HF-MODULE

Abstract

A first semiconductor circuit device with a local oscillator for generating a local oscillator signal is arranged on one side of a printed circuit board and electrically connected to a first signal line. A second semiconductor circuit device is arranged on the same side of the printed circuit board and electrically connected to a second signal line. The RF module includes a first RF terminal associated with the first semiconductor circuit device. A first opening in the printed circuit board is located between the first RF terminal and a first waveguide terminal associated with the first waveguide for transmitting the local oscillator signal from the first RF terminal to the first waveguide.A second opening in the circuit board is located between a second RF terminal associated with the second semiconductor circuit device and a second waveguide terminal associated with the first waveguide for receiving the local oscillator signal from the first waveguide. The second semiconductor circuit device is configured to process a first RF signal based on the received local oscillator signal. A third opening in the circuit board is located between a third RF terminal associated with the second semiconductor circuit device and a third waveguide terminal for transmitting the first RF signal between the third RF terminal and a third waveguide terminal.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to RF modules having multiple semiconductor circuit devices. BACKGROUND

[0002] RF systems using semiconductor circuit devices are used in many mmWave applications such as FMCW radar or 5G mobile communications. Monolithic microwave integrated circuits (MMICs) are semiconductor circuit devices that typically contain RF circuitry to implement multiple transmit (TX) channels and / or receive (RX) channels. To enable MIMO or phased antenna array operations, it is further desirable to increase the number of transmit (TX) or receive (RX) channels to transmit and / or receive signals via an increased number of antennas. To achieve a multi-antenna antenna array, implementations arrange the antennas on the circuit board.However, the manufacturing costs for such solutions are increased because antenna arrays on a printed circuit board require one or more specific layers to reduce the RF loss of the RF transmit signals in the microwave range above 20 GHz. Furthermore, implementations are known in which antennas are provided within each package of the semiconductor circuit devices or directly on each semiconductor chip. However, specific packages may be required, increasing costs, and space constraints can limit the number of antennas, which can increase the number of MMICs required for a given number of antennas. It is therefore desirable to provide an RF module that enables high-performance antenna array operation at reduced manufacturing costs. SUMMARY

[0003] According to one example, an RF module includes a circuit board comprising a plurality of signal lines and a waveguide antenna disposed on a first side of the circuit board, the waveguide antenna comprising a body, an antenna element formed in the body, a first waveguide formed in the body, and a second waveguide formed in the body, the second waveguide being coupled to the antenna element.

[0004] A first semiconductor circuit device is arranged on a second side of the circuit board and is electrically connected to a first signal line of the plurality of signal lines. A second semiconductor circuit device is arranged on the second side of the circuit board and is electrically connected to a second signal line of the plurality of signal lines.

[0005] The RF module includes a first RF port associated with the first semiconductor circuit device, the first semiconductor circuit device comprising a local oscillator for generating a local oscillator signal, the circuit board comprising a first opening between the first RF port and a first waveguide port associated with the first waveguide for transmitting the local oscillator signal from the first RF port into the first waveguide.

[0006] The RF module includes a second RF port associated with the second semiconductor circuit device, and the circuit board includes a second opening between the second RF port and a second waveguide port associated with the first waveguide for receiving the local oscillator signal from the first waveguide. The second semiconductor circuit device is configured to process a first RF signal based on the received local oscillator signal.

[0007] The RF module includes a third RF port associated with the second semiconductor circuit device, and herein the circuit board includes a third opening for transmitting the first RF signal between the third RF port and a third waveguide port associated with the second waveguide.

[0008] Those skilled in the art will recognize additional features and advantages upon reading the following detailed description and upon viewing the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The present disclosure is illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like reference numerals refer to similar or identical elements. The elements of the drawings are not necessarily to scale relative to one another. The features of the various illustrated examples may be combined, provided they are not mutually exclusive. Fig. 1A and Fig. 1B shows an example of an RF module. Fig. 2A and Fig. 2B shows another example of an RF module. Fig. 3A and Fig. 3B shows another example of an RF module. Fig. Figure 4 shows an example of an RF connector. Fig. 5A to Fig. 5G represents another example of an RF connection. Fig. Figure 6A shows an example of a waveguide splitter. Fig. Figure 6B illustrates an example of a transmission matching element. Fig. 7A, Fig. 7B and Fig. 7C show examples of an LO distribution. DETAILED DESCRIPTION

[0010] The examples described herein provide a novel concept for an RF module utilizing a waveguide antenna. In addition to providing waveguides within the waveguide antenna for transmitting RF signals from RF ports of the MMICs to antenna radiating structures, the waveguide antenna further provides a waveguide for transmitting a local oscillator (LO) signal generated at one semiconductor circuit device to another semiconductor circuit device for synchronization.

[0011] Therefore, a compact, cost-effective, and high-performance RF module is provided with the proposed concept. The waveguide antenna can be manufactured using plastic material and molding processes at a reduced cost compared to existing RF modules. Furthermore, the waveguide antenna enables synchronization of semiconductor devices by utilizing the local oscillator signal distributed from one semiconductor device to another via the waveguide. Similar waveguide shapes can be used for the distribution of the LO signal and for the transmission of the transmit or receive signals, making the design of the additional LO distribution waveguide effortless.Compared to existing solutions that require the local oscillator signal to be distributed via signal lines on the printed circuit board (PCB), the new concept is capable of distributing the local oscillator signal without downconversion and upconversion, as the LO signal is in the same frequency range as the transmit and receive signals. This makes it very attractive for applications requiring processing of RF signals in the microwave range above 60 GHz. Existing solutions required either specific layers on the PCB adapted to low-loss transmission at such high frequencies, or downconversion of the local oscillator signal before LO signal transmission, followed by upconversion after LO signal reception at the other semiconductor circuit device.In contrast, the new concept achieves local oscillator signal distribution even in high-frequency microwave ranges above 60 GHz without downconversion and upconversion by using waveguide structures within the waveguide antenna. Accordingly, no additional components such as high-frequency layers are required.

