Mixer with phase shift function and communication device including the mixer

Abstract

A mixer includes: a load portion connected between an input terminal of a first power supply voltage and an output terminal of a radio frequency transmission signal, and configured to adjust the amplitude of the radio frequency transmission signal; a first switching unit connected to the output terminal of the radio frequency transmission signal, and configured to perform a first switching operation in response to a plurality of local oscillation signals; and a second switching unit connected between the first switching unit and an input terminal of a second power supply voltage lower than the first power supply voltage, and configured to perform a second switching operation in response to a plurality of baseband signals, the plurality of local oscillation signals including an I+ baseband signal, an I- baseband signal, a Q+ baseband signal, and a Q- baseband signal, and the second switching unit including a first branch, a second branch, a third branch, and a fourth branch.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Korean Patent Application No. 10-2019-0127290 filed on October 14, 2019, in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The inventive concept relates to a mixer with a phase shift function and a communication device including the mixer. Background Art

[0004] Research and development of next-generation wireless communication technologies using extremely high frequency bands has been actively pursued. For example, in order to reduce losses in the transmission path of extremely high frequency signals and increase the transmission distance, technologies such as beamforming, massive multiple-input multiple-output (Massive MIMO), full-size MIMO (FD-MIMO), array antennas, and large antennas have been discussed.

[0005] In this next-generation wireless communication technology, beamforming is used to improve communication efficiency by focusing extremely high-frequency signals in a specific direction. Phase shifters are used to implement beamforming. However, when phase shifters operate in extremely high frequency bands, signal loss may increase, potentially leading to performance degradation, manifested as increased gain, increased current consumption, and increased chip area. Summary of the Invention

[0006] Exemplary embodiments of the present inventive concept provide a mixer that can shift a phase of a radio frequency (RF) signal without using a phase shifter, and a communication device including the same.

[0007] According to an exemplary embodiment of the present inventive concept, a mixer includes: a load section connected between an input terminal of a first power supply voltage and an output terminal of a radio frequency transmission signal and configured to adjust the amplitude of the radio frequency transmission signal; a first switching unit connected to the output terminal of the radio frequency transmission signal and configured to perform a first switching operation in response to a plurality of local oscillation signals; and a second switching unit connected between the first switching unit and an input terminal of a second power supply voltage lower than the first power supply voltage and configured to perform a second switching operation in response to a plurality of baseband signals, the plurality of local oscillation signals including an I+ baseband signal, an I− baseband signal, a Q+ baseband signal, and a Q− baseband signal, and the second switching unit includes a first branch, a second branch, a third branch, and a fourth branch, the first branch performing a switching operation under control of the I+ baseband signal and the Q+ baseband signal, the second branch performing a switching operation under control of the I− baseband signal and the Q− baseband signal, the third branch performing a switching operation under control of the Q+ baseband signal and the I+ baseband signal, and the fourth branch performing a switching operation under control of the Q− baseband signal and the I+ baseband signal.

[0008] According to an exemplary embodiment of the present inventive concept, a communication device includes: a modulator configured to generate a plurality of first baseband signals by modulating a transmission bit stream; a local oscillation signal generator configured to generate a plurality of first local oscillation signals and generate a plurality of second local oscillation signals that are phase-shifted by a first phase value relative to the plurality of first local oscillation signals by multiplexing the plurality of first local oscillation signals; and a mixer configured to generate a radio frequency transmission signal by up-converting the plurality of first baseband signals using the plurality of second local oscillation signals, the mixer being configured to generate a plurality of second baseband signals that are phase-shifted by a second phase value relative to the plurality of first baseband signals by combining the plurality of first baseband signals, and performing a mixing operation with respect to the plurality of second baseband signals and the plurality of second local oscillation signals.

[0009] According to an exemplary embodiment of the present inventive concept, a communication device includes: a modem configured to generate a transmission baseband signal by modulating a transmission bit stream and demodulating a reception baseband signal into a reception bit stream; a transmitter circuit configured to generate a radio frequency transmission signal by up-converting the transmission baseband signal using a transmission local oscillation signal; and a receiver circuit configured to generate a reception baseband signal by down-converting the radio frequency reception signal using a reception local oscillation signal, the transmission local oscillation signal and the reception local oscillation signal being obtained by phase-shifting an orthogonal signal, and the transmitter circuit being configured to perform up-conversion on the phase-shifted transmission baseband signal after phase-shifting the transmission baseband signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The above and other aspects of the present invention will be more clearly understood through the following detailed description taken in conjunction with the accompanying drawings, in which:

[0011] Figure 1 is a schematic diagram illustrating a wireless communication system according to an exemplary embodiment of the present inventive concept;

[0012] Figure 2 is a block diagram illustrating a communication device according to an exemplary embodiment of the present inventive concept;

[0013] Figure 3 is a mixing diagram illustrating a transceiver according to an exemplary embodiment of the present inventive concept;

[0014] Figure 4 It shows Figure 3 A circuit diagram of a portion of a local oscillation signal generator;

[0015] Figure 5 It shows Figure 4 The circuit diagram of the multiplexer;

[0016] Figure 6 It shows Figure 4 Tabular diagram of the multiplexer;

[0017] Figure 7A 、 Figure 7B 、 Figure 7C and Figure 7D yes Figure 4 Phase offset signal diagram of the multiplexer;

[0018] Figure 8 It shows Figure 4 The circuit diagram of the multiplexer;

[0019] Figure 9 is a circuit diagram illustrating a structure of a mixer according to an exemplary embodiment of the present inventive concept;

[0020] Figure 10A and Figure 10B is a phase diagram illustrating a method of collecting a baseband signal by a mixer and performing a phase shift according to an exemplary embodiment of the present inventive concept;

[0021] Figure 11 is a circuit diagram illustrating a structure of a mixer according to an exemplary embodiment of the present inventive concept;

[0022] Figure 12 is a flowchart illustrating a method of operating a communication device according to an exemplary embodiment of the present inventive concept;

[0023] Figure 13 is a flowchart illustrating a method of operating a communication device according to an exemplary embodiment of the present inventive concept;

[0024] Figure 14 is a schematic diagram illustrating an electronic device including a communication device according to an exemplary embodiment of the present inventive concept;

[0025] Figure 15 is a conceptual diagram illustrating an application of a communication device according to an exemplary embodiment of the present inventive concept; and

[0026] Figure 16 is a conceptual diagram illustrating applications of a communication device according to an exemplary embodiment of the inventive concept. DETAILED DESCRIPTION

[0027] Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings. It should be understood that such exemplary embodiments are illustrative of the present invention, but not limiting of the present invention.

[0028] Figure 1 A wireless communication system according to an exemplary embodiment of the present invention is shown.

[0029] refer to Figure 1 , the wireless communication system 1 may include a plurality of communication devices 10-1 to 10-6, each of which performs wireless communication using a transceiver. The wireless communication system 1 may include a fourth generation (4G) network system such as a long term evolution (LTE) system, a fifth generation (5G) network system supporting the new radio (NR) protocol specified in 3GPP, and the like.

[0030] Some of the multiple communication devices 10-1 to 10-6 may be base stations (BSs), while others may be user equipment (UEs). The BS may be the subject that communicates with the UE and may be referred to as a base transceiver station (BTS), a node b (NB), an evolved node b (eNB), an access point (AP), etc. The UE may be the subject that communicates with the BS and / or other UEs and may be referred to as a mobile station (MS), a mobile equipment (ME), a terminal, etc. Figure 1 An example is shown in which the first communication device 10-1 is implemented as a BS, and the second to sixth communication devices 10-2 to 10-6 are implemented as UEs. However, the embodiment is not limited thereto.

[0031] The plurality of communication devices 10-1 to 10-6 can perform wireless communication using wireless signals having wavelengths in the ultra-high frequency band. For example, the plurality of communication devices 10-1 to 10-6 can perform wireless communication using millimeter waves (mmWave) having wavelengths of 1 mm to 100 mm corresponding to wireless frequencies of 3 GHz to 300 GHz. The plurality of communication devices 10-1 to 10-6 can also perform wireless communication using waves in the terahertz band.

[0032] The plurality of communication devices 10 - 1 to 10 - 6 may perform beamforming to reduce signal loss caused by channel propagation characteristics of the ultra-high frequency band.

[0033] Beamforming can be divided into transmit beamforming performed by the transmitter of the communication devices 10-1 to 10-6 and receive beamforming performed by the receiver of the communication devices 10-1 to 10-6. Multiple communication devices 10-1 to 10-6 can use multiple antennas to perform transmit beamforming, and can concentrate the arrival area of ​​the signal (hereinafter referred to as the beam area) in a specific direction, thereby increasing the directivity of the signal. As the multiple communication devices 10-1 to 10-6 increase the directivity of the signal by performing transmit beamforming, the multiple communication devices 10-1 to 10-6 can increase the arrival distance of the signal and can reduce signal interference. In addition, the multiple communication devices 10-1 to 10-6 can use multiple antennas to perform receive beamforming, and can concentrate the reception direction of the signal in a specific direction, thereby increasing the reception sensitivity and reducing signal interference.

