KR20220042999A - Non-galvanic interconnect for planar rf devices - Google Patents

Abstract

The present invention relates to a radio frequency (RF) system comprising two planar RF devices coupled by a non-galvanic interconnect. According to various embodiments, the two planar RF devices are separated by a dielectric layer, each RF device having a plurality of pads disposed on a surface and surrounded by a common electrode serving as a grounded metal shield. Here, the pad of the first RF device and the pad of the second RF device face each other, and capacitive coupling is implemented between the pads. The present invention can reduce the complexity and size of the system and provide a more reliable and easily producible interconnect between the elements of the RF system.

Description

NON-GALVANIC INTERCONNECT FOR PLANAR RF DEVICES

TECHNICAL FIELD The present invention relates to radio engineering, and more particularly, to an RF system comprising two planar RF devices coupled via a non-galvanic interconnect.

Currently, mm-wave antennas are, for example, 5G (28 GHz), 　WiGig (60 GHz), Beyond 5G (60 GHz), 　 6G (sub-THz 　 range), long-distance wireless power transmission, 　 LWPT (24 GHz) and automotive radar systems (24 GHz, 　 79 GHz), such as communication systems of new and promising data transmission standards, applications continue to expand in various fields of technology.

In all these applications, the following requirements apply to ensure high-volume production and operation of the antenna array:

-Precise assembly of radio frequency integrated circuits (RFICs);

-　Low　Interconnection loss;

-　Inexpensive and compact structure;

-　Simple　Assembly Procedure;

-　Compact power supply system;

-　high 　efficiency, etc.

The prior art uses a galvanic contact to connect the RFIC with a mm-wave antenna array (antenna) and mount it on a printed circuit board. The most common examples of such galvanic contacts are ball grid array (BGA) and flip-chip (surface mount method). Flip-chip is also referred to as C4 (controlled collapse chip connection).

BGA is a type of surface-mount packaging used to mount integrated circuits on carriers of printed circuit boards (PCBs).

Flip-chip is one method of packaging integrated circuits, in which the chip is mounted on bumps provided directly on its chip pad.

This approach has the problem of damaging the galvanic connections between, for example, the components being connected (RFIC and antenna, or RFIC and PCB) due to vibration, thermal expansion, mechanical stress, etc. Also, when heating, incorrect assembly or uneven thermal expansion of the connected components may occur, causing relative movement of the component pads. This changes the RF transition parameters between the connected components and increases losses or causes contact failure. Therefore, it can be confirmed that the prior art has low reliability and accuracy, particularly in the case of microwaves.

On the other hand, the desire to further increase the function per unit volume and weight of equipment entails increasing the number of switching leads, reducing the length of the conduction path, and reducing the contact spacing, which, in turn, is the precision of the contact between the components of the RF equipment. and increasing the requirements for reliability.

Another disadvantage of the above approach is that it is very difficult to detect the soldering defects after soldering the chip. It is common to use x-rays or special microscopes to solve this problem, but these are expensive.

US published patent US20170345761A1 discloses a package structure comprising a first die, a second die, a third die, a molding compound, a first redistribution layer, an antenna and a conductive element. The first die, the second die and the third die are molded with a molding compound. The first redistribution layer is disposed on the molding compound and is electrically connected to the first die, the second die and the third die. An antenna is positioned on the molding compound and electrically connected to a first die, a second die and a third die, wherein the distance of the electrical connection path between the first die and the antenna is the electrical connection path between the second die and the antenna and the third die. It is less than or equal to the distance of the electrical connection path between the die and the antenna. The conductive elements are connected to a first redistribution layer, wherein the first redistribution layer is positioned between the conductive element and the molding compound. However, the galvanic connection between the control integrated circuit and the antenna PCB is sensitive to assembly quality and may affect device operation.

