P-band high-power high-impedance variable-ratio miniaturized planar balun and high-power amplifier

Abstract

This invention provides a miniaturized planar balun with high power and high impedance ratio in the P-band and a high-power amplifier, belonging to the field of semiconductor device technology. It includes: a ceramic substrate, an upper coupling line disposed on the upper surface of the ceramic substrate, and a lower coupling line disposed on the lower surface of the ceramic substrate; a first external window and a second external window are respectively disposed on opposite sides of the ceramic substrate; the upper coupling line has two balanced ports leading to the first external window; the lower coupling line has an unbalanced port passing through the ceramic substrate and leading to the second external window; wherein the two balanced ports and one unbalanced port form an external interface; the two balanced ports and the unbalanced port are located on the same dielectric layer within the ceramic substrate; the upper coupling line and the lower coupling line form a strip-shaped coupling line. This invention enables high impedance ratio and miniaturization of the planar balun for P-band kilowatt-level and above high-power amplifiers, significantly improving ease of use and reliability.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor device technology, specifically relating to a miniaturized planar balun with high power and high impedance ratio in the P-band and a high power amplifier. Background Technology

[0002] In the P-band, high-power amplifiers (hereinafter referred to as power amplifiers) with output power ranging from hundreds of watts to kilowatts have been developed based on GaN devices. While the output power has been greatly increased, the requirement to achieve a small size has brought considerable challenges to the design and implementation of power amplifiers.

[0003] Typically, P-band high-power amplifiers employ a push-pull structure based on cable baluns, coupled with a microstrip-lumped capacitor structure or a TLT (Transmission Line Transformer) matching circuit composed of cables, to achieve impedance matching between the device impedance of only a few ohms and the 50Ω port. However, the presence of the balun cable makes it difficult to miniaturize P-band high-power amplifiers. Furthermore, as the output power level of amplifiers increases, components such as cables and lumped capacitors suffer from overheating and insufficient voltage withstand capability, severely impacting the reliability of the amplifier and limiting further increases in output power.

[0004] In view of this, the present invention provides a miniaturized planar balun structure to solve the problems of difficulty in miniaturizing P-band high-power power amplifiers and insufficient reliability of matching components. Summary of the Invention

[0005] This invention provides a miniaturized planar balun with high power and high impedance ratio in the P-band and a high-power amplifier. It uses a stripline to replace the traditional balun cable, solving the problem of miniaturizing the matching circuit of P-band kilowatt-level and above high-power amplifiers.

[0006] To achieve the above objectives, in a first aspect, embodiments of the present invention provide a miniaturized planar balun with high power and high impedance ratio in the P-band, comprising: a ceramic substrate, an upper coupling line disposed on the upper surface of the ceramic substrate, and a lower coupling line disposed on the lower surface of the ceramic substrate; a first external window and a second external window are respectively disposed on opposite sides of the ceramic substrate; the upper coupling line has two balanced ports leading to the first external window; the lower coupling line has an unbalanced port passing through the ceramic substrate and leading to the second external window; The two balanced ports and the unbalanced port are located on the same dielectric layer within the ceramic substrate; both the upper coupling line and the lower coupling line are strip-shaped coupling lines.

[0007] In conjunction with the first aspect, in one feasible manner, the ceramic substrate comprises, from top to bottom, an upper ceramic substrate, a middle ceramic substrate, and a lower ceramic substrate, wherein the upper coupling line and the lower coupling line are respectively disposed on the upper and lower surfaces of the middle ceramic substrate, the upper surface of the upper ceramic substrate is provided with an upper metal, and the lower surface of the lower ceramic substrate is provided with a lower metal. The upper ceramic substrate is provided with the first external window and the second external window; The upper coupling line is connected to the upper metal through an upper metallized via in the upper ceramic substrate; The lower coupling line is connected to the lower metal through a lower metallized via in the lower ceramic substrate; The upper coupling line and the lower coupling line are connected through a metallized via in the middle ceramic substrate.

[0008] In conjunction with the first aspect, in one feasible manner, the upper ceramic substrate comprises multiple layers of ceramic dielectric, the lower ceramic substrate comprises multiple layers of ceramic dielectric, and the middle ceramic substrate comprises a single layer of ceramic dielectric.

[0009] In conjunction with the first aspect, in one feasible manner, the upper ceramic substrate and the lower ceramic substrate have the same thickness, each comprising 6-10 layers of ceramic dielectric.

