Multiband wireless communication device and method for transmitting multiband wireless communication signal

Abstract

The embodiment of the invention provides multi-band wireless communication equipment. The multi-band wireless communication equipment comprises a wireless communication chip, an external power amplifier and an external conversion circuit, a first transmission path circuit in the wireless communication chip is used for outputting a first output signal of a first frequency band; a second transmission path circuit in the wireless communication chip is used for outputting a pair of differential signals of a second frequency band different from the first frequency band; the external power amplifier is arranged outside the wireless communication chip, is coupled with the first transmission path circuit and is used for amplifying the first output signal to generate a first transmission signal of a first frequency band; and the external conversion circuit is arranged outside the wireless communication chip, is coupled with the second transmission path circuit and is used for converting the pair of differential signals into a second transmission signal of a second frequency band, and the second transmission signal is a single-ended signal. According to the embodiment of the invention, the interference introduced into the wireless communication chip can be reduced or eliminated.

Description

Technical Field

[0001] The present invention relates to wireless communication devices, and more particularly to a multi-band wireless communication device and a method for transmitting multi-band wireless communication signals. Background Art

[0002] In the global wireless communication specifications defined by the Federal Communications Commission (FCC), there are some restrictions on the spectral behavior when transmitting signals. For example, the FCC requires that when transmitting / receiving signals within the operating band, the interference energy in the signal needs to be lower than a specific value. However, in some cases, it may be challenging to meet the above requirements for multi-band transmission.

[0003] Therefore, a novel architecture and related methods are needed to enable multi-band transmission to meet the specifications without introducing any side effects or in a way that is less likely to introduce side effects. Summary of the Invention

[0004] The object of the present invention is to provide a multi-band wireless communication device and a method for transmitting multi-band wireless communication signals, so that the transmitted signals of the multi-band wireless communication device comply with the FCC regulations without significantly increasing additional costs.

[0005] An embodiment of the present invention provides a multi-band wireless communication device. The multi-band wireless communication device includes a wireless communication chip, an external power amplifier, and an external conversion circuit, where both the external power amplifier and the external conversion circuit are located outside the wireless communication chip. The wireless communication chip includes a first transmission path circuit and a second transmission path circuit, where the first transmission path circuit is configured to output a first output signal of a first band, and the second transmission path circuit is configured to output a pair of differential signals of a second band different from the first band. The external power amplifier is coupled to the first transmission path circuit and is configured to amplify the first output signal of the first band to generate a first transmission signal of the first band. The external conversion circuit is coupled to the second transmission path circuit and is used to convert the pair of differential signals of the second band into a second transmission signal of the second band, where the second transmission signal of the second band is a single-ended signal.

[0006] The multi-band wireless communication device may further include: a matching network, coupled between the second transmission path circuit and the external conversion circuit, located outside the wireless communication chip, and used to provide impedance matching, for example, to provide impedance matching between the output impedance of a power amplifier (PA) inside the second transmission path circuit and the input impedance of the external conversion circuit.

[0007] An embodiment of the present invention provides a method for transmitting a multi-band wireless communication signal, including: an internal first transmission path circuit integrated in a wireless communication chip outputs a first output signal of a first band; an external power amplifier (PA) disposed outside the wireless communication chip amplifies the first output signal of the first band to generate a first transmission signal of the first band; an internal second transmission path circuit integrated in the wireless communication chip outputs a pair of differential signals of a second band different from the first band; and an external conversion circuit disposed outside the wireless communication chip converts the pair of differential signals of the second band into a second transmission signal of the second band, where the second transmission signal is a single-ended signal.

[0008] The multi-band wireless communication device and the method for transmitting a multi-band wireless communication signal provided by the embodiment of the present invention place the conversion circuit (such as but not limited to a balanced-to-unbalanced (balun) transformer or an inductance-capacitance element serving as the conversion circuit) outside the wireless communication chip, rather than using an on-chip balanced-to-unbalanced transformer (the on-chip balanced-to-unbalanced transformer is implemented by an on-chip inductance coil) to implement the conversion circuit, so as to reduce or eliminate the interference and coupling introduced inside the wireless communication chip, thereby avoiding the interference of the second or third harmonic of a pair of differential signals of the second band in the first transmission signal of the first band exceeding an acceptable level due to the amplification of the external PA. In addition, the embodiment of the present invention does not significantly increase additional costs, so the present invention can enable the transmission signal output by the multi-band wireless communication device to comply with FCC regulations and will not introduce any side effects or is less likely to introduce side effects.