US published patent US20090289869A1 discloses an antenna structure for coupling electromagnetic energy between a chip and an off-chip element, comprising a first resonant structure disposed on or within the chip. The first resonant structure is configured to have a first resonant frequency. The antenna structure also includes a second resonant structure disposed on or within the off-chip element. The second resonant structure is configured to have a second resonant frequency substantially equal to the first resonant frequency. The first resonant structure and the second resonant structure are mutually disposed within a near field distance of each other to form a coupled antenna structure configured to transfer electromagnetic energy between the chip and the off-chip device. Electromagnetic energy is transmitted at selected wavelengths in the sub-millimeter wavelength range from microwaves. The non-galvanic interconnect between the elements includes substantially inductive coupling by a two coil resonator having a narrow-band. The structure does not support mm-wave operation.

International Patent Publication WO2018/097556A1 discloses an antenna substrate having an array antenna comprising at least one radiating element disposed thereon; and a cover spaced at least a predetermined distance from the antenna substrate and having at least one relay radiating element arranged to correspond to the at least one radiating element. The radiating element has a size large enough to provide electromagnetic wave radiation. The device does not solve problems such as RFIC and antenna co-integration, but tends to deal with problems such as flip-chip and BGA technologies.

Thus, in the prior art, a simple, reliable and easily producible non-galvanic interconnect between elements of an RF system, for example, between a Radio-frequency Integrated Circuit (RFIC) and an antenna array. ), it is necessary to provide technology that can ensure

SUMMARY OF THE INVENTION The present invention aims to overcome at least some of the aforementioned problems.

According to the present invention, there is provided a radio frequency (RF) system comprising two planar RF devices separated by a dielectric layer, each of a first RF device and a second RF device being disposed on a surface and serving as a grounded metal shield has a plurality of pads surrounded by a common electrode that Also, the radio frequency system is configured to transmit a signal between the RF devices through the pad.

According to another embodiment, the radio frequency system further comprises at least one additional printed circuit board disposed between the first RF device and the second RF device, wherein the at least one additional printed circuit board is on a surface thereof. and pads respectively aligned with the pads of the first RF device and the second RF device, wherein the pads on the facing surfaces of the at least one additional printed circuit board are interconnected by vias and a transmission line.

The present invention provides a simple, compact, reliable, efficient, and easily producible non-galvanic interconnect of components of a radio frequency system with a wide operating bandwidth.

Hereinafter, the present invention will be described by way of description of preferred embodiments with reference to the accompanying drawings.
1 is a cross-sectional view of an RF system according to an exemplary embodiment of the present invention.
Figure 2 shows (a) a cross-sectional view of a portion of an RF system according to an exemplary embodiment including one pad on each PCB, and (b) a signal direction of the portion.
3 is an equivalent circuit diagram of a portion of the RF system shown in FIG. 2A;
4 is a schematic diagram of capacitive coupling between components of a single transition of an RF system according to the present invention;
Figure 5 shows the possible options for the geometry of the pad and the location of the vias.
It should be understood that the drawings may be presented schematically rather than to scale, and are primarily intended to enhance the understanding of the present invention.

Embodiments of the present invention are not limited to those described herein, and other embodiments that do not depart from the spirit and scope of the present invention are provided to experts in the art based on the information described in the following description and the general knowledge it will become clear

The present invention substantially replaces galvanic contact between two planar RF devices (eg, an antenna PCB, and a carrier control PCB with RFIC).

In general, the present invention is a radio frequency (RF) system consisting of two planar RF devices coupled via a non-galvanic interconnect. The present invention describes the transition between RF path portions made on two planar structures that can be produced with different manufacturing techniques. In various exemplary embodiments of the present invention, the RF system may be one of:

-connection of antenna path parts made on different PCBs by structural efficiency;

-Co-integration of antenna array and phase control system of components;

-Co-integration of systems of power distribution elements (distributors) and emitters, etc., manufactured by different technologies.