[0034] refer to Figure 1 , the first communication device 10-1 can transmit a first wireless signal having a first beam area BA1 and a second wireless signal having a second beam area BA2. Since the second communication device 10-2 and the third communication device 10-3 are included in the first beam area BA1, the second communication device 10-2 and the third communication device 10-3 can receive the first wireless signal. In addition, since the fifth communication device 10-5 and the sixth communication device 10-6 are included in the second beam area BA2, the fifth communication device 10-5 and the sixth communication device 10-6 can receive the second wireless signal. However, since the third communication device 10-3 is not included in any of the first beam area BA1 or the second beam area BA2, the third communication device 10-3 may not receive the first wireless signal or the second wireless signal.

[0035] Multiple communication devices 10-1 to 10-6 can perform beamforming using multiple radio frequency (RF) signals with a specific phase difference between them. Typically, multiple communication devices can use phase shifters to generate multiple RF signals with a specific phase difference between them. However, when using phase shifters, signal loss may increase, and thus performance degradation may occur, such as a decrease in gain, an increase in current consumption, an increase in chip area, etc. Therefore, the communication device of the exemplary embodiment can multiplex the local oscillation signal into the orthogonal signal, and can input the orthogonal signal to the mixer, and can phase shift the baseband signal at the source terminal of the mixer, thereby generating multiple RF signals with a specific phase difference between them without using a phase shifter.

[0036] Figure 2A communication device according to an exemplary embodiment of the present invention is shown.

[0037] refer to Figure 2 , the communication device 10 may include a controller 100, a storage device 200 connected to at least one of the controller or the transceiver, and a transceiver 300 connected to at least one of the controller or the storage device.

[0038] The controller 100 can control the overall operation of the communication device 10. For example, the controller 100 can control the transceiver 300 of the communication device 10 to transmit and receive RF signals. In an exemplary embodiment, the controller 100 can control the transceiver 300 to generate multiple RF signals with specific phase differences between them for performing transmit beamforming. The controller 100 can also control the transceiver 300 to selectively activate at least some of the multiple antennas to perform receive beamforming. The controller 100 can include at least one processor or microprocessor.

[0039] The storage device 200 can store various data required for the operation of the communication device 10. For example, the storage device 200 can store various programs and setting information required for wireless communication. The storage device 200 can be implemented as a non-volatile memory such as NAND flash memory, a volatile memory such as DRAM, or a combination of non-volatile memory and volatile memory.

[0040] The transceiver 300 can transmit RF signals to other communication devices and receive RF signals from other communication devices via multiple antennas. For example, the transceiver 300 can up-convert baseband signals into RF signals and transmit RF signals via multiple antennas. The transceiver 300 can also down-convert RF signals received via multiple antennas into baseband signals.

[0041] To perform such wireless communication functions, the transceiver 300 may include a modem, a filter, a mixer, an amplifier, and the like. The transceiver 300 may also include multiple antennas. A collection of multiple antennas may be referred to as an antenna array, and each of the multiple antennas included in the antenna array may be referred to as an array element. The antenna array may be implemented as various types of antenna arrays, such as a linear array, a planar array, and the like.

[0042] Figure 2 An example is shown in which the transceiver 300 is implemented as a single element including a transmitter and a receiver integrated with each other, but the embodiment is not limited thereto. For example, the transceiver 300 may include a transmitter and a receiver separated from each other. In the following description, reference will be made to Figure 3 The transceiver 300 is described in more detail.

[0043] Figure 3A transceiver according to an exemplary embodiment of the present invention is shown.

[0044] refer to Figure 3 , the transceiver 300 may include a modem 310 , a transmitter circuit 330 , transmit amplifiers 341 and 343 , receive amplifiers 361 and 363 , a receiver circuit 370 , and an antenna array 350 .

[0045] The modem 310 may include a modulator 311 and a demodulator 313 and may interconvert a baseband signal and a bit stream according to a physical layer specification of a system.

[0046] The modulator 311 can modulate the transmit bit stream and generate transmit baseband signals BBI and BBQ. The transmit baseband signals BBI and BBQ can be digital signals and can be orthogonal signals including an in-phase (I-phase) baseband signal BBI in the real domain and a quadrature-phase (Q-phase) baseband signal BBQ in the imaginary domain. The I-phase baseband signal BBI can include an I+ baseband signal BBIp and an I- baseband signal BBIn with a 180-degree phase difference therebetween. The Q-phase baseband signal BBQ can include a Q+ baseband signal BBQp and a Q- baseband signal BBQn with a 180-degree phase difference therebetween.

[0047] The demodulator 313 can demodulate the received baseband signals RBBI′ and RBBQ′ and recover the received bit stream. The received baseband signals RBBI′ and RBBQ′ can be digital signals and can include an I-phase baseband signal RBBI′ and a Q-phase baseband signal RBBQ′. The I-phase baseband signal RBBI′ can include an I+ baseband signal RBBIp′ and an I-baseband signal RBBIn′. In addition, the Q-phase baseband signal RBBQ′ can include a Q+ baseband signal RBBQp′ and a Q-baseband signal RBBQn′.

[0048] The local oscillation signal generator 320 may generate a local oscillation signal, may multiplex the generated local oscillation signal, and may provide the multiplexed oscillation signal to the transmitter circuit 330 and the receiver circuit 370 . Figure 4 and Figure 8 The specific configuration and operation method of the local oscillation signal generator 320 are shown in FIG.

[0049] The transceiver can selectively activate multiple antennas or antenna elements with multiple phase shifts to perform receive beamforming on receive signals from specific directions. The transceiver 300 may include a receive mixer 371 configured to generate a plurality of first baseband receive signals RBBIp, RBBBIn, RBBOp, and RBBQn by downconverting a plurality of RF receive signals RXp and RXn using a plurality of second local oscillation signals LOIp′, LOIn′, LOQp′, and LOQn′. The transceiver can be configured to generate a plurality of second baseband receive signals RBBIp′, RBBBIn′, RBBOp′, and RBBQn′ by combining the plurality of first baseband receive signals and performing mixing operations on the plurality of second baseband receive signals using the plurality of second local oscillation signals and the plurality of first local oscillation signals LOIp, LOIn, LOQp, and LOQn, thereby generating a plurality of second baseband receive signals RBBIp′, RBBBIn′, RBBOp′, and RBBQn′ that are phase-shifted relative to the plurality of first baseband receive signals RBBIp, RBBIn, RBBQp, and RBBQn. The plurality of first baseband reception signals may be analog signals, and the plurality of second baseband reception signals may be digital signals.

[0050] Figures 4 to 8 A local oscillation signal generator according to an exemplary embodiment of the present invention is collectively shown.

[0051] refer to Figure 4 , the local oscillation signal generator 400 may include a local oscillator 410 and a local oscillation (LO) buffer 430 .

[0052] The local oscillator 410 may generate a plurality of quadrature signals LOIp, LOIn, LOQp, and LOQn as local oscillation signals. In an exemplary embodiment, the local oscillator 410 may include a voltage controlled oscillator (VCO).

[0053] The LO buffer 430 may shift the phases of the plurality of local oscillation signals LOIp, LOIn, LOQp, and LOQn by multiplexing the plurality of local oscillation signals LOIp, LOIn, LOQp, and LOQn generated by the local oscillator 410. In an exemplary embodiment, the phase shift values ​​of the plurality of local oscillation signals LOIp, LOIn, LOQp, and LOQn may be 90-degree units (i.e., 0 degrees, 90 degrees, 180 degrees, and 270 degrees).

[0054] The LO buffer 430 may include a first LO multiplexing unit 431 outputting I-phase local oscillation signals LOIp and LOIn and a second LO multiplexing unit 433 outputting Q-phase local oscillation signals LOQp and LOQn. Figure 4The example in which the LO buffer 430 includes the first LO multiplexing unit 431 and the second LO multiplexing unit 433 is shown, but exemplary embodiments thereof are not limited thereto. For example, the LO buffer 430 may include four LO multiplexing units that respectively output a plurality of local oscillation signals LOIp, LOIn, LOQp, and LOQn.

[0055] Figures 5 to 7D Shown Figure 4 Examples of a first LO multiplexing unit 431 and a second LO multiplexing unit 433 are shown.

