A method for implementing a frequency-controlled array transmitting front end

Abstract

The present invention provides a method for implementing a frequency-controlled array transmitting front end, comprising: frequency modulating an initial local oscillator signal and / or an initial intermediate frequency signal to obtain a local oscillator signal and an intermediate frequency signal; transmitting the local oscillator signal from left to right step by step to the local oscillator end of an image rejection mixer through a first power divider or coupler, wherein a first delay line is added between each two stages of the local oscillator signal; transmitting the intermediate frequency signal from right to left step by step to the intermediate frequency end of the image rejection mixer through a second power divider or coupler, wherein a second delay line is added between each two stages of the intermediate frequency signal; up-converting the local oscillator signal and the intermediate frequency signal through the image rejection mixer to obtain a radio frequency signal, and transmitting the signal through a transmitting antenna. The present invention implements a phased array and frequency-controlled array configuration of a radar transmitting front end without the use of expensive equipment and complex technology, thereby reducing costs while simplifying the structure of the radar transmitting front end.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a method for implementing a frequency-controlled array transmitting front end. Background Art

[0002] Frequency-steering array radar is a new type of array radar formed by applying different frequency offsets to the carrier frequency of each array element on the basis of conventional phased array. Unlike conventional phased array radar whose transmit beam is only dependent on azimuth, the frequency offset of frequency-steering array radar makes its transmit beam have joint dependence on distance and azimuth, such as Figure 1 Therefore, the frequency-controlled array not only has the functional characteristics of the phased array, but also has a wide range of application potentials in the fields of range-dependent beamforming, target detection, interference suppression, electronic countermeasures and secure communications.

[0003] Current analog phased array and frequency-controlled array radars require a digitally controlled phase shifter or vector modulator for each channel to adjust the phase of each antenna element. However, the inclusion of digitally controlled phase shifters and vector modulators significantly increases system complexity, is expensive, and occupies a large space, without leveraging the cost-effectiveness and miniaturization of TR (transmitter and receiver) components. Secondly, digital phased arrays primarily use DBF (Digital Beam Forming) technology to achieve phase control for each element, but the digital processing required makes this method costly.

[0004] There are two main methods for realizing frequency control array in the existing technology. One is the frequency control array realization method based on mixer step frequency, which generates a preset frequency signal and mixes the frequency signal with the step frequency signal with a saving frequency of Δf, thereby realizing the frequency configuration of the frequency control array. Figure 2 The disadvantage of this method is that it requires a complex frequency generator to generate n branch intermediate frequency signals, and the image frequency of the mixer and the intermodulation between the RF and the local oscillator frequency will result in poor spectral purity of the array signal, which can easily lead to target ambiguity in subsequent signal processing. The second implementation method is to use an independent local oscillator source, that is, to set an independent signal source for each array element. A direct digital frequency synthesizer or a programmable phase-locked loop can be used to generate the required waveform for each array element, but the influence of clock jitter and phase noise must be considered.

[0005] Therefore, there is an urgent need for a low-cost radar transmission front-end solution that can realize phased array and frequency-controlled array configuration. Summary of the Invention

[0006] Based on this, it is necessary to provide a method for implementing a frequency-controlled array transmitting front end to address the above technical issues.

[0007] A method for implementing a frequency-controlled array transmitting front end includes: frequency modulating an initial local oscillator signal and / or an initial intermediate frequency signal to obtain a local oscillator signal and an intermediate frequency signal; transmitting the local oscillator signal step by step from left to right to a local oscillator end of an image rejection mixer via a first power splitter or coupler, with a first delay line added between every two stages of the local oscillator signal; transmitting the intermediate frequency signal step by step from right to left to an intermediate frequency end of the image rejection mixer via a second power splitter or coupler, with a second delay line added between every two stages of the intermediate frequency signal; up-converting the local oscillator signal and the intermediate frequency signal via the image rejection mixer to obtain a radio frequency signal, and transmitting the signal via a transmitting antenna.

[0008] Furthermore, when both the initial local oscillator signal and the initial intermediate frequency signal are frequency modulated, the fixed frequency difference between two adjacent antennas is set to (m+k)*t. At the signal input, the local oscillator signal is expressed as:

[0009]

[0010] The intermediate frequency signal is expressed as:

[0011]

[0012] Among them, ω LO0 and ω IF0 is the initial frequency of the local oscillator signal and the intermediate frequency signal, t LO0 and t IF0 is 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.