[0009] After reading the following detailed description of the preferred embodiments shown in various drawings, these and other objects of the present invention will undoubtedly become obvious to those of ordinary skill in the art. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of a multi-band wireless communication device according to an embodiment of the present invention.

[0011] Figure 2 It is a schematic diagram of a multi-band wireless communication device according to another embodiment of the present invention.

[0012] Figure 3 It is a flowchart of the method for transmitting a multi-band wireless communication signal according to an embodiment of the present invention. DETAILED DESCRIPTION

[0013] The following description and claims use some terms that refer to specific components. As understood by those skilled in the art, electronic device manufacturers may use different names to refer to a component. This document does not intend to distinguish components with different names but the same function. In the following description and claims, the terms "comprising" and "including" are used in an open-ended manner and should therefore be interpreted as "including but not limited to...". In addition, the term "coupled" is intended to mean an indirect or direct electrical connection. Thus, if a device is coupled to another device, the coupling may be through a direct electrical connection or through an indirect electrical connection via other devices and connections.

[0014] Figure 1 is a schematic diagram showing a multi-band wireless communication device 20 according to an embodiment of the present invention. As Figure 1 shown, the multi-band wireless communication device 20 includes a wireless communication chip 200, an external power amplifier (PA) 110 (labeled "ePA" in the figure for simplicity), a matching network 120, and an external conversion circuit 130, which may be located on a printed circuit board (PCB). The wireless communication chip 200 may include a first transmission path circuit (e.g., an A-band transmission path circuit 200A) and a second transmission path circuit (e.g., a G-band transmission path circuit 200G), where the external PA 110 is coupled to the A-band transmission path circuit 200A, and the matching network 120 and the external conversion circuit 130 are coupled to the G-band transmission path circuit 200G. In this embodiment, the A-band transmission path circuit 200A and the external PA 110 are used to output a transmission signal VOA to the antenna, and the G-band transmission path circuit 200G, the matching network 120, and the external conversion circuit 130 are used to output a transmission signal VOG to the antenna, where the transmission signal VOA is in the A-band, such as the 5 GHz band or the 6 GHz band, and the transmission signal VOG is in the G-band, such as the 2.4 GHz band.

[0015] The A-band transmission path circuit 200A may include a programmable gain amplifier (PGA) 211 (labeled "TXA PGA" in the figure for ease of understanding), an impedance converter 212 connected to the reference voltage VDD (which can be implemented by an inductor coil), a PA driver 213 (labeled "TXA PAD" in the figure for ease of understanding), a balanced-to-unbalanced (balun) converter 214 connected to the reference voltage VDD (which can be implemented by an inductor coil), and capacitors CA1 and CA2. The PGA 211 is configured to receive a first differential signal pair in the A-band and amplify the first differential signal pair to generate an amplified first differential signal pair in the A-band. The impedance converter 212 is coupled between the PGA 211 and the PA driver 213 and is configured to provide impedance matching between the PGA 211 and the PA driver 213, where the impedance converter 212 receives the amplified first differential signal pair and outputs a second differential signal pair. The PA driver 213 is configured to receive the second differential signal pair and amplify the second differential signal pair to generate an amplified second differential signal pair (which can be represented as the output signal VDA1). The balun converter 214 is coupled between the PA driver 213 and the external PA 110 and is configured to convert the second differential signal pair into a first output signal (which can be represented as the output signal VDA2), where the first output signal is a single-ended signal. In some embodiments, the PGA 211 and the impedance converter 212 may be omitted, where the first differential signal pair may be received by the PA driver 213. In some embodiments, the impedance converter 212 and the PA driver 213 may be omitted, where the amplified first differential signal pair output from the PGA 211 is transmitted to the balun converter 214. In some embodiments, the PGA 211, the impedance converter 212, and the PA driver 213 may be omitted, where the first differential signal pair may be received by the balun converter 214.

