Electronic device and communication chip thereof

Abstract

The invention discloses an electronic device and a communication chip thereof. The electronic device is used for transmitting a radio frequency output signal or receiving a radio frequency input signal and comprises an antenna and a communication chip. The communication chip comprises a pin, an impedance matching circuit, a digital baseband circuit, a reference signal generating circuit, a transmitting end circuit and a receiving end circuit. The pin is electrically connected with the antenna. The impedance matching circuit is coupled to the pin. The reference signal generating circuit is coupled to the digital baseband circuit. The transmitting end circuit is coupled with the digital baseband circuit, the reference signal generating circuit and the impedance matching circuit, and is used for generating the radio frequency output signal. The receiving end circuit is coupled with the digital baseband circuit, the reference signal generating circuit and the impedance matching circuit and is used for processing the radio frequency input signal. The communication chip transmits the radio frequency output signal through the pin or receives the radio frequency input signal through the pin.

Description

TECHNICAL FIELD

[0001] The present application relates to an electronic device, and more particularly, to an electronic device supporting at least two modulation schemes and sharing an antenna. BACKGROUND

[0002] Figure 1 A functional block diagram of a conventional electronic device 100 is shown. The electronic device 100 includes a communication chip 110, a switch 120, and an antenna 130. The communication chip 110 includes a two-point modulation (TPM) transceiver 112, an in-phase quadrature modulation (IQM) transceiver 114, and a digital baseband circuit 116. The communication chip 110, the switch 120, and the antenna 130 are disposed on a circuit board.

[0003] The communication chip 110 provides two modulation schemes (i.e., two-point modulation and in-phase quadrature modulation) that share the antenna 130. The antenna 130 is coupled to a pin 111a or a pin 111b through the switch 120, and the pin 111a and the pin 111b are coupled to the two-point modulation transceiver 112 and the in-phase quadrature modulation transceiver 114, respectively.

[0004] The electronic device 100 has the following disadvantages: (1) a large area of the communication chip 110 (because of two independent transceivers); and (2) a cost increase due to the switch 120 (because the switch 120 must be used to share the antenna 130). SUMMARY

[0005] In view of the deficiencies of the prior art, the present application aims to provide an electronic device and a communication chip thereof to improve the deficiencies of the prior art.

[0006] An embodiment of the present application provides a communication chip for transmitting a radio frequency output signal, including a digital baseband circuit, a reference signal generating circuit, a digital-to-analog converter, a filter circuit, and a transmitting front-end circuit. The digital baseband circuit is configured to generate a control signal and a digital output signal. The reference signal generating circuit is coupled to the digital baseband circuit and configured to generate a reference signal. The digital-to-analog converter is coupled to the digital baseband circuit and configured to convert the digital output signal into an analog output signal. The filter circuit is coupled to the digital-to-analog converter and configured to filter the analog output signal to generate a filtered analog output signal. The transmitting front-end circuit is coupled to the filter circuit. When the communication chip operates in a first mode, the transmitting front-end circuit up-converts and amplifies the filtered analog output signal according to the reference signal to generate the radio frequency output signal. When the communication chip operates in a second mode, the reference signal generating circuit changes a frequency of the reference signal according to the control signal, and the transmitting front-end circuit amplifies the reference signal to generate the radio frequency output signal.

[0007] Another embodiment of the present application provides a communication chip for transmitting a radio frequency output signal or receiving a radio frequency input signal, comprising an impedance matching circuit, a pin, a digital baseband circuit, a reference signal generating circuit, a digital-to-analog converter, a filter circuit, a transmitting front-end circuit, and a receiving end circuit. The pin is coupled to the impedance matching circuit. The digital baseband circuit is configured to generate a control signal and a digital output signal. The reference signal generating circuit is coupled to the digital baseband circuit and configured to generate a reference signal. The digital-to-analog converter is coupled to the digital baseband circuit and configured to convert the digital output signal into an analog output signal. The filter circuit is coupled to the digital-to-analog converter and configured to filter the analog output signal to generate a filtered analog output signal. The transmitting front-end circuit is coupled to the filter circuit and the impedance matching circuit and configured to process the filtered analog output signal or the reference signal to generate the radio frequency output signal, and transmit the radio frequency output signal through the impedance matching circuit and the pin. The receiving end circuit is coupled to the impedance matching circuit and configured to receive the radio frequency input signal through the pin and the impedance matching circuit.

