CN115236638A - Method for realizing frequency control array transmitting front end - Google Patents

Method for realizing frequency control array transmitting front end Download PDF

Info

Publication number
CN115236638A
CN115236638A CN202210800368.0A CN202210800368A CN115236638A CN 115236638 A CN115236638 A CN 115236638A CN 202210800368 A CN202210800368 A CN 202210800368A CN 115236638 A CN115236638 A CN 115236638A
Authority
CN
China
Prior art keywords
signal
local oscillator
frequency signal
intermediate frequency
frequency
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202210800368.0A
Other languages
Chinese (zh)
Inventor
刘宇
朱睿
刘泉华
向寅
董锡超
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Beijing Institute of Technology BIT
Chongqing Innovation Center of Beijing University of Technology
Original Assignee
Beijing Institute of Technology BIT
Chongqing Innovation Center of Beijing University of Technology
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Beijing Institute of Technology BIT, Chongqing Innovation Center of Beijing University of Technology filed Critical Beijing Institute of Technology BIT
Priority to CN202210800368.0A priority Critical patent/CN115236638A/en
Publication of CN115236638A publication Critical patent/CN115236638A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/491—Details of non-pulse systems
    • G01S7/4912—Receivers
    • G01S7/4918—Controlling received signal intensity, gain or exposure of sensor
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/005—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission adapting radio receivers, transmitters andtransceivers for operation on two or more bands, i.e. frequency ranges
    • H04B1/0067—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission adapting radio receivers, transmitters andtransceivers for operation on two or more bands, i.e. frequency ranges with one or more circuit blocks in common for different bands
    • H04B1/0082—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission adapting radio receivers, transmitters andtransceivers for operation on two or more bands, i.e. frequency ranges with one or more circuit blocks in common for different bands with a common local oscillator for more than one band
    • H04B1/0085—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission adapting radio receivers, transmitters andtransceivers for operation on two or more bands, i.e. frequency ranges with one or more circuit blocks in common for different bands with a common local oscillator for more than one band where one band is the image frequency band of the other and the band selection is done by image rejection
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/02—Transmitters
    • H04B1/04—Circuits
    • H04B1/0475—Circuits with means for limiting noise, interference or distortion
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/02—Transmitters
    • H04B1/04—Circuits
    • H04B2001/0491—Circuits with frequency synthesizers, frequency converters or modulators
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
    • Y02D30/00—Reducing energy consumption in communication networks
    • Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks

Abstract

The invention provides a method for realizing a frequency control array transmitting front end, which comprises the following steps: performing frequency modulation on the initial local oscillator signal and/or the initial intermediate frequency signal to obtain a local oscillator signal and an intermediate frequency signal; gradually transmitting local oscillator signals to a local oscillator end of a mirror image rejection mixer from left to right through a first power divider or a coupler, wherein a first delay line is added between every two stages of the local oscillator signals; the intermediate frequency signal is transmitted from right to left to the intermediate frequency end of the image rejection mixer step by step through a second power divider or a coupler, and a second delay line is added between every two stages of the intermediate frequency signal; and performing up-conversion on the local oscillator signal and the intermediate frequency signal through the image rejection mixer to obtain a radio frequency signal, and transmitting the radio frequency signal through a transmitting antenna. The invention realizes the configuration of the phased array and the frequency control array of the radar transmitting front end, does not need to use expensive equipment and complex technology, reduces the cost and simplifies the structure of the radar transmitting front end.

