KR102235152B1 - Multiple antenna system for calibration of signal amplitude and phase with high-resolution in the RF millimeter-wave - Google Patents

Abstract

Disclosed is a multi-antenna system for calibrating a signal magnitude and phase in an RF millimeter wave band. A signal calibration apparatus according to an embodiment of the present invention includes: a direct digital synthesis for calibrating a received signal received through an antenna; A quadrature mixer for outputting a calibration signal based on a reference signal and an output signal of the direct digital synthesizer; And a mixer for calibrating the received signal by mixing the received signal and the calibration signal.

Description

Multiple antenna system for calibration of signal amplitude and phase with high-resolution in the RF millimeter-wave}

The present invention relates to an RF millimeter wave band antenna system, and more specifically, to a multi-antenna system capable of calibrating the signal amplitude and phase loss of the RF millimeter wave band that may be generated by active elements and temperature changes. .

The antenna system may refer to a device that performs a function of transmitting/receiving an RF signal according to an allocated frequency band, such as a mobile communication terminal, a tablet PC, a radar, and a satellite device. For example, these antenna systems transmit/receive high-frequency signals by embedding desired information in RF signals, thereby enabling wireless communication between mobile communication terminals. As the utilization of the antenna system increases and the wireless communication system is diversified, the allocated frequency band has recently increased, and thus, the development of the ultra-high frequency communication system is being made. For example, the current 4G (4th generation) mobile communication system uses a frequency signal in the 1.70 ~ 2.60 GHz band, but the 5G (5th generation) mobile communication system is assigned 3.42 ~ 3.70 GHz and 26.50 ~ 29.50 GHz, so that it is wireless. It can meet data traffic demand.

In the case of ultra-high frequency (millimeter wave) signals, since signal loss in the air increases, efforts to develop a beamforming system capable of controlling the signal amplification and signal transmission direction using a multi-antenna system to solve this problem This is being done.

The antenna system can generate and transmit a high-frequency signal by using a mixer or a frequency multiplier for a stable low-frequency band in order to implement wireless communication in the assigned frequency band. ) Or by using a frequency divider, you can obtain a low-frequency signal containing data. The multi-antenna system is an entire system in which the same antenna system is arranged in the same arrangement, and transmission/reception of signals having the same size and phase is required. If the size and phase of the multi-antenna signals are different, a beamforming system may be implemented or transmitted/received as signals that are not required due to the constructive/destructive interference characteristics of electromagnetic waves.

Embodiments of the present invention provide a multi-antenna system capable of calibrating a signal magnitude and phase loss in an RF millimeter wave band that may be caused by active elements and temperature changes.

Embodiments of the present invention provide a multi-antenna beamforming system capable of improving the accuracy of beam tilting through signal magnitude and phase control.

A signal calibration apparatus according to an embodiment of the present invention includes: a direct digital synthesis for calibrating a received signal received through an antenna; A quadrature mixer for outputting a calibration signal based on a reference signal and an output signal of the direct digital synthesizer; And a mixer for calibrating the received signal by mixing the received signal and the calibration signal.

The quadrature mixer may include a hybrid coupler configured to output a phase shift signal of 90 degrees by receiving the reference signal as an input; A first mixer for mixing a first output signal of the hybrid coupler and a Q (quadrature) channel intermediate frequency signal generated by the direct digital synthesizer; And a second mixer for mixing a second output signal of the hybrid coupler with an I (In-phase) channel intermediate frequency signal generated by the direct digital synthesizer, wherein the output signal of the first mixer and the second mixer The calibration signal may be output based on the output signal of.

The calibration signal may be a signal for calibrating a phase and a magnitude of the received signal.

The direct digital synthesizer may use a single channel or multiple channels to provide at least one output signal to the quadrature mixer.

The quadrature mixer may remove a sideband signal from the received signal.

A multi-antenna system according to an embodiment of the present invention includes a multi-antenna; And a signal calibration device for calibrating a received signal received through each of the multiple antennas, wherein the signal calibration device includes: a direct digital synthesizer for calibrating the received signal; A quadrature mixer for outputting a calibration signal based on a reference signal and an output signal of the direct digital synthesizer; And a mixer for calibrating the received signal by mixing the received signal and the calibration signal.