[0008] Another embodiment of the present application provides an electronic device for transmitting a radio frequency output signal or receiving a radio frequency input signal, comprising an antenna and a communication chip. The communication chip comprises a pin, an impedance matching circuit, a digital baseband circuit, a reference signal generating circuit, a transmitting end circuit, and a receiving end circuit. The pin is electrically connected to the antenna. The impedance matching circuit is coupled to the pin. The reference signal generating circuit is coupled to the digital baseband circuit. The transmitting end circuit is coupled to the digital baseband circuit, the reference signal generating circuit, and the impedance matching circuit and configured to generate the radio frequency output signal. The receiving end circuit is coupled to the digital baseband circuit, the reference signal generating circuit, and the impedance matching circuit and configured to process the radio frequency input signal. The communication chip transmits the radio frequency output signal through the pin or receives the radio frequency input signal through the pin.

[0009] The technical means embodied in the embodiments of the present application can improve at least one of the shortcomings of the prior art, so that the present application can save area and reduce cost compared with the prior art.

[0010] The features, practices, and effects of the present application will be described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 A functional block diagram of an existing electronic device is shown;

[0012] Figure 2 A functional block diagram of an embodiment of the electronic device of the present application is shown;

[0013] Figure 3 A detailed functional block diagram of an embodiment of the communication chip of the present application is shown; and

[0014] Figure 4 Show Figure 3 An embodiment of the connection relationship between the impedance matching circuit, the power amplifier driver and the power amplifier. DETAILED DESCRIPTION

[0015] The technical terms used in the following descriptions refer to the customary terms in this technical field. If this specification provides explanations or definitions for some terms, the interpretation of these terms shall be based on the explanations or definitions in this specification.

[0016] The disclosure of the present invention includes an electronic device and a communication chip thereof. Because some components of the electronic device and the communication chip thereof may be individually known components, details of known components will be omitted below without affecting the full disclosure and feasibility of the device invention.

[0017] See also Figure 2 , Figure 2 2 is a functional block diagram of an embodiment of an electronic device of the present invention. Electronic device 200 includes a communication chip 201 and an antenna 205. Communication chip 201 includes pin 203, a digital baseband circuit 212, a reference signal generating circuit 214, an impedance matching circuit 216, a receiving circuit 220, and a transmitting circuit 230. Receiver circuit 220 includes a receiving front-end circuit 222, a filtering circuit 224, and an analog-to-digital converter (ADC) 226. Transmitter circuit 230 includes a transmitting front-end circuit 232, a filtering circuit 234, and a digital-to-analog converter (DAC) 236. Impedance matching circuit 216 is used to achieve impedance matching of the transmission line. Filter circuits 224 and 234 can be complex filters or low-pass filters (LPFs). Communication chip 201 is coupled to antenna 205 via pin 203.

[0018] The digital baseband circuit 212 is coupled or electrically connected to the reference signal generation circuit 214, the receive-end circuit 220, and the transmit-end circuit 230. For the transmit-end circuit 230 (more specifically, the transmit front-end circuit 232), the reference signal generation circuit 214 generates a reference signal Rf_tx1 in an in-phase quadrature modulation (IQM) mode (hereinafter referred to as an IQM mode) and a reference signal Rf_tx2 in a two-point modulation (TPM) mode (hereinafter referred to as a TPM mode). For the receive-end circuit 220 (more specifically, the receive front-end circuit 222), the reference signal generation circuit 214 generates a reference signal Rf_rx in both the IQM mode and the TPM mode, and the frequency of the reference signal Rf_rx in the IQM mode can or can not be equal to the frequency of the reference signal Rf_rx in the TPM mode.