Description

Method for realizing frequency control array transmitting front end
Technical Field
The invention relates to the technical field of communication, in particular to a method for realizing a frequency control array transmitting front end.
Background
The frequency control array radar is a new system array radar formed by applying different frequency offsets to carrier frequencies of array elements in sequence on the basis of a conventional phased array, and the frequency control array radar only has azimuth angle dependence different from a transmitting beam of the conventional phased array radar, and the frequency offset of the frequency control array radar enables the transmitting beam to have joint dependence of distance and azimuth angle, as shown in figure 1. Therefore, the frequency control array not only has the functional characteristics of a phased array, but also has wide application potential in the fields of distance-related beam forming, target detection, interference suppression, electronic countermeasure, safety communication and the like.
The existing analog phased array and frequency control array radar needs each channel numerical control phase shifter or vector modulator to adjust the phase of each antenna unit; however, the addition of digitally controlled phase shifters and vector modulators greatly increases the complexity of the system, is expensive, occupies a large space, and does not utilize the low cost and miniaturization of TR (Transmitter and Receiver) components. Secondly, the Digital phased array mainly adopts a Digital Beam Forming (DBF) technology to realize the phase control of each unit, but the Digital processing technology makes the cost of the method high.
However, there are two main methods for implementing a frequency control array in the prior art, one is a frequency control array implementation method based on a step frequency of a mixer, and the frequency control array implementation method implements frequency configuration of the frequency control array by generating a preset frequency signal and mixing the frequency signal with a step frequency signal with a saving frequency Δ f, as shown in fig. 2. The method has the disadvantages that the intermediate frequency signals of n branches need to be generated by a complex frequency generator, and the image frequency of the mixer and the intermodulation influence of the radio frequency and the local oscillator frequency can cause the poor spectrum purity of the array signal, which easily causes the problem of target blurring in the subsequent signal processing. The other is a method for realizing the independent local oscillation source, namely, an independent signal source is arranged for each array element, a direct digital frequency synthesizer or a programmable phase-locked loop can be adopted to generate the required waveform of each array element, but the influence problems of clock jitter and phase noise need to be considered.
Therefore, a radar transmitting front-end scheme which can realize phased array and frequency control array configuration and has low cost is needed.
Disclosure of Invention
In view of the foregoing, it is necessary to provide a method for implementing a frequency control array transmit front end.
A method for realizing a frequency control array transmitting front end comprises the following steps: performing frequency modulation on the initial local oscillator signal and/or the initial intermediate frequency signal to obtain a local oscillator signal and an intermediate frequency signal; the method comprises the steps that local oscillation signals are transmitted to a local oscillation end of a mirror image rejection mixer step by step from left to right through a first power divider or a coupler, and a first delay line is added between every two stages of the local oscillation signals; the intermediate frequency signal is transmitted from right to left to the intermediate frequency end of the image rejection mixer step by step through a second power divider or a coupler, and a second delay line is added between every two stages of the intermediate frequency signal; and performing up-conversion on the local oscillator signal and the intermediate frequency signal through the image rejection mixer to obtain a radio frequency signal, and transmitting the radio frequency signal through a transmitting antenna.
Further, when performing frequency modulation on both the initial local oscillator signal and the initial intermediate frequency signal, let a fixed frequency difference value of a phase difference between two adjacent antennas be (m + k) × t, and at a signal input, represent the local oscillator signal as:
Figure BDA0003737329130000021
the intermediate frequency signal is represented as:
Figure BDA0003737329130000022
wherein, ω is LO0 And ω IF0 For the initial frequency, t, of the local oscillator and intermediate frequency signals LO0 And t IF0 For each frequency modulation cycleM and k are frequency modulation coefficients of the local oscillator signal and the intermediate frequency signal, respectively.
Further, at the nth node, the local oscillation signal is represented as:
Figure BDA0003737329130000023
the intermediate frequency signal is represented as:
Figure BDA0003737329130000024
