Ka-band ultra-wideband miniaturized frequency converter

Abstract

The application provides a ka-band ultra-wideband miniaturized frequency converter, which comprises a tube shell, two multilayer printed boards, radio frequency BGA balls, ground BGA balls and a ka-band wideband down-conversion circuit, the tube shell encapsulates the two multilayer printed boards, the radio frequency BGA balls and the ground BGA balls in a system level of the ka-band wideband down-conversion circuit, the multilayer printed boards are vertically interconnected through radio frequency transmission lines, have through holes at the same positions in the vertical direction, the radio frequency BGA balls are arranged below the through holes, the ground BGA balls are arranged around the radio frequency BGA balls at equal intervals, the radio frequency signals between the two multilayer printed boards in the vertical direction are transmitted through the radio frequency BGA balls and the ground BGA balls, the ka-band wideband down-conversion circuit is arranged on the surface of the two multilayer printed boards, and the ka-band wideband down-conversion circuit is used for down-converting the input ka-band ultra-wideband radio frequency signals to L-band intermediate frequency signals. The application solves the technical problem of miniaturizing the ka-band ultra-wideband frequency converter through the vertical interconnection of the multilayer printed boards through the radio frequency transmission lines, the radio frequency BGA transmission, the multilayer stacking process of the radio frequency printed boards and the ka-band wideband down-conversion circuit.

Description

Technical Field

[0001] This invention relates to the field of microwave and millimeter-wave circuits, and more particularly to a Ka-band ultra-wideband miniaturized frequency converter. Background Technology

[0002] Microwave frequency converters are a core component of modern communication systems, widely used in radar communication, electronic reconnaissance, telemetry and remote sensing, phased array radar, and other fields. With the rapid development of communication technology, system integration is increasing, especially in radar front-ends where miniaturization of frequency converters is becoming increasingly crucial. Traditional frequency converters, with their large size, weight, and high power consumption, can no longer meet the needs of current projects. This is particularly true for vehicle-mounted, shipborne, and airborne equipment, which place high demands on product weight and miniaturization. Therefore, there is an urgent need to develop a high-performance, miniaturized frequency converter. Summary of the Invention

[0003] To address the above problems, this invention provides a ka-band ultra-wideband miniaturized frequency converter.

[0004] This invention provides a ka-band ultra-wideband miniaturized frequency converter, comprising: a housing, two multilayer printed circuit boards, an RF BGA ball, a grounding BGA ball, and a ka-band wideband downconversion circuit.

[0005] The casing encapsulates two multilayer printed circuit boards, an RF BGA ball, a ground BGA ball, and a ka-band broadband downconversion circuit system-in-package.

[0006] The two multilayer printed circuit boards are vertically interconnected via radio frequency transmission lines.

[0007] The circuit has through-holes at the same position in the vertical direction through the two multilayer printed circuit boards. The radio frequency BGA ball is arranged below the through-hole, and the plurality of ground BGA balls are arranged around the radio frequency BGA ball at equal intervals. The radio frequency BGA ball and the ground BGA ball are coaxially connected to transmit radio frequency signals between the two multilayer printed circuit boards in the vertical direction.

[0008] The ka-band broadband downconversion circuit is arranged on the surface of the two multilayer printed circuit boards. The ka-band broadband downconversion circuit is used to downconvert the input ka-band ultra-wideband radio frequency signal to an L-band intermediate frequency signal.

[0009] Preferably, the vias for the transition between the microstrip line and the stripline of the multilayer printed circuit board include RF signal vias and ground vias, and the distance b between the ground via and the RF signal via is equal to twice the diameter a of the RF signal via.

[0010] Preferably, the diameter 2R of the RF BGA ball is equal to the diameter 2r of the ground BGA ball; the distance d between the RF BGA ball and the ground BGA ball is equal to 1.2R.