The quadrature mixer may include a hybrid coupler configured to output a phase shift signal of 90 degrees by receiving the reference signal as an input; A first mixer for mixing a first output signal of the hybrid coupler and a Q (quadrature) channel intermediate frequency signal generated by the direct digital synthesizer; And a second mixer for mixing a second output signal of the hybrid coupler with an I (In-phase) channel intermediate frequency signal generated by the direct digital synthesizer, wherein the output signal of the first mixer and the second mixer The calibration signal may be output based on the output signal of.

The calibration signal may be a signal for calibrating a phase and a magnitude of the received signal.

The direct digital synthesizer may use a single channel or multiple channels to provide at least one output signal to the quadrature mixer.

The quadrature mixer may remove a sideband signal from the received signal.

According to embodiments of the present invention, by calibrating the amplitude and phase loss of a signal in the RF millimeter wave band that may be caused by active elements and temperature changes, etc., by controlling the amplitude and phase of the signal, beam tilting is performed. Accuracy can be improved and a high-performance beamforming system can be implemented.

According to embodiments of the present invention, in a multi-probe system used in a multi-probe anechoic chamber for measuring 5G mobile communication antenna characteristics, the influence of noise and the signal size between multiple systems inevitable such as active elements And by calibrating the phase difference, it is possible to accurately measure the antenna characteristics.

According to the embodiments of the present invention, it can be applied to all multi-antenna systems including radar and satellite systems using high frequency bands as well as 5G ultra-high frequency bands, and precisely control the magnitude and phase of RF signals in each system. I can. If a mixer is used in the system, the signal control technology in the low frequency band can be implemented as a signal in the ultra high frequency band, and a high resolution can be maintained as it is, so a high-performance ultra high frequency signal control technology system can be constructed. have.

According to embodiments of the present invention, as a multi-antenna system for controlling multi-channel signal characteristics in 5G ultra-high frequency band, it is possible to precisely control the signal in the ultra high frequency band by using a high-performance low-frequency signal, and using this multi-antenna system. It is possible to develop a beamforming system that can control the signal amplification and signal transmission direction of the system, and in a multi-probe anechoic chamber system for measuring antennas with beamforming technology in the ultra-high frequency band.

Signal calibration between multiple probe antenna systems is possible.

1 shows a structure of a multi-antenna system according to a conventional embodiment.
2 shows a structure of a multi-antenna system according to another embodiment of the related art.
3 shows an exemplary diagram for explaining a structural analysis process for controlling the magnitude and phase of a signal using a mixer in the present invention.
4 is a schematic diagram of a direct digital synthesis capable of controlling the frequency, magnitude, and phase of an RF signal.
5 shows an exemplary diagram of a system structure for controlling the magnitude and phase of a signal using a quadrature mixer in the present invention.
6 shows a configuration of a multi-antenna system according to an embodiment of the present invention.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, only the present embodiments make the disclosure of the present invention complete, and common knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to those who have, and the invention is only defined by the scope of the claims.

The terms used in the present specification are for describing exemplary embodiments, and are not intended to limit the present invention. In this specification, the singular form also includes the plural form unless specifically stated in the phrase. As used herein, "comprises" and/or "comprising" refers to the recited component, step, operation, and/or element. It does not exclude presence or addition.

Unless otherwise defined, all terms (including technical and scientific terms) used in the present specification may be used with meanings that can be commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in advance that are generally used are not interpreted ideally or excessively unless explicitly defined specifically.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings. The same reference numerals are used for the same elements in the drawings, and duplicate descriptions for the same elements are omitted.

Embodiments of the present invention calibrate the magnitude and phase loss of a signal in the RF millimeter wave band that may be caused by active elements and temperature changes, etc., through the magnitude and phase control of the signal, thereby improving the accuracy of beam tilting. The purpose is to improve and implement a high-performance beamforming system.

Here, the present invention can compensate for the magnitude loss and phase loss of the RF millimeter wave band signal by using a direct digital synthesizer, a quadrature mixer, a plurality of mixers, and a 90 degree hybrid coupler.

1 shows a structure of a multi-antenna system according to a conventional embodiment, and a multi-antenna system structure capable of adjusting the size and phase of a signal using a digital controlled attenuator and a phase shifter. It shows an exemplary diagram.

Referring to FIG. 1, a multi-antenna system 100 enables wireless communication through a multi-antenna 105, and a mixer for increasing an intermediate frequency to an RF frequency in order to communicate in accordance with a mobile communication frequency band. It requires a (mixer) 104 and a mixer 103 for lowering the RF frequency to an intermediate frequency.

As shown in FIG. 1, in a multi-antenna system, a power divider/combiner or RF switch 102 may be included to transmit/receive the same frequency.