1 , the RF system is an antenna device 1 comprising first and second two printed circuit boards (PCBs) 2 , 3 separated by a dielectric layer; , the first PCB 2 comprises a part of the RF path of the system and an antenna emitter or set of antenna emitters (antenna array) 4 , and the second PCB 3 comprises the other part of the RF path of the system. part and a control RFIC chip (5). Both PCBs 2 and 3 have a plurality of pads 6 disposed on the surface and surrounded by a common electrode, and the pads of the first PCB 2 and the pads of the second PCB 3 are mutually They are opposite to each other, ie, the pads 6 and the common electrode of the first PCB 2 are disposed on the respective pads 6 and the common electrode of the second PCB 3 . Thus, the pads 6 and the common electrodes implement capacitive coupling to each other. Also, the pads of the first PCB 2 are connected to the RF path of the first PCB 2 via a via 7 , and the pads 6 of the second PCB 3 are similarly connected to the via 7 . connected to the RF path of the second PCB 3 via ?, which ultimately form one joint RF path. Thus, the signal is transmitted to and from the pads 6 via the via 7 .

In this exemplary embodiment of the present invention, the non-galvanic interconnect is configured to operate in millimeter and sub-millimeter wavelength ranges.

The gap between the PCBs is provided by spacers 8 and can be filled with air. The spacers 8 may be of any shape to provide the required spacing size. The spacers 8 may be made of a dielectric and may be placed anywhere between the PCBs. Alternatively, the spacers 8 may be made of a conductive material and should be spaced apart from the pads. In the future, it may be possible to fill the gaps between the PCB (and other components of the device) with a compound to protect it from external effects. In an alternative embodiment, the spacing between the PCBs may be formed of a solid dielectric that may also act as an adhesive between the PCBs. According to the present invention, the dielectric layer between the PCBs prevents galvanic contact between parts of the system RF path, and thus the present invention avoids disadvantages in the galvanic connection.

The best transition characteristics (minimum loss, maximum operating bandwidth) according to the invention will be achieved with the smallest possible spacing. This provides maximum capacitance and minimum transition impedance. If the gap is filled with air, its height must not be greater than half the diameter or half the maximum longitudinal dimension of the pad, which is sufficient to enable matching (matching) in the band (band) of sufficient electrical power between the pads. capacity will be provided. When the gap is filled with a dielectric having a dielectric constant of ε>1, the height of the gap may be increased.

2A is a cross-sectional view of a portion of an RF system according to an exemplary embodiment of the present invention including one pad on each PCB, ie, a cross-sectional view of a single non-galvanic transition in an RF system. A pad 62 on the surface of the first PCB 2 is disposed over the pad 63 on the surface of the second PCB 3 . The pad 62 on the 　 surface of the first PCB 2 is surrounded by the common electrode 92 and is separated therefrom at a predetermined interval. The pad 63 on the 　 surface of the second PCB 3 is surrounded by the common electrode 93 and is separated therefrom at a predetermined interval. In addition, the pad 62 is connected to a first port through a via 72 and a transmission line 82, from which a signal comes out in this embodiment. Similarly, the pad 63 is connected to a second port through a via 73 and a transmission line 83 and a signal is transmitted thereto.

It should be noted that vias 72 and 73 of FIG. 2A are aligned (eg, coaxially) or moved relative to each other. In an alternative embodiment, they can be aligned.

The pads 62 , 63 may thus be aligned (eg coaxially) or moved relative to each other.

The surfaces of the PCBs are separated by a dielectric layer and there is no galvanic connection, thus forming a non-galvanic RF interconnect.

The interface of the connection in Figure 2a includes, in each PCB, a transmission line, a common electrode, a matching transformer (described below), vias between the transmission line and the signal electrode layer, and a pad. The pads on each PCB are capacitively coupled electrodes.

In Fig. 2a, the transmission line is a symmetrical transmission line formed between two grounded metal layers. In general, transmission lines can be of any type (as described below).

Each signal via is surrounded by additional shielding vias interconnecting the grounded metal layer to prevent parasitic radiation (leakage) through the substrate.

FIG. 2B shows a signal direction in a part of the antenna device shown in FIG. 2A and a distribution of an electromagnetic field in this part. As indicated by the dashed line in FIG. 2B , the signal travels through the transmission line 82 , via 72 , pad 62 , dielectric layer, pad 63 , via 73 and transmission line 83 from the first port. through the second port. Under these conditions, signal transmission occurs with minimal loss. It should be noted that the signal can be transmitted in the opposite direction in the same way.