[0011] Preferably, the Ka-band broadband downconverter circuit takes the input Ka-band ultra-wideband radio frequency signal, filters it through a first pre-selected RF input filter, amplifies the low-noise signal through a first amplifier, then enters a first digitally controlled attenuator to achieve adjustable gain, then enters a second amplifier for amplification, then enters a first mixer for mixing with a first local oscillator signal, the first intermediate frequency signal output after mixing is filtered by a second filter, amplified by a third amplifier, filtered by a third filter to remove spurious signals, then enters a second mixer for a second mixing with the second local oscillator signal, the output L-band intermediate frequency signal is amplified by a fourth amplifier and filtered by a fourth filter, then enters a second digitally controlled attenuator for adjustable gain, amplified by a fifth amplifier and filtered by a sixth filter to output an L-band intermediate frequency signal without spurious signals.

[0012] The beneficial effects of this invention are:

[0013] This invention achieves spatial integration in the (x, y, z planes) through three-dimensional stacking technology and multi-layer packaging adapter boards. By utilizing the space in the Z direction, the space utilization rate can be increased several times. The design of the printed circuit board circuit and the design of the three-dimensional space realize the signal transmission in three-dimensional space and solve the problem of miniaturization of frequency converters. Attached Figure Description

[0014] Figure 1 A 3D schematic diagram of an ultra-wideband miniaturized system-integrated frequency converter;

[0015] Figure 2 This is a schematic diagram of vertical interconnection of multilayer printed circuit boards.

[0016] Figure 3 A schematic diagram of the HFSS transmission model for vertical interconnection of multilayer printed circuit boards;

[0017] Figure 4 For vertical interconnect input / output standing wave ratios of multilayer printed circuit boards;

[0018] Figure 5 For vertical interconnect transmission loss of multilayer printed circuit boards;

[0019] Figure 6 This is a schematic diagram of an RF BGA transmission model;

[0020] Figure 7 Schematic diagram of HFSS transmission model for RF BGA

[0021] Figure 8 For RF BGA input / output standing wave ratios;

[0022] Figure 9 This refers to the transmission loss of the radio frequency BGA.

[0023] Figure 10 This is a schematic diagram of multi-layer stacked RF BGA transmission.

[0024] Figure 11 A comparative schematic diagram showing the bottom view of an RF BGA and a cross-sectional view of a coaxial cable;

[0025] Figure 12 This is a block diagram of a ka-band broadband downconverter circuit.

[0026] Figure 13 A 3D schematic diagram of an ultra-wideband miniaturized system-integrated frequency converter; Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0028] This invention provides a Ka-band ultra-wideband miniaturized frequency converter, comprising: a housing, two multilayer printed circuit boards (PCBs), an RF BGA ball, a ground BGA ball, and a Ka-band broadband downconversion circuit. The housing integrates the two multilayer PCBs, the RF BGA ball, the ground BGA ball, and the Ka-band broadband downconversion circuit into a system-in-package (SIP). Based on the concept of System-in-Package (SIP), this invention integrates various active and passive components with different functions into a single package to form a system or subsystem component with a single function. Through multilayer vertical interconnection of RF transmission lines, RF BGA transmission, multilayer stacking of RF PCBs, and the Ka-band broadband downconversion circuit, it achieves an integrated design of multiple chips (active and passive chips) or devices, realizing a Ka-band ultra-wideband miniaturized frequency converter, i.e., a SIP RF module. This solves the problems of large size, heavy weight, and high power consumption of traditional RF modules, and the SIP module has advantages such as high flexibility, high integration, and short design cycle.