[0012] With reference to Fig. 1A, a first example of an RF module 100 is described. The RF module 100 includes a circuit board 12, a first semiconductor circuit device 2-1, and a second semiconductor circuit device 2-2. The first semiconductor circuit device 2-1 includes a first semiconductor chip 4-1, and the second semiconductor circuit device 2-2 includes a second semiconductor chip 4-2. The first semiconductor circuit device 2-1 includes a housing formed by a molded portion 6-1 and a redistribution layer 8-1. The second semiconductor circuit device 2-2 includes a housing formed by a molded portion 6-2 and a redistribution layer 8-2. The molded portions 6-1 and 6-2 can be formed by a molding process using molding material. The shaped portions 6-1 and 6-2 extend laterally to the first semiconductor chip 4-1 and the second semiconductor chip 4-2, respectively, to form respective fan-out regions.Redistribution layers 8-1 and 8-2 may each include one or more metal layers and one or more insulating layers to conduct signals transmitted to or from the respective semiconductor chips. Redistribution layers 8-1 and 8-2 may be formed by laminating layers. The respective formed portions and redistribution layers may form a wafer-level fan-out package, such as an embedded wafer-level ball grid array (eWLB).

[0013] The first semiconductor circuit device 2-1 and the second semiconductor circuit device 2-2 are mounted on a first side of the circuit board 12 and are electrically and mechanically connected to the circuit board 12 via external contacts 14. The external contacts 14 may be solder balls, copper pillars, or any other structures that can be used to mount semiconductor circuit devices on circuit boards. Although in Fig. 1A only two semiconductor circuit devices are shown, it should be noted that more than two semiconductor circuit devices may be mounted on the circuit board 12 depending on the required application.

[0014] The circuit board 12 includes a plurality of signal lines, which may include power supply signal lines that couple the first semiconductor circuit device 2-1 and the second semiconductor circuit device 2-2, respectively, to a power supply device. The circuit board 12 may further include data signal lines that couple the first semiconductor circuit device 2-1 and the second semiconductor circuit device 2-2 to a processor device mounted on the circuit board 12. The circuit board 12 may further include insulating material such as FR4 material.

[0015] The first semiconductor circuit device 2-1 and the second semiconductor circuit device 2-2 may be monolithic microwave integrated circuit (MMIC) devices. The first semiconductor circuit device 2-1 and the second semiconductor circuit device 2-2 may each include circuits for processing RF signals. More specifically, the first semiconductor circuit device 2-1 and the second semiconductor circuit device 2-2 may each include a plurality of transmit (TX) channels and a plurality of receive (RX) channels. Each of the first semiconductor circuit device 2-1 and the second semiconductor circuit device 2-2 may include RF circuits such as phase shifters, power amplifiers, RF couplers, RF mixers, and digital processing circuits such as digital processors, digital filters, digital Fourier transform circuits, or Goertzel filters.At least the first semiconductor circuit device 2-1 may further comprise RF signal generation circuitry, such as a local oscillator, to generate a local oscillator (LO) signal. In one example, the first semiconductor circuit device 2-1 and the second semiconductor circuit device 2-2 may be FMCW radar MMIC devices operating in a frequency range above 20 GHz, for example, in the ISM band, the Ultra Wide Band (UWB) band, the Automotive Long Range Radar (LRR) band, or the Automotive Short Range Radar (SRR) band. In such implementations, the local oscillator of the first semiconductor circuit device 2-1 may generate frequency-modulated RF signals comprising a plurality of chirps (also known as frequency ramps). According to examples described herein, the first semiconductor circuit device 2-1 and the second semiconductor circuit device 2-2 may form a cascaded system or may be part of a cascaded system.The first semiconductor circuit device 2-1 can be considered a primary device in the cascaded system because the device generates the LO signal, and the second semiconductor circuit device 2-2 can be considered a secondary device because the second semiconductor circuit device 2-2 receives the LO signal from the first semiconductor circuit device 2-1 and uses the LO signal to process an RF signal, for example, to generate a transmitted RF signal or to demodulate a received RF signal. The transmission of the LO signal from the first semiconductor circuit device 2-1 to the second semiconductor circuit device 2-2 enables synchronization of the RF processing. It should be noted that MIMO operations may require a predetermined phase relationship of the transmitted or received RF signals.Since RF signals are processed in multiple semiconductor circuit devices, the concept of generating an LO signal in one semiconductor circuit device and transmitting the signal to the other semiconductor circuit devices for RF processing can establish the required phase relationship.

