Cascade radio frequency device and operation and manufacturing method thereof

Abstract

The invention relates to a cascaded radio frequency device and an operation and manufacturing method thereof. A cascaded radio frequency (RF) device includes: a first RF chip including a first local oscillator configured to generate and output a first local oscillator signal during an operating time interval; a second RF chip including a second local oscillator configured to generate and output a second local oscillator signal during the operation time interval; and a power combiner configured to combine the first local oscillator signal and the second local oscillator signal into a combined local oscillator signal, and to output the combined local oscillator signal to an input of the first RF chip and an input of the second RF chip, wherein the first local oscillator signal and the second local oscillator signal have the same frequency behavior during the operating time interval.

Description

Technical Field

[0001] This disclosure relates to cascaded radio frequency (RF) devices and methods for operating and manufacturing cascaded RF devices. Background Technology

[0002] To increase the angular resolution of radar sensors, the number of transmit and receive channels can be increased to achieve a larger aperture. This increased number of channels can be achieved by cascading multiple radar MMICs (monochip microwave integrated circuits), where the primary MMIC supplies a shared local oscillator signal to the remaining secondary MMICs and itself. The guaranteed minimum output power of the primary local oscillator signal and the minimum required input power at the secondary MMICs limit the maximum number of MMICs and the maximum possible distance between them on the printed circuit board (PCB) holding the MMICs. Furthermore, for cost reasons, only inexpensive PCB laminates are typically used, which often results in higher attenuation of the local oscillator signal. Therefore, the use of inexpensive PCB laminates may be limited because the necessary length of the local oscillator signal is often not achievable.

[0003] Manufacturers and developers of RF devices are constantly striving to improve their products. In this context, it may be desirable to provide cascaded RF devices with improved performance at a lower cost, thereby at least partially addressing the identified problems. Additionally, suitable methods for operating and manufacturing such cascaded RF devices may also be required. Summary of the Invention

[0004] One aspect of this disclosure relates to a cascaded radio frequency (RF) device. The cascaded RF device includes a first RF chip comprising a first local oscillator configured to generate and output a first local oscillator signal during an operating time interval. The cascaded RF device also includes a second RF chip comprising a second local oscillator configured to generate and output a second local oscillator signal during the operating time interval. The cascaded RF device further includes a power combiner configured to combine the first and second local oscillator signals into a combined local oscillator signal, and to output the combined local oscillator signal to inputs of both the first and second RF chips. The first and second local oscillator signals have the same frequency behavior during the operating time interval.

[0005] Another aspect of this disclosure relates to a method for operating cascaded RF devices. The method includes the operation of generating and outputting a first local oscillator signal by a first local oscillator of a first RF chip during an operation time interval. The method also includes the operation of generating and outputting a second local oscillator signal by a second local oscillator of a second RF chip during the operation time interval. The method further includes the operation of combining the first and second local oscillator signals into a combined local oscillator signal by a power combiner. The method also includes the operation of outputting the combined local oscillator signal to inputs of both the first and second RF chips by the power combiner. The first and second local oscillator signals have the same frequency behavior during the operation time interval.

[0006] Another aspect of this disclosure relates to a method for manufacturing cascaded RF devices. The method includes the operation of placing a first RF chip including a first local oscillator configured to generate and output a first local oscillator signal during an operation time interval. The method further includes the operation of placing a second RF chip including a second local oscillator configured to generate and output a second local oscillator signal during the operation time interval. The method further includes the operation of placing a power combiner configured to combine the first local oscillator signal and the second local oscillator signal into a combined local oscillator signal, and outputting the combined local oscillator signal to inputs of both the first and second RF chips. The first local oscillator signal and the second local oscillator signal have the same frequency behavior during the operation time interval.

[0007] Those skilled in the art will recognize the additional features and advantages upon reading the following detailed description and reviewing the accompanying drawings. Attached Figure Description

[0008] The invention is illustrated in the accompanying drawings by way of example and not limitation, in which the same reference numerals refer to similar or identical elements. The elements in the drawings are not necessarily proportional to each other. Features of the various illustrated examples can be combined unless excluded from each other.

[0009] Figure 1 A cascaded RF device 100 according to the present disclosure is schematically illustrated.

[0010] Figure 2 The cascaded RF device 200 is schematically illustrated.

[0011] Figure 3 A flowchart illustrating a method for operating cascaded RF devices according to the present invention is shown.

[0012] Figure 4 A flowchart illustrating a method for manufacturing cascaded RF devices according to the present invention is shown. Detailed Implementation

[0013] In the following detailed description, reference is made to the accompanying drawings, in which specific aspects of this disclosure may be practiced by way of illustration. Other aspects may be utilized, and changes may be made to the structure or logic, without departing from the concept of the invention. Therefore, the following detailed description should not be considered limiting, and the concept of the invention is defined by the appended claims.

[0014] Now for reference Figure 1 A schematic diagram of a cascaded radio frequency (RF) device (or system) 100 according to this disclosure is shown. The RF device 100 may include a first RF chip 2A having a first local oscillator 4A. The first local oscillator 4A may be configured to generate and output a first local oscillator signal 6A during an operating time interval. The RF device 100 may also include a second RF chip 2B having a second local oscillator 4B. The second local oscillator 4B may be configured to generate and output a second local oscillator signal 6B during an operating time interval. The first local oscillator signal 6A and the second local oscillator signal 6B may have the same frequency behavior during the operating time interval. The RF device 100 may also include a power combiner 8 configured to combine the first local oscillator signal 6A and the second local oscillator signal 6B into a combined local oscillator signal 10, and output the combined local oscillator signal 10 to input 12A of the first RF chip 2A and input 12B of the second RF chip 2B. The RF device 100 may optionally include a power splitter 20, the function of which will be discussed later.