[0016] The G-band transmission path circuit 200G may include a PGA 221 (labeled as "TXG PGA" in the figure for ease of understanding), an impedance transformer 222 connected to the reference voltage VDD (which can be implemented by an inductance coil), and an internal PA 223 (labeled as "TXG iPA" in the figure for ease of understanding). The PGA 221 is configured to receive the first differential signal pair in the G-band and amplify the first differential signal pair in the G-band to generate an amplified first differential signal pair in the G-band. The impedance transformer 222 is coupled between the PGA 221 and the PA 223 and is used to provide impedance matching between the PGA 221 and the PA 223, where the impedance transformer 222 receives the amplified first differential signal pair in the G-band and outputs a second differential signal pair in the G-band. The PA 223 is configured to receive the second differential signal pair in the G-band and amplify the second differential signal pair in the G-band to generate an amplified second differential signal pair (which can be represented by the output signal VPG). In some embodiments, the PGA 221 and the impedance transformer 222 may be omitted, and the first differential signal pair in the G-band may be received by the internal PA 223.

[0017] The A-band may be a 5G band or a 6G band. The internal PA 223 (integrated in the wireless communication chip 200) is typically the main source of non-linear effects, and thus generates second and third harmonic interferences on its output (such as the output signal VPG, which is a pair of differential signals), where the main signal in the output signal VPG is in the G-band (for example, the frequency range of the G-band may be from 2.412 GHz to 2.472 GHz), the second harmonic interference in the output signal VPG is in a frequency band that partially overlaps with the 5G band (for example, the frequency range of the 5G band may be from 5.180 GHz to 5.850 GHz) or is very close to the lowest frequency of the 5G band, and the third harmonic interference in the output signal VPG is in a frequency band that partially overlaps with the 6G band (for example, the 6G band range may be from 5.925 GHz to 7.115 GHz) or is very close to the highest frequency of the 6G band. In some embodiments, the A-band may include both the 5G band and the 6G band.

[0018] During the design process of a multi-band wireless communication device, the inventors found that if a transformer with an inductive coil is provided in the wireless communication chip 200 and coupled to the output of the internal PA 223, since the impedance transformer 212 and the balun 214 are implemented using inductive coils, the second harmonic interference or third harmonic interference on this transformer coupled to the output of the internal PA 223 will be coupled to the impedance transformer 212 and the balun 214 by means of coupling. In addition, the components in the A-band transmission path circuit 200A and the external PA 110 are designed for transmitting A-band signals. Therefore, the second harmonic interference (falling within the frequency range of the A-band or very close to the lowest frequency of the A-band) or third harmonic interference (falling within the frequency range of the A-band or very close to the highest frequency of the A-band) from the G-band transmission path circuit 200G may be transmitted through the PA driver 213, the balun 214, and the external PA 110. Therefore, the second harmonic interference or third harmonic interference from the G-band transmission circuit 200G (more specifically, from the output of the internal PA 223) may appear in the output signal VDA1 of the PA driver 213 (the output signal VDA1 is a pair of differential signals), the output signal VDA2 of the balun 214 (generated by converting the output signal VDA1 into a single-ended signal), and the transmitted signal VOA output by the external PA110 (generated by amplifying the output signal VDA2). Moreover, the external PA 110 usually provides a gain of about 30 decibels (dB), so it will amplify the second harmonic interference or third harmonic interference in the output signal VDA2. In this case, when the multi-band wireless communication device 20 needs to meet the requirements of the transmission specification, the design of the wireless communication chip 200 will face challenges. For example, when, in order to meet the requirements of the transmission specification, the power of the second harmonic interference or third harmonic interference in the transmitted signal VOA needs to be lower than -48 decibel relative to one milliwatt (dBm), due to the 30 dB gain provided by the external PA 110, the power of the second harmonic interference or third harmonic interference in the output signal VDA2 needs to be lower than -78 dBm, making it difficult to achieve the target performance of the wireless communication chip 200. In some embodiments, the power of the output signal VPG can be reduced to reduce the power of the second harmonic or third harmonic generated by the internal PA 223, and one or more notch filters can be placed at the input and / or output of the external PA 110 for the frequencies of the second harmonic interference or third harmonic interference, thereby reducing the power of the second harmonic interference or third harmonic interference in the output signal VDA2 and the transmitted signal VOA.However, this solution degrades the transmitting performance of the G band, and due to the presence of the notch filter, the on-board cost will increase.