[0029] The aforementioned vertical interconnection of multilayer printed circuit boards (PCBs) is used to achieve vertical interconnection transmission of DC-40GHz radio frequency signals via coplanar waveguides and striplines. The key to DC-40GHz ultra-wideband RF multilayer transmission lies in the design of the via diameter and the degree of interconnection between the microstrip line and stripline. The continuity and impedance matching of RF signal transmission determine the success of DC-40GHz signal transmission. Multilayer PCB vertical interconnection, as shown... Figure 2 As shown, the HFSS transmission model for multilayer printed circuit boards vertical interconnect is as follows: Figure 3As shown. The electromagnetic characteristics of the vertical interconnect are optimized through modeling and simulation to achieve signal transmission continuity and ensure signal transmission quality, thereby improving system stability and reliability. The vias used for transitioning from microstrip lines to striplines on the multilayer printed circuit board include RF signal vias and ground shielding vias. The spacing b between the ground shielding via and the RF signal via is equal to twice the diameter a of the RF signal via. Simulation data is shown below. Figure 4 , Figure 5 As shown, an HFSS simulation model of vertical interconnect signal transmission on a multilayer printed circuit board (PCB) was established using the electromagnetic field simulation software HFSS to perform S-parameter simulation. Simulation data obtained through 3D model simulation software is shown in the figure above. Within the DC–40GHz range, the VSWR at the input and output ports is less than 1.14, and the insertion loss is less than or equal to 0.30. The simulation data demonstrates that coplanar waveguides and striplines exhibit excellent transmission characteristics at high frequencies, making them suitable for high-frequency transmission in the KA and above frequency bands. Not only is the port VSWR good, but the transmission loss is also low. Therefore, vertical interconnect transmission on multilayer PCBs provides a method for transmitting RF signals, facilitating inter-board integration of PCBs and offering a method for achieving high-integration designs.

[0030] The system has through-holes at the same vertical position penetrating both multilayer printed circuit boards. The RF BGA ball is positioned below the through-hole. Multiple ground BGA balls are equally spaced and arranged around the RF BGA ball. The RF BGA ball and the ground BGA ball achieve near-coaxial connection to transmit DC-40GHz RF signals between the two multilayer printed circuit boards in the vertical direction. The key to DC-40GHz ultra-wideband RF BGA transmission lies in the diameter of the BGA ball and the spacing design between the RF BGA and the ground BGA, which determines whether signal transmission from DC to 40GHz can be achieved. A schematic diagram of the BGA transmission model is shown below. Figure 6 As shown. The RF BGA transmission design involves calculating and simulating a BGA transmission model suitable for DC-40GHz RF transmission. Using the electromagnetic field simulation software HFSS, an HFSS simulation model of the RF BGA signal transmission is established for S-parameter simulation. The RF BGA transmission model is shown below. Figure 7 As shown, the simulation data is as follows Figure 8 , Figure 9As shown in the figure, the diameter 2R of the RF BGA ball is equal to the diameter 2r of the ground BGA ball; the distance d between the RF BGA ball and the ground BGA ball is equal to 1.2R. Simulation using 3D model software yields simulation data as shown in the figure above. Within DC-40GHz, the VSWR of the input and output ports is less than 1.2, and the insertion loss is less than or equal to 0.35. The simulation data shows that the RF BGA has excellent transmission characteristics at high frequencies, suitable for high-frequency transmission in KA and above frequency bands. It not only has good port VSWR but also low transmission loss. Therefore, RF BGA transmission provides a method for RF signal transmission, facilitating inter-board integration of printed circuit boards and providing a method for achieving high-integration designs. Traditional RF transmission technology generally uses two-dimensional (X, Y) plane transmission via microstrip lines. When transmission in the Z direction is required, vertical interconnection using RF beads is necessary. However, the assembly of these beads requires a metal cavity as a carrier, resulting in a large volume that cannot be used in highly integrated SIP modules. Figure 10 , 11 As shown, this invention uses BGA technology, commonly used for low-frequency digital signals, and achieves radio frequency transmission of BGA through architecture optimization and modeling simulation. Figure 10 , Figure 11 The architecture design enables BGA to achieve coaxial characteristics, thus enabling RF transmission in the vertical direction of the millimeter-wave band, solving the transmission problem in the Z direction of three-dimensional stacking technology, and making the integration of SIP higher.