3 is an equivalent circuit diagram of a portion of the RF system shown in FIG. 2A.

In FIG. 3 , L1 and L2 represent the inductance of the vias and transmission line portion in the first PCB and the second PCB, respectively, C _pad is the capacitance between the two pads, and C _GND is the first PCB and the second PCB, respectively is the capacitance in the gap between the common electrodes around the pads disposed on , and R _leak is the leakage impedance of the dielectric layer.

L1 and L2 can be adjusted by selecting the via diameter and the width of the transmission line section.

A large ground area (and hence capacitance) prevents EM power leakage into the gap between the PCB surfaces of the interconnect.

In order for the present system to function properly in the portion shown in FIG. 2A , a necessary resonance condition with the center frequency must be satisfied. The parameters of the components in the above section are selected in consideration of this condition.

simulation 1

The inventors of the present invention performed a simulation of a single transition operation according to the present invention to transmit a signal at a frequency of 140 GHz (suitable for 6G). According to the initial simulation data, the vias of the opposite PCB are placed in the center of the pad (ie opposite), and the 50μ gap between the PCBs is filled with a dielectric with ε=2.25. Simulations showed that the signal loss at the transition is about 1.2 dB, and the relative operating bandwidth of that transition is about 15%. The relative operating bandwidth is calculated as the ratio of the operating bandwidth to the center frequency in the ΔF/F ₀ range.

Thus, the present invention allows a non-galvanic interconnect to be provided between the control element and the antenna array, resulting in increased reliability, efficiency and adaptability to the manufacture of antenna devices and reducing assembly complexity and duration. , which has an advantage on the cost of the resulting device. The antenna device according to the present invention has a wide operating bandwidth, a small size and reduced losses.

It should be noted that the arrangement of vias for each pad affects the distribution of the electromagnetic field at each transition. For example, if the length around the pad is about half the wavelength of the slot line (the pad and common electrode being the electrode), the property of the transition loaded into this slot line is that an open transition across a transmission line having that electrical length is Because of the potential to convert to a closed transition (due to symmetry, half of the perimeter wavelength will load a port with two quarter-wave wavelength segments), which is a feed line with a small resistance (feeding line). will effectively load and cause a mismatch. More complex effects are also possible due to the fact that the complete transition structure will contain a line with four electrodes (two slot lines separated by an air gap), and the geometric symmetry of the structure (perpendicular to the electrode plane) Symmetry about the phosphorus axis) is almost impossible to achieve, which can lead to excitation of various types of waves in the structure.

Among the many possible options for the relative position of Via in the aforementioned transition, it should be noted in particular the following:

-　two 　vias　all 　move in the opposite direction;

-　The two 　vias are both centered;

-The two vias are all shifted in the same direction.

simulation 2

We further simulated the operation of a single transition according to the present invention in the V band (40-75 GHz) and the W band (75-110 GHz). The single transition in this simulation differs from the single transition in Simulation 1 described above in that the via moves in the opposite direction. Simulations show that the signal loss at this transition is about 1.2 dB, while the relative operating bandwidth of that transition is over 40%.

simulation 3

In addition, various options for placement of transmission lines and movement of vias in transitions were simulated. Without excluding vias and other locations of the transmission line with respect to the transition, the following situation was simulated:

- Two transmission lines placed on opposite sides of the transition, two vias moved to opposite sides of the transition:

- 　 two 　 transmission lines placed on one side of the transition, 　 two vias moved to the same side of the transition;

- Two transmission lines placed on one side of the transition, two vias placed in the center:

- 　 two 　 transmission lines placed on one side of the transition, 　 two vias moved to the opposite side.

According to the simulation, the position of the via has a significant effect on the s-parameter of the transition. As noted above, the worst match corresponds to the vias and feeding lines located on one side of the pad, where the unloaded side of the transition is mismatched to the transition port through the quarter-wave wavelength section, while the best match. corresponds to the vias and transmission lines located on the opposite side of the transition, where one of the ports loads the line, at the opposite end its impedance increases and stops mismatching the opposite port.