[0019] The digital baseband circuit 212 generates a control signal Ctrl and a digital output signal Dout. The digital baseband circuit 212 controls the reference signal generation circuit 214 to set or adjust (change) the frequency of the reference signal Rf_tx1 and / or the frequency of the reference signal Rf_tx2 by means of the control signal Ctrl. In the IQM mode, the frequency of the reference signal Rf_tx1 is constant (i.e., the reference signal Rf_tx1 is a single tone signal). In the TPM mode, the digital baseband circuit 212 frequency modulates (FM) the reference signal Rf_tx2 (equivalent to frequency modulating the radio frequency output signal STx) by means of the control signal Ctrl, i.e., changes the frequency of the reference signal Rf_tx2.

[0020] In the IQM mode, the transmit-end circuit 230 converts the digital output signal Dout generated by the digital baseband circuit 212 into a radio frequency output signal STx, which is coupled to the antenna 205 via the impedance matching circuit 216 and the pin 203. More specifically, the digital-to-analog converter 236 converts the digital output signal Dout into an analog output signal Sout. The filter circuit 234 filters the analog output signal Sout to generate a filtered analog output signal Sout'. The transmit front-end circuit 232 up-converts and amplifies the filtered analog output signal Sout' according to the reference signal Rf_tx1 to generate the radio frequency output signal STx.

[0021] In the TPM mode, the filter circuit 234 and the digital-to-analog converter 236 are inactive, while the transmit front-end circuit 232 amplifies the reference signal Rf_tx2 to generate a radio frequency output signal STx. The radio frequency output signal STx is coupled to the antenna 205 via the impedance matching circuit 216 and the pin 203.

[0022] The receive front-end circuit 222 down-converts the radio frequency input signal SRx according to the reference signal Rf_rx to generate an analog input signal Sin. The filter circuit 224 filters the analog input signal Sin to generate a filtered analog input signal Sin'. The analog-to-digital converter 226 converts the filtered analog input signal Sin' into the digital input signal Din.

[0023] Since the receive circuit 220 and the transmit circuit 230 share the impedance matching circuit 216, the communication chip 201 can transmit the radio frequency output signal STx or receive the radio frequency input signal SRx through the same pin (i.e., the pin 203). Moreover, because the receive circuit 220 and the transmit circuit 230 share the pin 203, the antenna 205 does not need to be switched between two pins. That is, the pin 203 and the antenna 205 can be electrically connected to each other to save the existing switch 120, thereby reducing the cost.

[0024] Please refer to Figure 3 , Figure 3 is a detailed functional block diagram of an embodiment of the communication chip 201 of the present application. The reference signal generation circuit 214 includes a synthesizer 214_1, a frequency divider circuit 214_3, and a buffer circuit 214_5. The receive front-end circuit 222 includes an in-phase / quadrature (IQ) generator 222_1, a mixing circuit 222_3, and a low noise amplifier (LNA) 222_5. The analog-to-digital converter 226 includes an analog-to-digital converter 226_1 and an analog-to-digital converter 226_3. The transmit front-end circuit 232 includes an IQ generator 232_1, a mixing circuit 232_3, a power amplifier driver (PAD) 232_5, and a power amplifier 232_7. The digital-to-analog converter 236 includes a digital-to-analog converter 236_1 and a digital-to-analog converter 236_3. The following is described with respect to the IQM mode and the TPM mode, respectively.

[0025] Mode (One): IQM mode.

[0026] The synthesizer 214_1 generates a frequency-fixed reference signal Rf_tx1 (i.e., the reference signal Rf_tx1 is a single-tone signal), and the frequency division circuit 214_3 and the buffer circuit 214_5 are inactive or disabled (in other words, the reference signal Rf_tx2 does not exist in the IQM mode). More specifically, the digital baseband circuit 212 sets the frequency of the reference signal Rf_tx1 with the control signal Ctrl, and then the synthesizer 214_1 operates at the frequency; or the synthesizer 214_1 operates at a preset frequency (i.e., the frequency of the reference signal Rf_tx1) without being controlled by the control signal Ctrl.