[0019] Therefore, an object of the present invention is to avoid the presence of an inductance coil at the output of the internal PA 223, thereby avoiding or reducing the coupling of second harmonic interference or third harmonic interference in the output of the internal PA 223 to the impedance transformer 212 (as shown by the interference signal 201 in Figure 1 ), and the balun 214 (as shown by the interference signal 202 in Figure 1 ).

[0020] To avoid the output signal VPG being transmitted through an on-chip transformer including an inductance coil, the multi-band wireless communication device 20 may further include a matching network 120 and an external conversion circuit 130, where the external conversion circuit 130 is coupled to the G-band transmission path circuit 200G through the matching network 120. In this configuration, the output signal VPG is transmitted through a trace, which can avoid or reduce the transmission (e.g., coupling) of second harmonic interference or third harmonic interference in the output signal VPG to the impedance transformer 212 and the balun 214. In this embodiment, the A-band transmission path circuit 200A is configured to output a first output signal (e.g., the output signal VDA2), and the G-band transmission path circuit 200G is configured to output a second output signal (e.g., the output signal VPG). The external PA 110 is located outside the wireless communication chip 200 and is used to amplify the output signal VDA2 to generate a first transmission signal in the first band, e.g., the transmission signal VOA in the A band. The external conversion circuit 130 is located outside the wireless communication chip 200 and is used to generate a second transmission signal in the second band, e.g., the transmission signal VOG in the G band, according to the output signal VPG, where the output signal VPG is a pair of differential signals and the transmission signal VOG is a single-ended signal.

[0021] As described above, the multi-band wireless communication device 20 may further include a matching network 120, where the matching network 120 is coupled to the G-band transmission path circuit 200G and the external conversion circuit 130. In this embodiment, the matching network 120 is located outside the wireless communication chip and is used to provide impedance matching between the output impedance of the internal PA 223 and the input impedance of the external conversion circuit 130. The matching network 120 is used to receive the output signal VPG (transmitted by an on-chip device (e.g., the internal PA 223)) and output the output signal VPG2 to the external conversion circuit. In some embodiments, the external conversion circuit may include an embedded input matching network to receive the output signal VPG, so the matching network 120 can be omitted, but the present invention is not limited thereto.

[0022] In this embodiment, an on-chip balun (the on-chip balun includes an inductance coil, which will introduce the above-mentioned second harmonic or third harmonic interference problem) is not placed at the output end of the internal PA 223. More specifically, the task of the on-chip balun is performed by the external conversion circuit 130. The external conversion circuit 130 can be a balun. In one embodiment, the balun can be a co-fired ceramic balun, such as a low temperature co-fired ceramic (LTCC) balun (for example, a co-fired ceramic balun manufactured at a sintering temperature below 1000 °C). Specifically, a typical package of the LTCC balun can include a plurality of terminals, such as an unbalanced port (which is coupled to the antenna), a ground port (which can be coupled to a ground voltage), a reference port (which can be coupled to a ground voltage, a direct current (DC) feeding voltage, or a radio frequency (RF) ground voltage), a first balanced port (which is coupled to the first output end of the internal PA 223 or the first output end of the matching network 120), a floating port (which is not connected to the outside of the package), and a second balanced port (which is coupled to the second output end of the internal PA 223 or the second output end of the matching network 120). In some embodiments, the reference port and the floating port can be omitted. It should be noted that the manufacturing and structure of the LTCC balun are well known to those skilled in the art, and relevant details are omitted here for the sake of brevity. The embedded input matching network can be integrated into the balun. At this time, the matching network 120 and the external conversion circuit 130 are integrated together as a balun.