[0015] The features of the first RF chip 2A will be described below. It should be noted that the second RF chip 2B may include some or all of the specific features of the first RF chip 2A. In the example, the first RF chip 2A and the second RF chip 2B may have the same chip design and / or the same specifications. It should be understood that the RF device 100 may include additional RF chips, the number of which may depend on the specific design of the RF device 100. The first RF chip 2A may be made of any semiconductor material or may include any semiconductor material (e.g., silicon). The first RF chip 2A (or its electronic circuitry) may be configured to operate in a frequency range greater than about 1 GHz, and in some examples greater than about 10 GHz. Therefore, the first RF chip 2A may also be referred to as a radio frequency chip, a high-frequency chip, or a microwave frequency chip. More specifically, the first RF chip 2A may be configured to operate in an RF range or microwave frequency range that can range from about 1 GHz to about 1 THz, and more specifically from about 10 GHz to about 300 GHz. The microwave circuitry may include, for example, a microwave transmitter, a microwave receiver, a microwave transceiver, a microwave sensor, a microwave detector, etc. The RF device according to this disclosure can be used in radar applications where the frequency of an RF signal can be modulated. The first RF chip 2A can therefore also be referred to as a radar chip. In particular, the first RF chip 2A may include or correspond to an MMIC (monolithic microwave integrated circuit).

[0016] Radar microwave devices can be used, for example, in automotive, industrial, military, and / or defense applications for distance and speed measurement systems. Automotive applications, for instance, may include advanced driver assistance systems, automatic vehicle cruise control systems, vehicle collision avoidance systems, etc. Such systems can operate within the microwave frequency range and can utilize FMCW (Frequency Modulated Continuous Wave) signals, such as in the 24 GHz, 76 GHz, or 79 GHz bands. The use of radar microwave systems can provide vehicles with constant and efficient driving. Efficient driving can, for example, reduce fuel consumption, thereby reducing CO2 emissions and enabling energy savings. Furthermore, it can reduce wear on vehicle tires, brake discs, and brake pads, thus reducing fine dust pollution. As described herein, improved RF or radar systems can therefore contribute to green technology solutions, i.e., climate-friendly solutions that provide reduced energy use.

[0017] In some examples, the first RF chip 2A may include at least one transmit (TX) channel configured to transmit RF signals via TX antenna 14A. In some examples, the first RF chip 2A may include at least one receive (RX) channel configured to receive RF signals via RX antenna 16A. In some examples, the first RF chip 2A may include at least one transmit (TX) channel and one receive (RX) channel, which may be referred to as a transceiver (TRX) chip. In the illustrated example, one TX antenna 14A and one RX antenna 16A are shown for simplicity. It should be understood that in other examples, the first RF chip 2A may include different numbers of TX antennas 14A and / or RX antennas 16A, which may depend on the specific design of the RF device 100. In a non-limiting example, the first RF chip 2A may include four TX antennas 14A (or four TX channels) and four RX antennas 16A (or four RX channels).

[0018] The first RF chip 2A and the second RF chip 2B can be interconnected and cascaded to form a cascaded RF system. In the example, the first RF chip 2A and the second RF chip 2B can be arranged on the same printed circuit board (PCB). The power combiner 8 and / or the power splitter 20 can also be arranged on the PCB. Cascading multiple transceiver RF chips can increase the number of transmit and receive channels, and thus increase the number of virtual antenna array elements, thereby improving target detection and target resolution, which may be required for some applications (e.g., L4 and L5 autonomous driving). RF chips 2A and 2B can be synchronized so that the cascaded RF system 100 operates as a single RF system, wherein each of the RF channels can have a predefined phase relationship with each other. To achieve proper synchronization between RF chips 2A and 2B, a specific signal can be shared between the first RF chip 2A and the second RF chip 2B. In this respect, the combined local oscillator signal 10 can be shared between the first RF chip 2A and the second RF chip 2B. In other words, both RF chips 2A and 2B can use the combined local oscillator signal 10 for operations such as transmitting signals or mixing with received signals. For example, mixer 18A can be used to mix the combined local oscillator signal 10 with the RF signal received via receiving antenna 16A to downconvert the frequency of the received RF signal to a more manageable range. Specifically, the input RF signal from receiving antenna 16A can be mixed with the combined local oscillator signal 10 to generate an intermediate frequency (IF) signal. The combined local oscillator signal 10 can be used to shift the frequency of the received RF signal to a frequency range that can be easily processed by the receiver and subsequent processing stage of RF device 100. The combined local oscillator signal 10 can be or may include a millimeter-wave LO signal. In some applications, the combined local oscillator signal 10 can be or may include an FMCW signal, which includes multiple frequency ramps.