[0056] refer to Figure 5 LO multiplexing unit 500 can be implemented as a multiplexer MUX. LO multiplexing unit 500 can select one of multiple input signals as one of the I-phase and Q-phase local oscillation signals, thereby outputting a phase-shifted local oscillation signal. For example, when LO multiplexing unit 500 is implemented as a 4×1 multiplexer, LO multiplexing unit 500 can receive multiple local oscillation signals LOIp, LOIn, LOQp, and LOQn from a local oscillator as first to fourth input signals in1 to in4, and can select one of the first to fourth input signals in1 to in4 as the I+ local oscillation signal LOIp based on the first control signal S0 and the second control signal S1, and can output the selected signal.

[0057] In an exemplary embodiment, one of the local oscillation signals LOIp, LOIn, LOQp, and LOQn determined as the output signal out may be phase-shifted according to a signal selection result based on a combination of the local oscillation signals LOIp, LOIn, LOQp, and LOQn as the input signals in1 to in4 and the control signals S0 and S1.

[0058] Figure 6 1 and 2 show combinations of local oscillation signals LOIp, LOIn, LOQp, and LOQn as input signals in1 to in4 and phase shifts of local oscillation signals LOIp′, LOIn′, LOQp′, and LOQn′ as output signals out.

[0059] refer to Figure 5 and Figure 6 In the first case, the I+ local oscillation signal LOIp, the Q+ local oscillation signal LOQp, the I- local oscillation signal LOIn, and the Q- local oscillation signal LOQn can be sequentially input to the LO multiplexing unit 500 as input signals in1 to in4. Furthermore, the LO multiplexing unit 500 can set the I+ local oscillation signal LOIp′ as the output signal out. This is achieved by connecting the output terminal of the LO multiplexing unit 500 to the source terminal of the I+ local oscillation signal LOIp′ of the mixer.

[0060] When the first control signal S0 is "0" (or logic low) and the second control signal S1 is "0", the LO multiplexing unit 500 can select the I+ local oscillation signal LOIp, the first input signal in1. Since there is no phase difference between the selected signal and the I+ local oscillation signal LOIp (first input signal in1), the phase shift of the I+ local oscillation signal LOIp' may not occur, such as Figure 7A As shown in .

[0061] When the first control signal S0 is "0" and the second control signal S1 is "1", the LO multiplexing unit 500 can select the Q+ local oscillation signal LOQp and the second input signal in2. Since the phase difference between the selected signal and the I+ local oscillation signal LOIp (output signal out) is 90 degrees, the I+ local oscillation signal LOIp' can be phase-shifted by 90 degrees, as shown in FIG. Figure 7B As shown in .

[0062] When the first control signal S0 is "1" and the second control signal S1 is "0", the LO multiplexing unit 500 can select the I- local oscillation signal LOIn and the third input signal in3. Since the phase difference between the selected signal and the I+ local oscillation signal LOIp (output signal out) is 180 degrees, the I+ local oscillation signal LOIp' can be phase-shifted by 180 degrees, as shown in FIG. Figure 7C As shown in .

[0063] When the first control signal S0 is "1" and the second control signal S1 is "1", the LO multiplexing unit 500 can select the Q-local oscillation signal LOQn and the fourth input signal in4. Since the phase difference between the selected signal and the I+local oscillation signal LOIp (output signal out) is 270 degrees, the I+local oscillation signal LOIp' can be phase-shifted by 270 degrees, as shown in FIG. Figure 7D As shown in .

[0064] In the second case, the I-local oscillation signal LOIn, the Q-local oscillation signal LOQn, the I+local oscillation signal LOIp, and the Q+local oscillation signal LOQp can be sequentially input to the LO multiplexing unit 500 as the first input signal in1 to the fourth input signal in4. The LO multiplexing unit 500 can set the I-local oscillation signal LOIn′ as the output signal out. This can be achieved by connecting the output terminal of the LO multiplexing unit 500 to the source terminal of the I-local oscillation signal LOIn′ of the mixer.

[0065] As in the first case, when the first control signal S0 is "0" and the second control signal S1 is "0", the phase shift of the I-local oscillation signal LOIn' (output signal out) may not occur. When the first control signal S0 is "0" and the second control signal S1 is "1", the I-local oscillation signal LOIn' (output signal out) may be phase-shifted by 90 degrees. When the first control signal S0 is "1" and the second control signal S1 is "0", the I-local oscillation signal LOIn' (output signal out) may be phase-shifted by 180 degrees. When the first control signal S0 is "1" and the second control signal S1 is "1", the I-local oscillation signal LOIn' (output signal out) may be phase-shifted by 270 degrees.

[0066] In the third scenario, the Q+ local oscillation signal LOQp, the I-local oscillation signal LOIn, the Q-local oscillation signal LOQn, and the I+local oscillation signal LOIp can be sequentially input to the LO multiplexing unit 500 as the first input signal in1 to the fourth input signal in4. Furthermore, the LO multiplexing unit 500 can set the Q+local oscillation signal LOQp′ as the output signal out. This is achieved by connecting the output terminal of the LO multiplexing unit 500 to the source terminal of the Q+local oscillation signal LOQp′ of the mixer.

[0067] As in the first case, when the first control signal S0 is "0" and the second control signal S1 is "0", the phase shift of the Q+ local oscillation signal LOQp' (output signal out) may not occur. When the first control signal S0 is "0" and the second control signal S1 is "1", the Q+ local oscillation signal LOQp' (output signal out) may be phase-shifted by 90 degrees. When the first control signal S0 is "1" and the second control signal S1 is "0", the Q+ local oscillation signal LOQp' (output signal out) may be phase-shifted by 180 degrees. When the first control signal S0 is "1" and the second control signal S1 is "1", the Q+ local oscillation signal LOQp' (output signal out) may be phase-shifted by 270 degrees.

[0068] In the fourth case, the Q-local oscillation signal LOQn, the I+local oscillation signal LOIp, the Q+local oscillation signal LOQp, and the I-local oscillation signal LOIn can be sequentially input to the LO multiplexing unit 500 as the first input signal in1 to the fourth input signal in4. Furthermore, the LO multiplexing unit 500 can set the Q-local oscillation signal LOQn′ as the output signal out. This is achieved by connecting the output terminal of the LO multiplexing unit 500 to the source terminal of the Q-local oscillation signal LOQn′ of the mixer.

[0069] As in the first case, when the first control signal S0 is "0" and the second control signal S1 is "0", the phase shift of the Q-local oscillation signal LOQn' (output signal out) may not occur. When the first control signal S0 is "0" and the second control signal S1 is "1", the Q-local oscillation signal LOQn' (output signal out) may be phase-shifted by 90 degrees. When the first control signal S0 is "1" and the second control signal S1 is "0", the Q-local oscillation signal LOQn' (output signal out) may be phase-shifted by 180 degrees. When the first control signal S0 is "1" and the second control signal S1 is "1", the Q-local oscillation signal LOQn' (output signal out) may be phase-shifted by 270 degrees.

[0070] The transceiver in the exemplary embodiment can multiplex the local oscillator signal at the LO buffer terminal before the mixer and perform a 90-degree phase shift, thereby giving the mixer a phase shift function. In addition, by not performing local oscillator signal multiplexing on the main signal path, signal loss can be prevented and gain can be increased.

[0071] Figure 8 Another example of the first LO multiplexing unit 431 and the second LO multiplexing unit 433 is shown.

[0072] refer to Figure 8 LO multiplexing unit 600 can be implemented by combining multiple buffers BUF. LO multiplexing unit 600 may include multiple buffer paths P1 to P4 that are activated in response to multiple control signals S00 to S11. Multiple different local oscillation signals LOIp, LOIn, LOQp, and LOQn may be input to the multiple buffer paths P1 to P4. LO multiplexing unit 600 can select one of the local oscillation signals input in response to the multiple control signals S00 to S11 to perform phase shifting of the local oscillation signals LOIp′, LOIn′, LOQp′, and LOQn′, which are determined as the output signal out. This operation is achieved by connecting the output terminal of LO multiplexing unit 600 to the source terminal of a specific local oscillation signal of a mixer.

[0073] For example, the LO multiplexing unit 600 may include: a first buffer path P1, which includes a plurality of buffers BUF that operate in response to a first control signal S00; a second buffer path P2, which includes a plurality of buffers BUF that operate in response to a second control signal S01; a third buffer path P3, which includes a plurality of buffers BUF that operate in response to a third control signal S10; and a fourth buffer path P4, which includes a plurality of buffers BUF that operate in response to a fourth control signal S11.

[0074] The phase shift of the local oscillation signals LOIp', LOIn', LOQp', and LOQn' (output signal out) may occur according to a combination of the multiple local oscillation signals LOIp, LOIn, LOQp, and LOQn input to the first buffer path P1 to the buffer path P4 and the activation states of the first buffer path P1 to the fourth buffer path P4 based on the first control signal S00 to the fourth control signal S11. In an exemplary embodiment, the LO multiplexing unit 600 may phase-shift the multiple local oscillation signals LOIp, LOIn, LOQp, and LOQn by 90 degrees and may output the signals LOIp', LOIn', LOQp', and LOQn'.