[0023] In another embodiment, the external conversion circuit 130 can include external capacitors C1 and C2 and external inductors L1 and L2, as Figure 2As shown, the capacitor C1 is coupled in parallel to the first output terminal of the matching network 120 (or the first output terminal of the internal PA223), and the inductor L1 is coupled in series between the first output terminal of the matching network 120 (or the first output terminal of the internal PA223) and the antenna. The inductor L2 is coupled in parallel to the second output terminal of the matching network 120 (or the second output terminal of the internal PA223), and the capacitor C2 is coupled in series between the second output terminal of the matching network 120 (or the second output terminal of the internal PA223) and the antenna. In addition, the external conversion circuit can also be other conversion circuits that can convert the output voltage VPG of the internal PA223 or the output voltage VPG2 of the matching network 120 into a single-ended signal (such as the transmission signal VOG). As long as the external conversion circuit 130 can perform differential-to-single-ended conversion and is located outside the wireless communication chip 200, these alternative designs fall within the scope of the present invention.

[0024] As Figure 1 shown, the output signal VPG is transmitted outside the wireless communication chip 200 through a trace instead of a balun with an inductive coil on the chip, which can significantly reduce the coupling effect from the output of the internal PA223 to the impedance converter 212 or the balun 214. Therefore, the second harmonic interference or third harmonic interference coupled to the impedance converter 212 (as shown by the interference signal 201) or the balun 214 (as shown by the interference signal 202) can be significantly reduced or eliminated. Therefore, Figure 1 the multi-band wireless communication device 20 shown does not need to sacrifice the transmission performance of the G band and can omit the above-mentioned notch filter.

[0025] In addition, Figure 1 some components that are usually included in the transceiver or transmitter are not shown. The application of these components to the operation and implementation of the multi-band wireless communication device 20 is well-known to those skilled in the art and will not be described in detail here.

[0026] Embodiments of the present invention can be applied to Dual Band Dual Concurrent (DBDC) operation. It should be noted that the two frequency bands (G band and A band) are only for illustrative purposes and are not a limitation of the present invention.

[0027] Figure 3 is a flowchart of a method for transmitting a multi-band wireless communication signal according to an embodiment of the present invention, where Figure 3 the process shown can be executed by the multi-band wireless communication device 20. It should be noted that Figure 3 the process shown is only for illustrative purposes and is not a limitation of the present invention. For example, it can be at Figure 3Add, delete, or modify one or more steps in the shown process. Additionally, these steps do not have to be executed strictly in the Figure 3 shown order if the same result can be obtained.

[0028] In step S310, the first transmission path circuit (such as the A-band transmission path circuit 200A) integrated inside the wireless communication chip 200 in the multi-band wireless communication device 20 outputs a first output signal of the first band (such as the output signal VDA2).

[0029] In step S320, the external PA110 located outside the wireless communication chip 200 in the multi-band wireless communication device 20 amplifies the first output signal of the first band to generate a first transmission signal of the first band (such as the transmission signal VOA of the A-band).

[0030] In step S330, the second transmission path circuit (such as the G-band transmission path circuit 200G) integrated inside the wireless communication chip 200 in the multi-band wireless communication device 20 outputs a pair of differential signals of the second band (such as the output signal VPG).

[0031] In step S340, the external conversion circuit (such as the external conversion circuit 130) located outside the wireless communication chip 200 in the multi-band wireless communication device 20 converts the pair of differential signals of the second band into a second transmission signal of the second band (such as the transmission signal VOG of the G-band), where the second transmission signal of the second band is a single-ended signal.

[0032] In some embodiments, the first output signal is output by a balun inside the first transmission path circuit, and the pair of differential signals is output by a PA inside the second transmission path circuit. In some embodiments, a matching network coupled between the second transmission path circuit and the external conversion circuit and located outside the wireless communication chip provides impedance matching. For example, the matching network provides impedance matching between the output impedance of the internal PA and the input impedance of the external conversion circuit. In some embodiments, the matching network is integrated with the external conversion circuit as a balun. In some embodiments, the external conversion circuit is a balun or a conversion circuit implemented by capacitors and inductors. In some embodiments, the balun is a co-fired ceramic balun. In some embodiments, the pair of differential signals is transmitted through traces inside the second transmission path circuit, and there is no balun on the transmission path of the pair of differential signals inside the second transmission path circuit in the wireless communication chip.