wherein, delta T LO And Δ T IF Delay between the intermediate frequency signal transmission line and the local oscillator signal transmission line of two adjacent mixers; at the nth node, if the local oscillation signal and the intermediate frequency signal are changed in a ratio according to modulation coefficients m and k, the following steps are performed:
Figure BDA0003737329130000025
Figure BDA0003737329130000026
in the formula, phi LO,n And phi IF,n The phases of the local oscillator signal and the intermediate frequency signal in the time domain, i.e., the exponential portions in equations (3) and (4), respectively, are represented.
Further, when the local oscillator signal and the intermediate frequency signal are up-converted by the image rejection mixer to obtain the radio frequency signal, it is assumed that a high local oscillator, i.e., the local oscillator signal frequency f, is selected LO Above the intermediate frequency signal frequency f IF Then the rf frequency is:
f RF ＝f LO -f IF
then at the nth node, the time domain phase of the output rf signal is:
Figure BDA0003737329130000031
ω RF ＝ω LO0 -ω IF0 -m·t LO0 +k·(t IF0 +NΔT IF ) (8)
Figure BDA0003737329130000032
Figure BDA0003737329130000033
Figure BDA0003737329130000034
when the frequency modulation coefficients of the local oscillator signal and the intermediate frequency signal are equal, that is, m = k, there are:
ω RF ＝ω LO0 -ω IF0 -m(t LO0 -t IF0 )-mNΔT IF (12)
Figure BDA0003737329130000035
Figure BDA0003737329130000036
Figure BDA0003737329130000037
delay time t LO0 ,t IF0 ,ΔT LO ,ΔT IF Neglect, there are:
Φ≈-ω LO0 t LO0 +ω IF0 t IF0 -Nω IF0 ΔT IF (16)
Figure BDA0003737329130000038
in the formula, omega RF Is the radio frequency carrier frequency.
Further, in the actual signal transmission, the signal is transmitted in l LO And l IF Respectively representing the length of a first delay line and the length of a second delay line, approximately equating the length of the first delay line and the length of the second delay line to an ideal non-dispersive transmission line in the whole working frequency band, and introducing v P Representing the phase velocity of the intermediate frequency signal and the local oscillator signal on the output line, there are:
Figure BDA0003737329130000041
Figure BDA0003737329130000042
at this time, equation (13) is expressed as:
Figure BDA0003737329130000043
wherein, the first and the second end of the pipe are connected with each other,
Figure BDA0003737329130000044
for the phase increment step, equation (20) represents
Figure BDA0003737329130000045
If the antenna array shows an increase in phase shift and can control the beam direction, the total phase of the frequency control array can be expressed as:
Figure BDA0003737329130000046
Figure BDA0003737329130000047
wherein, the first and the second end of the pipe are connected with each other,
Figure BDA0003737329130000048
is the integrated frequency modulation coefficient.
Further, let t be designed by the feeding circuit LO0 And T IF0 And if equal, equation (12) is expressed as:
ω RF ≈ω LO0 -ω IF0 -mNΔT IF (23)
further, when only the initial intermediate frequency signal is frequency-modulated, equations (12) to (15) are:
ω RF ＝ω LO0 -ω IF0 -m(-t IF0 )-mNΔT IF (24)
Figure BDA0003737329130000049
Figure BDA00037373291300000410
Figure BDA00037373291300000411
and (5) replacing the formulas (12) to (15) with the formulas (24) to (27) to obtain the time domain phase of the corresponding output radio frequency signal.
Further, when only the initial local oscillation signal is frequency-modulated, equations (8) to (11) are simplified as follows:
ω RF ＝ω LO0 -ω IF0 -m(t LO0 )-mNΔT IF (28)
Figure BDA0003737329130000051
Figure BDA0003737329130000052
Figure BDA0003737329130000053
and (4) replacing the formulas (8) to (11) with the formulas (28) to (31) to obtain the time domain phase of the corresponding output radio frequency signal.
Further, the first power divider and the second power divider are equal power dividers or unequal power dividers.
Further, when the first power divider and the second power divider are equal power dividers, the local oscillation signal sequentially passes through an amplifier, a local oscillation signal filter and a first attenuator from left to right and then enters the image rejection mixer, the amplifier is used for amplifying the power of the local oscillation signal, the local oscillation signal filter is used for ensuring the spectral purity of the local oscillation signal before frequency mixing, and the first attenuator is used for finely adjusting a local oscillation branch; the intermediate frequency signal enters the image rejection mixer after passing through a second attenuator, and the second attenuator is used for finely adjusting an intermediate frequency branch; and the radio frequency signal enters a radio frequency signal filter for filtering after passing through a radio frequency signal amplifier to obtain a pure radio frequency signal, and the pure radio frequency signal is transmitted through an antenna.