However, the geometry of the particular transition developed (the PCB material chosen, the size of the transition element, the type of transmission line used) may affect its parameters, and the parameters moving the vias may give results other than those described above. there is.

It should also be taken into account that the parasitic capacitance C _P at the breakpoint of the signal line arises at the transition between the signal line and ground (see Fig. 4). This reduces the transition impedance. A matching transformer (matching element) is needed at the end of the transmission line to compensate for the impedance drop at the end of the signal line and return the impedance to Z _in and Z _out of the initial impedance values on the input and output ports, respectively. In an exemplary embodiment, the matching transformer is a quarter-wave transformer configured as the end of the transmission line, and has a width that exceeds the width of the remaining transmission line. The vias are thus connected to the quarter-wave transformer, which is the end of the transmission line. Providing a transformer makes it possible to match the transition to the transmission line impedance (eg 50 Ohm), making the transition universal and usable at any point in the antenna path.

The matching 　 optimum position of the transformer is close to the above transition. The vias and pads can also adjust the transition impedance. However, in most designs (eg in the range of about 60 GHz), a matching transformer in the transmission line is more convenient for this purpose, since the diameter of the vias is selected from standard drill values and may be larger or smaller than the required size. because it can

In an alternative embodiment, the present invention may be applied to an “antenna-on-chip” structure. In this case, the antenna is placed directly on the control element chip. This means that instead of the second PCB containing the control element, this embodiment directly uses the control element chip. Pads are formed over the chip, which are coaxially disposed over the pads of the first PCB containing the antenna array upon assembly. This helps to further simplify the antenna device design.

In the present invention, various variations of the relative positions of various types of pads and vias may be used depending on the structural, functional and other requirements for the antenna device. 5 shows some exemplary shapes of pads and positions of vias.

In addition, the transmission line according to the present invention includes a symmetrical micro-strip line (as disclosed in the above embodiment), a non-symmetric micro-strip line, a coaxial line, a substrate integrated waveguide (SIW), a dielectric filling ( It should be noted that a waveguide with dielectric filling and a waveguide without dielectric filling may be implemented as one of a coplanar line, a grounding type coplanar line, and the like.

In an alternative embodiment, the transmission line may be omitted, for example, if the RFIC bump is used as the pad itself.

Elements containing a single transition on each PCB (transmission line, via, pad) may be of different sizes.

According to yet another alternative embodiment, the RF system may have at least one additional PCB disposed between the first and second PCBs, wherein the at least one additional PCB comprises pads of the first and second PCBs, respectively. Have the pads on the surface to be aligned. The pads on the opposite side surface of the at least one additional PCB are interconnected by vias and transmission lines. The arrangement of pads, vias and transmission lines in the at least one additional PCB is similar to the arrangement of these elements in the first PCB and in the second PCB. This embodiment can expand the ability to adapt the present antenna device to various structural, functional and other requirements in the development and production stages.

simulation 4

We further simulated the mutual influence between two adjacent single transitions according to the present invention. When the spacing between adjacent single transitions in the V band and W band is 1 mm, the coupling efficiency between adjacent transitions is less than -23 dB. For a 140 GHz operating frequency, when the spacing between adjacent single transitions is 0.6 mm, the coupling efficiency is less than -26 dB. These results suggest that this arrangement of transitions can be used for signal transmission.

simulation 5

In addition, we performed simulations for the stability of the transition properties described above while changing some of the geometric parameters such as gap height and changing the position of the PCB (and pads) with respect to each other. These changes are inevitably caused by the poor accuracy of PCB manufacturing and assembly. In general, the manufacturer guarantees an accuracy of at least 10% to comply with the specified layer thickness (thickness of the spacer) and, for example, the accuracy of etching the pads of transitional vias. These parameters were confirmed in this simulation.