[0019] As previously stated, the first local oscillator signal 6A and the second local oscillator signal 6B may have the same frequency behavior during the operating time interval. The frequency behavior of a signal can specify or may refer to how the signal changes or varies over time in terms of its frequency or frequency content. In other words, it can describe how the frequency components of the signal evolve or shift as a function of time. In the example, the frequency behavior of local oscillator signals 6A and 6B may include one or more frequency ramps having a start frequency and a stop frequency during the operating time interval, which is the same for both local oscillator signals 6A and 6B. Specifically, the first local oscillator 6A and the second local oscillator 6B can be controlled to generate and output the same local oscillator signal. That is, possible differences between the first local oscillator signal 6A and the second oscillator signal 6B may be unintentional and may be caused, for example, by tolerances or inaccuracies during the manufacture of the RF device 100 or its components. In the example, having the same frequency behavior may include: the first local oscillator signal 6A and the second local oscillator signal 6B may have different amplitudes. In the example, having the same frequency behavior can include: the first local oscillator signal 6A and the second local oscillator signal 6B can be identical except for their phase difference. Specifically, the phase difference between the first local oscillator signal 6A and the second local oscillator signal 6B can be constant. For example, a constant phase difference can be less than approximately π / 3, π / 4, π / 5, π / 6, π / 7, or π / 8. The generation of the first local oscillator signal 6A can be independent of the generation of the second local oscillator signal 6B, and vice versa. This can also be seen from... Figure 1 As can be seen, the first local oscillator 4A does not receive any input from the second local oscillator 4B, and vice versa.

[0020] The first local oscillator signal 6A and the second local oscillator signal 6B can be based on the same reference clock. In this respect, the RF device 100 may include at least one of a local oscillator or a crystal oscillator (not shown), configured to generate and provide the reference clock to the first RF chip 2A and the second RF chip 2B. In a first example, the local oscillator and / or the crystal oscillator may be located outside the first RF chip 2A and the second RF chip 2B. In another example, the local oscillator and / or the crystal oscillator may be arranged or included in the first RF chip 2A. Typically, the frequency of the first local oscillator signal 6A and / or the frequency of the second local oscillator signal 6B can be greater than the frequency of the reference clock. More specifically, the frequency of the first local oscillator signal 6A and / or the frequency of the second local oscillator signal 6B can be about 10 times higher than the frequency of the reference clock. 2 To about 10 4The reference clock may have a frequency of approximately 50 MHz in a non-limiting and exemplary manner.

[0021] By combining the first local oscillator signal 6A and the second local oscillator signal 6B into a combined local oscillator signal 10, the power of the local oscillator signal can be increased. That is, the power of the combined local oscillator signal 10 can be greater than the power of the first local oscillator signal 6A and greater than the power of the second local oscillator signal 6B. In one example, if the first local oscillator signal 6A and the second local oscillator signal 6B are combined in phase, the power of the combined local oscillator signal 10 can be increased by approximately +6 dB. Therefore, the signal paths from RF chips 2A and 2B to the power combiner 8 should have the same length to ensure the minimum possible phase difference. In this context, RF device 100 may include a first signal path and a second signal path, wherein the first signal path transmits a first local oscillator signal 6A from the local oscillator output 22A of the first RF chip 2A to the first local oscillator input 24A of the power combiner 8, and the second signal path transmits a second local oscillator signal 6B from the local oscillator output 22B of the second RF chip 2B to the second local oscillator input 24B of the power combiner 8. In the example, the signal paths may extend on a PCB on which RF chips 2A and 2B may be mounted. To provide the minimum possible phase difference between the first local oscillator signal 6A and the second local oscillator signal 6B at inputs 24A and 24B of the combiner 8, the lengths of the first signal path and the second signal path should be similar or the same.

[0022] In some examples, achieving the minimum possible phase difference between the first local oscillator signal 6A and the second local oscillator signal 6B at inputs 24A and 24B of combiner 8 may be problematic. In this case, at least one of the first RF chip 2A or the second RF chip 2B may include a phase shifter disposed between the local oscillator and the local oscillator output of the respective RF chip. In the illustrated example, the first RF chip 2A may include a first phase shifter 30A, and the second RF chip 2B may include a second phase shifter 30B. The phase shifter may be configured to compensate for the phase difference between the first local oscillator signal 6A and the second local oscillator signal 6B. In a non-limiting example, the phase shifter may include or may correspond to an IQ modulator.

[0023] In the illustrated example, RF device 100 may optionally include a power splitter 20, which may be coupled to a power combiner 8 and configured to split a combined local oscillator signal 10 received from the power combiner 8 into a first split local oscillator signal 26A for a first RF chip 2A and a second split local oscillator signal 26B for a second RF chip 2B. RF device 100 may include: a third signal path for transmitting the first split local oscillator signal 26A from the output 28A of the power splitter 20 to the input 12A of the first RF chip 2A; and a fourth signal path for transmitting the second split local oscillator signal 26B from the output 28B of the power splitter 20 to the input 12B of the second RF chip 2B. Specifically, the lengths of the third and fourth signal paths may be the same. Since the third and fourth signal paths are of the same length, each of the first RF chip 2A and the second RF chip 2B can receive the same local oscillator signal from the power splitter 20, allowing the operation of the first RF chip 2A and the second RF chip 2B to be based on the same local oscillator signal. Specifically, the same local oscillator signal can be received at the same phase at the RF inputs 12A and 12B of the RF chips 2A and 2B, thereby providing coherence between the RF chips 2A and 2B. For example, all RX channels can thus down-convert the received signal with the same phase from RF to baseband. Furthermore, since the length of the local oscillator signal distribution can be the same for each RF chip, temperature effects can affect each RF chip in the same way, thereby reducing phase changes due to temperature variations.