[0016] The RF module 100 further includes a waveguide antenna 15, which includes a body 16 and waveguides formed in cavities within the body 16. The waveguide antenna 15 is attached to the circuit board 12 on a first side of the body 16, such that the circuit board 12 is located between the waveguide antenna 15 and the semiconductor circuit devices 2-1 and 2-2. The waveguide antenna 15 includes multiple antennas to provide an antenna array, as described later. The body 16 of the waveguide antenna 15 may comprise plastic material and may be formed using molding techniques or other manufacturing methods. The waveguides are formed by metal surfaces 17 of the cavities within the body 16. The body 16 may be a single piece or may be formed by attaching two or more pieces of the body 16 together.Attaching the parts may involve screwing, gluing, soldering, or other fastening methods. The waveguide antenna 15 further includes receive and / or transmit antennas formed by antenna elements 18. The antenna elements 18 may be configured to transmit RF signals outside the RF module or to receive RF signals from outside. Each of the antenna elements 18 may include one or more slots formed on a second side of the body 16 such that slot antennas are formed by the antenna elements 18. The antenna elements 18 may form an antenna array for providing MIMO operation of the RF module 100 such that RF signals are transmitted by multiple antennas outside the RF module 100 and RF signals from outside the RF module 100 are received by multiple antennas.Each of the antennas is associated with one or more respective RF channels in one of the first semiconductor circuit device 2-1 or the second semiconductor circuit device 2-2. In some examples, an antenna may be associated with one RF channel, while in other examples, an antenna may be associated with multiple RF channels.

[0017] The waveguide antenna 15 includes a first waveguide 20-1 for transmitting the LO signal from the first semiconductor circuit device 2-1 to the second semiconductor circuit device 2-2. Since the LO signal distribution is provided for synchronizing the RF processing in the first semiconductor circuit device 2-1 with the second semiconductor circuit device 2-2, the first waveguide 20-1 can also be referred to as a synchronization waveguide.

[0018] The RF module 100 includes a first waveguide port 22-1 associated with the first waveguide 20-1 and a second waveguide port 22-2 associated with the first waveguide. The first waveguide port 22-1 and the second waveguide port 22-2 are disposed in the waveguide antenna 15 and, in one example, may be a first end and a second end of the waveguide, respectively, or may be coupled to a first end and a second end of the first waveguide 20-1.

[0019] A first opening 24-1 is formed in the circuit board 12 such that the first opening 24-1 is located between a first RF port 10-1 associated with the first semiconductor circuit device 2-1 and the first waveguide port 22-1. The first RF port 10-1, the first opening 24-1, and the first waveguide port 22-1 are configured to enable the coupling of the LO signal from the first semiconductor circuit device 2-1 into the first waveguide 20-1. A second opening 24-2 is formed in the circuit board 12 such that the second opening 24-2 is located between a second RF port 10-2 associated with the second semiconductor circuit device 2-2 and the second waveguide port 22-2. Metal walls 13 can be formed on sidewalls of the circuit board 12 associated with the openings 24-1 and 24-2.The second RF port 10-2, the second opening 24-2, and the second waveguide port 22-2 are configured to enable coupling of the LO signal from the first waveguide 20-1 into the second semiconductor circuit device 2-2. As shown in FIG. Fig. 1A, the RF terminals 10-1 and 10-2 extend into a respective fan-out region of the first semiconductor circuit device 2-1 and the second semiconductor circuit device 2-2. As shown in Fig. 1A, the first waveguide 20-1 may have vertical sections extending perpendicular to a major surface of the body 16 and one or more lateral sections extending parallel to the major surface of the body 16.

[0020] As explained above, the second semiconductor circuit device 2-2 uses the LO signal received from the first semiconductor circuit device 2-1 to process a first RF signal. Specifically, the LO signal is used to generate an RF transmission signal or to generate a baseband signal by feeding the LO signal to a mixer and mixing the LO signal with a received RF signal.

[0021] The RF module 100 includes a third RF port 10-3 associated with the second semiconductor circuit device 2-2, and the circuit board 12 includes a third opening 24-3 for transmitting the first RF signal between the third RF port 10-3 and a third waveguide port 22-3 associated with a second waveguide 20-2. The second waveguide 20-2 is formed in the body 16 and couples the third waveguide port 22-3 to the respective antenna element 18. If the third RF port 10-3 is a receive RF port, the first RF signal is received by the respective antenna element 18 via the second waveguide 20-2 and the third waveguide port 22-3. If the first RF port 10-3 is a transmit RF port, the first RF signal is transmitted from the third RF port 10-3 via the third waveguide port 22-3 and the second waveguide 20-2 to the respective antenna element 18.

[0022] The first waveguide 20-1 and the second waveguide 20-2 may be rectangular waveguides with a rectangular cross-section, or may be circular or ellipsoidal waveguides with a circular or ellipsoidal cross-section. The first waveguide 10-1 and the second waveguide 10-2 may be configured for transmission in a TE mode or a TM mode. In examples, the first waveguide 10-1 and the second waveguide 10-2 may have the same cross-sectional shape and the same cross-sectional area, since the signals transmitted in the first waveguide 10-1 and the second waveguide 10-2 may have the same frequency or be in the same frequency range. This enables the implementation of LO distribution in the waveguide antenna without specific design changes for the waveguides provided in the body 16.

[0023] It is further noted that the first semiconductor circuit device 2-1 and the second semiconductor circuit device 2-2 may have additional RF terminals coupled to respective antenna elements 18 in the same manner as described above. Fig. Fig. 1B schematically shows an example in which each of the first semiconductor circuit device 2-1 and the second semiconductor circuit device 2-2 has 3 transmission channels and 4 reception channels coupled to respective antenna elements via waveguides as described above. Accordingly, the RF system of Fig. 1B shows a MIMO system with 6 transmit and 8 receive channels, in which each of the transmit and receive channels is based on the LO signal generated in the first semiconductor circuit device 2-1. Fig. 1 shows the distribution of the LO signal from the first semiconductor circuit device 2-1 to the second semiconductor circuit device 2-2 via the first waveguide 20-1 and the transmission of the transmit and receive signals via respective second waveguides.