[0013] Furthermore, at the nth node, the local oscillator signal is expressed as:

[0014]

[0015] The intermediate frequency signal is expressed as:

[0016]

[0017] Where ΔT LO and ΔT IF is the delay between the IF signal transmission line and the LO signal transmission line of two adjacent mixers; at the nth node, the LO signal and the IF signal change proportionally according to the modulation coefficients m and k, then:

[0018]

[0019]

[0020] Where, φ LO,n and φ IF,nThey represent the phases of the local oscillator signal and the intermediate frequency signal in the time domain, namely the exponential parts in formulas (3) and (4).

[0021] Furthermore, 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 is selected, that is, the local oscillator signal frequency f LO Higher than the intermediate frequency signal frequency f IF , then the RF frequency is:

[0022] f RF =f LO -f IF

[0023] Then at the nth node, the time domain phase of the output RF signal is:

[0024]

[0025] ω RF =ω LO0 -ω IF0 -m·t LO0 +k·(t IF0 +NΔT IF ) (8)

[0026]

[0027]

[0028]

[0029] When the frequency modulation coefficients of the local oscillator signal and the intermediate frequency signal are equal, that is, m = k, we have:

[0030] ω RF =ω LO0 -ω IF0 -m(t LO0 -t IF0 )-mNΔT IF (12)

[0031]

[0032]

[0033]

[0034] In the time delay {t LO0 ,t IF0 ,ΔT LO ,ΔT IF}When ignored, there are:

[0035] Φ≈-ωLO0 t LO0 +ω IF0 t IF0 -Nω IF0 ΔT IF (16)

[0036]

[0037] Where, ω RF is the RF carrier frequency.

[0038] Furthermore, in actual signal transmission, LO and l IF Represent the length of the first delay line and the length of the second delay line respectively. In the entire working frequency band, the length of the first delay line and the length of the second delay line are approximately equivalent to an ideal dispersion-free transmission line. P Represents the phase velocity of the intermediate frequency signal and the local oscillator signal on the output line, then:

[0039]

[0040]

[0041] At this time, formula (13) can be expressed as:

[0042]

[0043] in, is the phase increment step, formula (20) expresses On the antenna array, it is manifested as an increase in phase offset, and the beam direction can be controlled. The total phase of the frequency-controlled array can be expressed as:

[0044]

[0045]

[0046] in, is the comprehensive frequency modulation coefficient.

[0047] Furthermore, through the feed circuit design, let t LO0 and T IF0 If they are equal, then formula (12) can be expressed as:

[0048] ω RF ≈ω LO0 -ω IF0 -mNΔT IF (twenty three)

[0049] Furthermore, when only the initial intermediate frequency signal is frequency modulated, formulas (12) to (15) are:

[0050] ω RF =ω LO0 -ω IF0 -m(-t IF0 )-mNΔT IF (twenty four)

[0051]

[0052]

[0053]

[0054] Formulas (24) to (27) are used to replace formulas (12) to (15) to obtain the time domain phase of the corresponding output RF signal.

[0055] Furthermore, when only the initial local oscillator signal is frequency modulated, formulas (8) to (11) are simplified to:

[0056] ω RF =ω LO0 -ω IF0 -m(t LO0 )-mNΔT IF (28)

[0057]

[0058]

[0059]

[0060] Formulas (28) to (31) are used to replace formulas (8) to (11) to obtain the time domain phase of the corresponding output RF signal.

[0061] Furthermore, the first power splitter and the second power splitter are equal power splitters or unequal power splitters.

[0062] Furthermore, when the first power divider and the second power divider are equal power dividers, the local oscillator signal passes through the amplifier, the local oscillator signal filter and the first attenuator from left to right in sequence, and enters the image suppression mixer. The amplifier is used to amplify the local oscillator signal power, and the local oscillator signal filter is used to ensure the spectral purity of the local oscillator signal before mixing. The first attenuator is used to fine-tune the local oscillator branch; the intermediate frequency signal enters the image suppression mixer after passing through the second attenuator, and the second attenuator is used to fine-tune the intermediate frequency branch; the radio frequency signal passes through the radio frequency signal amplifier and enters the radio frequency signal filter for filtering to obtain a pure radio frequency signal, which is then transmitted through the antenna.