[0075] For example, when the I+ local oscillation signal LOIp, the Q+ local oscillation signal LOQp, the I- local oscillation signal LOIn, and the Q- local oscillation signal LOQn are sequentially input into the first to fourth buffer paths P1 to P4, since there is no phase difference between the I+ local oscillation signal LOIp input into the activated first buffer path P1 and the I+ local oscillation signal LOIp′ determined as the output signal out, a phase shift of the I+ local oscillation signal LOIp may not occur. In addition, since the phase difference between the Q+ local oscillation signal LOQp input into the activated second buffer path P2 and the I+ local oscillation signal LOIp′ determined as the output signal out is 90 degrees, the I+ local oscillation signal LOIp′ may be phase shifted by 90 degrees. In other exemplary embodiments, the LO multiplexing unit 600 may perform a phase shift of the output signal out using the same method as described above, which can be easily obtained from the reference signal. Figures 5 to 7D The exemplary embodiments described are derived.

[0076] For ease of description, return reference Figure 3 , the transmitter circuit 330 may generate RF transmission signals TXp and TXn by up-converting the I-phase baseband signal BBI′ and the Q-phase baseband signal BBQ′ converted into analog signals.

[0077] Transmitter circuit 330 may include a digital-to-analog converter 331 , an analog filter 333 , and a mixer 335 .

[0078] The digital-to-analog converter 331 may convert the I-phase baseband signal BBI and the Q-phase baseband signal BBQ output from the modulator 311 into analog signals.

[0079] The analog filter 333 may perform frequency filtering on the I-phase baseband signal BBI′ and the Q-phase baseband signal BBQ′ converted into the analog signals. In an exemplary embodiment, the analog filter 333 may include a low pass filter (LPF).

[0080] The mixer 335 may up-convert the frequencies of the plurality of baseband signals BBI′ and BBQ′ received from the analog filter 333 using the plurality of local oscillation signals LOIp′, LOIn′, LOQp′, and LOQn′ received from the local oscillation signal generator 320 .

[0081] In an exemplary embodiment, the mixer 335 may perform a mixing operation using the plurality of phase-shifted local oscillation signals LOIp′, LOIn′, LOQp′, and LOQn′, thereby providing a phase shift function relative to the RF signals TXp and TXn (output signals). For example, the mixer 335 may perform a mixing operation using the plurality of local oscillation signals LOIp′, LOIn′, LOQp′, and LOQn′ phase-shifted by 90 degrees by the local oscillation signal generator 320, thereby generating the RF signals TXp and TXn each having a 90-degree phase shift.

[0082] In an exemplary embodiment, the mixer 335 may perform a mixing operation by combining the plurality of baseband signals BBI′ and BBQ′ received from the analog filter 333, thereby providing a phase shift function with respect to the RF signals TXp and TXn (output signals). For example, the mixer 335 may use the baseband signals BBI′ and BBQ′ received from the analog filter 333 to generate a phase shift function. times I + baseband signal BBIP′ and A mixing operation is performed on a signal obtained by combining the doubled Q+baseband BBQp′, thereby generating a first RF signal TXp and a second RF signal TXn each having a phase shift of 45 degrees.

[0083] In this case, the first RF signal TXp output from the mixer 335 may be transmitted to the first transmit amplifier 341. The first transmit amplifier 341 may amplify the first RF signal TXp and output the amplified first RF signal TXp to the antenna 350. In addition, the second RF signal TXn output from the mixer 335 may be transmitted to the second transmit amplifier 343. The second transmit amplifier 343 may amplify the second RF signal TXn and output the amplified second RF signal TXn to the antenna 350. The first RF signal TXp and the second RF signal TXn may have a phase difference of 180 degrees.

[0084] In an exemplary embodiment, the first transmit amplifier 341 and the second transmit amplifier 343 may include power amplifiers.

[0085] The antenna 350 can externally transmit the first RF signal TXp and the second RF signal TXn transmitted from the transmitter circuit 330 through the first transmit amplifier 341 and the second transmit amplifier 343. The antenna 350 can transmit the first RF signal TXp and the second RF signal TXn as omnidirectional signals, or can form at least one beam B1 to B3 having directivity using the first RF signal TXp and the second RF signal TXn, and can transmit (beamforming) the beam in a specific direction.

[0086] The antenna 350 may be implemented as an array antenna for performing beamforming. The array antenna may include a plurality of antenna elements 351, and the communication device 300 may selectively activate the plurality of antenna elements 351 and perform beamforming. Figure 3 The example in which the antenna 350 is implemented as a planar array antenna is shown, but exemplary embodiments thereof are not limited thereto. For example, the antenna 350 may have various structures, a linear array antenna, etc.

[0087] A plurality of RF signals RXp and RXn received from an external entity through the antenna 350 may be amplified by the reception amplifiers 361 and 363 and may be transmitted to the receiver circuit 370. For example, the first RF signal RXp received through the antenna 350 may be amplified by the first reception amplifier 361 and may be transmitted to the receiver circuit 370. In addition, the second RF signal RXn received through the antenna 350 may be amplified by the second reception amplifier 363 and may be transmitted to the receiver circuit 370. The first RF signal RXp and the second RF signal RXn may have a phase difference of 180 degrees.

[0088] In an exemplary embodiment, the first reception amplifier 361 and the second reception amplifier 363 may include a low noise amplifier (LNA).

[0089] Receiver circuit 370 may include a mixer 371 , an analog filter 373 , and an analog-to-digital converter 375 .

[0090] The mixer 371 can down-convert the multiple RF signals RXp and RXn received from the receive amplifiers 361 and 363 using the multiple local oscillation signals LOIp′, LOIn′, LOQp′, and LOQn′ received from the local oscillation signal generator 320, thereby generating multiple baseband signals RBBI and RBBQ. The generated baseband signals RBBI and RBBQ may be orthogonal signals and may include I-phase baseband signals RBBIp and RBBIn and Q-phase baseband signals RBBQp and RBBQn.

[0091] The analog filter 373 may perform a frequency filtering operation on the baseband signals RBBI and RBBQ received from the mixer 371. In an exemplary embodiment, the analog filter 373 may include a low pass filter (LPF).

[0092] The analog-to-digital converter 375 may convert the baseband signals RBBI and RBBQ into digital signals. The baseband signals RBBI′ and RBBQ′ converted into digital signals may be transmitted to the demodulator 313 and may be restored to a received bit stream through a demodulation process.

[0093] In the following description, reference will be made to Figures 9 to 11 The mixer is described in more detail in accordance with exemplary embodiments of the present invention.

[0094] Figure 9 The structure of a mixer according to an exemplary embodiment of the present invention is shown. Figure 10A and Figure 10B A method of collecting a baseband signal by a mixer and performing phase shifting according to an exemplary embodiment of the present invention is shown.

[0095] refer to Figure 9 The mixer 700 may include a load portion 710, a first switching unit 730 that performs a switching operation in response to local oscillation signals LOIp′, LOIn′, LOQp′, and LOQn′, and a second switching unit 750 that performs a switching operation in response to baseband signals BBIp′, BBIn′, BBQp′, and BBQn′.

[0096] The load portion 710 may be connected between the input node N1 of the first power supply voltage VDD and the output node N2 and may adjust the amplitude of the RF signal. The load portion 710 may include a first load L1 connected between the input node of the external power supply voltage VDD and the first output node N1, and a second load L2 connected between the input node of the external power supply voltage VDD and the second output node N2.

[0097] When the communication device performs wireless communication using millimeter waves (mmWave), the first load L1 and the second load L2 may be implemented as inductors. In an exemplary embodiment, the inductances of the first load L1 and the second load L2 may be 0.1 nH or more and 0.5 nH or less, respectively.

[0098] When the communication device performs wireless communication using terahertz waves, the first load L1 and the second load L2 may be implemented as microstrip lines.

[0099] The first switching unit 730 can perform a switching operation using the local oscillation signals LOIp′, LOIn′, LOQp′, and LOQn′ that are phase-shifted by a first phase value by the LO multiplexing unit, thereby shifting the first RF signal TXp and the second RF signal TXn outputted through the first output node N1 and the second output node N2 by the first phase value. In an exemplary embodiment, the first phase value can be in increments of 90 degrees, for example, including 0 degrees, 90 degrees, 180 degrees, and 270 degrees.

[0100] The first switching unit 730 may include first to eighth LO transistors TLO1 to TLO8 , which may be implemented as PMOS transistors, NMOS transistors, or the like.