[0010] In conjunction with the first aspect, in one feasible manner, the thickness of the monolayer ceramic medium is 90-100 μm, and the dielectric constant of the ceramic medium is 5.7.

[0011] In conjunction with the first aspect, in one feasible manner, the upper coupling line and the lower coupling line have the same thickness, both being 8-12 μm. In conjunction with the first aspect, in one feasible manner, the upper metal layer and the lower metal layer have the same thickness, both being 8-12 μm.

[0012] In conjunction with the first aspect, in one feasible manner, the planar balun has external dimensions of (7.5±0.15mm)×(12±0.15mm).

[0013] In conjunction with the first aspect, in one feasible manner, the impedance of each of the balanced ports is 3.8Ω; the impedance of the unbalanced ports is 50Ω.

[0014] The miniaturized planar balun with high power and high impedance ratio provided by this invention has the following advantages compared with the prior art: First, it is made using a low temperature co-fired ceramic (LTCC) process and features a planar balun with a coupled dual stripline structure. It uses two parallel striplines instead of traditional balun cables. The two striplines are located on the upper and lower sides of the ceramic substrate, respectively. By leading out two balanced ports and matching them with a 50Ω unbalanced port, it achieves the function of a balun while also functioning as an impedance transformer, thus achieving a high impedance ratio.

[0015] Secondly, by using striplines as coupling lines, leading the coupling lines out in the same layer, and increasing the coupling degree by adding through holes between the coupling lines, the size of the planar balun is effectively reduced, enabling miniaturization.

[0016] Thirdly, the planar balun provided by this invention improves its power handling capability through the following design: the ceramic dielectric thickness between the coupling line and the back ground is less than 0.8 mm, which improves heat dissipation; numerous grounding vias are designed in the ceramic dielectric between the coupling line and the back ground, significantly improving heat dissipation while achieving grounding functionality; the coupling line uses a wider pattern width, which helps achieve a high impedance ratio and improves over-power capability; and the internal metal thickness is 8-12 μm thick gold, further improving power handling capability. Based on the above design, the planar balun provided by this invention can achieve kilowatt-level and above power output.

[0017] Therefore, the planar balun provided by this invention combines the power distribution function of a planar balun with the impedance transformer function, which can reduce the size of the matching circuit of P-band kilowatt-level and above high-power amplifiers by several times, while increasing the power handling capability by several times. It greatly reduces the physical size of the balun structure in the matching network, simplifies the circuit matching form and physical size, and greatly reduces the circuit size of P-band high-power broadband amplifiers, broadens the application range, and can generate significant economic benefits. It solves the problems of the difficulty in miniaturizing P-band high-power amplifiers and the application limitation caused by insufficient reliability of matching components.

[0018] Secondly, embodiments of the present invention also provide a high-power amplifier, including the aforementioned P-band high-power, high-impedance-ratio miniaturized planar balun.

[0019] It is understandable that the beneficial effects of the second aspect mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here.

[0020] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this specification. Attached Figure Description

[0021] Figure 1A three-dimensional structural schematic diagram of a miniaturized planar balun with high power and high impedance ratio in the P-band provided in an embodiment of the present invention (from the perspective of the unbalanced port). Figure 2 A schematic diagram of the structure of the miniaturized planar balun with high power and high impedance ratio provided in the embodiment of the present invention (from the perspective of the balanced port). Figure 3 A schematic diagram of the exploded structure of a miniaturized planar balun with high power and high impedance ratio in the P-band provided in an embodiment of the present invention. Figure 4 A top view of the miniaturized planar balun with high power and high impedance ratio provided in an embodiment of the present invention. Figure 5 For along Figure 4 Cross-sectional view of line AA in the middle; Figure 6 A top view (dimensions marked) of a miniaturized planar balun with high power and high impedance ratio in the P-band provided in an embodiment of the present invention. Figure 7 for Figure 6 The diagram shows the rear view of the miniaturized planar balun with high power and high impedance ratio in the P-band. Figure 8 A schematic diagram of the circuit structure for matching a push-pull structure TLT transmission line transformer based on a cable balun.