[0024] With reference to Fig. 2A and Fig. 2B, another example of an RF module 200 is described. In contrast to the example described with respect to Fig. 1A and Fig. In the example described in FIG. 1B, the RF module 200 includes a self-feed of the LO signal back to the first semiconductor circuit device 2-1. For this purpose, the first waveguide 20-1 is divided into a first part and a second part. The first part is coupled to the second waveguide port 22-2 to transmit the LO signal via the second waveguide port 22-2 and the second opening 24-2 to the RF port 10-2, as described above. The second part is coupled to a fourth waveguide port 22-4 associated with the first semiconductor circuit device 2-1. A fourth opening 24-4 is provided in the circuit board 12 to transmit the LO signal transmitted in the second part of the first waveguide 20-1 to an RF port associated with the first semiconductor circuit device 2-1.In the first semiconductor circuit device 2-1, the LO signal received by the second part of the first waveguide 20-1 is then transmitted to the first semiconductor chip 4-1. Instead of directly using the LO signal generated in the first semiconductor chip 4-1, the first semiconductor chip 4-1 uses the LO signal fed back via the second part of the first waveguide 20-1 to process RF signals, e.g., to generate a transmission signal or to down-convert a reception signal. The feedback of the LO signal makes it possible to maintain synchronization of the reception and transmission channels in the semiconductor circuit devices 2-1 and 2-2 in a more stable manner. Temperature fluctuations cause changes in the length of waveguides, which in the example of . Fig. 1A and Fig. 1B can lead to relative phase changes of the LO signal used in the first semiconductor circuit device 2-1 and the second semiconductor circuit device 2-2. In the example of Fig. 2A, the LO signal transmitted to the second semiconductor circuit device 2-2 and the LO signal transmitted to the first semiconductor circuit device 2-1 are influenced in the same way, and therefore relative phases are compensated or reduced. In some examples, in the first waveguide 20-1, the length from the first waveguide port 22-1 to the second waveguide port 22-2 is the same as the length from the first waveguide port 22-1 to the fourth waveguide port 22-4, which makes the distribution of the LO signal to both waveguide ports symmetrical. Other features of the RF module 200 are similar to the RF module 100, and reference is made to the description of Fig. 1A is referred to.

[0025] Fig. Figure 2B schematically shows the RF module 200 implementing LO feedback. Compared to the Fig. Compared to the RF module 100 shown in FIG. 1B, the RF module 200 has one less receive channel because the corresponding RF port is now used to receive the LO signal fed back to the first semiconductor circuit device 2-1. However, in other embodiments, dedicated LO signal ports may be used to transmit and receive the LO signal, in which the feedback of the LO signal may not reduce the number of RF channels.

[0026] With reference to Fig. 2A and Fig. 2B, another example of an RF module 300 is described.

[0027] Instead of generating the LO signal in an MMIC comprising RF channels, the first semiconductor circuit device 2-1 is implemented in the RF module 300 as a dedicated LO generation device. The LO signal generated in the first semiconductor circuit device 2-1 is then transmitted via a first part of the first waveguide 20-1 to the second waveguide port 22-2 and via the second opening 24-2 to the second RF port 10-2 associated with the second semiconductor circuit device 2-2. Furthermore, the LO signal generated in the first semiconductor circuit device 2-1 is transmitted via a second part of the first waveguide 20-1 to the fourth waveguide port 22-4 and via the fourth opening 24-4 to the fourth RF port 10-2 associated with the third semiconductor circuit device 2-3.The second semiconductor circuit device 2-2 and the third semiconductor circuit device 2-3 are implemented as MMICs that have RF channels, e.g., RF receive channels or RF transmit channels. The LO signal is used in the second semiconductor circuit device 2-2 and the third semiconductor circuit device 2-3 to process RF signals as described above. In some examples, in the first waveguide 20-1, the length from the first waveguide port 22-1 to the second waveguide port 22-2 is the same as the length from the first waveguide port 22-1 to the fourth waveguide port 22-4, which makes the distribution of the LO signal to both waveguide ports symmetrical. Other features of the RF module 200 are similar to the RF module 100 and the RF module 300, and reference is made to the description of FIG. Fig. 1A and Fig. 1B is referred to.

[0028] Fig. 3B schematically shows the LO distribution of the RF module 300 with the first semiconductor circuit device 2-1, which distributes the LO signal symmetrically to the second semiconductor circuit device 2-2 and the third semiconductor circuit device 2-3 via the first waveguide 20-1.

[0029] With reference to Fig. 4, an example of an RF connector 10 is described. The RF connector 10 includes a substrate-integrated waveguide 42 configured to transmit the RF signal from a semiconductor chip 4 into an opening 24 of the circuit board 12. The substrate-integrated waveguide 42 may utilize a coupler integrated into the redistribution layer 8 of the associated semiconductor circuit device to provide the coupling from the substrate-integrated waveguide 42 via the opening 24 of the circuit board 12 to the respective waveguide connector. In other examples, a coupler may be integrated into or disposed on the circuit board 12 to provide the coupling from the substrate-integrated waveguide 42 to the respective waveguide connector.In some examples, the coupler may be configured to receive the RF signals from the semiconductor chip 4 with a substantially lateral transmission direction and may be configured to convert them into RF signals with a substantially vertical transmission direction to enable efficient transmission of the RF signals to a vertical portion of the waveguide. Similar RF ports may be provided to implement RF ports configured to receive signals from a respective waveguide. The same RF ports may be used to transmit LO signals and to transmit RF transmit or receive signals, since both may use the same frequencies or be in the same frequency range.