[0101] The first LO transistor TLO1 may be connected between the third node N3 and the seventh node N7 and may perform a switching operation in response to the I+ oscillation signal LOIp′ input to the gate terminal. The second LO transistor TLO2 may be connected between the fourth node N4 and the seventh node N7 and may perform a switching operation in response to the I- oscillation signal LOIn′ input to the gate terminal. The third LO transistor TLO3 may be connected between the third node N3 and the eighth node N8 and may perform a switching operation in response to the I- oscillation signal LOIn′ input to the gate terminal. The fourth LO transistor TLO4 may be connected between the fourth node N4 and the eighth node N8 and may perform a switching operation in response to the I+ oscillation signal LOIp′ input to the gate terminal.

[0102] The fifth LO transistor TLO5 may be connected between the fifth node N5 and the ninth node N9 and may perform a switching operation in response to the Q+ oscillation signal LOQp′ input to the gate terminal. The sixth LO transistor TLO6 may be connected between the sixth node N6 and the ninth node N9 and may perform a switching operation according to the Q-local oscillation signal LOQn′ input to the gate terminal. The seventh LO transistor TLO7 may be connected between the fifth node N5 and the tenth node N10 and may perform a switching operation according to the Q-local oscillation signal LOQn′ input to the gate terminal. The eighth LO transistor TLO8 may be connected between the sixth node N6 and the tenth node N10 and may perform a switching operation according to the Q+local oscillation LOQp′ input to the gate terminal.

[0103] The second switching unit 750 can perform a switching operation based on a combination of the plurality of baseband signals BBIP′, BBIn′, BBQp′, and BBQn′, thereby shifting the first RF signal TXp and the second RF signal TXn outputted through the first output node N1 and the second output node N2 by a second phase value. In an exemplary embodiment, the second phase value can be a value equal to or less than 45 degrees, such as 45 degrees, 30 degrees, or the like.

[0104] The second switch unit 750 may include first to fourth branches R1 to R4, each branch including a plurality of transistors. The plurality of transistors included in the second switch unit 750 may be PMOS transistors or NMOS transistors.

[0105] The first branch R1 may include a plurality of first I-phase transistors Ta1 to Tan (n is a natural number) and a plurality of first Q-phase transistors Tb1 to Tbm (m is a natural number), for example, connected in parallel between a seventh node N7 and an input node (such as a ground voltage terminal) of a second power supply voltage lower than the first power supply voltage VDD. The first I-phase transistors Ta1 to Tan may perform switching operations in response to an I+ baseband signal BBIP′ input to a gate terminal of each of the plurality of first I-phase transistors Ta1 to Tan. The first Q-phase transistors Tb1 to Tbn may perform switching operations in response to a Q+ baseband signal BBQp′ input to a gate terminal of each of the first Q-phase transistors Tb1 to Tbn.

[0106] The I+ baseband signal BBBI′ and the Q+ baseband signal BBQp′ input to the plurality of transistors of the first branch R1 can be coupled to each other and coupled to the plurality of transistors of the other branch according to the switching operation of the first LO transistor TLO1 and the second LO transistor TLO2 connected to the seventh node N7. Therefore, the I+ baseband signal BBIp″ phase-shifted by the second phase value can be output from the plurality of transistors of the first branch R1.

[0107] The second branch R2 may include a plurality of second I-phase transistors Tcl to Tcn and a plurality of second Q-phase transistors Tdl to Tdm, for example, which are connected in parallel between an eighth node N8 and an input node of a second power supply voltage (such as a ground terminal). The second I-phase transistors Tcl to Tcn may perform a switching operation in response to an I-baseband signal BBIn′ input to a gate terminal of each of the second I-phase transistors Tcl to Tcn. The second Q-phase transistors Td1 to Tdn may perform a switching operation in response to a Q-baseband signal BBnn′ input to a gate terminal of each of the second Q-phase transistors Td1 to Tdn.

[0108] The I-baseband signal BBIn′ and the Q-baseband signal BBQn′ input to the plurality of transistors of the second branch R2 can be coupled to each other and coupled to the plurality of transistors of the other branch according to the switching operation of the third LO transistor TLO3 and the fourth LO transistor TLO4 connected to the eighth node N8. Therefore, the I-baseband signal BBIn″ phase-shifted by the second phase value can be output from the plurality of transistors of the second branch R2.

[0109] The phase-shifted I+ baseband signal BBIp″ output from the first branch R1 and the phase-shifted I- baseband signal BBIn″ output from the second branch R2 may have a phase difference of 180 degrees and thus may be combined to remove the image signal.

[0110] The third branch R3 may include a plurality of third Q-phase transistors Te1 to Ten and a plurality of third I-phase transistors Tf1 to Tfm, which are connected in parallel between a ninth node N9 and an input node of a second power supply voltage (such as a ground terminal). The third Q-phase transistors Te1 to Ten may perform switching operations in response to a Q+ baseband signal BBQp′ input to a gate terminal of each of the third Q-phase transistors Te1 to Ten. The third I-phase transistors Tf1 to Tfm may perform switching operations in response to an I- baseband signal BBIn′ input to a gate terminal of each of the third I-phase transistors Tf1 to Tfm.

[0111] The Q+ baseband signal BBQp′ and the I- baseband signal BBIn′ input to the plurality of transistors of the second branch R2 can be coupled to each other and coupled to the plurality of transistors of the other branch according to the switching operation of the fifth LO transistor TLO5 and the sixth LO transistor TLO6 connected to the ninth node N9. Therefore, the Q+ baseband signal BBQp″ phase-shifted by the second phase value can be output from the plurality of transistors of the third branch R3.

[0112] The fourth branch R4 may include a plurality of fourth Q-phase transistors Tg1 to Tgn and a plurality of fourth I-phase transistors Th1 to Thm, which are connected in parallel between a tenth node N10 and an input node of a second power supply voltage (such as a ground terminal). The fourth Q-phase transistors Tg1 to Tgn may perform a switching operation in response to a Q-baseband signal BBQn′ input to a gate terminal of each of the fourth Q-phase transistors Tg1 to Tgn. The fourth I-phase transistors Th1 to Thm may perform a switching operation in response to an I+baseband signal BBIp′ input to a gate terminal of each of the fourth I-phase transistors Th1 to Thm.

[0113] The Q-baseband signal BBQn′ and the I+baseband signal BBIp′ input to the plurality of transistors of the fourth branch R4 can be coupled to each other and coupled to the plurality of transistors of the other branch according to the switching operation of the seventh LO transistor TLO7 and the eighth LO transistor TLO8 connected to the tenth node N10. Therefore, the Q-baseband signal BBQn″ phase-shifted by the second phase value can be output from the plurality of transistors of the fourth branch R4.

[0114] The phase-shifted Q+ baseband signal BBQp″ output from the third branch R3 and the phase-shifted Q- baseband signal BBQn′ output from the fourth branch R4 may have a phase difference of 180 degrees and thus may be combined to remove the image signal.

[0115] The phase shift method of the plurality of baseband signals BBIp′, BBIn′, BBQp′ and BBQn′ performed by the first branch R1 to the fourth branch R4 can be the same as Figure 10A and Figure 10B The same as in .

[0116] Figure 10A A method of phase-shifting the plurality of baseband signals BBIp′, BBIn′, BBQp′, and BBQn′ by 45 degrees is shown.

[0117] Reference together Figure 9 and Figure 10A The mixer 700 can shift the phases of the multiple baseband signals BBIp′, BBIn′, BBQp′, and BBQn′ by a specific phase value by combining a plurality of pairs of signals selected from the multiple baseband signals BBIp′, BBIn′, BBQp′, and BBQn′. For example, the mixer 700 can shift the phase of the I+ baseband signal BBIp′ by 45 degrees (=BBIp′×1∠45°) by combining the I+ baseband signal BBIp′ with the Q+ baseband signal BBQp′ of the same amplitude.

[0118] In an exemplary embodiment, the mixer 700 may adjust the amplitudes of the plurality of baseband signals BBIp′, BBIn′, BBQp′, and BBQn′ so that the amplitudes of the plurality of baseband signals BBIp′, BBIn′, BBQp′, and BBQn′ remain the same before and after signal conversion. For example, the mixer 700 may adjust the amplitude of each of the I+ baseband signal BBIp′ and the Q+ baseband signal BBQp′ to The amplitude of the combined signal BBIp″ may be the same as that of the I+ baseband signal BBIp′, and the phase may be 45 degrees different from that of the I+ baseband signal BBIp′ (BBIp″=BBIp′×1∠45°).

[0119] In an exemplary embodiment, the mixer 700 can adjust the amplitudes of the plurality of baseband signals BBIp′, BBIn′, BBQp′, and BBQn′ input to the first to fourth branches R1 to R4 by controlling the number of transistors activated in each of the first to fourth branches R1 to R4. For example, in order to adjust the amplitude of each of the I+ baseband signal BBIp′ and the O+ baseband signal BBQp′ to times, the mixer 700 can control the number of transistors operating in response to the I+ baseband signal BBIp′ among the plurality of transistors included in the first branch R1 and the number of transistors operating in response to the Q+ baseband signal BBQp′ among the plurality of transistors included in the first branch R1 to be a number k (k is a natural number smaller than n and m).

[0120] In order to shift the phase of the Q+ baseband signal BBQp′ by 45 degrees, the mixer 700 can adjust the amplitude of the Q+ baseband signal BBQp′ and the amplitude of the I- baseband signal BBIn′ to The amplitude of the combined signal BBQp″ may be the same as the amplitude of the I+ baseband signal BBIp′, and the phase may be 135 degrees different from the phase of the I+ baseband signal BBIp′ (BBQp″=BBIp′×1∠135°).

[0121] In order to shift the phase of the I-baseband signal BBIn′ by 45 degrees, the mixer 700 can adjust the amplitude of the I-baseband signal BBIn′ and the amplitude of the Q-baseband signal BBQn′ to The amplitude of the combined signal BBIn″ may be the same as the amplitude of the I+ baseband signal BBIp′, and the phase may be 225 degrees different from the phase of the I+ baseband signal BBIp′ (BBIn″=BBIp′×1∠225°).

[0122] In order to shift the phase of the Q-baseband signal BBQn′ by 45 degrees, the mixer 700 may adjust each of the amplitude of the Q-baseband signal BBQn′ and the amplitude of the I+baseband signal BBIp′ to The amplitude of the combined signal BBQn″ may be the same as that of the I+ baseband signal BBIp′, and the phase may be 315 degrees different from that of the I+ baseband signal BBIp′ (BBQn″=BBIp′×1∠315°).

[0123] The mixer 700 of the exemplary embodiment can achieve a phase shift of 90 degrees by phase shifting the multiple local oscillator signals LOIp, LOIn, LOQp, and LOQn, and can achieve a phase shift of 45 degrees by phase shifting the multiple baseband signals BBIp', BBIn', BBQp', and BBQn', thereby providing a phase shift function of 45 degrees (i.e., 0 degrees, 45 degrees, 90 degrees, 135 degrees, 180 degrees, 225 degrees, 270 degrees, and 315 degrees) relative to the RF signal. Since the mixer 700 provides a phase shift function relative to the RF signal, a phase shifter may not be required, allowing the communication device to reduce signal degradation, increase in chip area, and increase in current consumption caused by adding a phase shifter.

[0124] Figure 10B A method of phase shifting multiple transmit signals by 30 degrees and 60 degrees is shown.

[0125] refer to Figure 10B and Figure 9 The mixer 700 can shift the phases of the multiple baseband signals BBIp′, BBIn′, BBQp′, and BBbln′ by a specific phase value by combining multiple pairs of signals selected from the multiple baseband signals BBIp′, BBIn′, BBQp′, and BBQn′. For example, the mixer 700 can adjust the amplitude of the I+ baseband signal BBIp′ and the amplitude of the Q+ baseband signal BBQp′ at a certain ratio and combine the signals to shift the phase of the I+ baseband signal BBIp′ by 30 degrees (=BBIp′×1∠30°).

[0126] In an exemplary embodiment, the mixer 700 may adjust the amplitudes of the plurality of baseband signals BBIp′, BBIn′, BBQp′, and BBbln′ so that the amplitudes of the plurality of baseband signals BBIp′, BBIn′, BBQp′, and BBQn′ remain the same before and after the combination. For example, in order to shift only the phase of the I+ baseband signal BBIp′ by 30 degrees, the mixer 700 may adjust the amplitude of the I+ baseband signal BBIp′ to times, and the amplitude of the Q+ baseband signal BBQp′ can be adjusted to The amplitude of the combined signal BBIp″ may be the same as that of the I+ baseband signal BBIp′, and the phase may be 30 degrees different from that of the I+ baseband signal BBIp′ (BBIp″=BBIp′×1∠30°).

[0127] In an exemplary embodiment, the mixer 700 can adjust the amplitudes of the plurality of baseband signals BBBI′, BBIn′, BBQp′, and BBbl′ input to the first to fourth branches R1 to R4, respectively, by controlling the number of transistors activated in each of the first to fourth branches R1 to R4.

[0128] In order to shift the phase of the I+ baseband signal BBIp′ by 60 degrees, the mixer 700 can adjust the amplitude of the I+ baseband signal BBIp′ to times, and the amplitude of the Q+ baseband signal BBQp′ can be adjusted to The amplitude of the combined signal BBQp″ may be the same as that of the I+ baseband signal BBIp′, and the phase may be 60 degrees different from that of the I+ baseband signal BBIp′ (BBIp″=BBIp′×1∠60°).

[0129] In order to shift the phase of the Q+ baseband signal BBQp′ by 30 degrees, the mixer 700 may adjust the amplitude of the Q+ baseband signal BBQp′ to times, and the amplitude of the I-baseband signal BBIn′ can be adjusted to The amplitude of the combined signal BBQp″ may be the same as that of the I+ baseband signal BBIp′, and the phase may be 120 degrees different from that of the I+ baseband signal BBIp′ (BBQp″=BBIp′×1∠120°).

[0130] In order to shift the phase of the Q+ baseband signal BBQp′ by 60 degrees, the mixer 700 can adjust the amplitude of the Q+ baseband signal BBQp′ to times, and the amplitude of the I-baseband signal BBIn′ can be adjusted to The amplitude of the combined signal BBQp″ may be the same as that of the I+ baseband signal BBIp′, and the phase may be 150 degrees different from that of the I+ baseband signal BBIp′ (BBQp″=BBIp′×1∠150°).

[0131] In order to shift the phase of the I-baseband signal BBIn′ by 30 degrees, the mixer 700 may adjust the amplitude of the I-baseband signal BBIn′ to times, and the amplitude of the Q-baseband signal BBQn′ can be adjusted to The amplitude of the combined signal BBIn″ may be the same as that of the I+ baseband signal BBIp′, and the phase may be 210 degrees different from that of the I+ baseband signal BBIp′ (BBIn″=BBIp′×1∠210°).

[0132] In order to shift the phase of the I-baseband signal BBIn′ by 60 degrees, the mixer 700 may adjust the amplitude of the I-baseband signal BBIn′ to times, and the amplitude of the Q-baseband signal BBQn′ can be adjusted to The amplitude of the combined signal BBIn″ may be the same as that of the I+ baseband signal BBIp′, and the phase may be 240 degrees different from that of the I+ baseband signal BBIp′ (BBIn″=BBIp′×1∠240°).

[0133] In order to shift the phase of the Q-baseband signal BBQn′ by 30 degrees, the mixer 700 may adjust the amplitude of the Q-baseband signal BBQn′ to times, and the amplitude of the I+ baseband signal BBIp′ can be adjusted to The amplitude of the combined signal BBQn″ may be the same as that of the I+ baseband signal BBIp′, and the phase may be 300 degrees different from that of the I+ baseband signal BBIp′ (BBQn″=BBIp′×1∠300°).

[0134] In order to shift the phase of the Q-baseband signal BBQn′ by 60 degrees, the mixer 700 may adjust the amplitude of the Q-baseband signal BBQn′ to times, and adjust the amplitude of the I+ baseband signal BBIp′ to The amplitude of the combined signal BBQn″ may be the same as that of the I+ baseband signal BBIp′, and the phase may be 330 degrees different from that of the I+ baseband signal BBIp′ (BBQn″=BBIp′×1∠330°).

[0135] The mixer 700 in the exemplary embodiment can achieve a phase shift of 90 degrees by phase shifting a plurality of local oscillation signals LOIp, LOIn, LOQp, and LOQn, and can achieve a phase shift of 30 degrees and 60 degrees by phase shifting a plurality of baseband signals BBIp′, BBIn′, BBQp′, and BBQn′, thereby providing a phase shift of 30 degrees (i.e., 0 degrees, 30 degrees, 60 degrees, 90 degrees, 120 degrees, 150 degrees, 180 degrees, 210 degrees, 240 degrees, 270 degrees, 300 degrees, 330 degrees, and 360 degrees) relative to the RF signal.

[0136] Figure 10A and Figure 10B The mixer 700 is shown as an example in which it can provide a phase shift function of 45 degrees and 30 degrees relative to the RF signal, but the exemplary embodiment is not limited thereto. Alternatively, the mixer 700 in the exemplary embodiment can provide a phase shift function of 45 degrees or less, for example, 20 degrees.

[0137] In the following description, reference will be made to Figure 11 The structure of the mixer 371 included in the receiver circuit 370 is described in more detail.

[0138] Figure 11 A mixer according to an exemplary embodiment of the present invention is shown.

[0139] refer to Figure 11 , the mixer 800 may include a load part 810 , a first switching unit 830 and a second switching unit 850 .

[0140] The load part 810 may be connected between an input node of the first power supply voltage VDD and a plurality of output nodes N1 to N4 and may generate a reception baseband signal RBBIp according to switching operations of the first and second switching units 830 and 850 .

[0141] The load portion 810 may include first to fourth loads L1 to L4 connected between the input node of the first power supply voltage VDD and the first to fourth nodes N1 to N4, respectively. In an exemplary embodiment, when the communication device including the mixer 800 performs wireless communication using millimeter waves (mmWave), the first to fourth nodes N1 to N4 may be implemented as inductive devices. In this case, the inductance value of each of the first to fourth nodes N1 to N4 may be greater than 0.1 nH and less than 0.5 nH. In an exemplary embodiment, when the communication device including the mixer 800 performs wireless communication using terahertz waves, the first to fourth nodes N1 to N4 may be implemented as microstrip lines.

[0142] The first switching unit 830 may include first to eighth LO transistors TLO1 to TLO8 that perform switching operations in response to a plurality of local oscillation signals LOIp′, LOIn′, LOQp′, and LOQn′. The first to eighth LO transistors TLO1 to TLO8 may be PMOS transistors or NMOS transistors.

[0143] The first LO transistor TLO1 may be connected between the fifth node N5 and the ninth node N9 and may perform a switching operation in response to the I+local oscillation signal LOIp′ input to the gate. The second LO transistor TLO2 may be connected between the sixth node N6 and the ninth node N9 and may perform a switching operation in response to the I-local oscillation signal LOIn′ input to the gate. The third LO transistor TLO3 may be connected between the fifth node N5 and the tenth node N10 and may perform a switching operation in response to the I-local oscillation signal LOIn′ input to the gate. The fourth LO transistor TLO4 may be connected between the sixth node N6 and the tenth node N10 and may perform a switching operation in response to the I+local oscillation signal LOIp′ input to the gate.

[0144] The fifth LO transistor TLO5 may be connected between the seventh node N7 and the eleventh node N11 and may perform a switching operation in response to the Q+ local oscillation signal LOQp′ input to the gate. The sixth LO transistor TLO6 may be connected to the eighth node N8 and the eleventh node N11 and may perform a switching operation in response to the Q- local oscillation signal LOQn′ input to the gate. The seventh LO transistor TLO7 may be connected between the seventh node N7 and the twelfth node N12 and may perform a switching operation in response to the Q- local oscillation signal LOQn′ input to the gate. The eighth LO transistor TLO8 may be connected to the eighth node N8 and the twelfth node N12 and may perform a switching operation in response to the Q+ local oscillation signal LOQp′ input to the gate.

[0145] The second switching unit 850 may include a first transistor T1 and a second transistor T2 that perform a switching operation in response to a plurality of RF reception signals RXp and RXn. The first transistor T1 and the second transistor T2 may be PMOS transistors or NMOS transistors.

[0146] For example, the first transistor T1 may be connected between the thirteenth node N13 and an input node (ground terminal) of a second power supply voltage lower than the first power supply voltage VDD, and may perform a switching operation in response to a first RF receive signal RXp input to the gate. The second transistor T2 may be connected between the fourteenth node N14 and an input node of the second power supply voltage, and may perform a switching operation in response to a second RF receive signal RXn.

[0147] The mixer 800 can perform an operation of mixing a plurality of local oscillation signals LOIp′, LOIn′, LOQp′, and LOQn′ with the reception signals RXp and RXn according to the switching operation of the first switching unit 830 and the second switching unit 850, and can generate a plurality of baseband signals RBBIp, RBBIn, RBBQp, and RBBQn. In an exemplary embodiment, the I+ baseband signal RBBIp, the I- baseband signal RBBIn, the Q+ baseband signal RBBQp, and the Q- baseband signal RBBQn can be output through the first node N1 to the fourth node N4, respectively.

[0148] In the following description, reference will be made to Figure 12 and Figure 13 The exemplary embodiments of the present invention describe a method of performing wireless communication by a communication device.

[0149] Figure 12 A method of transmitting an RF signal by a communication device according to an exemplary embodiment of the present invention is shown.

[0150] refer to Figure 12In operation S10, the communication device may multiplex local oscillation signals generated by the local oscillator and may shift the phase of the local oscillation signals. In an exemplary embodiment, the communication device may include a local oscillation (LO) multiplexing unit for multiplexing the local oscillation signals, and the LO multiplexing unit may include a multiplexer and an LO buffer including a plurality of buffer paths. A detailed description of the LO multiplexing unit is provided with reference to FIG. Figures 4 to 8 The same as in the described exemplary embodiments.

[0151] In operation S20, the communication device may offset the phases of the plurality of transmission baseband signals by combining the plurality of transmission baseband signals generated from a specific transmission bit stream and input to the mixer. In an exemplary embodiment, the communication device may adjust the offset phase value by adjusting the amplitude of the transmission baseband signals to be combined. For example, the communication device may generate a 45-degree phase shift by combining two transmission baseband signals that intersect each other with the same amplitude. In addition, the communication device may adjust the amplitudes of the two transmission baseband signals that intersect each other differently to Double times, thus generating a 30-degree or 60-degree phase shift.

[0152] In operation S30, the communication device may generate a plurality of RF transmit signals by up-converting the phase-shifted transmit baseband signal using the phase-shifted local oscillation signal. In an exemplary embodiment, the plurality of RF transmit signals may include a first RF transmit signal and a second RF transmit signal having a phase difference of 180 degrees therebetween.

[0153] In operation S40, the communication device may perform wireless communication using the plurality of RF transmit signals generated in operation S30. In an exemplary embodiment, the communication device may perform transmit beamforming by forming at least one beam using the plurality of RF transmit signals.

[0154] Figure 13 A method of receiving an RF signal by a communication device according to an exemplary embodiment of the present invention is illustrated.

[0155] refer to Figure 13 In operation S50, the communication device may receive an RF transmission signal from an external entity through an antenna. In an exemplary embodiment, the communication device may perform receive beamforming and may receive at least one beam.

[0156] In operation S60, the communication device may multiplex the local oscillation signals generated by the local oscillator and may shift the phases of the local oscillation signals. In an exemplary embodiment, the communication device may include an LO multiplexing unit for multiplexing the local oscillation signals.

[0157] In operation S70, the communication device may generate a plurality of baseband signals by downconverting the RF reception signal using the local oscillation signal phase-shifted in operation S60. In an exemplary embodiment, the plurality of baseband signals may be quadrature signals including an in-phase signal and a quadrature phase signal.

[0158] In operation S80 , the communication device may multiplex the plurality of baseband signals generated in operation S70 and may obtain a specific reception bit stream.

[0159] In the aforementioned exemplary embodiments, reference is made to Figures 1 to 13 The described communication device can perform a phase shift function by a mixer without a phase shifter, thereby reducing signal degradation, an increase in chip area, and an increase in current consumption.

[0160] Figure 14 An electronic device including a communication device according to an exemplary embodiment of the present invention is shown.

[0161] refer to Figure 14 , the electronic device 1000 may include a display 1010, a storage device 1020, a communication device 1030, a processor 1040, and the like.

[0162] The electronic device 1000 may include a smart phone, a tablet PC, a smart wearable device, and the like.

[0163] The display 1010 may include an organic light emitting diode (OLED), a liquid crystal display (LCD), a plasma display panel (PDP), etc., and may display various images on the screen. The display 1010 may also provide a user interface function. For example, the display 1010 may provide a device for the user to input various commands.

[0164] The memory device 1020 may be a storage medium for storing data required for the operation of the electronic device 1000, multimedia data, etc. The memory device 1020 may include a memory device based on a semiconductor device. For example, the memory device 1020 may include a dynamic random access memory device such as DRAM, synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), low power double data rate SDRAM (LPDDR SDRAM), graphic double data rate SDRAM (GDDR SDRAM), DDR2 SDRAM, DDR3 SDRAM, DDR4 SDRAM, etc., or a resistive memory device such as phase change random access memory (PRAM), magnetic random access memory (MRAM), resistive random access memory (RRAM), etc.

[0165] The storage device 1020 may be implemented by a storage device, and may include at least one of a solid state drive (SSD), a hard disk drive (HDD), and an optical disk drive (ODD).

[0166] The communication device 1030 may include a Figures 1 to 13 For example, since the communication device 1030 includes a mixer that performs a phase shift function, performance degradation such as an increase in signal loss, a decrease in gain, an increase in current consumption, an increase in chip area, etc. caused by including a separate phase shifter can be prevented.

[0167] The processor 1040 may execute calculations or command words, tasks, etc. The processor 1040 may be a central processing unit (CPU), a microprocessor unit (MCU), a system on a chip (SoC), etc., and may exchange various data with the display 1010, the memory device 1020, and the communication device 1030 through the bus 1050.

[0168] Figure 15 and Figure 16 An application example of the communication device according to the exemplary embodiment of the present invention is shown.

[0169] refer to Figure 15 , the communication device in the exemplary embodiment may be installed on the smart phone 1100 and may provide a wireless communication function.