Compared with the prior art, the invention has the advantages and beneficial effects that: the method comprises the steps that frequency modulation is carried out on an initial local oscillator signal and/or an initial intermediate frequency signal to obtain a local oscillator signal and an intermediate frequency signal, the frequency control array function is achieved, a double-wave frequency mixing mode is adopted, the local oscillator signal is transmitted to a local oscillator end of an image rejection frequency mixer from left to right step by step through a first power divider or a coupler, and a first delay line is added between every two stages of the local oscillator signal; meanwhile, the intermediate frequency signal is transmitted to the image rejection mixer from right to left step by step through a second power divider or a coupler, and a second delay line is added between every two stages of the intermediate frequency signal; after the local oscillator signal and the intermediate frequency signal are subjected to up-conversion through the image rejection mixer, a dual-wave mixing phased array structure is formed, a radio frequency signal is obtained, signal transmission is carried out through the transmitting antenna, the configuration of the phased array and the frequency control array of the radar transmitting front end is realized, expensive equipment and complex technology are not needed, the cost is reduced, and meanwhile the structure of the radar transmitting front end is simplified.
Drawings
FIG. 1 shows the frequency control array structure principle and frequency distribution;
FIG. 2 illustrates a prior art implementation of a frequency control array;
FIG. 3 is a schematic flow chart of a method for implementing a frequency controlled array transmit front end according to the present invention;
FIG. 4 is a schematic diagram of a method for implementing a frequency controlled array transmit front end according to the present invention;
FIG. 5 is a circuit diagram of a frequency control array for modulating both local and intermediate frequency signals according to the present invention;
FIG. 6 is a circuit diagram of a frequency control array for modulating only an intermediate frequency signal according to the present invention;
fig. 7 is a circuit diagram of a frequency control array when only local oscillation signals are modulated according to the present invention;
FIG. 8 is a circuit diagram of the present invention using an unequal power divider to implement a frequency control array;
fig. 9 is a circuit diagram of an unequal power divider for a frequency controlled array according to the present invention.
Detailed Description
In order that the invention may be more clearly understood, the following detailed description of the invention is given with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
As shown in fig. 3 and 4, a method for implementing a frequency controlled array transmit front end is provided, which includes the following steps:
step S101, performing frequency modulation on the initial local oscillation signal and/or the initial intermediate frequency signal to obtain a local oscillation signal and an intermediate frequency signal.
And S102, gradually transmitting the local oscillation signals to a local oscillation end of the image rejection mixer from left to right through a first power divider or a coupler, wherein a first delay line is added between each two stages of the local oscillation signals.
And step S103, the intermediate frequency signal is transmitted from right to left to the intermediate frequency end of the image rejection mixer step by step through a second power divider or a coupler, and a second delay line is added between every two stages of the intermediate frequency signal.
And step S104, performing up-conversion on the local oscillation signal and the intermediate frequency signal through the image rejection mixer to obtain a radio frequency signal, and transmitting the radio frequency signal through the transmitting antenna.
In this embodiment, a dual-wave frequency mixing mode is adopted to perform frequency modulation on an initial local oscillator signal and/or an initial intermediate frequency signal to obtain the local oscillator signal and the intermediate frequency signal, so as to implement a frequency control array function, the local oscillator signal is gradually transmitted to a local oscillator end of an image rejection mixer from left to right through a first power divider or a coupler, and a first delay line is added between each two stages of the local oscillator signal; the intermediate frequency signal is transmitted to the image rejection mixer from right to left step by step through a second power divider or a coupler, and a second delay line is added between every two stages of the intermediate frequency signal; after the local oscillator signal and the intermediate frequency signal are subjected to up-conversion through the image rejection mixer, a dual-wave mixing phased array structure is formed, a radio frequency signal is obtained, signal transmission is carried out through the transmitting antenna, the configuration of the phased array and the frequency control array of the radar transmitting front end is realized, expensive equipment and complex technology are not needed, the cost is reduced, and meanwhile the structure of the radar transmitting front end is simplified.