[0030] Another example of an RF connector 10 is shown in Fig. 5A to Fig. 5G shown in detail. Fig. 5A shows a side view of a portion of a redistribution layer of a semiconductor circuit device (e.g., the first semiconductor circuit device 2-1 or the second semiconductor circuit device 2-2). A first layer 502 is the layer closest to the chip plane in a vertical direction. The first layer 502 includes signal lines and ground lines connected to a third layer 504 by vias arranged in a second layer 503. The signal lines and ground lines may form a planar waveguide for transmitting the RF signal. The third layer 504 forms an upper part of a substrate-integrated waveguide and is connected to a fifth layer 506 by vias arranged in a fourth layer 505. The fifth layer 506 forms a lower part of the substrate-integrated waveguide.

[0031] Fig. 5B shows a top view of the first layer 502. A signal line 502-1 is formed in the first layer 502, extending over and crossing a region 504-1 associated with a gap (an opening) in the third layer 504, as explained later. The signal line 502-1 is connected at one end to a signal line of the semiconductor chip 4. The first layer 502 further includes ground lines 502-2 connected to ground potential. As can be seen, the ground lines 502-2 do not extend into the region 504-1 and do not cross the region 504-1. The signal lines 502-1 and the ground lines 502-2 are metal lines and form a planar RF waveguide. For coupling the RF signals into the substrate-integrated waveguide, the signal line 502-1 is electrically connected to a via 503-1 and the ground lines 502-2 are electrically connected to respective vias of a plurality of vias 503-2 arranged in Fig. 5C. Vias 503-1 and 503-2 provide an electrical connection in the vertical direction from the first layer 502 to the third layer 504 to excite a current in the third layer 504 that enables RF coupling into the substrate-integrated waveguide.

[0032] Fig. Figure 5D shows the third layer 504, which is formed as a continuous metal layer having a gap in the region 504-1. Since the signal line 502-1 crosses the region 504-1 while the ground line 502-2 does not cross the region 504-1, alternating currents are excited in the third layer 504, which flow around the gap region 504-1. Since the third layer 504 is the top plate of the substrate-integrated waveguide, the alternating currents excite an RF signal in the substrate-integrated waveguide. Fig. In Figure 5D, the opening is shown as a rectangular U-shaped slot, however, other shapes such as a straight slot, a V-shaped slot, or a semicircular slot are also possible. Compared to a straight slot, a U-shaped, V-shaped, or semicircular slot reduces the dimension in a lateral direction, increasing design flexibility and allowing for more RF connectors to be implemented in a specific area.

[0033] The third layer 504 is connected by vias 505-1 arranged in the layer 505 to the fifth layer 506, which acts as a bottom plate of the substrate-integrated waveguide. Fig. Figure 5E shows the vias 505-1, which define a lateral boundary of the substrate-integrated waveguide. Fig. Figure 5F shows the fifth layer 506 as a continuous metal layer having an opening 506-1 to define a coupler 506-2.

[0034] The coupler 506-2 provides a vertical RF coupling with a corresponding opening in the circuit board 12 and a corresponding waveguide port to excite RF signal transmission in the waveguide below the coupler.

[0035] Fig. 5G shows a transparent top view of the structures in layers 502 to 506, as described above, that form the RF port. If the RF port is a transmit RF port, the substrate-integrated waveguide is formed with structures to couple the RF signals from the planar waveguide into the substrate-integrated waveguide and with a coupler to couple the RF signal from the substrate-integrated waveguide into the opening of the circuit board 12. If the RF port is a receive RF port, the substrate-integrated waveguide is formed with a coupler to couple the RF signal from the opening of the circuit board 12 into the substrate-integrated waveguide and with structures to couple the RF signals from the substrate-integrated waveguide into the planar waveguide.

[0036] With reference to Fig. 6A and Fig. 6B describes functional structures provided in the waveguides of the waveguide antenna.

[0037] Fig. 6A shows a splitter element 600 as a functional element that can be implemented in a waveguide 20. The splitter element 600 includes a first splitter port 20-A, a second splitter port 20-B, and a third splitter port 20-C. The splitter 600 is configured to split the RF signal into a first RF signal portion and a second RF signal portion, which are sent via the second splitter port 20-B and the third splitter port 20-C to respective waveguide portions of the waveguide 20. The splitting can be symmetrical, such that the first RF signal portion and a second RF signal portion have an equal amount of power. The splitter described above can, for example, be implemented in the example of Fig. 2A and Fig. 2B, which implements a LO distribution with self-feeding. Furthermore, the divider can be used in the following with respect to Fig. 7A and Fig. 7B described examples.

[0038] Fig. 6B shows a matching element 602 as another functional element that can be implemented in a waveguide 20. The matching element 602 includes a section 20-D in which, for example, a waveguide shape or a waveguide cross-sectional area is varied to modify RF signals output or received via a port 20-E. The matching element 602 can be used, for example, at the waveguide ports 22-1, 22-2, 22-3, 22-4 described in the examples above, for coupling the RF signals into the openings 24-1, 24-2, 24-3, 24-4 or for receiving the RF signals from the openings 24-1, 24-2, 24-3, 24-4. This can increase the coupling efficiency and can reduce losses of the RF signals.