According to simulations of the transition behavior in the 57-71 GHz band of the first PCB shifted relative to the second PCB along and across the feed lines by 10% relative to the size of the pad, this band is the It shows that motion is maintained despite the shift. Considering the wide-band behavior of transitions described above, it should be pointed out that for some systems, this movement (or, depending on the required operating bandwidth of the device, more than 10% relative to the pad size) may be specifically considered for transition structures. It is worth 　

As a result of simulating the above-described transition behavior while changing its gap height by 20% for a given height, it was found that the transition matching band remains stable despite these changes.

Accordingly, the present invention provides a simple, compact, reliable, efficient, and easily producible antenna device having a wide operating bandwidth.

The present invention can be used in wireless communication systems such as 5G, WiGig, Beyond 5G, 6G, which are developed standards.

When used in robotics and radar devices in autonomous vehicles, the present invention can be used to detect/avoid obstacles.

The present invention is also applicable to all types of wireless power transmission systems such as LWPT, outdoor/indoor, automobile, and mobile. Accordingly, high-efficiency power transmission is ensured in all scenarios.

Terms such as “first,” “second,” “third,” etc. may be used herein to describe various elements, components, regions, layers, and/or portions, such elements, configuration It should be understood that elements, regions, layers and portions are not limited by these terms. The above terms are only used to distinguish one element, component, region, layer or portion from another element, component, region, layer or portion. Accordingly, a first element, component, region, layer or portion may be referred to as a second element, component, resistor, layer or portion without departing from the scope of the present invention. In this description, the term “and/or” includes any and all combinations of one or more of each recited reference number. Elements referred to in the singular do not exclude plural elements, unless otherwise specified.

The function of an element designated as a single element in the above description or in a claim may actually be implemented by several components of the device, and conversely, the function of an element designated in the above description or claim may actually be implemented as a single element. may be implemented.

Although this disclosure does not teach specific software or hardware for implementing the devices in the drawings, those skilled in the art will not be limited to the concept of the present invention to specific software or hardware, and existing software and hardware may be used to implement the present invention. It will be appreciated that implementations may be possible. For example, hardware may include one or more specialized integrated circuits, digital signal processors, digital signal processing devices, programmable logic devices, user programmable gate arrays, processors, controllers, microcontrollers, microprocessors, electronic devices, and the present disclosure. It may be implemented in another electronic module, a computer, or a combination thereof configured to perform the functions described in .

While exemplary embodiments have been described in detail and shown in the accompanying drawings, such embodiments are illustrative only and not intended to limit the broader scope of the invention, as various other modifications will be apparent to those skilled in the art. It should be understood that the invention is not limited to the particular arrangements and structures shown as above.

Elements recited in the singular form do not exclude elements in the plural form unless otherwise specified.

The features recited in the various dependent claims, as well as the embodiments disclosed in various parts of the description, may be combined in order to achieve advantageous effects, even if the possibility of such combinations is not explicitly disclosed.

As described above, according to the present invention, there is provided a radio frequency (RF) system comprising two planar RF devices separated by a dielectric layer, each of a first RF device and a second RF device disposed on a surface and grounded and a plurality of pads surrounded by a common electrode serving as a metal shielding material, wherein the pads of the first RF device and the pads of the second RF device face each other, so that the capacitance between the pads and the common electrodes Implementing capacitive coupling, the radio frequency system may also be configured to transmit signals between the RF devices via a pad.

In an embodiment of a radio frequency system, the first RF device comprises a first printed circuit board comprising a portion of an RF path of the radio frequency system, wherein a portion of the RF path is provided through vias to the pads. It may include transmission lines connected to and also connected to the common electrode.

In another embodiment of the radio frequency system, the second RF device comprises a second printed circuit board comprising another portion of an RF path of the radio frequency system, wherein the other portion of the RF path connects to the pad through vias. and may also include transmission lines connected to the common electrode.

In another embodiment of the radio frequency system, the first RF device may include an antenna array, and the second RF device may include a radio frequency integrated circuit (RFIC).

In another embodiment of the radio frequency system, the vias may be moved from the center of the pad.

In another embodiment of the radio frequency system, the vias of the first RF device may be moved relative to the vias of the second RF device.