[0027] In some embodiments, the control signal Ctrl is a digital signal, and the synthesizer 214_1 is a digitally controlled synthesizer (e.g., including a digital controlled oscillator (DCO)).

[0028] When the communication chip 201 transmits a signal, the in-phase / quadrature generation circuit 232_1 generates in-phase and quadrature signals according to the reference signal Rf_tx1, and the mixing circuit 232_3 up-converts the filtered analog output signal Sout' to generate a radio frequency signal S_RF. The radio frequency signal S_RF is amplified by the power amplifier driver 232_5 and the power amplifier 232_7 to generate a radio frequency output signal STx.

[0029] When the communication chip 201 receives a signal, the synthesizer 214_1 generates a reference signal Rf_rx, the in-phase / quadrature generation circuit 222_1 generates in-phase and quadrature signals according to the reference signal Rf_rx, and the mixing circuit 222_3 down-converts the output signal of the low noise amplifier 222_5 to generate an analog input signal Sin.

[0030] Mode (two): TPM mode.

[0031] When communication chip 201 transmits a signal, digital baseband circuit 212 uses control signal Ctrl to control synthesizer 214_1, varying the frequencies of reference signals Rf_tx1 and Rf_tx2 to frequency modulate the RF output signal STx. Reference signal Rf_tx2 is the result of processing reference signal Rf_tx1 through frequency divider circuit 214_3 and buffer circuit 214_5. Power amplifier driver 232_5 and power amplifier 232_7 amplify reference signal Rf_tx2 to generate RF output signal STx. Frequency divider circuit 214_3 ensures that the frequency of RF output signal STx is not equal to that of reference signal Rf_tx1. This prevents the high energy of RF output signal STx from affecting the operation of synthesizer 214_1 when the frequency of RF output signal STx and reference signal Rf_tx1 are the same. Buffer circuit 214_5 boosts signal energy to counteract signal attenuation on the transmission line.

[0032] In some embodiments, if the energy of the RF output signal STx is relatively small or the synthesizer 214_1 is relatively ideal, the frequency dividing circuit 214_3 may be omitted.

[0033] In some embodiments, if the signal attenuation on the transmission line is relatively small, the buffer circuit 214_5 may be omitted.

[0034] The operation of the receiving front-end circuit 222 in TPM mode is the same as that in IQM mode, so it will not be repeated here. It should be noted that when the communication chip 201 receives a signal, whether in IQM mode or TPM mode, the reference signal Rf_rx is a single-tone signal. In other words, the digital baseband circuit 212 does not frequency modulate the reference signal Rf_rx.

[0035] As can be seen from the above, in the TPM mode, the digital baseband circuit 212 modulates the frequency of the reference signal Rf_tx1 (equivalent to modulating the frequencies of the reference signal Rf_tx2 and the RF output signal STx) via the control signal Ctrl.

[0036] In some embodiments, since the in-phase and quadrature generation circuit 232_1 , the mixing circuit 232_3 , the filtering circuit 234 , and the digital-to-analog converter 236 are inactive in the TPM mode, the digital baseband circuit 212 may shut down or disable these components to save power.

[0037] See also Figure 4 , Figure 4 Show Figure 3 The embodiment of the connection relationship between the impedance matching circuit 216, the power amplifier driver 232_5 and the power amplifier 232_7. Figure 4In the embodiment, the impedance matching circuit 216 is a transformer, and the transmit front-end circuit 232 includes a transformer 430 in addition to the power amplifier driver 232_5 and the power amplifier 232_7. The power amplifier driver 232_5 includes a sub-power amplifier driver 410 and a sub-power amplifier driver 420 for processing (e.g., amplifying) the reference signal Rf_tx2 and the radio frequency signal S_RF, respectively. The primary side of the transformer 430 is coupled or electrically connected to the sub-power amplifier drivers 410 and 420, and the secondary side is coupled or electrically connected to the power amplifier 232_7, in which the voltage PA_Vg is the gate bias voltage of the main transistor of the power amplifier 232_7. The primary side of the impedance matching circuit 216 is coupled or electrically connected to the power amplifier 232_7, and the secondary side is coupled or electrically connected to the antenna 205, in which the voltage VDD is the power supply voltage of the power amplifier 232_7.