[0039] With reference to Fig. 7A to Fig. Figure 7C describes examples of LO signal distribution implemented in the RF modules, such as RF modules 100, 200, and 300. Fig. 7A shows an example of symmetrical LO signal distribution from the first semiconductor circuit device 2-1 to the semiconductor circuit devices 2-2, 2-3, 2-4, and 2-5. The first waveguide 2-1 is divided into two waveguide sections using a first splitter 600-1. Each of the waveguide sections is further divided using splitters 600-2 and 600-3. The first waveguide couples the RF terminal of the first semiconductor circuit device 2-1, which distributes the LO signal, to the respective RF terminals of the semiconductor circuit devices 2-2, 2-3, 2-4, and 2-5, which receive the LO signal. The lengths of the waveguide sections between the first semiconductor circuit device 2-1 and each of the semiconductor circuit devices 2-2, 2-3, 2-4 and 2-5 are the same, which makes the LO signal distribution symmetrical, and phases of the LO signals received at the semiconductor circuit devices 2-2, 2-3, 2-4 and 2-5 are the same.

[0040] Fig. 7B shows an example of LO signal distribution from the first semiconductor circuit device 2-1 to the self-feeding semiconductor circuit devices 2-2, 2-3, and 2-4. The first waveguide 2-1 is divided into two waveguide sections using a first splitter 600-1. Each of the waveguide sections is further divided into further waveguide sections using splitters 600-2 and 600-3. One of the further waveguide sections coupled to splitter 600-2 is coupled to an RF terminal of the second semiconductor circuit device 2-2, while one of the further waveguide sections coupled to splitter 600-2 is coupled back to an RF input terminal of the first semiconductor circuit device 2-1. In operation, the first semiconductor circuit device 2-1 uses the feedback LO signal for processing, such as generating transmission signals or mixing received signals.Furthermore, the further waveguide sections coupled to the splitter 600-3 are respectively coupled to RF terminals of the semiconductor circuit devices 2-3 and 2-4. The length of the waveguide sections between the first semiconductor circuit device 2-1 and the RF input terminal of the first semiconductor circuit device 2-1 is the same as the length of the waveguide sections between the first semiconductor circuit device 2-1 and each of the semiconductor circuit devices 2-2, 2-3, and 2-4, which makes the LO signal distribution symmetrical, and the phases of the LO signals received at the semiconductor circuit devices 2-1, 2-2, 2-3, and 2-4 are the same.The LO distribution to the plurality of semiconductor circuit devices 2-2, 2-3 and 2-4 including the feedback to the first semiconductor circuit device 2-1 makes it possible to maintain stability of the phases of the LO signals processed by the semiconductor circuit devices 2-1, 2-2, 2-3 and 2-4, which enables the use of the semiconductor circuit devices 2-1, 2-2, 2-3 and 2-4 in a MIMO operation for transmitting and receiving signals.

[0041] Another example of LO signal distribution is in Fig. 7C shown. Fig.Figure 7C shows the LO distribution in a daisy-chain configuration. An RF terminal of the first semiconductor circuit device 2-1 is coupled to a first portion of the first waveguide 20-1 to couple the LO signal into the first waveguide 20-1. The LO signal is received at an RF input terminal of the second semiconductor circuit device 2-2 and transmitted to a second portion of the first waveguide 20-1. The LO signal is received at an RF input terminal of the third semiconductor circuit device 2-3 and transmitted to a third portion of the first waveguide 20-1. The LO signal is received from the third portion of the first waveguide 20-1 at an RF input terminal of the fourth semiconductor circuit device 2-4. In this example, the LO signals received at the semiconductor circuit devices 2-2, 2-3, and 2-4 have different phases, and the phase differences may change with temperature.A compensation or calibration technique can be applied to address phase changes resulting from temperature variations to achieve MIMO operation.

[0042] The above describes various examples of an RF module using a waveguide antenna with hollow guides formed inside a body of the waveguide antenna. The hollow guides are used to transmit transmit and receive signals between the antenna elements of the waveguide antenna and a plurality of semiconductor circuit devices, as well as to distribute LO signals between the plurality of semiconductor circuit devices. This enables a simple and cost-effective implementation of an RF module, for example, for MIMO operations, while avoiding the routing of LO signals on a circuit board.

[0043] In addition to the examples described above, the following examples are disclosed herein.

[0044] Example 1 is an RF module comprising: a printed circuit board comprising a plurality of signal lines, a waveguide antenna arranged on a first side of the circuit board, the waveguide antenna comprising a body, an antenna element formed in the body, a first waveguide formed in the body, and a second waveguide formed in the body, the second waveguide being coupled to the antenna element, a first semiconductor circuit device arranged on a second side of the circuit board and electrically connected to a first signal line of the plurality of signal lines, a second semiconductor circuit device arranged on the second side of the circuit board and electrically connected to a second signal line of the plurality of signal lines, wherein the RF module comprises a first RF port associated with the first semiconductor circuit device, the first semiconductor circuit device comprising a local oscillator for generating a local oscillator signal, the circuit board comprising a first opening between the first RF port and a first waveguide port associated with the first waveguide for transmitting the local oscillator signal from the first RF port into the first waveguide; wherein the RF module comprises a second RF port associated with the second semiconductor circuit device, wherein the circuit board comprises a second opening between the second RF port and a second waveguide port associated with the first waveguide for receiving the local oscillator signal from the first waveguide, wherein the second semiconductor circuit device is configured to process a first RF signal based on the received local oscillator signal, wherein the RF module comprises a third RF port associated with the second semiconductor circuit device, and wherein the circuit board comprises a third opening for transmitting the first RF signal between the third RF port and a third waveguide port associated with the second waveguide.

[0045] Example 2 is the RF module of Example 1, wherein the first RF signal is an RF transmit signal, and wherein the second semiconductor circuit device is configured to generate the RF transmit signal based on the received local oscillator signal, wherein the third RF port comprises a coupler for transmitting the RF transmit signal via the third opening to the first waveguide port for transmission via the antenna element.

[0046] Example 3 is the RF module of Example 1, wherein the first RF signal is an RF receive signal received by the antenna element, and wherein the third RF port comprises a coupler for receiving the RF receive signal from the second waveguide via the third opening, and wherein the second semiconductor circuit device is configured to down-convert the RF receive signal using the received local oscillator signal.

[0047] Example 4 is the RF module of Examples 2 and 3, wherein the coupler is integrated into the second semiconductor circuit device.

[0048] Example 5 is the RF module of any of the preceding examples, wherein the first semiconductor circuit device and the second semiconductor circuit device comprise a redistribution layer and a molding material defining a fan-out region, and wherein at least one of the second RF terminal or the third RF terminal is disposed in the fan-out region.

[0049] Example 6 is the RF module of any of the preceding examples, wherein the RF module comprises a fourth RF port associated with the first semiconductor circuit device, and wherein the circuit board comprises a fourth opening between the fourth RF port and a fourth waveguide port associated with the first waveguide, wherein the first waveguide comprises a splitter for splitting the local oscillator signal into a first portion transmitted to the second RF port and a second portion transmitted to the fourth RF port.

[0050] Example 7 is the RF module of any of the preceding examples, wherein the first semiconductor circuit device is a primary monolithic microwave integrated circuit device and wherein the second semiconductor circuit device is a secondary monolithic microwave integrated circuit device, wherein the first monolithic microwave integrated circuit device comprises a first plurality of RF channels and wherein the secondary monolithic microwave integrated circuit device comprises a second plurality of RF channels, wherein the secondary monolithic microwave integrated circuit device is configured to synchronize the second plurality of RF channels to the first plurality of RF channels using the received local oscillator signal.

[0051] Example 8 is the RF module of any of the preceding examples, wherein the body comprises body parts that are attached to one another.

[0052] Example 9 is the RF module of any of the preceding examples, wherein the body comprises plastic material and wherein the first waveguide and the second waveguide comprise metal layers formed on walls of openings in the body.

[0053] Example 10 is the RF module of any of the preceding examples, wherein the antenna element includes a plurality of slots formed on an outer surface of the body.

[0054] Example 11 is the RF module of any of the preceding examples, wherein the RF module further comprises at least one of a power supply disposed on the circuit board or a processing device disposed on the circuit board.

[0055] Example 12 is the RF module of any of the preceding examples, wherein each of the first waveguide port, the second waveguide port, and the third waveguide port includes a transmission matching element to match transmission characteristics for coupling to the first opening, the second opening, and the third opening, respectively.

[0056] Example 13 is the RF module of Example 12, wherein the transmission matching element comprises a varying waveguide section, the varying waveguide section comprising at least one of the following: a varying waveguide shape or a varying waveguide cross-section.

[0057] Example 14 is the RF module of any of the preceding examples, wherein the first semiconductor circuit device and the second semiconductor circuit device are FMCW radar devices, and wherein the local oscillator signal comprises a plurality of frequency modulated radar chirps.

[0058] Example 15 is the RF module of any of the preceding examples, wherein the first waveguide comprises a first portion extending perpendicular to a major surface of the circuit board and a second portion extending parallel to a major surface of the circuit board, and wherein the second waveguide comprises a third portion extending perpendicular to a major surface of the circuit board and a fourth portion extending parallel to a major surface of the circuit board.

[0059] Example 16 is the RF module of Example 15, with the second section being closer to the circuit board than the fourth section.

[0060] Example 17 is the RF module of any of the preceding examples, wherein the second semiconductor circuit device comprises a semiconductor package, the semiconductor package comprising a redistribution layer, the third RF port comprising a substrate-integrated waveguide structure formed by a first metal layer of the redistribution layer, a second metal layer of the redistribution layer, and a plurality of vertical metal structures formed between the first metal layer and the second metal layer.

[0061] Example 18 is the RF module of Example 17, wherein the redistribution layer comprises a third metal layer, the third metal extending across a gap in the second metal layer.

[0062] Example 19 is the RF module of any of the preceding examples, wherein the RF module comprises a coupler associated with at least one of the first RF port, the second RF port, or the third RF port, wherein the coupler is integrated into the circuit board or disposed on the circuit board.

[0063] Although specific examples have been illustrated and described herein, those skilled in the art will recognize that a variety of alternative and / or equivalent implementations may be substituted for the specific examples shown and described without departing from the scope of the present invention. This application is intended to cover any adaptations or variations of the specific examples discussed herein. Therefore, it is intended that this invention be limited only by the claims and their equivalents.

[0064] It should be noted that the methods and devices, including their preferred embodiments, as set forth in this document can be used alone or in combination with the other methods and devices disclosed in this document. Furthermore, the features set forth in connection with one device are also applicable to a corresponding method, and vice versa. Furthermore, all aspects of the methods and devices set forth in this document can be combined in any desired manner. In particular, the features of the claims can be combined with one another in any desired manner.

[0065] It should be noted that the description and drawings merely illustrate the principles of the proposed methods and systems. Those skilled in the art will be able to implement various arrangements that, although not expressly described or shown herein, embody the principles of the invention and are included within its spirit and scope. Furthermore, all examples and embodiments set forth herein are primarily intended to be expressly provided for illustrative purposes only to assist the reader in understanding the principles of the proposed methods and systems. Furthermore, all statements herein providing principles, aspects, and embodiments of the invention, as well as specific examples thereof, are intended to include equivalents thereof.