[0022] Explanation of reference numerals in the attached figures: 1. Upper metal layer; 2. Upper ceramic substrate; 3. Upper coupling line; 4. Middle ceramic substrate; 5. Lower coupling line; 6. Lower ceramic substrate; 7. Lower metal layer; 8. First external window; 9. Second external window; 10. Upper metallized hole; 11. Middle metallized hole; 12. Lower metallized hole. Detailed Implementation

[0023] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0024] Similar to the understanding in the Examination Guidelines, in this application, expressions such as "greater than," "less than," and "exceeding" are understood to exclude the stated number; expressions such as "above," "below," and "within" are understood to include the stated number. Furthermore, in the description of the embodiments in this application, "multiple" means two or more (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups" and "multiple times," unless otherwise explicitly specified.

[0025] In the claims, description and accompanying drawings of this invention, the terms "comprising," "having," and variations thereof are used to mean "including but not limited to."

[0026] Please refer to the following: Figures 1 to 7 The present invention will now describe the miniaturized planar balun with high power and high impedance ratio in the P-band. The miniaturized planar balun with high power and high impedance ratio in the P-band includes: a ceramic substrate, an upper coupling line 3 disposed on the upper surface of the ceramic substrate, and a lower coupling line 5 disposed on the lower surface of the ceramic substrate; a first external window 8 and a second external window 9 are respectively disposed on opposite sides of the ceramic substrate; the upper coupling line 3 has two balanced ports leading to the first external window 8; the lower coupling line 5 has an unbalanced port passing through the ceramic substrate and leading to the second external window 9; wherein the two balanced ports and one unbalanced port form an external interface, which can be connected to other circuits using a gold wire bonding process. The two balanced ports and the unbalanced port are located on the same dielectric layer within the ceramic substrate; both the upper coupling line 3 and the lower coupling line 5 are strip-shaped coupling lines.

[0027] The miniaturized planar balun with high power and high impedance ratio provided in this invention has the following advantages compared with the prior art: First, it is made using low temperature co-fired ceramic (LTCC) technology and features a planar balun with a strip-coupled double-line structure. Its core structure consists of two parallel strip-coupled lines located on the upper and lower sides of the ceramic substrate, respectively. By leading out two balanced ports, the impedance ratio is changed, thereby increasing the impedance of the planar balun and giving it the function of an impedance converter.

[0028] Secondly, by using striplines as coupling lines, leading the coupling lines out in the same layer, and increasing the coupling degree by adding through holes between the coupling lines, the size of the planar balun is effectively reduced, enabling miniaturization.

[0029] Thirdly, the planar balun provided by this invention improves its power handling capability through the following design: the ceramic dielectric thickness between the coupling line and the back ground is less than 0.8 mm, which improves heat dissipation; numerous grounding vias are designed in the ceramic dielectric between the coupling line and the back ground, significantly improving heat dissipation while achieving grounding functionality; the coupling line uses a wider pattern width, which helps achieve a high impedance ratio and improves over-power capability; and the internal metal thickness is 8-12 μm thick gold, further enhancing power handling capability. Based on the above design, the planar balun provided by this invention can achieve kilowatt-level and above maximum power output.

[0030] Therefore, the planar balun provided by this invention combines the power distribution function of a planar balun with the impedance transformer function, which can reduce the size of the matching circuit of P-band kilowatt-level and above high-power amplifiers by several times, while increasing the power handling capability by several times. It greatly reduces the physical size of the balun structure in the matching network, simplifies the circuit matching form and physical size, and greatly reduces the circuit size of P-band high-power broadband amplifiers, improves ease of use, broadens the application range, and generates significant economic benefits. It solves the problems of difficulty in miniaturizing P-band high-power amplifiers and insufficient reliability of matching components that limit their application.

[0031] In some embodiments, see Figure 3 and Figure 5 As shown, the ceramic substrate comprises, from top to bottom, an upper ceramic substrate 2, a middle ceramic substrate 4, and a lower ceramic substrate 6. Upper coupling lines 3 and lower coupling lines 5 are respectively disposed on the upper and lower surfaces of the middle ceramic substrate 4. An upper metal layer 1 is disposed on the upper surface of the upper ceramic substrate 2, and a lower metal layer 7 is disposed on the lower surface of the lower ceramic substrate 6. The upper ceramic substrate 2 has a first external window 8 and a second external window 9. The upper coupling line 3 and the upper metal layer 1 are connected through an upper metallized via 10 within the upper ceramic substrate 2. The lower coupling line 5 and the lower metal layer 7 are connected through a lower metallized via 12 within the lower ceramic substrate 6. The upper coupling line 3 and the lower coupling line 5 are connected through a middle metallized via 11 within the middle ceramic substrate 4.