As shown in fig. 5, when performing frequency modulation on both the initial local oscillator signal and the initial intermediate frequency signal, let a fixed frequency difference value of a phase difference between two adjacent antennas be (m + m) × t, and at a signal input, represent the local oscillator signal as:
Figure BDA0003737329130000071
the intermediate frequency signal is represented as:
Figure BDA0003737329130000072
wherein, ω is LO0 And ω IF0 Is the initial frequency, t, of the local oscillator signal and the intermediate frequency signal LO0 And t IF0 For the initial time of each frequency modulation cycle, m and k are the frequencies of the local oscillator signal and the intermediate frequency signal, respectivelyAnd (4) modulating the coefficient.
Generally, t LO0 And t IF0 May be different, but to avoid frequency hopping per frequency debug cycle, t will generally be LO0 And t IF0 And calibrating to be consistent.
At the nth node, the local oscillator signal is represented as:
Figure BDA0003737329130000073
the intermediate frequency signal is represented as:
Figure BDA0003737329130000074
wherein, delta T LO And Δ T IF For the delay between the transmission line of the intermediate frequency signal and the transmission line of the local oscillator signal of two adjacent mixers, at the nth node, the local oscillator signal and the intermediate frequency signal change in proportion according to the modulation factors m and k, and the phase in the time domain, i.e., the exponential part of equations (3) and (4), can be expressed as:
Figure BDA0003737329130000075
Figure BDA0003737329130000076
in the formula, phi LO,n And phi IF,n The phases of the local oscillator signal and the intermediate frequency signal in the time domain, i.e., the exponential portions in equations (3) and (4), respectively, are represented.
The local oscillator signal and the intermediate frequency signal are subjected to up-conversion by the image rejection mixer to obtain a radio frequency signal, and if a high local oscillator is selected, namely the local oscillator signal frequency f LO Higher than the intermediate frequency signal frequency f IF Then the rf frequency is:
f RF ＝f LO -f IF
then at the nth node, the time-domain phase of the radio frequency signal is:
Figure BDA0003737329130000081
ω RF ＝ω LO0 -ω IF0 -m·t LO0 +k·(t IF0 +NΔT IF ) (8)
Figure BDA0003737329130000082
Figure BDA0003737329130000083
Figure BDA0003737329130000084
in general, when the frequency modulation coefficients of the local oscillator signal and the intermediate frequency signal are equal, that is, m = k, there are:
ω RF ＝ω LO0 -ω IF0 -m(t LO0 -t IF0 )-mNΔT IF (12)
Figure BDA0003737329130000085
Figure BDA0003737329130000086
Figure BDA0003737329130000087
since the time delay is small, the time can be delayed by t LO0 ,t IF0 ,ΔT LO ,ΔT IF Ignoring, then:
Φ≈-ω LO0 t LO0 +ω IF0 t IF0 -Nω IF0 ΔT IF (16)
Figure BDA0003737329130000088
wherein, ω is RF Is the radio frequency carrier frequency.
In the actual signal transmission,/ IF And l LO The lengths of the delay lines respectively representing adjacent nodes of the intermediate frequency signal and the local oscillator signal, namely the length of the second delay line and the length of the first delay line, are limited, so that the length of the delay lines can be approximately equivalent to an ideal non-dispersive transmission line in the whole working frequency band, and v is introduced P Representing the phase velocity of the intermediate frequency signal and the local oscillator signal on the output line, there are:
Figure BDA0003737329130000091
Figure BDA0003737329130000092
at this time, equation (13) is expressed as:
Figure BDA0003737329130000093
as can be seen from equation (16), Φ can be considered as a constant general phase that does not affect beamforming, where,
Figure BDA0003737329130000094
for the phase increment step, equation (20) represents
Figure BDA0003737329130000095
If the phase offset is increased on the antenna array and the beam direction can be controlled, the total phase of the frequency controlled array can be expressed as:
Figure BDA0003737329130000096
Figure BDA0003737329130000097
wherein the content of the first and second substances,
Figure BDA0003737329130000098
for synthesizing the frequency modulation coefficients, as can be seen from equations (18) and (19), at l IF And l LO At fixed time,. DELTA.T IF And Δ T LO Is also fixed, then
Figure BDA0003737329130000099
The influence factor of (2) is the frequency modulation coefficient m of the intermediate frequency signal and the local oscillator signal.
Radio frequency carrier frequency omega RF Determined mainly by intermediate frequency signals and local oscillator signals, t LO0 And t OF0 The mapping is not large, therefore, t can be designed by the feed circuit LO0 And T IF0 And if equal, equation (12) is expressed as:
ω RF ≈ω LO0 -ω IF0 -mNΔT IF (23)
equation (19) shows that the frequency of the mixer outputs increases gradually along the line array, while equation (16) shows that their initial phase also changes in a constant step, thus forming a frequency controlled array. While the phase is incremented by the step size
Figure BDA00037373291300000912
Can be derived from an initial frequency ω LO0 And ω IF0 The control is independent of the frequency modulation index, so that the frequency control array can independently control the frequency increment step length and the phase offset along the array.