Claims

[1] RF module, comprising: a printed circuit board comprising a plurality of signal lines, a waveguide antenna arranged on a first side of the circuit board, wherein the waveguide antenna comprises a body, an antenna element formed in the body, a first waveguide formed in the body, and a second waveguide formed in the body, wherein the second waveguide is coupled to the antenna element, a first semiconductor circuit device arranged on a second side of the circuit board and electrically connected to a first signal line of the plurality of signal lines, a second semiconductor circuit device arranged on the second side of the circuit board and electrically connected to a second signal line of the plurality of signal lines, wherein the RF module comprises a first RF port associated with the first semiconductor circuit device, wherein the first semiconductor circuit device comprises a local oscillator for generating a local oscillator signal, wherein the circuit board comprises a first opening between the first RF port and a first waveguide port associated with the first waveguide for transmitting the local oscillator signal from the first RF port into the first waveguide, wherein the RF module comprises a second RF port associated with the second semiconductor circuit device, wherein the circuit board comprises a second opening between the second RF port and a second waveguide port associated with the first waveguide for receiving the local oscillator signal from the first waveguide, wherein the second semiconductor circuit device is configured to process a first RF signal based on the received local oscillator signal, wherein the RF module comprises a third RF port associated with the second semiconductor circuit device, and wherein the circuit board has a third opening for transmitting the first RF signal between the third RF port and a third waveguide port associated with the second waveguide, includes. [2] The RF module of claim 1, wherein the first RF signal is an RF transmit signal, and wherein the second semiconductor circuit device is configured to generate the RF transmit signal based on the received local oscillator signal, wherein the third RF port comprises a coupler for transmitting the RF transmit signal via the third opening to the first waveguide port for transmission via the antenna element. [3] The RF module of claim 1, wherein the first RF signal is an RF reception signal received by the antenna element, and wherein the third RF port comprises a coupler for receiving the RF reception signal from the second waveguide via the third opening, and wherein the second semiconductor circuit device is configured to down-convert the RF reception signal using the received local oscillator signal. [4] RF module according to claim 2 and 3, wherein the coupler is integrated into the second semiconductor circuit device. [5] The RF module of any preceding claim, wherein the first semiconductor circuit device and the second semiconductor circuit device each comprise a redistribution layer and a molding material defining a respective fan-out region, and wherein at least one of the second RF terminal or the third RF terminal is disposed in the respective fan-out region. [6] The RF module according to any one of the preceding claims, wherein the RF module comprises a fourth RF port associated with the first semiconductor circuit device, and wherein the circuit board comprises a fourth opening between the fourth RF port and a fourth waveguide port associated with the first waveguide, the first waveguide comprising a splitter for splitting the local oscillator signal into a first portion transmitted to the second RF port and a second portion transmitted to the fourth RF port. [7] The RF module of any preceding claim, wherein the first semiconductor circuit device is a primary monolithic microwave integrated circuit device and wherein the second semiconductor circuit device is a secondary monolithic microwave integrated circuit device, wherein the first monolithic microwave integrated circuit device comprises a first plurality of RF channels and wherein the secondary monolithic microwave integrated circuit device comprises a second plurality of RF channels, wherein the secondary monolithic microwave integrated circuit device is configured to synchronize the second plurality of RF channels to the first plurality of RF channels using the received local oscillator signal. [8] RF module according to one of the preceding claims, wherein the body comprises body parts which are attached to one another. [9] An RF module according to any preceding claim, wherein the body comprises plastic material and wherein the first waveguide and the second waveguide comprise metal layers formed on walls of openings in the body. [10] An RF module according to any preceding claim, wherein the antenna element comprises a plurality of slots formed on an outer surface of the body. [11] The RF module of any preceding claim, wherein the RF module further comprises at least one of a power supply disposed on the circuit board or a processing device disposed on the circuit board. [12] The RF module of any preceding claim, wherein each of the first waveguide port, the second waveguide port, and the third waveguide port comprises a transmission matching element for matching the transmission characteristics for coupling to the first opening, the second opening, and the third opening, respectively. [13] The RF module of claim 12, wherein the transmission matching element comprises a varying waveguide section, the varying waveguide section comprising at least one of the following: a varying waveguide shape or a varying waveguide cross-section. [14] The RF module of any preceding claim, wherein the first semiconductor circuit device and the second semiconductor circuit device are FMCW radar devices, and wherein the local oscillator signal comprises a plurality of frequency-modulated radar chirps. [15] RF module according to one of the preceding claims, wherein the first waveguide comprises a first portion extending perpendicular to a main surface of the circuit board and a second portion extending parallel to a main surface of the circuit board, and wherein the second waveguide comprises a third portion extending perpendicular to a main surface of the circuit board and a fourth portion extending parallel to a main surface of the circuit board. [16] The RF module of claim 15, wherein the second portion is closer to the circuit board than the fourth portion. [17] The RF module of any preceding claim, wherein the second semiconductor circuit device comprises a semiconductor package, the semiconductor package comprising a redistribution layer, the third RF port comprising a substrate-integrated waveguide structure formed by a first metal layer of the redistribution layer, a second metal layer of the redistribution layer, and a plurality of vertical metal structures formed between the first metal layer and the second metal layer. [18] The RF module of claim 17, wherein the redistribution layer comprises a third metal layer, the third metal extending across a gap in the second metal layer. [19] RF module according to one of the preceding claims, wherein the RF module comprises a coupler associated with at least one of the first RF port, the second RF port or the third RF port, wherein the coupler is integrated into the circuit board or arranged on the circuit board.

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