[0024] It should be noted that the power splitter 20 of RF device 100 can be considered optional. In another example, RF device 100 may not need to include power splitter 20, and the combined local oscillator signal 10 can be directly transmitted from power combiner 8 to inputs 12A and 12B of RF chips 2A and 2B. Similar to the example including power splitter 20, the signal path length between power combiner 8 and RF chips 2A and 2B can be selected to provide the minimum possible phase difference. In this regard, the RF device 100 may include: a first signal path for transmitting a first local oscillator signal 6A from the local oscillator output 22A of the first RF chip 2A to the first local oscillator input 24A of the power combiner 8; a second signal path for transmitting a second local oscillator signal 6B from the local oscillator output 22B of the second RF chip 2B to the second local oscillator input 24B of the power combiner 8; a third signal path for transmitting a combined local oscillator signal 10 from the power combiner 8 to the input 12A of the first RF chip 2A; and a fourth signal path for transmitting the combined local oscillator signal 10 from the power combiner 8 to the input 12B of the second RF chip 2B. The power combiner 8, the first signal path, the second signal path, the third signal path, and the fourth signal path may be configured such that the phase of the combined local oscillator signal 10 at the input 12A of the first RF chip 2A is the same as the phase of the combined local oscillator signal 10 at the input 12B of the second RF chip 2B. For example, at least one of the following can be adjusted or selected: the internal structure of the power combiner 8, the length of the first signal path, the length of the second signal path, the length of the third signal path, the length of the fourth signal path, or the relative arrangement between the RF chips 2A, 2B and the power combiner 8, in order to obtain phase similarity or equivalence.

[0025] As previously described, in the example, the first RF chip 2A, the second RF chip 2B, the power combiner 8, and the power splitter 20 can be arranged on the same PCB (or PCB laminate). In other examples, the first RF chip 2A, the second RF chip 2B, the power combiner 8, and the power splitter 20 can be integrated in the same semiconductor package. In this context, a substrate can be integrated into the semiconductor package, and the components (and the signal paths coupling these components, as discussed above) can be arranged on the substrate. Therefore, the RF device 100 can include or may correspond to a multi-chip package. A multi-chip package can be viewed as an assembly of multiple separate semiconductor chips (or semiconductor dies) and other optional electronic components. In some examples, sealing or molding multiple semiconductor chips together and forming an electrical redistribution can be part of forming a multi-chip package. The package can provide a means for connecting the semiconductor package to its external environment (e.g., a printed circuit board (PCB)) via appropriate electrical connection elements (e.g., leads, pads, balls, pins, etc.). Therefore, the RF device 100 implemented in a multi-chip package may include at least one external connection element (not shown) configured to mechanically and electrically couple the multi-chip package to, for example, a PCB (not shown). Furthermore, the package may optionally provide means for protecting its components from threats such as mechanical shock, chemical contamination, moisture, and exposure. In this regard, the RF device 100 implemented in a multi-chip package may include a chip package housing, wherein the first RF chip 2A, the second RF chip 2B, the power combiner 8, the power splitter 20, and the signal paths electrically coupling these components can be sealed within the chip package housing.

[0026] exist Figure 1In the example, for simplicity, an exemplary number of two RF chips 2A and 2B are shown. However, it should be understood that the RF device 100 may include additional RF chips, the number and arrangement of which may depend on the specific design of the RF device 100. Such additional RF chips may include some or all of the features of the RF chips 2A and 2B as described above. In the example, the power combiner 8 may be configured to provide the combined local oscillator signal 10 to at least one of the additional RF chips of the RF device 100. Alternatively or additionally, the local oscillator signal provided by the local oscillator of the additional RF chip may also be used to generate the combined local oscillator signal. Specifically, the RF device 100 may include a third RF chip (not shown) that includes a third local oscillator configured to generate and output a third local oscillator signal during an operating time interval. The first local oscillator signal 6A, the second local oscillator signal 6B, and the third local oscillator signal may have the same frequency behavior during the operating time interval. The power combiner 8 can be configured to combine the first local oscillator signal 6A, the second local oscillator signal 6B, and the third local oscillator signal into a combined local oscillator signal, and output the combined local oscillator signal to the inputs of the first RF chip 2A, the second RF chip 2B, and the third RF chip.

[0027] It should be noted that RF device 100 may include, for simplicity, Figure 1 Additional components are not shown. For example, RF device 100 may include a 3D waveguide antenna that can be coupled to at least one of the first RF chip 2A or the second RF chip 2B. Furthermore, RF chips 2A and 2B may include additional electronic circuitry 46A and 46B, for example, for processing transmitted and / or received RF signals in the analog and / or digital domains. For simplicity, details of the additional electronic circuitry 46A and 46B are not included. Figure 1 Examples are clearly shown and discussed.

[0028] Figure 1 The cascaded RF device 100 can outperform other cascaded RF devices in various ways. Figure 2 Other exemplary cascaded RF devices 200 are schematically illustrated. RF devices 200 may have features combined with those previously described. Figure 1 Similar components as described. In Figure 2In the example, the local oscillator 4A of the first RF chip 2A can generate and output a local oscillator signal 6 at the local oscillator output 22A of the first RF chip 2A. The power splitter 20 can be configured to split the local oscillator signal 6 received from the first RF chip 2A into a first split local oscillator signal 26A for the first RF chip 2A and a second split local oscillator signal 26B for the second RF chip 2B. That is, the local oscillator signal 6 generated by the first RF chip 2A is self-fed and provided to the second RF chip 2B. In the example, the first RF chip 2A can be referred to as the master RF chip (or main unit), and the second RF chip 2B can be referred to as the slave RF chip (or secondary unit). The RF device 200 does not include a power combiner configured to combine the local oscillator signals from both RF chips 2A and 2B into a combined local oscillator signal, which can be input to and used by both RF chips 2A and 2B.