[0031] The Ka-band broadband downconverter circuit is arranged on the upper surface of at least two multilayer printed circuit boards. This circuit performs a secondary frequency conversion on the input Ka-band ultra-wideband radio frequency signal, downconverting the RF signal to an L-band intermediate frequency signal. This downconversion is used to achieve the downconversion of the Ka-band ultra-wideband radio frequency signal to an L-band intermediate frequency signal for demodulation by backend equipment. Two digitally controlled attenuators are used to achieve an adjustable dynamic range of 0–60 dB. The internal mixer integrates a local oscillator drive amplifier to amplify the local oscillator signal. The specific working principle block diagram of the Ka-band broadband downconverter circuit is shown below. Figure 12As shown, the Ka-band broadband downconverter circuit takes the input Ka-band ultra-wideband radio frequency signal, filters it through a first pre-selected RF input filter, amplifies the low-noise signal through a first amplifier, then enters a first digitally controlled attenuator for adjustable gain, then enters a second amplifier for amplification, then enters a first mixer for mixing with the first local oscillator signal, the output first intermediate frequency signal after mixing is filtered by a second filter, amplified by a third amplifier, filtered by a third filter to remove spurious signals, then enters a second mixer for a second mixing with the second local oscillator signal, the output L-band intermediate frequency signal is amplified by a fourth amplifier, filtered by a fourth filter, then enters a second digitally controlled attenuator for adjustable gain, amplified by a fifth amplifier, filtered by a sixth filter, and finally outputs an L-band intermediate frequency signal without spurious signals.

[0032] This invention is primarily applied to microwave and millimeter-wave electronic systems and equipment, such as satellite communication channel equipment and phased-array radar. SIP (Self-Installing RF) modules are mainly used to address the miniaturization and cost reduction of large-scale, mass-produced equipment. Especially in airborne radar, where fighter jets are small and have high weight requirements, SIP RF modules solve the weight and size issues of airborne equipment. Increasing the number of SIP RF modules can significantly improve the tactical and technical specifications of fighter jet radar, enhance detection range and intelligence gathering capabilities, and greatly improve battlefield situational awareness and survivability. Furthermore, SIP RF modules can be mass-produced and automated, significantly reducing production costs, improving product reliability, and further reducing equipment costs. This facilitates the widespread use of weapons and communication equipment, such as communication base stations, airborne, shipborne, and portable communication and reconnaissance equipment, phased-array radar, and satellite communication stations.

[0033] Compared with similar domestic products, the miniaturized frequency converter of this invention has leading performance indicators. The specific parameters are compared in the table below:

[0034]

[0035]

[0036] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A Ka-band ultra-wideband miniaturized frequency converter, characterized in that It comprises: a tube shell, two multi-layer printed boards, a radio frequency BGA ball, a ground BGA ball, and a ka-band broadband down-conversion circuit. The tube shell system-in-package encapsulates the two multi-layer printed boards, the radio frequency BGA ball, the ground BGA ball, and the ka-band broadband down-conversion circuit. The two multi-layer printed boards are vertically interconnected through radio frequency transmission lines. The two multi-layer printed boards have through holes at the same position in the vertical direction, the radio frequency BGA ball is arranged below the through hole, and a plurality of ground BGA balls are arranged around the radio frequency BGA ball at equal intervals, so that the radio frequency signals between the two multi-layer printed boards in the vertical direction are transmitted through the radio frequency BGA ball and the ground BGA ball. The via hole between the microstrip line and the stripline of the multi-layer printed board comprises an RF signal via hole and a shield ground via hole, the spacing b between the RF signal via hole and the shield ground via hole is equal to twice the diameter a of the RF signal via hole; the diameter 2R of the radio frequency BGA ball is equal to the diameter 2r of the ground BGA ball; and the spacing d between the radio frequency BGA ball and the ground BGA ball is equal to 1.2R. The ka-band broadband down-conversion circuit is arranged on the surface of the two multi-layer printed boards, and is used for down-converting the input ka-band ultra-wideband radio frequency signal to an L-band intermediate frequency signal.

2. The miniaturized Ka-band UWB frequency converter according to claim 1, characterized in that, The ka-band broadband down-conversion circuit filters the input ka-band ultra-wideband radio frequency signal through a pre-selected first filter, and then amplifies the low-noise signal through a first amplifier. Then, the signal enters a first digital control attenuator to realize gain adjustment, and then enters a second amplifier for amplification. Then, the signal enters a second mixer and a second local oscillator signal for the second mixing. After mixing, the output L-band intermediate frequency signal is amplified through a fourth amplifier and filtered through a fourth filter. Then, the signal enters a second digital control attenuator for gain adjustment, and then is amplified through a fifth amplifier and filtered through a sixth filter to output a L-band intermediate frequency signal without spurious signals.

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