[0033] In summary, in the embodiments of the present invention, the component for converting differential to single-ended is placed outside the wireless communication chip 200, thereby avoiding or reducing the coupling of the signal output by the internal PA 223 to any on-chip inductance coil in the A-band transmission path circuit. Therefore, the second harmonic interference or third harmonic interference coupled to the components in the A-band transmission path circuit 200A is reduced. Through the architecture of the multi-band wireless communication device 20, the transmission specification can be satisfied without reducing the output power of the internal PA 223, and no additional notch filter is required. Therefore, the embodiments of the present invention can enable the transmission signals VOA and VOG output by the multi-band wireless communication device 20 to comply with the FCC regulations, and no side effects or fewer possible side effects are introduced.

[0034] Those skilled in the art will readily observe that some modifications and changes can be made to the devices and methods while retaining the teachings of the present invention. Therefore, the above disclosure should be understood as being limited only by the scope of the appended claims.

Claims

1. A multi-band wireless communication device, characterized in that, Comprising: A wireless communication chip, comprising: A first transmission path circuit for outputting a first output signal of a first frequency band; A second transmission path circuit for outputting a pair of differential signals of a second frequency band different from the first frequency band; An external power amplifier placed outside the wireless communication chip and coupled to the first transmission path circuit for amplifying the first output signal to generate a first transmission signal of the first frequency band; An external conversion circuit placed outside the wireless communication chip and coupled to the second transmission path circuit for converting the pair of differential signals into a second transmission signal of the second frequency band, wherein the second transmission signal is a single-ended signal.

2. The multi-band wireless communication device according to claim 1, characterized in that, A balun inside the first transmission path circuit outputs the first output signal, and a power amplifier PA inside the second transmission path circuit outputs the pair of differential signals.

3. The multi-band wireless communication device according to claim 2, characterized in that, Further comprising: A matching network coupled between the second transmission path circuit and the external conversion circuit, located outside the wireless communication chip, for providing impedance matching.

4. The multi-band wireless communication device according to claim 3, characterized in that, The matching network and the external conversion circuit are integrated together as a balun.

5. The multi-band wireless communication device according to claim 1, wherein The external conversion circuit is a balun or a conversion circuit implemented by capacitors and inductors.

6. The multi-band wireless communication device according to claim 5, characterized in that, The balun is a co-fired ceramic balun.

7. The multi-band wireless communication device according to claim 2, wherein The pair of differential signals is transmitted through traces inside the second transmission path circuit, and there is no balun on the transmission path of the pair of differential signals inside the second transmission path circuit in the wireless communication chip.

8. The multi-band wireless communication device according to claim 2, wherein The internal balun is a differential-to-single-ended converter, and the internal balun is used to receive a pair of differential signals of the first frequency band and convert the pair of differential signals of the first frequency band into a single-ended signal of the first frequency band.

9. The multi-band wireless communication device according to claim 1, characterized in that, The first frequency band is a 5G frequency band or a 6G frequency band, and the second frequency band is a 2.4G frequency band.

10. The multi-band wireless communication device according to claim 2, wherein The second harmonic or third harmonic of the pair of differential signals of the second frequency band is prevented or reduced from being coupled to the internal balun.

11. A method for transmitting a multi-band wireless communication signal, characterized in that, Comprising: A first transmission path circuit integrated inside the wireless communication chip outputs a first output signal of a first frequency band; A power amplifier placed outside the wireless communication chip amplifies the first output signal to generate the first transmission signal of the first frequency band; A second transmission path circuit integrated inside the wireless communication chip outputs a pair of differential signals of a second frequency band different from the first frequency band; and An external conversion circuit placed outside the wireless communication chip converts the pair of differential signals into the second transmission signal of the second frequency band, wherein the second transmission signal is a single-ended signal.

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