[0029] Figure 1 The RF device 100 can outperform Figure 2 The RF device 200 can provide increased signal power to the local oscillator signal. Figure 1 The signal power of the combined local oscillator signal 10 can be higher than Figure 2 The signal power of the local oscillator signal 6. If the first local oscillator signal 6A and the second local oscillator signal 6B are combined in phase, the signal power of the combined local oscillator signal 10 can increase by approximately +6 dB. Even when there is a phase difference between local oscillator signals 6A and 6B, the signal power can be increased when combining local oscillator signals 6A and 6B, such as when combining... Figure 1 As shown and described. For example, the phase difference (approximately 40 degrees) between the local oscillator signals 6A and 6B at the power combiner 8 can still result in an increase in signal power of approximately +5.5 dB. That is, even with a phase difference of approximately 40 degrees, the signal power of the combined local oscillator signal 10 can still, for example... Figure 2 The signal is approximately +5.5 dB high when only one RF chip provides the local oscillator signal. This is because... Figure 1 In the example, both RF chips 2A and 2B can generate and output corresponding local oscillator signals, therefore each of RF chips 2A and 2B can be programmed to operate as the main RF chip of RF device 100. That is, in Figure 1In the example, RF chips 2A and 2B do not need to be distinguished as primary RF chips and secondary RF chips. It should be understood that RF device 100 may include additional secondary RF chips that can receive the combined local oscillator signal 10 for operational purposes, but which may not necessarily contribute to the generation of the combined local oscillator signal 10.

[0030] exist Figure 2 In the example, the guaranteed minimum output power of the primary local oscillator signal 6 and the minimum required input power at input 12A of the secondary RF chip 2B can limit the maximum number of RF chips used in device 200 and the maximum possible distance between the RF chips. Furthermore, using a cheaper PCB laminate may result in higher attenuation of the local oscillator signal. Conversely, Figure 2 Device 200 can provide increased signal power for the local oscillator signal as described above. In this way, the local oscillator power budget between the RF chips of device 200 can be improved, thereby allowing the use of a less expensive PCB laminate and / or a larger number of RF chips in RF device 100.

[0031] Figure 1 The RF device 100 can outperform Figure 2 The RF device 200 is used because it can reduce phase noise. When the first local oscillator signal 6A and the second local oscillator signal 6B are combined into the combined local oscillator signal 10, the relative increase in signal power may be greater than the relative increase in phase noise. As mentioned earlier, when combining the two local oscillator signals 6A and 6B, the signal power of the combined local oscillator signal 10 can increase by up to about +6 dB. At the same time, the phase noise of the combined local oscillator signal 10 can only increase by about +3 dB. Therefore, the combined local oscillator signals 6A and 6B can result in a phase noise improvement of about -3 dB.

[0032] Figure 3 A flowchart illustrating a method for operating a cascaded RF device according to this disclosure is shown. This method can be used to operate the cascaded RF device as described above, and therefore can be read in conjunction with the preceding figures. Described in a general manner. Figure 3 This method is used to qualitatively specify aspects of this disclosure. It should be understood that this method may include other aspects. For example, the method may be extended by combining any of the aspects described in conjunction with other examples according to this disclosure.

[0033] At point 32, a first local oscillator signal can be generated and output by a first local oscillator of the first RF chip during the operation time interval. At point 34, a second local oscillator signal can be generated and output by a second local oscillator of the second RF chip during the operation time interval. At point 36, a power combiner can combine the first and second local oscillator signals into a combined local oscillator signal. At point 38, a power combiner can output the combined local oscillator signal to the inputs of the first and second RF chips. The first and second local oscillator signals can have the same frequency behavior during the operation time interval.

[0034] Figure 4 A flowchart illustrating a method for manufacturing a cascaded RF device according to this disclosure is shown. This method can be used to manufacture the cascaded RF device as described above, and therefore can be read in conjunction with the preceding figures. Described in a general manner. Figure 4 This method is used to qualitatively specify aspects of this disclosure. It should be understood that this method may include other aspects. For example, the method may be extended by combining any of the aspects described in conjunction with other examples according to this disclosure.

[0035] At position 40, a first RF chip may be arranged, the first RF chip including a first local oscillator configured to generate and output a first local oscillator signal during an operation time interval. At position 42, a second RF chip may be arranged, the second RF chip including a second local oscillator configured to generate and output a second local oscillator signal during an operation time interval. At position 44, a power combiner may be arranged, the power combiner configured to combine the first local oscillator signal and the second local oscillator signal into a combined local oscillator signal and output the combined local oscillator signal to the inputs of the first RF chip and the second RF chip. The first local oscillator signal and the second local oscillator signal may have the same frequency behavior during the operation time interval.

[0036] Example

[0037] The examples described in this article provide cascaded RF devices and methods for operating and manufacturing cascaded RF devices.

[0038] Example 1 is a cascaded radio frequency (RF) device comprising: a first RF chip including a first local oscillator configured to generate and output a first local oscillator signal during an operation time interval; a second RF chip including a second local oscillator configured to generate and output a second local oscillator signal during an operation time interval; and a power combiner configured to combine the first local oscillator signal and the second local oscillator signal into a combined local oscillator signal, and to output the combined local oscillator signal to an input of the first RF chip and an input of the second RF chip, wherein the first local oscillator signal and the second local oscillator signal have the same frequency behavior during the operation time interval.

