave transmission from DC to 67GHz.

[0008] A further aspect of the solution is that the microwave transmission straight conductors at both ends of the series capacitor C, which are perpendicular to the grounding plate at a 90-degree angle, are respectively aligned with the center of the RF connection port and the RF+DC connection port.

[0009] The solution further includes: the insulating support frame material is PEI, and the microwave transmission linear conductor is a copper conductor.

[0010] The beneficial effects of this invention are:

[0011] It overcomes the traditional transmission method of microstrip lines or striplines used in Bias-T circuits, which have high transmission line loss, and achieves minimum loss transmission in high-frequency applications ≥50GHz.

[0012] The invention will be further explained in detail below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the circuit structure of the present invention from an isometric perspective;

[0014] Figure 2 This is a planar schematic diagram of the circuit structure of the present invention;

[0015] Figure 3 This is a schematic diagram of a Bias-T circuit;

[0016] Figure 4 This is the VSWR diagram of the radio frequency port of the circuit structure of this invention;

[0017] Figure 5 This is a waveform diagram of the transmission loss of the circuit structure of the present invention. Detailed Implementation

[0018] A circuit structure for ultra-wideband Bias-T includes, as follows: Figure 3 The Bias-T circuit shown is a known T-type bias circuit. The RF terminal and the RF+DC terminal of the Bias-T circuit are connected in series with a capacitor C via a microwave transmission straight conductor 1. The DC bias terminal of the Bias-T circuit is connected to the microwave transmission straight conductor on the RF+DC side via an inductor L. Where: Figure 1 and Figure 2As shown, the Bias-T circuit is fixed in a metal housing 2. The metal housing has a T-shaped structure. The three-terminal interface of the T-shaped structure corresponds to the three terminals of the Bias-T circuit, namely the RF terminal interface, the RF+DC terminal interface, and the DC terminal interface. The RF terminal interface is directly connected to the RF+DC terminal interface. A low-frequency cavity 201 and a high-frequency cavity 202 are respectively arranged inside the metal housing. The low-frequency cavity 201 is connected to the DC connection port. The high-frequency cavity 202 is arranged between the RF connection port and the RF+DC connection port. In the high-frequency cavity 102, the microwave transmission linear conductor and the series capacitor C are fixed on the insulating support frame 3. Grounding end plates 4 and 5 are respectively arranged at both ends of the insulating support frame 3. The grounding end plates at both ends and the microwave transmission linear conductor 1 at both ends of the series capacitor C are spaced apart and perpendicular to each other at 90 degrees to form the edge line transmission state between the RF connection port and the RF+DC connection port of the Bias-T circuit.

[0019] Wherein: a PCB board 6 is provided in the low-frequency cavity, and a bias power supply is connected to the copper foil surface of the PCB board through a DC connection port. The inductor L is connected to the copper foil surface of the PCB board in the low-frequency cavity 201 in the high-frequency cavity.

[0020] In this embodiment: the grounding end plates at both ends are spaced apart from the microwave transmission straight conductor and are perpendicular to each other at a 90-degree angle to form an edge line transmission state between the Bias-T circuit RF connection port and the RF+DC connection port, realizing ultra-wideband microwave transmission from DC to 67GHz. The distance between the grounding end plates at both ends and the microwave transmission straight conductor is 0.06mm to 0.1mm. The microwave transmission straight conductor is a flat copper conductor with a width of 1.0mm to 1.06mm and a thickness of 0.03mm to 0.07mm. The insulating support frame material is PEI, and the microwave transmission straight conductor is a copper conductor. The flat copper conductor can be achieved by etching a copper-clad laminate.

[0021] Wherein: the microwave transmission straight conductors at both ends of the series capacitor C, which are perpendicular to the grounding plate at 90 degrees, are respectively aligned with the center of the RF connection port and the RF+DC connection port; the RF terminal interface, the RF+DC terminal interface, and the DC terminal interface are all coaxial connectors.

[0022] Figure 4 The measured VSWR diagram of the RF port in this embodiment is as follows. Figure 5 This is a waveform diagram of the transmission loss in this embodiment, obtained through actual measurement. The measured data demonstrates that the above transmission structure has the following advantages compared to the traditional structure:

[0023] 1) The edge line is in TEM mode, which is converted into coaxial transmission TEM mode. Under the same mode, the transmission achieves the minimum loss.

[0024] 2) The edge line is an air-type transmission line with a very high Q value and very low RF link loss.

[0025] 3) At the same frequency and impedance, the conduction band width of the edge line is much larger than that of other transmission lines, which reduces resistance loss and improves high-frequency performance.

[0026] 4) The requirements for the installation position of the center conductor are not very high, and the fault tolerance is large.

Claims

1. A circuit structure for an ultra-wideband bias-T circuit, comprising a bias-T circuit, wherein a capacitor C is connected in series between the RF terminal and the RF+DC terminal of the bias-T circuit via a microwave transmission linear conductor, and the DC bias terminal of the bias-T circuit is connected to a conductor on the RF+DC terminal side via an inductor L, characterized in that, The Bias-T circuit is fixed in a metal housing with a T-shaped structure. The three-terminal interface of the T-shaped structure corresponds to the three terminals of the Bias-T circuit: the RF terminal, the RF+DC terminal, and the DC terminal. The RF terminal is directly opposite the RF+DC terminal. A low-frequency cavity and a high-frequency cavity are respectively arranged inside the metal housing. The low-frequency cavity is connected to the DC connection port, and the high-frequency cavity is positioned between the RF connection port and the RF+DC connection port. In the high-frequency cavity, the microwave transmission linear conductor and the series capacitor C are fixed on an insulating support frame. Grounding plates are provided at both ends of the insulating support frame. The grounding plates at both ends and the microwave transmission linear conductors at both ends of the series capacitor C are spaced apart and perpendicular to each other at a 90-degree angle, forming the edge line transmission state between the RF connection port and the RF+DC connection port of the Bias-T circuit. The insulating support frame is made of PEI, and the microwave transmission linear conductor is a copper conductor with a width of 1.0mm to 1.06mm and a thickness of 0.03mm to 0.07mm, achieved through copper-clad laminate etching.

2. The circuit structure of the ultra-wideband Bias-T according to claim 1, characterized in that, A PCB board is installed in the low-frequency cavity, and the bias power supply is connected to the copper foil surface of the PCB board through a DC connection port. The inductor is connected to the copper foil surface of the PCB board in the high-frequency cavity.

3. The circuit structure of the ultra-wideband Bias-T according to claim 1, characterized in that, The circuit structure enables ultra-wideband microwave transmission from DC to 67 GHz.

4. The circuit structure of the ultra-wideband Bias-T according to claim 1, 2, or 3, characterized in that, The microwave transmission straight conductors at both ends of the series capacitor C, which are perpendicular to the grounding plate at a 90-degree angle, are respectively aligned with the center of the RF connection port and the RF+DC connection port.

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