[0063] Compared with the prior art, the advantages and beneficial effects of the present invention are: by frequency modulating the initial local oscillator signal and / or the initial intermediate frequency signal, the local oscillator signal and the intermediate frequency signal are obtained, and the frequency-controlled array function is realized. The local oscillator signal is transmitted step by step from left to right to the local oscillator end of the image suppression mixer through a first power divider or a coupler, and a first delay line is added between every two stages of the local oscillator signal; at the same time, the intermediate frequency signal is transmitted step by step from right to left to the image suppression mixer 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 up-converting the local oscillator signal and the intermediate frequency signal through the image suppression mixer, a dual-wave mixing phased array structure is formed, the radio frequency signal is obtained, and the signal is transmitted through the transmitting antenna, thereby realizing the phased array and frequency-controlled array configuration of the radar transmitting front end, without the need to use expensive equipment and complex technology, reducing costs while simplifying the structure of the radar transmitting front end. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 The structural principle and frequency distribution of frequency-controlled array;

[0065] Figure 2 This is an existing frequency control array implementation method;

[0066] Figure 3 A flow chart of a method for implementing a frequency-controlled array transmitting front end according to the present invention;

[0067] Figure 4 This is a schematic diagram of a method for implementing a frequency-controlled array transmitting front end of the present invention;

[0068] Figure 5 This is a frequency control array circuit diagram when the present invention modulates both the local oscillator signal and the intermediate frequency signal;

[0069] Figure 6 This is a frequency control array circuit diagram when only the intermediate frequency signal is modulated in the present invention;

[0070] Figure 7 This is a frequency control array circuit diagram when only the local oscillator signal is modulated in the present invention;

[0071] Figure 8 This is a circuit diagram of the present invention using an unequal power divider to implement a frequency control array;

[0072] Figure 9 The present invention is a circuit diagram of an unequal power divider used in a frequency-controlled array. DETAILED DESCRIPTION

[0073] In order to make the present invention more clearly understood, the present invention will be further described in detail below through specific embodiments in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0074] like Figure 3 and Figure 4 As shown, a method for implementing a frequency-controlled array transmitting front end is provided, comprising the following steps:

[0075] Step S101 : frequency modulate an initial local oscillator signal and / or an initial intermediate frequency signal to obtain a local oscillator signal and an intermediate frequency signal.

[0076] In step S102, the local oscillator signal is transmitted from left to right to the local oscillator end of the image rejection mixer through a first power divider or coupler, with a first delay line added between every two stages of the local oscillator signal.

[0077] Step S103: The intermediate frequency signal is transmitted to the intermediate frequency end of the image rejection mixer from right to left step by step through the second power divider or coupler, with a second delay line added between every two stages of the intermediate frequency signal.

[0078] Step S104 , up-converting the local oscillator signal and the intermediate frequency signal through an image rejection mixer to obtain a radio frequency signal, and transmitting the signal through a transmitting antenna.

[0079] In this embodiment, dual-wave mixing is used to frequency modulate the initial local oscillator signal and / or the initial intermediate frequency signal to obtain a local oscillator signal and an intermediate frequency signal, thereby realizing a frequency-controlled array function. The local oscillator signal is transmitted step by step from left to right to the local oscillator end of the image rejection mixer through a first power divider or coupler, and a first delay line is added between every two stages of the local oscillator signal; the intermediate frequency signal is transmitted step by step from right to left to the image rejection mixer through a second power divider or 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 up-converted by the image rejection mixer, a dual-wave mixing phased array structure is formed to obtain a radio frequency signal, and the signal is transmitted through the transmitting antenna, thereby realizing the phased array and frequency-controlled array configuration of the radar transmitting front end without the use of expensive equipment and complex technology, reducing costs while simplifying the structure of the radar transmitting front end.

[0080] like Figure 5 As shown, when both the initial local oscillator signal and the initial intermediate frequency signal are frequency modulated, the fixed frequency difference between two adjacent antennas is set to be (m+m)*t. At the signal input, the local oscillator signal is expressed as:

[0081]

[0082] The intermediate frequency signal is expressed as:

[0083]

[0084] Among them, ω LO0 and ω IF0 is the initial frequency of the local oscillator signal and the intermediate frequency signal, tLO0 and t IF0 is 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.

[0085] Typically, t LO0 and t IF0 It can be different, but in order to avoid frequency jumps in each frequency debugging cycle, t LO0 and t IF0 Calibrate to consistency.