[0039] Example 2 is a cascaded RF device according to Example 1, wherein the frequency behavior includes a frequency ramp having a start frequency and a stop frequency during an operating time interval.

[0040] Example 3 is a cascaded RF device according to Example 1 or 2, wherein a first local oscillator and a second local oscillator are controlled to generate and output the same local oscillator signal.

[0041] Example 4 is a cascaded RF device according to any of the preceding examples, wherein the first local oscillator signal and the second local oscillator signal are identical except for the phase difference.

[0042] Example 5 is a cascaded RF device according to any of the preceding examples, wherein the phase difference between the first local oscillator signal and the second local oscillator signal is constant.

[0043] Example 6 is a cascaded RF device according to Example 5, wherein the constant phase difference is less than π / 3.

[0044] Example 7 is a cascaded RF device according to any of the preceding examples, wherein the first local oscillator signal and the second local oscillator signal are based on the same reference clock.

[0045] Example 8 is a cascaded RF device according to Example 7, further comprising: at least one of a local oscillator or a crystal oscillator disposed outside the first RF chip and the second RF chip, and configured to generate a reference clock and provide the reference clock to the first RF chip and the second RF chip.

[0046] Example 9 is a cascaded RF device according to Example 7, further comprising: at least one of a local oscillator or a crystal oscillator disposed in a first RF chip and configured to generate a reference clock, and to provide the reference clock to the first RF chip and to the second RF chip.

[0047] Example 10 is a cascaded RF device according to any of the preceding examples, further comprising: a first signal path for transmitting a first local oscillator signal from the output of a first RF chip to a first input of a power combiner; and a second signal path for transmitting a second local oscillator signal from the output of a second RF chip to a second input of a power combiner, wherein the lengths of the first signal path and the second signal path are the same.

[0048] Example 11 is a cascaded RF device according to any of the preceding examples, further comprising: a first signal path for transmitting a first local oscillator signal from the output of a first RF chip to a first input of a power combiner; a second signal path for transmitting a second local oscillator signal from the output of a second RF chip to a second input of the power combiner; a third signal path for transmitting a combined local oscillator signal from the power combiner to the first input of the first RF chip; and a fourth signal path for transmitting the combined local oscillator signal from the power combiner to the second input of the second RF chip, wherein the power combiner, the first signal path, the second signal path, the third signal path, and the fourth signal path are configured such that the phase of the combined local oscillator signal at the first input of the first RF chip is the same as the phase of the combined local oscillator signal at the second input of the second RF chip.

[0049] Example 12 is a cascaded RF device according to any one of Examples 1-10, further comprising: a power splitter coupled to a power combiner and configured to split a combined local oscillator signal received from the power combiner into a first split local oscillator signal for a first RF chip and a second split local oscillator signal for a second RF chip.

[0050] Example 13 is a cascaded RF device according to Example 12, further comprising: a third signal path for transmitting a first shunt local oscillator signal from the output of a power splitter to the input of a first RF chip; and a fourth signal path for transmitting a second shunt local oscillator signal from the output of a power splitter to the input of a second RF chip, wherein the length of the third signal path is the same as the length of the fourth signal path.

[0051] Example 14 is a cascaded RF device according to any of the preceding examples, wherein when the first local oscillator signal and the second local oscillator signal are combined into a combined local oscillator signal, the relative increase in signal power is greater than the relative increase in phase noise.

[0052] Example 15 is a cascaded RF device according to any of the preceding examples, wherein: the first RF chip and the second RF chip are integrated in the same semiconductor package, and the power combiner is arranged in the semiconductor package.

[0053] Example 16 is a cascaded RF device according to any of the preceding examples, wherein each of the first RF chip and the second RF chip is programmed to operate as the master RF chip of the cascaded RF device.

[0054] Example 17 is a cascaded RF device according to any of the preceding examples, wherein: at least one of the first RF chip or the second RF chip includes a phase shifter disposed between the local oscillator and the output of the respective RF chip, and the phase shifter is configured to compensate for the phase difference between the first local oscillator signal and the second local oscillator signal.

[0055] Example 18 is a cascaded RF device according to any of the preceding examples, wherein a power combiner is configured to provide a combined local oscillator signal to a third RF chip of the cascaded RF device.

[0056] Example 19 is a cascaded RF device according to any of the preceding examples, further comprising: a third RF chip including a third local oscillator configured to generate and output a third local oscillator signal during an operation time interval, wherein a power combiner is configured to combine the first local oscillator signal, the second local oscillator signal, and the third local oscillator signal into a combined local oscillator signal, and output the combined local oscillator signal to the inputs of the first RF chip, the second RF chip, and the third RF chip, wherein the first local oscillator signal, the second local oscillator signal, and the third local oscillator signal have the same frequency behavior during the operation time interval.

[0057] Example 20 is a cascaded RF device according to any of the preceding examples, further comprising: a 3D waveguide antenna coupled to at least one of a first RF chip or a second RF chip.

[0058] Example 21 is a method for operating cascaded RF devices, the method comprising: generating and outputting a first local oscillator signal by a first local oscillator of a first RF chip during an operation time interval; generating and outputting a second local oscillator signal by a second local oscillator of a second RF chip during the operation time interval; combining the first local oscillator signal and the second local oscillator signal into a combined local oscillator signal by a power combiner; and outputting the combined local oscillator signal to an input of the first RF chip and an input of the second RF chip by the power combiner, wherein the first local oscillator signal and the second local oscillator signal have the same frequency behavior during the operation time interval.