[0038] In summary, the communication chip 201 of the present application supports both the IQM mode and the TPM mode, and both modes share the impedance matching circuit 216, the receive front-end circuit 222, the filter circuit 224, the analog-to-digital converter 226, part of the reference signal generation circuit 214, and part of the transmit front-end circuit 232. Therefore, compared with the prior art, the communication chip 201 of the present application has the following advantages: (1) saving area (because of sharing components); and (2) no need to set the switch 120 on the circuit board (because the two modes share the pin 203).

[0039] Although the foregoing embodiments are exemplified by the BPSK and QPSK modulation, this is not a limitation of the present application, and those skilled in the art can appropriately apply the present application to other types of modulation mechanisms according to the disclosure of the present application.

[0040] Please note that in the foregoing drawings, the shapes, sizes, and proportions of the components are only for illustration and are for those skilled in the art to understand the present application, and are not intended to limit the present application.

[0041] Although the embodiments of the present application are described above, these embodiments are not intended to limit the present application, and those skilled in the art can make changes to the technical features of the present application according to the explicit or implicit content of the present application, and any such changes can be within the scope of the patent protection sought by the present application. In other words, the scope of patent protection of the present application shall be subject to the scope of the patent application defined in the specification.

[0042]

Symbol Description

[0043] 100, 200: electronic device

[0044] 110, 201: communication chip

[0045] 111a, 111b, 203: pin

[0046] 112: two-point modulator transceiver

[0047] 114: in-phase quadrature modulator transceiver

[0048] 116, 212: digital baseband circuitry

[0049] 120: switch

[0050] 130, 205: antenna

[0051] 214: reference signal generation circuitry

[0052] 216: impedance matching circuitry

[0053] 220: receive circuitry

[0054] 222: receive front-end circuitry

[0055] 224, 234: filter circuitry

[0056] 226, 226_1, 226_3: analog-to-digital converter

[0057] 230: transmit circuitry

[0058] 232: transmit front-end circuitry

[0059] 236, 236_1, 236_3: digital-to-analog converter

[0060] Ctrl: control signal

[0061] Din: digital input signal

[0062] Dout: digital output signal

[0063] Rf_rx, Rf_tx1, Rf_tx2: reference signal

[0064] Sin: analog input signal

[0065] Sin': filtered analog input signal

[0066] Sout: analog output signal

[0067] Sout': filtered analog output signal

[0068] SRx: radio frequency input signal

[0069] STx: radio frequency output signal

[0070] 214_1: synthesizer

[0071] 214_3: frequency elimination circuit

[0072] 214_5: buffer circuit

[0073] 222_1, 232_1: in-phase quadrature generation circuit

[0074] 222_3, 232_3: mixing circuit

[0075] 222_5: low noise amplifier

[0076] 232_5: power amplifier driver

[0077] 232_7: power amplifier

[0078] S_RF: radio frequency signal

[0079] 410, 420: sub power amplifier driver

[0080] 430: transformer

[0081] PA_Vg, VDD: voltage

Claims

1. A communication chip for transmitting a radio frequency output signal, comprising: a digital baseband circuit for generating a control signal and a digital output signal; a reference signal generation circuit coupled to the digital baseband circuit for generating a reference signal; a digital-to-analog converter coupled to the digital baseband circuit for converting the digital output signal into an analog output signal; a filter circuit coupled to the digital-to-analog converter for filtering the analog output signal to generate a filtered analog output signal; and a transmit front-end circuit coupled to the filter circuit; wherein when the communication chip operates in a first mode, the transmit front-end circuit up-converts and amplifies the filtered analog output signal according to the reference signal to generate the radio frequency output signal; and wherein when the communication chip operates in a second mode, the reference signal generation circuit changes a frequency of the reference signal according to the control signal, and the transmit front-end circuit amplifies the reference signal to generate the radio frequency output signal. The reference signal is a tone signal when the communication chip operates in the first mode.