[0086] At the nth node, the local oscillator signal is expressed as:

[0087]

[0088] The intermediate frequency signal is expressed as:

[0089]

[0090] Where, ΔT LO and ΔT IF is the delay between the IF signal transmission line and the LO signal transmission line of two adjacent mixers. At the nth node, the LO signal and the IF signal change proportionally according to the modulation coefficients m and k. The phase in the time domain is the exponential part of formulas (3) and (4), which can be expressed as:

[0091]

[0092]

[0093] Where, φ LO,n and φ IF,n They represent the phases of the local oscillator signal and the intermediate frequency signal in the time domain, namely the exponential parts in formulas (3) and (4).

[0094] The local oscillator signal and the intermediate frequency signal are up-converted by the image rejection mixer to obtain the RF signal. Assuming that a high local oscillator is selected, that is, the local oscillator signal frequency f LO Higher than the intermediate frequency signal frequency f IF , then the RF frequency is:

[0095] f RF =f LO -f IF

[0096] Then at the nth node, the time domain phase of the RF signal is:

[0097]

[0098] ω RF =ω LO0 -ωIF0 -m·t LO0 +k·(t IF0 +NΔT IF ) (8)

[0099]

[0100]

[0101]

[0102] In general, the frequency modulation coefficients of the local oscillator signal and the intermediate frequency signal can be made equal, that is, when m=k, we have:

[0103] ω RF =ω LO0 -ω IF0 -m(t LO0 -t IF0 )-mNΔT IF (12)

[0104]

[0105]

[0106]

[0107] Since the time delay is very small, the time delay {t LO0 ,t IF0 ,ΔT LO ,ΔT IF} is ignored, then:

[0108] Φ≈-ω LO0 t LO0 +ω IF0 t IF0 -Nω IF0 ΔT IF (16)

[0109]

[0110] Among them, ω RF is the RF carrier frequency.

[0111] In actual signal transmission, l IF and l LO The delay line lengths of the adjacent nodes representing the intermediate frequency signal and the local oscillator signal, namely the second delay line length and the first delay line length, are limited in length. Therefore, the delay line lengths can be approximately equivalent to ideal dispersion-free transmission lines in the entire working frequency band. PRepresents the phase velocity of the intermediate frequency signal and the local oscillator signal on the output line, then:

[0112]

[0113]

[0114] At this time, formula (13) can be expressed as:

[0115]

[0116] From formula (16), we can see that Φ can be regarded as a constant universal phase that does not affect beamforming, where is the phase increment step, formula (20) expresses On the antenna array, it is manifested as an increase in phase offset, and the beam direction can be controlled. The total phase of the frequency-controlled array can be expressed as:

[0117]

[0118]

[0119] in, is the comprehensive frequency modulation coefficient. According to formulas (18) and (19), IF and l LO When fixed, ΔT IF and ΔT LO Also fixed, then The factors affecting the IF signal are the frequency modulation coefficient m of the LO signal.

[0120] RF carrier frequency ω RF Mainly determined by the intermediate frequency signal and the local oscillator signal, t LO0 and t OF0 The image on it is not large, so we can design the feed circuit and let t LO0 and T IF0 If they are equal, then formula (12) can be expressed as:

[0121] ω RF ≈ω LO0 -ω IF0 -mNΔT IF (twenty three)

[0122] Formula (19) shows that the frequency of the mixer output gradually increases along the linear array, and formula (16) shows that their initial phase also changes at a constant step size, thus forming a frequency-controlled array. The initial frequency ω LO0 and ω IF0The control is independent of the frequency modulation index. Therefore, the frequency control array can independently control the frequency increment step and phase offset along the array.

[0123] In addition, the present invention can also realize frequency-controlled array through unilateral frequency modulation. In this case, formula (22) needs to be modified accordingly, and the terms that do not change with time are omitted.

[0124] like Figure 6 As shown, when only the initial intermediate frequency signal is frequency modulated, formulas (12) to (15) are simplified to:

[0125] ω RF =ω LO0 -ω IF0 -m(-t IF0 )-mNΔT IF (twenty four)

[0126]

[0127]

[0128]

[0129] Formulas (24) to (27) are used to replace formulas (12) to (15) to obtain the time domain phase of the corresponding output RF signal.

[0130] like Figure 7 As shown, when only the initial local oscillator signal is frequency modulated, formulas (8) to (11) are simplified to:

[0131] ω RF =ω LO0 -ω IF0 -m(t LO0 )-mNΔT IF (28)

[0132]

[0133]

[0134]

[0135] Formulas (28) to (31) are used to replace formulas (8) to (11) to obtain the time domain phase of the corresponding output RF signal.