[0059] Example 22 is a method for manufacturing cascaded RF devices, the method comprising: arranging a first RF chip including a first local oscillator configured to generate and output a first local oscillator signal during an operation time interval; arranging a second RF chip including a second local oscillator configured to generate and output a second local oscillator signal during an operation time interval; and arranging a power combiner configured to combine the first local oscillator signal and the second local oscillator signal into a combined local oscillator signal, and outputting the combined local oscillator signal to an input of the first RF chip and an input of the second RF chip, wherein the first local oscillator signal and the second local oscillator signal have the same frequency behavior during the operation time interval.

[0060] As used in this specification, the terms “connected,” “coupled,” “electrically connected,” and / or “electrically coupled” do not necessarily mean that components must be directly connected or coupled together. Intermediate components may be provided between “connected,” “coupled,” “electrically connected,” or “electrically coupled” components.

[0061] Furthermore, with regard to the use of the terms “having,” “containing,” “including,” “with,” or variations thereof in the detailed description or claims, such terms are intended to be inclusive in a manner similar to the term “comprising.” That is, as used herein, the terms “having,” “containing,” “including,” “with,” “comprising,” etc., are open-ended terms that indicate the presence of the stated element or feature but do not exclude additional elements or features. The articles “a,” “an,” and “the” are intended to include both plural and singular forms unless the context clearly indicates otherwise.

[0062] Furthermore, the terms “exemplary” and “example” are used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as “exemplary” or “example” is not necessarily to be construed as superior to other aspects or designs. Rather, the use of the terms “exemplary” and “example” is intended to present concepts in a specific manner. As used in this application, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” That is, unless otherwise stated or clearly apparent from the context, “X uses A or B” is intended to mean either of the natural inclusive substitutions. That is, “X uses A or B” is satisfied in any prior instance if X uses A; X uses B; or X uses both A and B. Furthermore, the articles “a” and “an” used in this application and the appended claims are generally to be interpreted as meaning “one or multiple” unless otherwise stated or clearly apparent from the context to the singular form. In addition, expressions such as “at least one of A and B” generally refer to A, or B, or both A and B.

[0063] Although specific examples have been shown and described herein, those skilled in the art will understand that various substitutions and / or equivalent embodiments may be used to replace the specific examples shown and described without departing from the scope of the invention. This application is intended to cover any modifications or variations of the specific examples discussed herein. Therefore, the invention is limited only by the claims and their equivalents.

[0064] It should be noted that the methods and devices, including their preferred embodiments as outlined in this document, can be used alone or in combination with other methods and devices disclosed in this document. Furthermore, features outlined in the context of the device also apply to the corresponding method, and vice versa. Moreover, all aspects of the methods and devices outlined in this document can be combined arbitrarily. In particular, the features of the claims can be combined with each other in any manner.

[0065] It should be noted that the specification and drawings merely illustrate the principles of the proposed methods and systems. Those skilled in the art will be able to implement various arrangements, although these arrangements are not explicitly described or shown herein, but they embody the principles of the invention and are included within the spirit and scope of the invention. Furthermore, all examples and embodiments outlined in this document are primarily intended for illustrative purposes only to aid the reader in understanding the principles of the proposed methods and systems. Moreover, all statements herein providing the principles, aspects, and embodiments of the invention, as well as specific examples thereof, are intended to cover their equivalents.

Claims

1. A cascaded radio frequency, RF, device, comprising: a first RF chip (2A) comprising a first local oscillator (4A) configured to generate and output a first local oscillator signal (6A) during an operational time interval; a second RF chip (2B) comprising a second local oscillator (4B) configured to generate and output a second local oscillator signal (6B) during the operational time interval; and a power combiner (8) configured to combine the first local oscillator signal (6A) and the second local oscillator signal (6B) into a combined local oscillator signal (10) and to output the combined local oscillator signal (10) to an input of the first RF chip (2A) and to an input of the second RF chip (2B), wherein the first local oscillator signal (6A) and the second local oscillator signal (6B) have a same frequency behavior during the operational time interval.

2. The cascaded RF device according to claim 1, wherein the frequency behavior comprises a frequency ramp having a start frequency and a stop frequency during the operational time interval.

3. The cascaded RF device according to claim 1 or 2, wherein the first local oscillator (4A) and the second local oscillator (4B) are controlled to generate and output the same local oscillator signal.

4. The cascaded RF device according to any one of the preceding claims, wherein the first local oscillator signal (6A) and the second local oscillator signal (6B) are identical except for a phase difference.

5. The cascaded RF device according to any one of the preceding claims, wherein a phase difference between the first local oscillator signal (6A) and the second local oscillator signal (6B) is constant.

6. The cascaded RF device according to claim 5, wherein the constant phase difference is less than π / 3.

7. The cascaded RF device according to any one of the preceding claims, wherein the first local oscillator signal (6A) and the second local oscillator signal (6B) are based on a same reference clock.

8. The cascaded RF device according to claim 7, further comprising: at least one of a local oscillator or a crystal oscillator arranged outside the first RF chip (2A) and outside the second RF chip (2B) and configured to generate the reference clock and to provide the reference clock to the first RF chip (2A) and to the second RF chip (2B).

9. The cascaded RF device according to claim 7, further comprising: at least one of a local oscillator or a crystal oscillator arranged in the first RF chip (2A) and configured to generate the reference clock and to provide the reference clock to the first RF chip (2A) and to the second RF chip (2B).

10. The cascaded RF device according to any one of the preceding claims, further comprising: ​ a first signal path for conveying the first local oscillator signal (6A) from a local oscillator output (22A) of the first RF chip (2A) to a first local oscillator input (24A) of the power combiner (8); and a second signal path for conveying the second local oscillator signal (6B) from a local oscillator output (22B) of the second RF chip (2B) to a second local oscillator input (24B) of the power combiner (8), wherein the length of the first signal path and the length of the second signal path are the same.

11. The cascode RF device of any preceding claim, further comprising: a first signal path for conveying the first local oscillator signal (6A) from a local oscillator output (22A) of the first RF chip (2A) to a first local oscillator input (24A) of the power combiner (8); a second signal path for conveying the second local oscillator signal (6B) from a local oscillator output (22B) of the second RF chip (2B) to a second local oscillator input (24B) of the power combiner (8); a third signal path for conveying the combined local oscillator signal (10) from the power combiner (8) to a first input (12A) of the first RF chip (2A); and a fourth signal path for conveying the combined local oscillator signal (10) from the power combiner (8) to a second input (12B) of the second RF chip (2B), wherein the power combiner (8), the first signal path, the second signal path, the third signal path and the fourth signal path are configured such that the phase of the combined local oscillator signal (10) at the first input (12A) of the first RF chip (2A) is the same as the phase of the combined local oscillator signal (10) at the second input (12B) of the second RF chip (2B).

12. The cascode RF device of any of claims 1 to 10, further comprising: a power splitter (20) coupled to the power combiner (8) and configured to split the combined local oscillator signal (10) received from the power combiner (8) into a first split local oscillator signal (26A) for the first RF chip (2A), a second split local oscillator signal (26B) for the second RF chip (2B).

13. The cascode RF device of claim 12, further comprising: a third signal path for conveying the first split local oscillator signal (26A) from an output (28A) of the power splitter (20) to an input (12A) of the first RF chip (2A); and a fourth signal path for conveying the second split local oscillator signal (26B) from an output (28B) of the power splitter (20) to an input (12B) of the second RF chip (2B), ​ wherein the length of the third signal path and the length of the fourth signal path are identical.

14. The cascaded RF device according to any one of the preceding claims, wherein a relative increase in signal power is larger than a relative increase in phase noise when combining the first local oscillator signal (6A) and the second local oscillator signal (6B) into the combined local oscillator signal (10).

15. The cascaded RF device according to any one of the preceding claims, wherein: the first RF chip (2A) and the second RF chip (2B) are integrated in the same semiconductor package, and the power combiner (8) is arranged in the semiconductor package.

16. The cascaded RF device according to any one of the preceding claims, wherein each of the first RF chip (2A) and the second RF chip (2B) is programmed to operate as a master RF chip of the cascaded RF device.

17. The cascaded RF device according to any one of the preceding claims, wherein: at least one of the first RF chip (2A) or the second RF chip (2B) comprises a phase shifter (30) arranged between the local oscillator (4) and a local oscillator output (22) of the respective RF chip (2), and the phase shifter (30) is configured to compensate for a phase difference between the first local oscillator signal (6A) and the second local oscillator signal (6B).

18. The cascaded RF device according to any one of the preceding claims, wherein the power combiner (8) is configured to provide the combined local oscillator signal (10) to a third RF chip of the cascaded RF device.

19. The cascaded RF device according to any one of the preceding claims, further comprising: a third RF chip comprising a third local oscillator configured to generate and output a third local oscillator signal during the operation time interval, wherein the power combiner (8) is configured to combine the first local oscillator signal (6A), the second local oscillator signal (6B) and the third local oscillator signal into a combined local oscillator signal and to output the combined local oscillator signal to an input (12A) of the first RF chip (2A), to an input (12B) of the second RF chip (2B), and to an input of the third RF chip, wherein the first local oscillator signal (6A), the second local oscillator signal (6B) and the third local oscillator signal have identical frequency behavior during the operation time interval.

20. The cascaded RF device according to any one of the preceding claims, further comprising: a 3D waveguide antenna coupled to at least one of the first RF chip (2A) or the second RF chip (2B).

21. A method for operating a cascaded RF device, the method comprising: generating and outputting, by a first local oscillator (4A) of a first RF chip (2A), a first local oscillator signal (6A) during an operational time interval; generating and outputting, by a second local oscillator (4B) of a second RF chip (2B), a second local oscillator signal (6B) during the operational time interval; combining, by a power combiner (8), the first local oscillator signal (6A) and the second local oscillator signal (6B) into a combined local oscillator signal (10); and outputting, by the power combiner (8), the combined local oscillator signal (10) to an input (12A) of the first RF chip (2A) and to an input (12B) of the second RF chip (2B), wherein the first local oscillator signal (6A) and the second local oscillator signal (6B) have the same frequency behavior during the operational time interval.

22. A method for manufacturing a cascaded RF device, the method comprising: arranging a first RF chip (2A) comprising a first local oscillator (4A) configured to generate and output a first local oscillator signal (6A) during an operational time interval; arranging a second RF chip (2B) comprising a second local oscillator (4B) configured to generate and output a second local oscillator signal (6B) during the operational time interval; and arranging a power combiner (8) configured to combine the first local oscillator signal (6A) and the second local oscillator signal (6B) into a combined local oscillator signal (10) and to output the combined local oscillator signal (10) to an input (12A) of the first RF chip (2A) and to an input (12B) of the second RF chip (2B), wherein the first local oscillator signal (6A) and the second local oscillator signal (6B) have the same frequency behavior during the operational time interval.

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