[0032] In the above embodiment, the upper metal 1 is grounded to the lower metal 7 through each metallized via; the upper coupling line 3 and the lower coupling line 5 are coupled to improve the coupling degree through the addition of a middle metallized via 11 in the middle ceramic substrate 4, which effectively reduces the size; external windows are provided on opposite sides of the upper ceramic substrate 2, and the balanced port and unbalanced port are led to the upper surface of the middle ceramic substrate 4 to form an external interface for connecting other circuits.

[0033] The external window on the upper ceramic substrate 2 needs to be exposed to the lead-out coupling line; therefore, the shape of the upper ceramic substrate 2 forms notches on opposite sides, and the size of the corresponding upper metal 1 is consistent with the external size of the upper ceramic substrate 2.

[0034] In some embodiments, see Figure 3 and Figure 5 As shown, the upper ceramic substrate 2 includes multiple layers of ceramic dielectric, the lower ceramic substrate 6 includes multiple layers of ceramic dielectric, and the middle ceramic substrate 4 includes one layer of ceramic dielectric.

[0035] In the above embodiments, a single-layer ceramic dielectric is placed between the upper and lower coupled microstrip lines. Compared with multi-layer dielectric stacking schemes, this eliminates interference parameters such as parasitic capacitance and inductance at the interfaces of different dielectric layers, ensuring a stable and controllable electromagnetic coupling path between the two coupled lines and accurately achieving the impedance matching requirements of high impedance ratio in the P-band. Simultaneously, the uniformity of the single-layer dielectric avoids coupling coefficient fluctuations caused by differences in dielectric constants in multi-layer dielectrics, ensuring the impedance transformation consistency of the balun across the entire P-band, reducing signal reflection loss, and improving the output power and gain flatness of the power amplifier. This enhances the operational reliability of the planar balun while maintaining high power, high impedance ratio, and miniaturization.

[0036] The upper ceramic substrate 2 and the lower ceramic substrate 6 adopt a multilayer ceramic dielectric structure. By optimizing the thickness and dielectric strength of the multilayer dielectric, the insulation performance between the coupling line and the external environment can be improved, the breakdown voltage threshold can be increased, and the risk of arc breakdown or leakage in high-power scenarios can be avoided, breaking through the withstand voltage limit of traditional single-layer dielectric baluns. At the structural level, the multilayer ceramic dielectric can improve the mechanical strength and flatness of the substrate, prevent the coupling line from deforming or breaking due to external impact or thermal expansion and contraction, and ensure the structural stability and service life of the balun.

[0037] Therefore, the above embodiment achieves synergistic optimization of coupling performance, heat dissipation, withstand voltage, and mechanical performance through a layered design of "single-layer dielectric in the coupling region + multi-layer dielectric on the outer side." The single-layer dielectric in the coupling region ensures the core function of impedance matching and avoids parasitic interference caused by multi-layer dielectrics; the multi-layer dielectric on the outer side compensates for the deficiencies of the single-layer dielectric in terms of heat dissipation, withstand voltage, and structural strength, eliminating the need for additional heat dissipation or withstand voltage protection components. Thus, while ensuring the core performance of the balun, the overall size is further reduced, meeting the design requirements of miniaturization and high reliability for P-band high-power amplifiers.

[0038] For further explanation, please refer to the following: Figure 3 and Figure 5 As shown, several embodiments of the miniaturized planar balun with high power and high impedance ratio in the P-band provided by the present invention are given.

[0039] Example 1 Material selection: Ceramic material with a dielectric constant of 5.7 is used. The thickness of a single ceramic dielectric layer is 96 μm. The upper ceramic substrate 2 uses 8 layers of ceramic dielectric, and the lower ceramic substrate 6 uses 8 layers of ceramic dielectric. The total thickness of the 8 ceramic dielectric layers is 768 μm, for a total of 17 ceramic dielectric layers. The upper coupling line 3 and the lower coupling line 5 are strip lines made of gold with a thickness of 8μm. The thickness of the upper metal layer 1 and the lower metal layer 7 is 8μm, and the material is gold.

[0040] Fabrication Process: Low-Temperature Co-fired Ceramic (LTCC) process is employed. The balanced port is directly led out from the upper coupling line 3 to the first external window 8 to form an external interface. The unbalanced port is led out from the lower coupling line 5, connected through a through-hole to the ceramic dielectric on the same layer as the upper coupling line 3, and led to the second external window 9 to form an external interface. Gold wire bonding or gold strip soldering is used at the external interface to connect to other circuits for signal transmission. The overall mounting of the planar balun employs gold-tin sintering and / or bonding processes, among others. These processes can be used individually or in combination, depending on design requirements.

[0041] The planar balun obtained in Example 1 has an unbalanced port P1 with a port impedance of 50Ω. The balanced port is transformed into two balanced ports, P2 and P3, with a single port impedance of 3.8Ω and the combined impedance of the two balanced ports is 7.6Ω, achieving an impedance ratio of more than 6.6 times for the dual-port system. The balun's dimensions (L×W) are 12mm×7.5mm, and the total thickness H is 1.64±0.15mm.

[0042] Example 2 The difference from Example 1 is that the thickness of the upper coupling line 3, the lower coupling line 5, the upper metal 1, and the lower metal 7 is 10 μm; the thickness of the single-layer ceramic dielectric is 90 μm; and the number of layers of the upper ceramic substrate 2 and the lower ceramic substrate 6 is 6.

[0043] The planar balun obtained in Example 2 has an unbalanced port P1 with a port impedance of 50Ω. The balanced port is transformed into two balanced ports, P2 and P3, with a single port impedance of 3.8Ω and the combined impedance of the two balanced ports is 7.6Ω, achieving an impedance ratio of more than 6.6 times for the two ports. The balun dimensions are (7.5±0.15mm)×(12±0.15mm).

[0044] Example 3 The difference from Example 1 is that the thickness of the upper coupling line 3, the lower coupling line 5, the upper metal 1, and the lower metal 7 is 12 μm; the thickness of the single-layer ceramic dielectric is 100 μm; and the number of layers of the upper ceramic substrate 2 and the lower ceramic substrate 6 is 10.

[0045] The planar balun obtained in Example 3 has an unbalanced port P1 with a port impedance of 50Ω. The balanced port is transformed into two balanced ports P2 and P3, with a single port impedance of 3.8Ω and the combined impedance of the two balanced ports is 7.6Ω, achieving an impedance ratio of more than 6.6 times for the two ports. The balun dimensions are (7.5±0.15mm)×(12±0.15mm).

[0046] Example 4 The difference from Example 1 is that: the upper coupling line 3 and the lower coupling line 5 have the same thickness of 8μm; the upper metal 1 and the lower metal 7 have the same thickness of 12μm; the thickness of the single-layer ceramic dielectric is 100μm; the upper ceramic substrate 2 has 8 layers and the lower ceramic substrate 6 has 10 layers.

[0047] Comparative Example The push-pull structure based on cable baluns mentioned in the background technology, combined with a microstrip-lumped capacitor structure or a TLT transmission line transformer matching circuit structure composed of cables, can be found in the following examples. Figure 8 .

[0048] Figure 8 P1 is the unbalanced balun port with an impedance of 50Ω, while ports P2 and P3 are balanced ports with an impedance of 7.6Ω (50 / 7.6≈6.6). Figure 8 The medium-voltage cable (COAX3) is a 50-ohm characteristic impedance cable, also known as a balun cable. Cables (COAX1 and COAX2) are 12.5-ohm characteristic impedance cables, and impedance transformation is performed. The P-band balun cable (COAX3) is 70mm or longer, while the cables (COAX1 and COAX2) are generally longer than 70mm. The cables are generally installed using a floating installation (cable ends are welded, and the rest is suspended).

[0049] Compared with the comparative example, the embodiments of this invention are fabricated using a low-temperature co-fired ceramic (LTCC) process, and a planar balun with a strip-coupled double-line structure is designed. The external dimensions of the balun are shown in the figure below. Figure 6 and Figure 7 As shown. Figure 6 P1 is the unbalanced port of the balun with a port impedance of 50Ω, while ports P2 and P3 are balanced ports with a port impedance of 3.8Ω. This achieves an impedance ratio of over 6.6 times that of a dual-port balun, and the balun's dimensions are only 7.5mm × 12mm. Compared to... Figure 8 The TLT transmission line transformer matching circuit structure based on the push-pull structure of the cable balun shown in this invention significantly reduces the size of the planar balun, and greatly improves its ease of use and reliability.

[0050] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0051] Based on the same inventive concept, this application also provides a high-power amplifier, including the aforementioned P-band high-power, high-impedance-ratio miniaturized planar balun.

[0052] The high-power amplifier provided in this application, by employing a miniaturized planar balun with high P-band power and high impedance ratio, significantly reduces the external dimensions of the balun structure in the matching network, simplifies the circuit matching form and external dimensions, and greatly reduces the circuit size of the P-band high-power amplifier. While significantly increasing output power, it achieves high impedance ratio and miniaturization, meeting the increasingly miniaturized requirements of devices, broadening its application range, and resulting in significant economic benefits. Here, "high power" refers to kilowatt-level and above high power based on the P-band.

[0053] This invention proposes a planar balun structure based on LTCC technology with a multilayer stripline structure. While realizing the power distribution function of the balun structure, it transforms the impedance of the balanced port to 7.6Ω at both ends, achieving an impedance transformation of more than 6.6 times. In terms of functionality, it is superior to the traditional balun cable + cable transmission line transformer. However, the size of the planar balun is only 7.5mm × 12mm, which greatly reduces the circuit size and thus significantly reduces the size of the assembled device. The micro-assembly process is used during installation, which greatly simplifies the assembly process and can significantly improve assembly efficiency.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A miniaturized planar balun with high power and high impedance ratio in the P-band, characterized in that, include: The ceramic substrate has an upper coupling line (3) disposed on the upper surface of the ceramic substrate and a lower coupling line (5) disposed on the lower surface of the ceramic substrate. A first external window (8) and a second external window (9) are respectively disposed on opposite sides of the ceramic substrate. The upper coupling line (3) has two balanced ports leading to the first external window (8). The lower coupling line (5) has an unbalanced port passing through the ceramic substrate and leading to the second external window (9). The two balanced ports and the unbalanced port are located on the same dielectric layer within the ceramic substrate; the upper coupling line (3) and the lower coupling line (5) are both strip coupling lines.

2. The P-band high-power, high-impedance ratio miniaturized planar balun as described in claim 1, characterized in that, The ceramic substrate comprises, from top to bottom, an upper ceramic substrate (2), a middle ceramic substrate (4), and a lower ceramic substrate (6). The upper coupling line (3) and the lower coupling line (5) are respectively disposed on the upper and lower surfaces of the middle ceramic substrate (4). The upper surface of the upper ceramic substrate (2) is provided with an upper metal (1), and the lower surface of the lower ceramic substrate (6) is provided with a lower metal (7). The upper ceramic substrate (2) is provided with the first external window (8) and the second external window (9); The upper coupling line (3) is connected to the upper metal (1) through the upper metallization hole (10) in the upper ceramic substrate (2); The lower coupling line (5) and the lower metal (7) are connected through the lower metallization hole (12) in the lower ceramic substrate (6); The upper coupling line (3) and the lower coupling line (5) are connected through the middle metallized hole (11) in the middle ceramic substrate (4).

3. The P-band high-power, high-impedance ratio miniaturized planar balun as described in claim 2, characterized in that, The upper ceramic substrate (2) includes multiple ceramic media, the lower ceramic substrate (6) includes multiple ceramic media, and the middle ceramic substrate (4) includes one ceramic media.

4. The P-band high-power, high-impedance ratio miniaturized planar balun as described in claim 3, characterized in that, The upper ceramic substrate (2) and the lower ceramic substrate (6) have the same thickness and both include 6-10 layers of ceramic dielectric.

5. The P-band high-power, high-impedance ratio miniaturized planar balun as described in claim 3, characterized in that, The thickness of the single-layer ceramic dielectric is 90-100 μm, and the dielectric constant of the ceramic dielectric is 5.

7.

6. The P-band high-power, high-impedance ratio miniaturized planar balun as described in claim 1, characterized in that, The upper coupling line (3) and the lower coupling line (5) have the same thickness, both being 8-12 μm.

7. The P-band high-power, high-impedance ratio miniaturized planar balun as described in claim 1, characterized in that, The upper metal layer (1) and the lower metal layer (7) have the same thickness, both being 8-12 μm.

8. The P-band high-power, high-impedance ratio miniaturized planar balun as described in claim 1, characterized in that, The external dimensions of the planar balun are (7.5±0.15mm)×(12±0.15mm).

9. The P-band high-power, high-impedance ratio miniaturized planar balun as described in claim 1, characterized in that, The impedance of each of the balanced ports is 3.8Ω; the impedance of each of the unbalanced ports is 50Ω.

10. A high-power amplifier, characterized in that, Including the P-band high-power, high-impedance-ratio miniaturized planar balun as described in any one of claims 1-8.

Images