[0136] like Figure 8 and Figure 9 As shown, the first power divider and the second power divider are equal power dividers or unequal power dividers.

[0137] Specifically, the power divider used in the present invention may adopt equal power division or unequal power division, with the purpose of making the signal powers reaching the mixer equal.

[0138] Since the power difference of delay lines of different lengths is taken into account when designing the unequal power divider, the signal power reaching the mixer is made consistent. Therefore, when using the unequal power divider, the use of filters can be omitted. Figure 9 A power divider based on the Gysel unequal power division principle is proposed. At the same time, the power divider has been designed to compensate for the different delay lines between ports. The power divider can achieve consistent power at each output port and keep the delay of each output port at a fixed value.

[0139] like Figures 5 to 7 As shown, when the first power divider and the second power divider are equal power dividers, the local oscillator signal passes through the amplifier, the local oscillator signal filter and the first attenuator from left to right, and then enters the image suppression mixer. The amplifier is used to amplify the local oscillator signal power, the local oscillator signal filter is used to ensure the spectrum purity of the mixer local oscillator signal, and the first attenuator is used to fine-tune the local oscillator branch; the intermediate frequency signal enters the image suppression mixer after passing through the second attenuator, and the second attenuator is used to fine-tune the intermediate frequency branch; the radio frequency signal passes through the radio frequency signal amplifier and enters the radio frequency signal filter for filtering to obtain a pure radio frequency signal, which is then transmitted through the antenna.

[0140] Specifically, when an equal-division power splitter is used, it is necessary to ensure that the phases of the branches are consistent, and the present invention introduces an attenuator to fine-tune the branch power to offset the power differences caused by delay lines of different lengths.

[0141] To ensure the use of a passive mixer, the present invention incorporates an amplifier to amplify the power of the local oscillator signal and a local oscillator signal filter to ensure the spectral purity of the local oscillator signal before mixing. Furthermore, the simultaneous provision of a local oscillator signal filter and an RF signal filter mitigates the impact of spurious signals from the mixer's output, such as the image frequency and intermodulation frequency, on signal processing. The RF signal filter, placed after the RF signal amplifier, filters the amplified RF signal to produce a pure RF signal. This pure RF signal is then transmitted to the antenna, radiating microwaves from the antenna port into the air, completing the transmission of the frequency-controlled array signal.

[0142] The present invention can select a method for implementing the frequency control array as needed, for example, frequency modulating both the local oscillator signal and the intermediate frequency signal, or frequency modulating only the local oscillator signal, or frequency modulating only the intermediate frequency signal.

[0143] Compared to circuits that use traditional phased arrays to implement frequency-controlled arrays, the present invention does not use a digitally controlled phase modulator, and the digital portion does not require the assistance of DBF technology to implement a frequency-controlled array transmission circuit. Therefore, the present invention has the advantages of simple structure and low cost.

[0144] The above contents are further detailed descriptions of the present invention in conjunction with specific embodiments, and the specific implementation of the present invention cannot be considered to be limited to these descriptions. For those skilled in the art of the present invention, several simple deductions or substitutions can be made without departing from the concept of the present invention, and all of these should be considered to fall within the scope of protection of the present invention.

Claims

1. A method for implementing a frequency-controlled array transmitting front end, characterized in that: The following steps are involved: Frequency modulating the initial local oscillator signal and / or the initial intermediate frequency signal to obtain the local oscillator signal and the intermediate frequency signal includes: Let the fixed frequency difference between two adjacent antennas be (m+k)*t. At the signal input, the local oscillator signal is expressed as: The intermediate frequency signal is expressed as: Among them, ω LO0 and ω IF0 is the initial frequency of the local oscillator signal and the intermediate frequency signal, t LO0 and t IF0 is 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; The local oscillator signal is transmitted step by step to the local oscillator end of the image rejection mixer through a first power divider or a coupler, wherein a first delay line is added between every two stages of the local oscillator signal; The intermediate frequency signal is transmitted step by step to the intermediate frequency end of the image rejection mixer through the second power divider or coupler, and a second delay line is added between every two stages of the intermediate frequency signal; Wherein, the first power divider and the second power divider are equal power dividers or unequal power dividers; When the first power divider and the second power divider are equal power dividers, the local oscillator signal passes through the first power divider, then passes through an amplifier, a local oscillator signal filter, and a first attenuator in sequence, and enters the local oscillator end of the image rejection mixer; the intermediate frequency signal passes through the second power divider, then passes through the second attenuator and enters the intermediate frequency end of the image rejection mixer; When the first power divider and the second power divider are unequal power dividers, the local oscillator signal passes through the first power divider, then passes through the amplifier and the first attenuator in sequence, and enters the local oscillator end of the image rejection mixer; the intermediate frequency signal passes through the second power divider, then passes through the second attenuator and enters the intermediate frequency end of the image rejection mixer; The amplifier is used to amplify the power of the local oscillator signal, the local oscillator signal filter is used to ensure the spectral purity of the local oscillator signal before mixing, the first attenuator is used to fine-tune the local oscillator branch, and the second attenuator is used to fine-tune the intermediate frequency branch; The local oscillator signal and the intermediate frequency signal are up-converted by the image rejection mixer to obtain a radio frequency signal, which is then transmitted through a transmitting antenna.

2. The method for implementing a frequency-controlled array transmitting front end according to claim 1, wherein: At the nth node, the local oscillator signal is expressed as: The intermediate frequency signal is expressed as: Where ΔT LO and ΔT IF is the delay between the intermediate frequency signal transmission line and the local oscillator signal transmission line of two adjacent mixers; At the nth node, the local oscillator signal and the intermediate frequency signal change proportionally according to the modulation coefficients m and k, and then: Where, φ LO,n and φ IF,n They represent the phases of the local oscillator signal and the intermediate frequency signal in the time domain, namely the exponential parts in formulas (3) and (4).

3. The method for implementing a frequency-controlled array transmitting front end according to claim 2, wherein: 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 is selected, that is, 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 output RF signal is: oh RF =ω LO0 -oh IF0 -m·t LO0 +k·(t IF0 +NΔT IF ) (8) When the frequency modulation coefficients of the local oscillator signal and the intermediate frequency signal are equal, that is, m = k, we have: oh RF =ω LO0 -oh IF0 -m(t LO0 -t IF0 )-mNΔT IF (12) In the time delay {t LO0 ,t IF0 ,ΔT LO ,ΔT IF }When ignored, there are: F≈-ω LO0 t LO0 +oh IF0 t IF0 -No IF0 ΔT IF (16) Where, ω RF is the RF carrier frequency, is the comprehensive frequency modulation coefficient.

4. The method for implementing a frequency-controlled array transmitting front end according to claim 3, wherein: In actual signal transmission, LO and l IF Represent the length of the first delay line and the length of the second delay line respectively. In the entire working frequency band, the length of the first delay line and the length of the second delay line are approximately equivalent to an ideal dispersion-free transmission line. P Represents the phase velocity of the intermediate frequency signal and the local oscillator signal on the output line, then: At this time, formula (13) can be expressed as: in, is the phase increment step, formula (20) expresses On the antenna array, it is manifested as an increase in phase offset, and the beam direction can be controlled. The total phase of the frequency-controlled array can be expressed as:

5. The method for implementing a frequency-controlled array transmitting front end according to claim 4, wherein: Through the feed circuit design, let t LO0 and t IF0 If they are equal, then formula (12) can be expressed as: oh RF ≈ω LO0 -oh IF0 -mNΔT IF (23) According to the above formula, the RF carrier frequency is determined by the intermediate frequency input and the local oscillator input.

6. The method for implementing a frequency-controlled array transmitting front end according to claim 3, wherein: When only the initial intermediate frequency signal is frequency modulated, formulas (12) to (15) are: oh RF =ω LO0 -oh IF0 -m(-t IF0 )-mNΔT IF (24) Formulas (24) to (27) are used to replace formulas (12) to (15) to obtain the time domain phase of the corresponding output RF signal.

7. The method for implementing a frequency-controlled array transmitting front end according to claim 3, wherein: When only the initial local oscillator signal is frequency modulated, formulas (8) to (11) are: oh RF =ω LO0 -oh IF0 -m(t LO0 )-mNΔT IF (28) Formulas (28) to (31) are used to replace formulas (8) to (11) to obtain the time domain phase of the corresponding output RF signal.

8. The method for implementing a frequency-controlled array transmitting front end according to claim 1, wherein: When the first power splitter and the second power splitter are equal power splitters, the radio frequency signal passes through the radio frequency signal amplifier and then enters the radio frequency signal filter for filtering to obtain a pure radio frequency signal, which is then transmitted through the antenna.

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