Here, by connecting the low noise amplifier (LNA) 106 after the antenna in the receiver system and the power amplifier 107 before the antenna 105 in the transmitter system, RF signals can be easily transmitted/received. .

In such a multi-antenna system, a difference in magnitude and phase of a signal may occur between systems due to the effect of noise and characteristics of active elements, and the magnitude and phase difference of such a signal is determined by a digital controlled attenuator 108 and a phase shifter. It can be calibrated using a phase shifter (109). That is, the digital controlled attenuator 108 may control the magnitude of the signal, and the phase shifter 109 may control the phase of the signal.

A multi-antenna system in the millimeter wave band using a digital controlled attenuator 108 and a phase shifter 109 is expensive to implement, and each has a low resolution due to the limitations of the current technology. Have.

Here, the digital controlled attenuator 108 and the phase shifter 109 can be used together with a direct digital synthesis or independently to determine the size of the signal and the resolution of the phase. have.

In addition, the digital controlled attenuator 108 may be replaced with an element or circuit capable of adjusting the size of an RF signal, such as a variable gain amplifier, for controlling the size of a signal.

FIG. 2 shows a structure of a multi-antenna system according to another exemplary embodiment of the related art, and shows an exemplary view of a structure of a multi-antenna system capable of controlling the magnitude and phase of a mobile communication system signal using a signal from a local oscillator. .

As shown in FIG. 2, the multi-antenna system 200 includes a power divider/combiner 202, an antenna 203, a low noise amplifier (LNA) 204, a power amplifier 205, and a mixer ( mixer) 206.

In addition, in the multi-antenna system, a mixer 206 may be used to control the signal of the entire system through the magnitude and phase of the signal of the local oscillator 207. For example, in the case of a transmitter system, it is possible to control an RF signal transmitted to the antenna 203 by controlling a local oscillator signal, and in the case of a receiver system, the RF signal received by the antenna 203 is a mixer. ) By passing through 206, it is possible to control the characteristics of the generated IF (intermediate frequency) signal.

FIG. 3 shows an exemplary diagram for explaining a structural analysis process for controlling the magnitude and phase of a signal using a mixer in the present invention. FIG. 3A is an up-conversion in order to increase the frequency of the mixer 302 ( It is a structure used for up-conversion, and FIG. 3B shows a structure used for down-conversion in order to reduce the frequency of the mixer 301.

As shown in FIG. 3, the magnitude and phase of the local oscillator signal is transmitted to the signal passing through the mixers 301 and 302 as it is, so the characteristics of the local oscillator signal in the low frequency band It is possible to implement a system capable of controlling the signal amplitude and phase of the entire high-frequency band by controlling

Such a system can have a higher resolution than that of FIG. 1 because characteristics are transmitted to the RF ultra-high frequency signal even if the signal is controlled in the low frequency band, but in 5G mobile communication, the local oscillator frequency is also in the RF high frequency band. Direct digital synthesis (DDS) for realizing the frequency has not yet been implemented, or if the frequency is increased using a frequency multiplier, the phase resolution of the signal may decrease.

4 is a schematic diagram of a direct digital synthesis capable of controlling the frequency, magnitude, and phase of an RF signal, FIG. 4a is a schematic diagram of a single direct digital synthesis, and FIG. 4b It shows a schematic diagram of a channel direct digital synthesis.

As shown in Fig. 4A, the direct digital synthesis includes an accumulator 402, an adder 403, a phase-to-amplitude converter 404, and a digital/analog converter 405. For example, a signal can be generated by an integer multiple of the frequency of the reference clock 401 divided by 2N.

Here, since the direct digital synthesis has a phase register, the phase of the signal can be controlled by the corresponding bit.

This system can be used to control the characteristics of a local oscillator signal as shown in FIG. 2, but as shown in FIG. 3 due to the characteristics of a mixer, the upper-band and the lower-band are output together. The quality of the signal may be degraded.

As shown in Fig. 4b, when a multi-channel direct digital synthesis is used, a synchronized signal can be output because the frequency, magnitude, and phase of the signals are all the same in the multi-channel, and the signals of each channel are independent. Can be controlled.

Using such a multi-channel direct digital synthesis, it is possible to implement a multi-antenna system inexpensively and improve the quality of the signal.

5 shows an exemplary diagram of a system structure for controlling the magnitude and phase of a signal using a quadrature mixer in the present invention.

As shown in FIG. 5, the present invention uses two mixers 501 and 502 to output a high-quality local oscillator signal by removing a sideband signal output due to the characteristics of a mixer. I can.