In addition, the invention can also realize the frequency control array through unilateral frequency modulation, and the formula (22) needs to be modified correspondingly, and the items which do not change along with time are omitted.
As shown in fig. 6, when only the initial intermediate frequency signal is frequency-modulated, equations (12) to (15) are simplified as follows:
ω RF ＝ω LO0 -ω IF0 -m(-t IF0 )-mNΔT IF (24)
Figure BDA00037373291300000910
Figure BDA00037373291300000911
Figure BDA0003737329130000101
and (5) replacing the formulas (12) to (15) with the formulas (24) to (27) to obtain the time domain phase of the corresponding output radio frequency signal.
As shown in fig. 7, when only the initial local oscillator signal is frequency-modulated, equations (8) to (11) are simplified as follows:
ω RF ＝ω LO0 -ω IF0 -m(t LO0 )-mNΔT IF (28)
Figure BDA0003737329130000102
Figure BDA0003737329130000103
Figure BDA0003737329130000104
and (4) replacing the formulas (8) to (11) with the formulas (28) to (31) to obtain the time domain phase of the corresponding output radio frequency signal.
As shown in fig. 8 and 9, the first power divider and the second power divider are equal power dividers or unequal power dividers.
Specifically, the power divider used in the present invention may adopt equal division or unequal division, so as to achieve equal signal power of the mixer.
Because the power difference of the delay lines with different lengths is considered in the unequal power division design, the signal power of the frequency mixer is consistent, and therefore, when the unequal power divider is adopted, a filter can be omitted. Fig. 9 shows a power divider based on the Gysel unequal power division principle, and the power divider has been designed to compensate different delay lines between ports, so that the power divider can achieve consistent power of each output port, and the delay of each output port is kept at a fixed value.
As shown in fig. 5 to 7, when the first power divider and the second power divider are equal power dividers, the local oscillation signal sequentially passes through an amplifier, a local oscillation signal filter and a first attenuator from left to right, and then enters the image rejection mixer, the amplifier is used for amplifying the power of the local oscillation signal, the local oscillation signal filter is used for ensuring the spectral purity of the local oscillation signal of the mixer, and the first attenuator is used for finely adjusting the local oscillation branch; the intermediate frequency signal enters an image rejection mixer after passing through a second attenuator, and the second attenuator is used for finely adjusting an intermediate frequency branch; the radio frequency signal enters a radio frequency signal filter for filtering after passing through a radio frequency signal amplifier to obtain a pure radio frequency signal, and the pure radio frequency signal is transmitted through an antenna.
Specifically, when the equal power divider is adopted, the phases of all branches need to be ensured to be consistent, and the attenuator is introduced to finely adjust the power of the branches, so that the power difference caused by delay lines with different lengths is offset.
In order to ensure that a passive mixer can be used, the invention adds an amplifier to amplify the power of the local oscillation signal, and simultaneously introduces a local oscillation signal filter to ensure the frequency spectrum purity of the local oscillation signal before frequency mixing. In addition, a local oscillator signal filter and a radio frequency signal filter are arranged at the same time, the influence of stray waves caused by the image frequency and the intermodulation frequency output by the frequency mixer on signal processing can be solved, the radio frequency signal filter is arranged behind the radio frequency signal amplifier, the amplified radio frequency signal can obtain a pure radio frequency signal after passing through the filter, the pure radio frequency signal is transmitted to the antenna, and therefore microwaves are radiated into the air from an antenna port to finish the transmission of the frequency control array signal.
The invention can select the mode of realizing the frequency control array according to the requirement, such as carrying out frequency modulation on both the local oscillator signal and the intermediate frequency signal, or carrying out frequency modulation on only the local oscillator signal, or carrying out frequency modulation on only the intermediate frequency signal.
Compared with a circuit for realizing a frequency control array by adopting a traditional phased array, the frequency control array transmitting circuit can be realized without adopting a numerical control phase modulator and simultaneously without the assistance of a DBF (digital base function) technology in a digital part. Therefore, the invention has the advantages of simple structure and low cost.
The present invention has been described in detail with reference to the specific embodiments, and it should not be construed that the embodiments of the present invention are limited to the description. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.