2. The communication chip of claim 1, wherein, 3. The communication chip of claim 1, further comprising: an impedance matching circuit coupled to the transmit front-end circuit; a pin coupled to the impedance matching circuit; and a receive end circuit coupled to the impedance matching circuit for receiving a radio frequency input signal through the pin and the impedance matching circuit; wherein the transmit front-end circuit transmits the radio frequency output signal through the impedance matching circuit and the pin. The transmit front-end circuit comprises: a mixing circuit coupled to the filter circuit for up-converting the filtered analog output signal to generate a radio frequency signal; 4. The communication chip of claim 1, wherein, a power amplifier driver coupled to the mixing circuit, comprising: a first sub-power amplifier driver coupled to the mixing circuit for amplifying the reference signal; and a second sub-power amplifier driver coupled to the mixing circuit for amplifying the radio frequency signal; a power amplifier; and a transformer coupled between the power amplifier driver and the power amplifier. The digital baseband circuit disables the digital-to-analog converter and the filter circuit in the second mode.

6. A communication chip for transmitting a radio frequency output signal or receiving a radio frequency input signal, comprising:

5. The communication chip of claim 1, wherein, an impedance matching circuit; a pin coupled to the impedance matching circuit; a digital baseband circuit for generating a control signal and a digital output signal; a reference signal generation circuit coupled to the digital baseband circuit for generating a reference signal; a digital-to-analog converter coupled to the digital baseband circuit for converting the digital output signal into an analog output signal; a filter circuit coupled to the digital-to-analog converter for filtering the analog output signal to generate a filtered analog output signal; a transmit front-end circuit coupled to the filter circuit and the impedance matching circuit for processing the filtered analog output signal or the reference signal to generate the radio frequency output signal, and transmitting the radio frequency output signal through the impedance matching circuit and the pin; and a receive end circuit coupled to the impedance matching circuit for receiving the radio frequency input signal through the pin and the impedance matching circuit. ​ ​ ​ 7. The communication chip of claim 6, wherein, When the communication chip operates in the first mode, the reference signal is a single tone signal; and when the communication chip operates in the second mode, the reference signal generation circuit changes the frequency of the reference signal according to the control signal.

8. The communication chip of claim 7, wherein, The transmit front-end circuit includes: a mixing circuit coupled to the filtering circuit, for up-converting the filtered analog output signal to generate a radio frequency signal; a power amplifier driver coupled to the mixing circuit, including: a first sub-power amplifier driver coupled to the mixing circuit, for amplifying the reference signal; and a second sub-power amplifier driver coupled to the mixing circuit, for amplifying the radio frequency signal; a power amplifier; and a transformer coupled between the power amplifier driver and the power amplifier.

9. The communication chip of claim 7, wherein, The digital baseband circuit disables the digital-to-analog converter and the filtering circuit in the second mode.

10. An electronic device for transmitting a radio frequency output signal or receiving a radio frequency input signal, comprising: an antenna; and a communication chip, including: a pin electrically connected to the antenna; an impedance matching circuit coupled to the pin; a digital baseband circuit; a reference signal generation circuit coupled to the digital baseband circuit; a transmit end circuit coupled to the digital baseband circuit, the reference signal generation circuit, and the impedance matching circuit, for generating the radio frequency output signal; and a receive end circuit coupled to the digital baseband circuit, the reference signal generation circuit, and the impedance matching circuit, for processing the radio frequency input signal; wherein the communication chip transmits the radio frequency output signal through the pin, or receives the radio frequency input signal through the pin.

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