In this case, according to the present invention, the phase of the reference signal may be shifted by 90° using the 90 degree hybrid coupler 503 before the reference signal is input to the mixers 501 and 502.

As shown in Fig. 5, the signal passing through the mixer is upper- Band or lower-band signals can be removed. For example, the sideband signal is difficult to remove even when a filter having a very narrow band is used, and a lot of cost may be consumed in manufacturing the filter.

Such a system can lower the power of the sideband signal by using a band pass filter with a quadrature mixer to improve the signal quality.

Intermediate frequency signals input to two mixers 501 and 502 in FIG. 5, for example, IF1(Q) and IF1(I) in FIG. 6 are output signals of a direct digital synthesizer (DDS), and s _n may be a phase-controlled signal.

6 shows a configuration of a multi-antenna system according to an embodiment of the present invention, and shows an exemplary diagram of a structure of a multi-antenna system capable of precise signal amplitude and phase control.

6, the multi-antenna system 600 of the present invention uses a mixer (608, 609, 610), as shown in FIGS. 2 and 3, the characteristics of a single mixer (mixer) As a result, sidebands are formed to prevent the quality of a local oscillator signal from deteriorating.

That is, in the present invention, by utilizing the millimeter wave (26.5 ~ 29.5 GHz) system of 5G mobile communication as a low frequency system, it is possible to control the precise size and phase of the signal.

Here, the mixer 606 may be included to commonly up-conversion or down-conversion a multi-antenna system signal. For example, the mixer 608, 609, 610 can precisely control the RF signal with a relatively low frequency system, and in the case of a transmission system using the mixer 606, the 5G mobile communication frequency band In the case of the reception system, the 5G mobile communication frequency can be output as a low frequency signal capable of controlling the size and phase.

Such a multi-antenna system can have a high resolution because it controls signals as a system of a low frequency band, and is cheaper than a system of a high frequency band, and a high performance system can be configured.

Reference numeral 601 in FIG. 6 may be a signal calibration apparatus for calibrating the phase or magnitude of a received signal received through multiple antennas.

In this way, the signal calibration apparatus or multi-antenna system according to an embodiment of the present invention can remove a sideband signal generated by passing through a mixer using at least two mixers. And it is possible to improve the quality of the signal controlling the phase. Such a system may include a plurality of 90 degree hybrid couplers, and a plurality of mixers may be configured according to an ultra-high frequency signal band. To implement a multi-antenna system, it may include a multi-channel direct digital synthesis capable of a multi-channel synchronization structure. This multi-channel direct digital synthesizer can independently control the signal frequency, magnitude and phase of each channel.

The present invention can control an arbitrary phase in the range of 0 to 360 degrees, not a predetermined phase, and does not use a phase shifter having a low resolution, and direct digital synthesis. It is possible to implement a system having a high phase resolution by utilizing. In addition, it is possible to implement synchronization of multiple channels by using a direct digital synthesis of multiple channels, and it is possible to control a signal level by a dynamic range characteristic of a mixer.

Further, according to the present invention, a plurality of mixers and a 90 degree hybrid coupler can be used to increase the signal in the millimeter wave band while maintaining high resolution.

Accordingly, the present invention can calibrate the characteristics of a signal shaken due to the effect of noise and active elements in a beamforming system with high performance.

Further, in the present invention, a local oscillator or an intermediate frequency oscillator is for up-conversion frequency conversion for converting a low-frequency signal capable of precise signal control into a high-frequency signal, or a down-conversion for converting a high-frequency signal into a low-frequency signal. conversion For frequency conversion, the transmission/reception frequency of the entire antenna system can be determined.

The mixer in the present invention multiplies the frequency by multiplying a direct digital synthesis signal or a digital controlled attenuator signal and a signal of a local oscillator or intermediate frequency oscillator. It can be converted, and unnecessary sideband RF signals can be removed using a quadrature mixer.

In addition, in the present invention, all of the IF channels entering the intermediate frequency signal can be synchronized using a plurality of multi-channel direct digital synthesis, and the frequency, magnitude, and phase characteristics of the signal can be controlled. I can.