Claims (10)

1. A method for realizing a frequency control array transmitting front end is characterized by comprising the following steps:
performing frequency modulation on the initial local oscillator signal and/or the initial intermediate frequency signal to obtain a local oscillator signal and an intermediate frequency signal;
the method comprises the steps that local oscillation signals are transmitted to a local oscillation end of a mirror image rejection mixer step by step from left to right through a first power divider or a coupler, and a first delay line is added between every two stages of the local oscillation signals;
the intermediate frequency signal is transmitted from right to left to the intermediate frequency end of the image rejection mixer step by step through a second power divider or a coupler, and a second delay line is added between every two stages of the intermediate frequency signal;
and performing up-conversion on the local oscillator signal and the intermediate frequency signal through the image rejection mixer to obtain a radio frequency signal, and transmitting the radio frequency signal through a transmitting antenna.
2. The method according to claim 1, wherein when performing frequency modulation on both the initial local oscillator signal and the initial intermediate frequency signal, a fixed frequency difference between two adjacent antennas is set to be (m + k) × t, and at a signal input, the local oscillator signal is represented as:
Figure FDA0003737329120000011
the intermediate frequency signal is represented as:
Figure FDA0003737329120000012
wherein, ω is LO0 And ω IF0 Is the initial frequency, t, of the local oscillator signal and the intermediate frequency signal LO0 And t IF0 For the initial time of each frequency modulation cycle, m and k are the frequency modulation coefficients of the local oscillator signal and the intermediate frequency signal, respectively.
3. The method of claim 2, wherein at the nth node, the local oscillator signal is represented as:
Figure FDA0003737329120000013
the intermediate frequency signal is represented as:
Figure FDA0003737329120000014
wherein, Δ T LO And Δ T IF Delay between the intermediate frequency signal transmission line and the local oscillator signal transmission line of two adjacent mixers;
at the nth node, if the local oscillation signal and the intermediate frequency signal are changed in a ratio according to modulation coefficients m and k, the following steps are performed:
Figure FDA0003737329120000015
Figure FDA0003737329120000021
in the formula, phi LO,n And phi IF,n The phases of the local oscillator signal and the intermediate frequency signal in the time domain, i.e., the exponential portions in equations (3) and (4), respectively, are represented.
4. The method as claimed in claim 3, wherein the local oscillator signal frequency f is selected as a high local oscillator signal frequency when the image reject mixer up-converts the local oscillator signal and the intermediate frequency signal to obtain the radio frequency signal LO Above the intermediate frequency signal frequency f IF Then, the rf frequency is:
f RF ＝f LO -f IF
then at the nth node, the time domain phase of the output rf signal is:
Figure FDA0003737329120000022
ω RF ＝ω LO0 -ω IF0 -m·t LO0 +k·(t IF0 +NΔT IF ) (8)
Figure FDA0003737329120000027
Figure FDA0003737329120000023
Figure FDA0003737329120000024
when the frequency modulation coefficients of the local oscillator signal and the intermediate frequency signal are equal, that is, m = k, there are:
ω RF ＝ω LO0 -ω IF0 -m(t LO0 -t IF0 )-mNΔt IF (12)
Figure FDA0003737329120000028
Figure FDA0003737329120000025
Figure FDA0003737329120000026
delay time t LO0 ,t IF0 ,ΔT LO ,ΔT IF Neglect, there are:
Φ≈-ω LO0 t LO0 +ω IF0 t IF0 -Nω IF0 ΔT IF (16)
Figure FDA0003737329120000031
in the formula, ω RF Is the radio frequency carrier frequency.
5. The method as claimed in claim 4, wherein the actual signal transmission is performed by l LO And l IF Respectively representing the length of a first delay line and the length of a second delay line, approximately equating the length of the first delay line and the length of the second delay line to an ideal non-dispersive transmission line in the whole working frequency band, and introducing v P Representing the phase velocity of the intermediate frequency signal and the local oscillator signal on the output line, there are:
Figure FDA0003737329120000032
Figure FDA0003737329120000033
at this time, equation (13) is expressed as:
Figure FDA0003737329120000034
wherein the content of the first and second substances,
Figure FDA0003737329120000035
for the phase increment step, equation (20) represents
Figure FDA0003737329120000036
If the phase offset is increased on the antenna array and the beam direction can be controlled, the total phase of the frequency controlled array can be expressed as:
Figure FDA0003737329120000037
Figure FDA0003737329120000038
wherein, the first and the second end of the pipe are connected with each other,
Figure FDA0003737329120000039
is the integrated frequency modulation coefficient.
6. The method of claim 5, wherein t is the design of the feed circuit LO0 And t IF0 Equal, then the formula (12) tableShown as follows:
ω RF ≈ω LO0 -ω IF0 -mNΔT IF (23)
the radio frequency carrier frequency is determined by the intermediate frequency input and the local oscillator input according to the formula.
7. The method as claimed in claim 4, wherein when only the initial intermediate frequency signal is frequency modulated, the equations (12) to (15) are:
ω RF ＝ω LO0 -ω IF0 -m(-t IF0 )-mNΔT IF (24)
Figure FDA00037373291200000310
Figure FDA00037373291200000311
Figure FDA0003737329120000041
and (5) replacing the formulas (12) to (15) with the formulas (24) to (27) to obtain the time domain phase of the corresponding output radio frequency signal.
8. The method according to claim 4, wherein when only the initial local oscillator signal is frequency modulated, equations (8) to (11) are:
ω RF ＝ω LO0 -ω IF0 -m(t LO0 )-mNΔT IF (28)
Figure FDA0003737329120000042
Figure FDA0003737329120000043
Figure FDA0003737329120000044
and (4) replacing the formulas (8) to (11) with the formulas (28) to (31) to obtain the time domain phase of the corresponding output radio frequency signal.
9. The method of claim 1, wherein the first power divider and the second power divider are equal power dividers or unequal power dividers.
10. The method according to claim 9, wherein when the first power divider and the second power divider are equal power dividers, the local oscillator signal sequentially passes through an amplifier, a local oscillator signal filter, and a first attenuator from left to right, and then enters the image rejection mixer, the amplifier is configured to amplify a power of the local oscillator signal, the local oscillator signal filter is configured to ensure a spectral purity of the local oscillator signal before mixing, and the first attenuator is configured to perform fine adjustment on a local oscillator branch; the intermediate frequency signal enters the image rejection mixer after passing through a second attenuator, and the second attenuator is used for finely adjusting an intermediate frequency branch; and the radio frequency signal enters a radio frequency signal filter for filtering after passing through a radio frequency signal amplifier to obtain a pure radio frequency signal, and the pure radio frequency signal is transmitted through an antenna.
CN202210800368.0A 2022-07-08 2022-07-08 Method for realizing frequency control array transmitting front end Pending CN115236638A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210800368.0A CN115236638A (en) 2022-07-08 2022-07-08 Method for realizing frequency control array transmitting front end