In another embodiment of the radio frequency system, a matching transformer may be provided at the end of the transmission line in contact with the vias.

In another embodiment of a radio frequency system, the matching transformer may be a quarter-wave transformer configured with a transmission line end having a width exceeding that of the rest of the transmission line.

In another embodiment of the radio frequency system, the pads of the first RF device and the pads of the second RF device may be aligned with each other.

In another embodiment of the radio frequency system, the transmission line is a symmetrical microstrip line, a non-symmetric microstrip line, a coaxial line, a substrate integrated waveguide, a waveguide with/without dielectric filling, a coplanar line. line), and may be implemented as one of a group of grounded coplanar lines.

According to another embodiment, the radio frequency system further comprises at least one additional printed circuit board disposed between the first RF device and the second RF device, wherein the at least one additional printed circuit board is on a surface thereof. having pads respectively aligned with the pads of the first RF device and the second RF device, wherein the pads on the facing surfaces of the at least one additional printed circuit board may be interconnected by vias and a transmission line.

In another embodiment of the radio frequency system, the RF devices are separated from each other by an air layer, and the spacing between the RF devices may be provided by spacers.

In another embodiment of a radio frequency system, the spacers may be made of a dielectric.

In another embodiment of a radio frequency system, the RF devices may be separated from each other by a solid dielectric layer.

1: antenna device
2: 1st PCB
3: 2nd PCB
4: Antenna Array
5: RFIC chip
6: pad
7: Via
8 : spacer

Claims (13)

A radio frequency (RF) system comprising two planar RF devices separated by a dielectric layer, comprising:
each of the first RF device and the second RF device has a plurality of pads disposed on its surface and surrounded by a common electrode serving as a grounded metal shield;
The pads of the first RF device and the pads of the second RF device face each other to implement capacitive coupling between the pads and the common electrodes,
and the radio frequency system is configured to transmit a signal between the first RF device and the second RF device via the pads.
The method of claim 1,
wherein the first RF device comprises a first printed circuit board comprising a portion of an RF path of the radio frequency system;
a portion of the RF path includes transmission lines coupled to the pads via vias and coupled to the common electrode;
the second RF device comprises a second printed circuit board comprising another portion of the RF path of the radio frequency system;
and the other portion of the RF path includes transmission lines connected to the pads via vias and also connected to the common electrode.
3. The method of claim 2,
wherein the first RF device comprises an antenna array and the second RF device comprises a control radio frequency integrated circuit (RFIC).
4. The method of claim 2 or 3,
and the vias are shifted from the center of the pad.
3. The method of claim 2,
and the vias of the first RF device are shifted with respect to the vias of the second RF device.
6. The method according to any one of claims 2 to 5,
and a matching transformer is provided at the end of the transmission line in contact with the vias.
7. The method of claim 6,
wherein the matching transformer is a quarter-wave transformer configured with a transmission line end having a width exceeding that of the remaining transmission line.
According to any one of the preceding claims,
and the pads of the first RF device and the pads of the second RF device are aligned with respect to each other.
9. The method according to any one of claims 2 to 8,
The transmission line may be a symmetrical microstrip line, a non-symmetrical microstrip line, a coaxial line, a substrate integrated waveguide, a waveguide with dielectric filling, a waveguide without dielectric filling, a coplanar line, a ground A radio frequency system implemented as one of a group of grounded coplanar lines.
According to any one of the preceding claims,
and at least one additional printed circuit board disposed between the first RF device and the second RF device, the at least one additional printed circuit board having on a surface thereof the first RF device and the second RF device. and having pads respectively aligned with pads of the device, wherein the pads on opposite surfaces of the at least one additional printed circuit board are interconnected by vias and a transmission line.
The method of claim 1,
wherein the RF devices are separated from each other by a layer of air, and the spacing between the RF devices is provided by spacers.
12. The method of claim 11,
wherein the spacers are made of a dielectric.
The method of claim 1,
wherein the RF devices are separated from each other by a solid dielectric layer.

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