The apparatus described above may be implemented as a hardware component, a software component, and/or a combination of a hardware component and a software component. For example, the devices and components described in the embodiments include, for example, a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable array (FPA), It may be implemented using one or more general purpose or special purpose computers, such as a programmable logic unit (PLU), a microprocessor, or any other device capable of executing and responding to instructions. The processing device may execute an operating system (OS) and one or more software applications executed on the operating system. Further, the processing device may access, store, manipulate, process, and generate data in response to the execution of software. For the convenience of understanding, although it is sometimes described that one processing device is used, one of ordinary skill in the art, the processing device is a plurality of processing elements and/or a plurality of types of processing elements. It can be seen that it may include. For example, the processing device may include a plurality of processors or one processor and one controller. In addition, other processing configurations are possible, such as a parallel processor.

The software may include a computer program, code, instructions, or a combination of one or more of these, configuring the processing unit to behave as desired or processed independently or collectively. You can command the device. Software and/or data may be interpreted by a processing device or, to provide instructions or data to a processing device, of any type of machine, component, physical device, virtual equipment, computer storage medium or device. Can be embodyed. The software may be distributed over networked computer systems and stored or executed in a distributed manner. Software and data may be stored on one or more computer-readable recording media.

The method according to the embodiment may be implemented in the form of program instructions that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like alone or in combination. The program instructions recorded on the medium may be specially designed and configured for the embodiment, or may be known and usable to those skilled in computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic media such as floptical disks. -A hardware device specially configured to store and execute program instructions such as magneto-optical media, and ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine language codes such as those produced by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like.

As described above, although the embodiments have been described by the limited embodiments and drawings, various modifications and variations are possible from the above description to those of ordinary skill in the art. For example, the described techniques are performed in a different order from the described method, and/or components such as systems, structures, devices, circuits, etc. described are combined or combined in a form different from the described method, or other components Alternatively, even if substituted or substituted by an equivalent, an appropriate result can be achieved.

Therefore, other implementations, other embodiments, and those equivalent to the claims also fall within the scope of the claims to be described later.

Claims (10)

A multi-channel synchronization structure is possible, and a multi-channel direct digital synthesis for calibrating a received signal received through an antenna;
A quadrature mixer for outputting a calibration signal based on a reference signal and an output signal of the multi-channel direct digital synthesizer; And
Mixer for calibrating the received signal by mixing the received signal and the calibration signal
Including,
The calibration signal is
It is a signal for calibrating the phase and magnitude of the received signal,
The quadrature mixer
A hybrid coupler for outputting a phase shift signal of 90 degrees by receiving the reference signal as an input;
A first mixer for mixing a first output signal of the hybrid coupler and a Q (quadrature) channel intermediate frequency signal generated by the multi-channel direct digital synthesizer; And
A second mixer for mixing the second output signal of the hybrid coupler and an I (In-phase) channel intermediate frequency signal generated by the multi-channel direct digital synthesizer
Including,
Outputting the calibration signal based on the output signal of the first mixer and the output signal of the second mixer,
The multi-channel direct digital synthesizer
A signal calibration device for synchronizing the Q-channel intermediate frequency signal and the I-channel intermediate frequency signal, and independently controlling signal frequencies, magnitudes, and phases of the Q and I channels.
delete delete delete The method of claim 1,
The quadrature mixer
And removing a sideband signal of the received signal.
Multiple antennas; And
Signal calibration device for calibrating a received signal received through each of the multiple antennas
Including,
The signal calibration device
A multi-channel synchronization structure is possible, and a multi-channel direct digital synthesizer for calibrating the received signal;
A quadrature mixer for outputting a calibration signal based on a reference signal and an output signal of the multi-channel direct digital synthesizer; And
Mixer for calibrating the received signal by mixing the received signal and the calibration signal
Including,
The calibration signal is
It is a signal for calibrating the phase and magnitude of the received signal,
The quadrature mixer
A hybrid coupler for outputting a phase shift signal of 90 degrees by receiving the reference signal as an input;
A first mixer for mixing a first output signal of the hybrid coupler and a Q (quadrature) channel intermediate frequency signal generated by the multi-channel direct digital synthesizer; And
A second mixer for mixing the second output signal of the hybrid coupler and an I (In-phase) channel intermediate frequency signal generated by the multi-channel direct digital synthesizer
Including,
Outputting the calibration signal based on the output signal of the first mixer and the output signal of the second mixer,
The multi-channel direct digital synthesizer
A multi-antenna system for synchronizing the Q-channel intermediate frequency signal and the I-channel intermediate frequency signal, and independently controlling signal frequencies, magnitudes, and phases of the Q-channel and the I-channel.
delete delete delete The method of claim 6,
The quadrature mixer
A multi-antenna system, comprising removing a sideband signal from the received signal.

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