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210800368.0A CN115236638A (en) 2022-07-08 2022-07-08 Method for realizing frequency control array transmitting front end

Publications (1)

Publication Number Publication Date
CN115236638A true CN115236638A (en) 2022-10-25

Family

ID=83670759

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210800368.0A Pending CN115236638A (en) 2022-07-08 2022-07-08 Method for realizing frequency control array transmitting front end

Country Status (1)

Country Link
CN (1) CN115236638A (en)

Similar Documents

Publication Publication Date Title
CN113630194B (en) X-band high-isolation radio frequency receiving and transmitting system and channel consistency calibration method thereof
EP2843839B1 (en) Circuit and method for suppressing a phase mismatch between the outputs of a plurality of phase synchronisation circuits in an electronic circuit
CA2048148C (en) Transmitter
US8914068B2 (en) Array antenna apparatus
US7859459B2 (en) Phased array receivers and methods employing phase shifting downconverters
KR100612206B1 (en) Radar system using quadrature signal
KR20080072649A (en) Phased array radar systems and subassemblies thereof
US20140232598A1 (en) Rf system with integrated phase shifters using dual multi-phase phase-locked loops
US11329378B2 (en) High-resolution phase shifter
JP4652188B2 (en) High frequency module device
CN111987995A (en) Comb signal source based on mixing modulation feedback loop
CN108169742A (en) Wideband adaptive frequency-tracking system and method
CN210111948U (en) Comb signal source based on mixing modulation feedback loop
KR102077620B1 (en) Low Phase Noise Ultra-wideband Frequency Synthesizer and Frequency Synthesizer method
CN115236638A (en) Method for realizing frequency control array transmitting front end
JP2013187697A (en) Frequency synthesizer, phased array transmitter and power amplification circuit
US5576713A (en) Compensation circuit for improving modulation characteristic, and modulator and radar equipment using the same
CN113366768B (en) Dual-polarization millimeter wave front end integrated circuit
US10411875B2 (en) Hybrid type transceiver for broadband large area beamforming
CN207780234U (en) Wideband adaptive frequency-tracking system
CN112305515A (en) Signal processing method, signal processing system and millimeter wave sensor chip
CN112564628B (en) Modulator with wide frequency band high local oscillation inhibition degree
JP2016219916A (en) Vector synthesis phase shifter and control method of vector synthesis phase shifter
KR100573013B1 (en) Radar system using balance topology
JP3941783B2 (en) Retro directive antenna device

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination