A coaxial-like resonator with harmonic suppression, radio frequency transmission structure and method

Abstract

The application belongs to the field of microwave and millimeter wave technology, and discloses a coaxial resonator with harmonic suppression, a radio frequency transmission structure and a method. The application adds a coaxial resonator with harmonic suppression on a component HTCC radio frequency transmission path of chip assembly application. A resonator resonating at a second harmonic frequency is formed by a metal block equivalent capacitor and a bonding gold wire equivalent inductor outside the coaxial transmission line, a second harmonic signal is short-circuited to the ground, and second harmonic suppression of the overall system is formed. In the application, the metal block is placed on the upper layer of the HTCC plate through an insulating medium, and the bonding gold wire is also an element originally used in system assembly, so that other processes and devices do not need to be introduced, the cost is low, the resonator is integrated in the radio frequency signal transmission path, no additional assembly space is needed, and the application has significant advantages for high integration, and has the advantages of simple assembly, low cost and small space.

Description

Technical Field

[0001] This invention relates primarily to the fields of microwave and millimeter-wave technology, and in particular to a coaxial resonator with harmonic suppression, a radio frequency transmission structure, and a method. Background Technology

[0002] In most radio frequency (RF) systems, the second harmonic (HH) is a signal component that needs to be suppressed. In communication systems, the HH at the power amplifier output can cause signal distortion through the AM-PM effect with the fundamental frequency, affecting signal transmission quality. Simultaneously, the transmitter's HH may fall into other communication frequency bands, causing interference. In full-duplex systems, the transmitter's HH falling into the receiver's own frequency band can directly block the receiver link, leading to decreased sensitivity. In radar systems, HH suppression is even more stringent than in ordinary communication systems, directly affecting the radar's detection accuracy and range. If the transmitter's HH is radiated by the antenna and reflects back from a strong target, the receiver may mistakenly perceive a target at the harmonic frequency, generating a false alarm. Furthermore, radars typically share a common transmitting and receiving antenna; if the HH leaks into the receiver through a circulator or falls directly into the receiving frequency band (such as in frequency-modulated continuous wave radar), it will raise the noise floor, causing weak target echoes to be submerged, significantly shortening the effective detection range.

[0003] Currently, commonly used harmonic suppression techniques include filter suppression, antenna suppression, and circuit structure suppression. Among these, filter suppression is the most common and mature technique. By designing appropriate low-pass, band-pass, or notch filters, second harmonics can be suppressed. However, filters may occupy a large space in RF system components and are costly, limiting their application in some miniaturized, low-cost scenarios. Antenna suppression involves adding filtering or harmonic suppression structures to the transmit antenna design, but this increases design complexity and time. Circuit structure suppression involves adding a filter-like response structure to the chip design for harmonic suppression. This method offers high integration but suffers higher losses than off-chip devices, reducing overall efficiency.

[0004] Therefore, there is an urgent need for a coaxial resonator with harmonic suppression, an HTCC radio frequency transmission structure and method. Summary of the Invention

[0005] To address the issues of existing harmonic suppression technologies being space-consuming, difficult to design, and costly, this invention provides a coaxial resonator with harmonic suppression, a radio frequency transmission structure, and a method.

[0006] To achieve the above objectives, the present invention provides a coaxial resonator with harmonic suppression, comprising a metal block equivalent capacitance disposed on the surface of an HTCC board and located outside the coaxial transmission line, and a plurality of bonded alloy wire equivalent inductances connected between the metal block equivalent capacitance and the pads of the coaxial transmission line.

[0007] An insulator is placed between the equivalent capacitance of the metal block and the surface layer of the HTCC board. Based on the RF operating frequency of the power amplifier, the capacitance value of the equivalent capacitance of the metal block and the inductance value of the equivalent inductance of the bonding wire are designed so that the target resonant frequency of the LC resonator composed of the equivalent capacitance of the metal block and several equivalent inductances of the bonding wire are equal to the second harmonic of the operating frequency of the power amplifier. This allows the second harmonic signal component transmitted to the pad to be transmitted to the equivalent capacitance of the metal block via the equivalent inductance of the bonding wire, thus achieving a short circuit of the second harmonic to ground.

[0008] Furthermore, the capacitance value of the equivalent capacitance of the metal block and the inductance value of the equivalent inductance of the bonding wire are set as follows:

[0009] Step S1: Based on the RF operating frequency of the power amplifier, calculate the second harmonic of the power amplifier's operating frequency to obtain the target resonant frequency;

[0010] Step S2: Based on the target resonant frequency, determine the product of the capacitance value of the equivalent capacitance of the metal block and the inductance value of the equivalent inductance of the bonding wire, and use it as the target value;

[0011] Step S3: Based on the target value, control the area of ​​the metal block to determine the capacitance design value of the equivalent capacitance of the metal block, and control the number, length and radius of the bonding wires to determine the inductance design value of the equivalent inductance of the bonding wires.

[0012] Furthermore, the formula for calculating the target value in step S2 is as follows: ,in, , , This refers to the radio frequency operating frequency of the power amplifier. The target resonant frequency, For the target value, The inductance value is the equivalent inductance of the bonding alloy wire. This is the capacitance value of the equivalent capacitance of the metal block.

[0013] Furthermore, step S3 includes the following steps:

[0014] Step S3.1: Determine the area of ​​the metal block, and in conjunction with the dielectric constant and thickness of the HTCC board, determine the design value of the equivalent capacitance of the metal block.

[0015] Step S3.2: Based on the target value and the capacitance design value, determine the inductance design value of the equivalent inductance of the bonding alloy wire;

[0016] Step S3.3: Based on the inductance design value, adjust the number, length, and radius of the bonding wire.

[0017] Furthermore, the formula for calculating the capacitor design value in step S3 is as follows: In the formula, This is the design value for the capacitor. The dielectric constant of the HTCC board is given. Let the area of ​​the metal block be... The dielectric thickness of the HTCC board;

[0018] The formula for calculating the inductance design value in step S3 is as follows: In the formula, This is the inductance design value. The length of the bonding alloy wire, Let be the radius of the bonding alloy wire. The number of bonding alloy wires.

[0019] Furthermore, step S3 includes the following steps:

[0020] Step S3.4: Determine the quantity, length, and radius of the bonding wires, and determine the inductance design value of the equivalent inductance of the bonding wires;

[0021] Step S3.5: Based on the target value and the inductance design value, determine the capacitance design value of the equivalent capacitance of the metal block;

[0022] Step S3.6: Adjust the area of ​​the metal block based on the capacitor design value.

[0023] Furthermore, multiple metal blocks with partitions are arranged on the surface of the HTCC board and around the coaxial transmission line. The capacitance value of the equivalent capacitance of the metal blocks is adjusted based on the number of metal blocks connected by the bonding wire.

[0024] The present invention also provides a radio frequency transmission structure, characterized in that it includes a coaxial resonator, an HTCC board, an MMIC radio frequency chip, and a coaxial transmission line using any one of claims 1 to 7;

[0025] The MMIC RF chip and the coaxial resonator are set on the surface of the HTCC board, the coaxial transmission line is set inside the HTCC board, and the top of the through-hole transmission line in the center of the coaxial transmission line is provided with a pad, which is set on the surface of the HTCC board.

[0026] The MMIC RF chip contains a power amplifier. Gold wires connect the MMIC RF chip to the pads. The RF transmission signal emitted by the MMIC RF chip is transmitted to the pads via the gold wires. The second harmonic signal component of the power amplifier in the RF transmission signal is short-circuited to ground via a coaxial resonator.

[0027] The present invention also provides a radio frequency transmission method based on a coaxial resonator, characterized by comprising the following steps:

[0028] Step 1: Based on the RF operating frequency of the power amplifier, design the capacitance value of the equivalent capacitance of the metal block and the inductance value of the equivalent inductance of the bonded alloy wire, so that the target resonant frequency of the LC resonator composed of the equivalent capacitance of the metal block and the equivalent inductance of several bonded alloy wires is equal to the second harmonic of the operating frequency of the power amplifier.

[0029] Step 2: The second harmonic signal component transmitted to the pads is transferred to the equivalent capacitance of the metal block via the equivalent inductance of the bonding wire, achieving a short circuit to ground for the second harmonic. Beneficial effects:

[0030] Beneficial Effects: This invention provides a coaxial resonator with harmonic suppression, an RF transmission structure, and a method. A coaxial resonator with harmonic suppression is added to the RF transmission path of an HTCC component in chip assembly applications. A resonator resonating at the second harmonic frequency is formed around the coaxial transmission line using the equivalent capacitance of a metal block and the equivalent inductance of bonding wires. This short-circuits the second harmonic signal to ground, thus suppressing the second harmonic of the entire system. In this invention, the metal block can be a surface metal, placed on the surface of the HTCC board through an insulating medium. The bonding wires are also components originally used in system assembly, requiring no additional processes or devices, resulting in low cost. Furthermore, integrating this resonator into the RF signal transmission path eliminates the need for additional assembly space, offering significant advantages for highly integrated applications. Compared to existing technologies, the coaxial resonator with harmonic suppression in this solution offers advantages such as simple assembly, low cost, and small space requirement. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of a coaxial resonator with harmonic suppression according to an embodiment of the present invention;

[0032] Figure 2 This is a flowchart of the HTCC radio frequency transmission method according to an embodiment of the present invention. Detailed Implementation

[0033] like Figures 1 to 2 As shown, the present invention provides a coaxial resonator with harmonic suppression, a radio frequency transmission structure and method. Figure 1 This is a schematic diagram of a coaxial resonator with harmonic suppression according to an embodiment of the present invention; Figure 2 This is a flowchart of the HTCC radio frequency transmission method according to an embodiment of the present invention.

[0034] Example 1: Please refer to Figure 1 The present invention provides a coaxial resonator with harmonic suppression. The coaxial resonator includes: a metal block equivalent capacitance disposed on the surface of an HTCC board and located outside the coaxial transmission line, and a plurality of bonded alloy wire equivalent inductances connected between the metal block equivalent capacitance and the pads of the coaxial transmission line.

[0035] An insulator is placed between the equivalent capacitance of the metal block and the surface layer of the HTCC board. Based on the RF operating frequency of the power amplifier, the capacitance value of the equivalent capacitance of the metal block and the inductance value of the equivalent inductance of the bonding wire are designed so that the target resonant frequency of the LC resonator composed of the equivalent capacitance of the metal block and several equivalent inductances of the bonding wire are equal to the second harmonic of the operating frequency of the power amplifier. This allows the second harmonic signal component transmitted to the pad to be transmitted to the equivalent capacitance of the metal block via the equivalent inductance of the bonding wire, thus achieving a short circuit of the second harmonic to ground.

[0036] In this embodiment of the invention, a coaxial resonator with harmonic suppression is added to the RF transmission path of the HTCC component in chip assembly applications. A resonator resonating at the second harmonic frequency is formed around the coaxial transmission line using the equivalent capacitance of a metal block and the equivalent inductance of the bonding wires. This short-circuits the second harmonic signal to ground, thus suppressing the second harmonic of the entire system. In this solution, the metal block can be a surface metal layer placed on the surface of the HTCC board through an insulating medium. The bonding wires are also components originally used in system assembly, requiring no additional processes or devices, resulting in low cost. Furthermore, integrating this resonator into the RF signal transmission path eliminates the need for additional assembly space, offering significant advantages for highly integrated applications. Compared to existing technologies, the coaxial resonator with harmonic suppression in this solution offers advantages such as simple assembly, low cost, and small space requirements.

[0037] The following is based on Figure 1 Please provide an explanation.

[0038] like Figure 1 As shown, the dashed box represents the upper surface of the HTCC board. The coaxial transmission line is located inside the HTCC board (the board thickness is not shown in the figure). The coaxial transmission line (gray area) is implemented through the through-hole of the HTCC board. The RF signal transmission path is as follows: output from the MMIC RF chip, transmitted through gold wire to the pad of the coaxial transmission line, and then transmitted through the transmission line to the subsequent antenna and other transmission structures.

[0039] In this embodiment of the invention, a series LC resonator is formed by the equivalent capacitance of the metal block around the coaxial transmission line (green ring in the figure) and the equivalent inductance of several bonding wires connected between the equivalent capacitance of the metal block and the pad. Since there is an insulator between the equivalent capacitance of the metal block and the surface layer of the HTCC board, the equivalent capacitance of the metal block is in a floating state. When the target resonant frequency of the LC resonator is equal to the second harmonic, the second harmonic signal component transmitted to the pad will be transmitted to the floating equivalent capacitance of the metal block through the equivalent inductance of the bonding wires, realizing the second harmonic short circuit to ground, thereby achieving harmonic suppression.

[0040] In some embodiments, the capacitance value of the equivalent capacitance of the metal block and the inductance value of the equivalent inductance of the bonding wire are set in the following steps S1-S3:

[0041] S1, Based on the RF operating frequency of the power amplifier, calculate the second harmonic of the power amplifier's operating frequency to obtain the target resonant frequency;

[0042] S2, based on the target resonant frequency, determine the product of the capacitance value of the equivalent capacitance of the metal block and the inductance value of the equivalent inductance of the bonding wire, as the target value.

[0043] In this embodiment, the formula for calculating the target value is as follows: ,in, , In the formula, This refers to the radio frequency operating frequency of the power amplifier. The target resonant frequency, For the target value, The inductance value is the equivalent inductance of the bonding alloy wire. This is the capacitance value of the equivalent capacitance of the metal block.

[0044] S3, based on the target value, control the area of ​​the metal block to determine the capacitance design value of the equivalent capacitance of the metal block, and control the number, length and radius of the bonding wires to determine the inductance design value of the equivalent inductance of the bonding wires.

[0045] In some implementations, based on target values, the design value of the equivalent capacitance of the metal block is determined by controlling the area of ​​the metal block, and the design value of the inductance of the equivalent inductance of the bond wires is determined by controlling the number, length, and radius of the bond wires, including:

[0046] Determine the area of ​​the metal block, and based on the dielectric constant and thickness of the HTCC board, determine the design value of the equivalent capacitance of the metal block.

[0047] Based on the target value and the capacitance design value, determine the inductance design value of the equivalent inductance of the bonding alloy wire.

[0048] Based on the inductance design values, adjust the number, length, and radius of the bonding alloy wires.

[0049] In this embodiment, the capacitor design value can be determined first, and then the inductor design value can be determined based on the quotient of the target value and the capacitor design value. This allows for the adjustment of the number, length, and radius of the bonding wires. Since the metal block needs to be designed during the fabrication of the HTCC board, its area is difficult to change. However, the number, length, and diameter of the bonding wires are relatively easy to adjust. Therefore, in this embodiment, the capacitor design value can be determined first, and then the bonding wires can be fine-tuned.

[0050] In this embodiment of the invention, the formula for calculating the capacitor design value is as follows: In the formula, This is the design value for the capacitor. The dielectric constant of the HTCC board is given. Let the area of ​​the metal block be... This refers to the dielectric thickness of the HTCC board.

[0051] In this embodiment of the invention, the formula for calculating the inductance design value is as follows: In the formula, This is the inductance design value. The length of the bonding alloy wire, Let be the radius of the bonding alloy wire. The number of bonding alloy wires.

[0052] In some implementations, based on target values, the design value of the equivalent capacitance of the metal block is determined by controlling the area of ​​the metal block, and the design value of the inductance of the equivalent inductance of the bond wires is determined by controlling the number, length, and radius of the bond wires, including:

[0053] Determine the quantity, length, and radius of the bonding wire, and determine the inductance design value of the equivalent inductance of the bonding wire;

[0054] Based on the target value and the inductance design value, determine the capacitance design value of the equivalent capacitance of the metal block;

[0055] Adjust the area of ​​the metal block based on the capacitor design value.

[0056] In this embodiment, since the metal blocks need to be designed during the fabrication of the HTCC board, the area of ​​the metal blocks is inconvenient to change, making it difficult to adjust the capacitance design value. To address this drawback, this embodiment has multiple spaced metal blocks on the top surface of the HTCC board, located around the coaxial transmission line. The capacitance value of the equivalent capacitance of the metal blocks is adjusted based on the number of metal blocks connected by the bonding wires. Therefore, this embodiment allows for determining the inductance design value first, followed by fine-tuning the area of ​​the metal blocks.

[0057] Example 2: Figure 1 As shown, this embodiment also provides an HTCC radio frequency transmission structure, including: an HTCC board, an MMIC radio frequency chip, a coaxial transmission line, and a coaxial resonator as described in any embodiment of the specification;

[0058] The MMIC RF chip and the coaxial resonator are set on the surface of the HTCC board, the coaxial transmission line is set inside the HTCC board, and the top of the through-hole transmission line in the center of the coaxial transmission line is provided with a pad, which is set on the surface of the HTCC board.

[0059] The MMIC RF chip contains a power amplifier. Gold wires connect the MMIC RF chip to the pads. The RF transmission signal emitted by the MMIC RF chip is transmitted to the pads via the gold wires. The second harmonic signal component of the power amplifier in the RF transmission signal is short-circuited to ground via a coaxial resonator.

[0060] It should be noted that the above-mentioned HTCC radio frequency transmission structure embodiment and the coaxial resonator embodiment belong to the same concept. For details of its implementation process, please refer to the coaxial resonator embodiment, which will not be repeated here.

[0061] Example 3: This example also provides a radio frequency transmission method based on a coaxial resonator, including the following steps:

[0062] Step 1: Based on the RF operating frequency of the power amplifier, design the capacitance value of the equivalent capacitance of the metal block and the inductance value of the equivalent inductance of the bonded alloy wire, so that the target resonant frequency of the LC resonator composed of the equivalent capacitance of the metal block and the equivalent inductance of several bonded alloy wires is equal to the second harmonic of the operating frequency of the power amplifier.

[0063] Step 2: The second harmonic signal component transmitted to the pad is transmitted to the equivalent capacitance of the metal block through the equivalent inductance of the bonding wire, thereby achieving a short circuit of the second harmonic to ground.

[0064] This invention provides a harmonic-suppressed quasi-coaxial resonator, RF transmission structure, and method. A harmonic-suppressed quasi-coaxial resonator is added to the RF transmission path of an HTCC component in chip assembly applications. A resonator resonating at the second harmonic frequency is formed around the quasi-coaxial transmission line using the equivalent capacitance of a metal block and the equivalent inductance of bonding wires. This short-circuits the second harmonic signal to ground, thus suppressing the second harmonic of the entire system. In this invention, the metal block can be a surface metal layer placed on the surface of the HTCC board through an insulating dielectric. The bonding wires are also components already used in system assembly, eliminating the need for additional processes and devices, resulting in low cost. Furthermore, integrating this resonator into the RF signal transmission path requires no additional assembly space, offering significant advantages for highly integrated applications. Compared to existing technologies, this harmonic-suppressed quasi-coaxial resonator offers advantages such as simple assembly, low cost, and small space requirement.

[0065] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. However, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A coaxial resonator with harmonic suppression, characterized in that, This includes the equivalent capacitance of a metal block disposed on the surface of the HTCC board and located outside the coaxial transmission line, and several bonded wire equivalent inductances connected between the equivalent capacitance of the metal block and the pads of the coaxial transmission line. An insulator is placed between the equivalent capacitance of the metal block and the surface layer of the HTCC board. Based on the RF operating frequency of the power amplifier, the capacitance value of the equivalent capacitance of the metal block and the inductance value of the equivalent inductance of the bonding wire are designed so that the target resonant frequency of the LC resonator composed of the equivalent capacitance of the metal block and several equivalent inductances of the bonding wire are equal to the second harmonic of the operating frequency of the power amplifier. This allows the second harmonic signal component transmitted to the pad to be transmitted to the equivalent capacitance of the metal block via the equivalent inductance of the bonding wire, thus achieving a short circuit of the second harmonic to ground.

2. The coaxial resonator with harmonic suppression according to claim 1, characterized in that, The method for setting the capacitance value of the equivalent capacitance of the metal block and the inductance value of the equivalent inductance of the bonding wire is as follows: Step S1: Based on the RF operating frequency of the power amplifier, calculate the second harmonic of the power amplifier's operating frequency to obtain the target resonant frequency; Step S2: Based on the target resonant frequency, determine the product of the capacitance value of the equivalent capacitance of the metal block and the inductance value of the equivalent inductance of the bonding wire, and use it as the target value; Step S3: Based on the target value, control the area of ​​the metal block to determine the capacitance design value of the equivalent capacitance of the metal block, and control the number, length and radius of the bonding wires to determine the inductance design value of the equivalent inductance of the bonding wires.

3. The coaxial resonator with harmonic suppression according to claim 2, characterized in that, The formula for calculating the target value in step S2 is as follows: ,in, , , This refers to the radio frequency operating frequency of the power amplifier. The target resonant frequency, For the target value, The inductance value is the equivalent inductance of the bonding alloy wire. This is the capacitance value of the equivalent capacitance of the metal block.

4. The coaxial resonator with harmonic suppression according to claim 2, characterized in that, Step S3 includes the following steps: Step S3.1: Determine the area of ​​the metal block, and in conjunction with the dielectric constant and thickness of the HTCC board, determine the design value of the equivalent capacitance of the metal block. Step S3.2: Based on the target value and the capacitance design value, determine the inductance design value of the equivalent inductance of the bonding alloy wire; Step S3.3: Based on the inductance design value, adjust the number, length, and radius of the bonding wire.

5. The coaxial resonator with harmonic suppression according to claim 4, characterized in that, The formula for calculating the capacitor design value in step S3 is as follows: In the formula, This is the design value for the capacitor. The dielectric constant of the HTCC board is given. Let the area of ​​the metal block be... The dielectric thickness of the HTCC board; The formula for calculating the inductance design value in step S3 is as follows: In the formula, This is the inductance design value. The length of the bonding alloy wire, Let be the radius of the bonding alloy wire. The number of bonding alloy wires.

6. The coaxial resonator with harmonic suppression according to claim 2, characterized in that, Step S3 includes the following steps: Step S3.4: Determine the quantity, length, and radius of the bonding wires, and determine the inductance design value of the equivalent inductance of the bonding wires; Step S3.5: Based on the target value and the inductance design value, determine the capacitance design value of the equivalent capacitance of the metal block; Step S3.6: Adjust the area of ​​the metal block based on the capacitor design value.

7. The coaxial resonator with harmonic suppression according to claim 6, characterized in that, On the surface of the HTCC board, around the coaxial transmission line, there are multiple metal blocks with partitions. The capacitance value of the equivalent capacitance of the metal blocks is adjusted based on the number of metal blocks connected by the bonding wire.

8. A radio frequency transmission structure, characterized in that, Includes the use of any one of claims 1 to 7, such as a coaxial resonator, HTCC board, MMIC RF chip, or coaxial transmission line; The MMIC RF chip and the coaxial resonator are set on the surface of the HTCC board, the coaxial transmission line is set inside the HTCC board, and the top of the through-hole transmission line in the center of the coaxial transmission line is provided with a pad, which is set on the surface of the HTCC board. The MMIC RF chip contains a power amplifier. Gold wires connect the MMIC RF chip to the pads. The RF transmission signal emitted by the MMIC RF chip is transmitted to the pads via the gold wires. The second harmonic signal component of the power amplifier in the RF transmission signal is short-circuited to ground via a coaxial resonator.

9. A radio frequency transmission method based on a coaxial resonator, characterized in that, Includes the following steps: Step 1: Based on the RF operating frequency of the power amplifier, design the capacitance value of the equivalent capacitance of the metal block and the inductance value of the equivalent inductance of the bonded alloy wire, so that the target resonant frequency of the LC resonator composed of the equivalent capacitance of the metal block and the equivalent inductance of several bonded alloy wires is equal to the second harmonic of the operating frequency of the power amplifier. Step 2: The second harmonic signal component transmitted to the pad is transmitted to the equivalent capacitance of the metal block through the equivalent inductance of the bonding wire, thereby achieving a short circuit of the second harmonic to ground.

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