[0170] The smartphone 1100 may include a body 1110 having a display function and a case forming the exterior of the smartphone 1100 and providing a support function. A display may be arranged on the externally exposed front side of the body 1110, and various information and images may be displayed on the display.

[0171] The communication device may be provided in the smartphone 1100, and the antenna of the communication device may be provided in each corner area of ​​the smartphone 1100. In an exemplary embodiment, the communication device may include an array antenna including a plurality of antenna elements. The communication device may perform transmit beamforming by forming at least one beam 1130 having a specific directivity and transmitting the formed beam 1130 through the array antenna.

[0172] refer to Figure 16 , the communication device in the exemplary embodiment may be provided in the vehicle 1200 , for example, in the engine room 1210 , and may provide a wireless communication function.

[0173] The vehicle 1200 can use the communication device to perform an autonomous driving function. In this case, the communication device set in the vehicle 1200 can sense the lane and can determine whether the vehicle 1200 deviates from the lane by performing beamforming using at least one beam 1230.

[0174] According to the aforementioned exemplary embodiments, the mixer may perform up-conversion on a plurality of baseband signals using a plurality of phase-shifted local oscillation signals, thereby generating phase-shifted RF signals.

[0175] Additionally, mixers can generate phase-shifted RF signals by combining multiple baseband signals.

[0176] Furthermore, the mixer can perform phase shift of the RF signal in the local oscillation signal region and the baseband signal region in a separate manner, thereby simplifying the circuit structure and reducing power consumption and chip area.

[0177] Furthermore, according to the aforementioned exemplary embodiments, the communication device can perform multiplexing of all signals at a local oscillation (LO) buffer terminal before the mixer and source terminals of the baseband signal, thereby reducing signal loss on the main signal path and increasing gain.

[0178] While exemplary embodiments have been shown and described above, it will be apparent to those skilled in the relevant art that various substitutions, modifications and alterations may be made without departing from the scope or spirit of the inventive concept as defined by the appended claims and their equivalents.

Claims

1. A mixer for generating a radio frequency transmission signal, the mixer comprising: a load part, connected between the input terminal of the first power supply voltage and the output terminal of the radio frequency transmission signal, and configured to adjust the amplitude of the radio frequency transmission signal; a first switching unit connected to the output terminal of the radio frequency transmission signal and configured to perform a first switching operation in response to a plurality of local oscillation signals; as well as a second switching unit connected between the first switching unit and an input terminal of a second power supply voltage lower than the first power supply voltage and configured to perform a second switching operation in response to a plurality of baseband signals, wherein the plurality of local oscillation signals include an I+ baseband signal, an I- baseband signal, a Q+ baseband signal, and a Q- baseband signal, and The second switching unit includes: a first branch, wherein the first branch performs a first switching operation under the control of the I+ baseband signal and the Q+ baseband signal; a second branch, wherein the second branch performs a second switching operation under the control of the I- baseband signal and the Q- baseband signal; a third branch, wherein the third branch performs a third switching operation under the control of the Q+ baseband signal and the I- baseband signal; and a fourth branch, wherein the fourth branch performs a fourth switching operation under the control of the Q- baseband signal and the I+ baseband signal. 2 . The mixer according to claim 1 , wherein the plurality of local oscillation signals are obtained by phase-shifting a quadrature signal by a first phase value.

3. The mixer according to claim 1 , wherein the first to fourth branches are configured to shift the phase of each of the plurality of baseband signals by a second phase value by combining control signals for the first to fourth switch operations of the first to fourth branches, respectively.

4. The mixer according to claim 3, wherein each of the first to fourth branches includes a plurality of transistors connected in parallel with each other, and The second phase value varies according to the number of activated transistors among the plurality of transistors.

5. The mixer according to claim 1, The load portion includes: a first load connected between the input terminal of the first power supply voltage and the first output terminal of the radio frequency transmission signal, and a second load connected to the input terminal of the first power supply voltage and the second output terminal of the radio frequency transmission signal, and When the radio frequency transmission signal is a millimeter wave, each of the first load and the second load includes an inductive device. The mixer according to claim 5 , wherein an inductance value of the inductor device is greater than or equal to 0.1 nH and less than or equal to 0.5 nH.

7. A communication device comprising: a modulator configured to generate a plurality of first baseband signals by modulating a transmit bit stream; a local oscillation signal generator configured to generate a plurality of first local oscillation signals and generate a plurality of second local oscillation signals that are phase-shifted by a first phase value relative to the plurality of first local oscillation signals by multiplexing the plurality of first local oscillation signals; as well as a mixer configured to generate a radio frequency transmission signal by up-converting the plurality of first baseband signals using the plurality of second local oscillation signals, The mixer is configured to generate a plurality of second baseband signals shifted by a second phase value relative to the plurality of first baseband signals by combining the plurality of first baseband signals, and perform a mixing operation with respect to the plurality of second baseband signals and the plurality of second local oscillation signals. 8 . The communication device according to claim 7 , further comprising a reception mixer configured to generate a plurality of first baseband reception signals by down-converting a plurality of radio frequency reception signals based on the plurality of second local oscillation signals.

9. The communication device according to claim 7, further comprising: Array antennas used to perform beamforming.

10. The communication device according to claim 7, wherein the radio frequency transmission signal is obtained by phase-shifting the plurality of first local oscillation signals by a sum of the first phase value and the second phase value.

11. The communication device according to claim 7, further comprising: A plurality of loads are connected to the output terminals of the radio frequency transmission signal and are configured to adjust the amplitude of the radio frequency transmission signal. 12 . The communication device according to claim 11 , wherein when the communication device performs wireless communication using waves in a terahertz band, each of the plurality of loads includes at least one microstrip line.

13. The communication device according to claim 7, wherein the local oscillation signal generator comprises: a local oscillator configured to generate quadrature signals as the plurality of first local oscillation signals; as well as A local oscillation buffer is configured to generate the plurality of second local oscillation signals by selectively outputting one of the plurality of first local oscillation signals.

14. The communication device according to claim 13, wherein the plurality of first local oscillation signals include an I+ transmit local oscillation signal, an I- transmit local oscillation signal, a Q+ transmit local oscillation signal, and a Q- transmit local oscillation signal, and The local oscillator buffer is configured to select one of the I+ transmit local oscillation signal, the I- transmit local oscillation signal, the Q+ transmit local oscillation signal and the Q- transmit local oscillation signal, and output the selected transmit local oscillation signal as one of the multiple second local oscillation signals.

15. The communication device according to claim 13, wherein the plurality of first local oscillation signals include an I+ transmit local oscillation signal, an I- transmit local oscillation signal, a Q+ transmit local oscillation signal, and a Q- transmit local oscillation signal, and The local oscillator buffer includes first to fourth buffer paths, each buffer path includes a plurality of buffers, and the local oscillator buffer is configured to generate the plurality of second local oscillation signals based on a combination of the plurality of first local oscillation signals input to the first to fourth buffer paths and activation states of the first to fourth buffer paths.

16. The communication device according to claim 7, The mixer comprises: a first switching unit configured to perform a switching operation in response to the plurality of second local oscillation signals; as well as a second switching unit configured to perform a switching operation in response to the plurality of first baseband signals; The plurality of second baseband signals are generated in response to a switching operation of the first switching unit.

17. A communication device comprising: a modem configured to generate a transmit baseband signal by modulating a transmit bit stream and demodulate a receive baseband signal into a receive bit stream; a transmitter circuit configured to generate a radio frequency transmit signal by up-converting the transmit baseband signal using a transmit local oscillation signal; as well as A receiver circuit is configured to generate the received baseband signal by down-converting a radio frequency received signal using a received local oscillation signal, wherein the transmitting local oscillator signal and the receiving local oscillator signal are obtained by phase shifting the orthogonal signal; and The transmitter circuit is configured to perform the up-conversion on the transmit baseband signal after phase-shifting the transmit baseband signal based on the transmit local oscillation signal.

18. The communication device of claim 17, wherein the transmitter circuit comprises: an analog-to-digital converter configured to convert the transmit baseband signal into an analog signal; an analog filter configured to perform frequency filtering on the transmission baseband signal converted into the analog signal; as well as The mixer is configured to mix the frequency-filtered transmit baseband signal with the transmit local oscillation signal.

19. The communication device of claim 17, wherein the transmitter circuit is configured to phase shift the transmit baseband signal by 45 degrees or less.

20. The communication device according to claim 17, The transmission baseband signal includes an I+ transmission baseband signal, an I- transmission baseband signal, a Q+ transmission baseband signal and a Q- transmission baseband signal. The transmitter circuit is configured to phase shift the transmit baseband signal by forming a plurality of pairs of signals selected from the I+ transmit baseband signal, the I- transmit baseband signal, the Q+ transmit baseband signal, or the Q- transmit baseband signal.

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