CN103779659B - Based on the single channel array emitter antenna of frequency precoding - Google Patents

Abstract

The invention discloses a single-channel array transmitting antenna based on frequency precoding, which mainly solves the problems of complex structure, large size, high price and inconsistency of amplitude and phase caused by multiple channels of conventional array transmitting antennas. It includes: a waveform generator (1), a frequency modulator (2), a digital-to-analog converter (3), an up-converter (4), a low-noise amplifier (5), a frequency tracker (6) and an antenna element (7 ). The multi-channel signal generated by the waveform generator is modulated and aggregated into a single-channel signal by the frequency modulator. The signal is sequentially converted by a digital-to-analog converter, mixed by an up-converter, and amplified by a low-noise amplifier to obtain an analog radio frequency signal. The analog radio frequency signal The multi-channel signal is output after quadrature demodulation and filtering by the frequency tracker, and the multi-channel signal is transmitted after being converted into the signal form of the antenna oscillator. The invention has the advantages of simple structure, small size, low cost, good antenna amplitude and phase consistency, and can achieve the same performance index as the conventional array transmitting antenna.

Description

Single channel array transmitting antenna based on frequency precoding

technical field

The invention belongs to the technical field of antennas, in particular to a single-channel array transmitting antenna, in particular to a single-channel array transmitting antenna for realizing multi-channel signals through orthogonal frequency modulation aggregation and demodulation recovery, which can be used for communication and radar signal processing.

Background technique

Antennas are widely used in radio fields such as communications, radar, navigation, broadcasting, and television. They effectively radiate, receive, and transmit information through radio waves, and are an indispensable device in radio technology equipment. With the development of microwave integrated circuits, the array antenna composed of high-frequency electronic devices has attracted more and more attention. Its main feature is multi-channel processing, that is, using multiple parallel circuits to process multi-channel signals in parallel. Multi-channel is the main feature that distinguishes the array transmitting antenna from the mechanical transmitting antenna. The array transmitting antenna uses the antenna elements of each channel to transmit signals separately to realize power synthesis in space. Since the array transmitting antenna transmits multi-channel signals, it has higher beam shape and beam pointing control capabilities than the mechanical transmitting antenna. However, in practical engineering applications, due to the inevitable precision errors and mutual interference between the high-frequency devices that make up each channel, it will cause problems such as low signal-to-noise ratio, inconsistent amplitude and phase, and mutual coupling. There will always be a certain degree of deviation or disturbance in the model, at this time, the performance of the usual signal processing algorithm will seriously deteriorate, or even fail.

Another major obstacle to the widespread use of array transmit antennas is the cost, size, weight and power requirements. Since each channel of a conventional array transmitting antenna includes an up-converter, DAC, memory, and amplifier, etc., for expensive high-performance electronic devices, a large number of uses directly increase the cost of the array transmitting antenna, which is huge. The price has become the bottleneck of its popularization. Furthermore, the use of a large number of devices in each channel makes its volume and weight the main constraints on the scalability of conventional array transmitting antennas, especially the area available for heat dissipation is very limited.

Contents of the invention

The purpose of the present invention is to address the deficiencies of the above-mentioned prior art, and propose a single-channel array transmitting antenna based on frequency precoding, so as to transmit multiple signals through a single channel, thereby reducing the size and cost of the antenna and improving the channel amplitude. Phase consistency and signal-to-noise ratio.

To achieve the above object, the present invention includes: waveform generator, digital-to-analog converter, up-converter, low-noise amplifier, antenna oscillator, characterized in that:

There are M frequency modulators connected between the waveform generator and the digital-to-analog converter, which are used to generate orthogonal subcarriers to frequency modulate the signal output by the waveform generator, and perform orthogonal aggregation processing on the modulated signal, Among them, M is the number of antenna dipoles;

M frequency trackers are connected between the low-noise amplifier and the antenna oscillator for generating orthogonal sub-carriers to demodulate the single-channel signal output by the low-noise amplifier to obtain multiple analog radio frequency signals.

Preferably, each frequency modulator of the frequency precoding-based single-channel array transmitting antenna includes a primary oscillator, a primary mixer, and an aggregation transmission module;

The primary oscillator is used to generate the subcarrier F _cM to modulate the frequency of the output signal of the waveform generator, and the expression of the subcarrier is: $f_{cm}=\left\{\begin{array}{cccccc}{e}^{j2{\mathrm{\πf}}_{0}t}& e^{j2{\mathrm{\πf}}_{1}t}& \mathrm{...}& e^{j2{\mathrm{\πf}}_{m}t}& \mathrm{...}& e^{j2{\mathrm{\πf}}_{m-1}t}\end{array}\right\},$ Among them, f _m is the subcarrier frequency, f _m =f _c +m·Δf, m=0,1,2...M-2,M-1, M is the number of antenna elements, f _c is the reference carrier frequency, Δf is Subcarrier frequency step length;

The first-stage mixer is used to modulate the output signal of the waveform generator, and the modulated signal obtained is:

$\begin{array}{c}\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; =</span>\left\{\begin{array}{ccc}{\mathrm{<span\; class="notranslate">\; \&Gamma;\&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}\mathrm{<span\; class="notranslate">\; 2</span>}{\mathrm{<span\; class="notranslate">\; \&pi;f</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}\mathrm{<span\; class="notranslate">\; t</span>}}& {\mathrm{<span\; class="notranslate">\; \&Gamma;\&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; \&Delta;</span>}\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; t</span>}}& \mathrm{<span\; class="notranslate">\; ...</span>}\end{array}\right.\\ \left.\begin{array}{ccc}{\mathrm{<span\; class="notranslate">\; \&Gamma;\&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}{\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; \&Delta;</span>}\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; t</span>}}& \mathrm{<span\; class="notranslate">\; ...</span>}& {\mathrm{<span\; class="notranslate">\; \&Gamma;\&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}{\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; \&Delta;</span>}\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; t</span>}}\end{array}\right\}\end{array}<span\; class="notranslate">\; ,</span>$

Among them, Γ is the signal amplitude value, ω _m is the baseband signal waveform generated by the waveform generator, m=0,1,2,...,M-1;

The aggregation transmission module is used to aggregate the output signals of the primary mixer to obtain the aggregation signal S _aggr as: $S_{aggr}=\underset{m=0}{\overset{m-1}{\&Sigma;}}{\mathrm{\&Gamma;\&omega;}}_m{e}^{j2{\mathrm{\&pi;f}}_{m}t}.$

As preferably, each frequency tracker of the above-mentioned single-channel array transmitting antenna based on frequency precoding includes a secondary oscillator, a secondary mixer and a bandpass filter;

The secondary oscillator generator is used to generate the subcarrier _FcdeM to frequency modulate the output signal of the low noise amplifier. The subcarrier _FcdeM is the same as the subcarrier _FcM generated by the primary oscillator, that is, _FcdeM = _FcM ;

The secondary mixer is used to mix the sub-carriers output by the secondary oscillator with the output signal of the low-noise amplifier respectively, so that the mixed multi-channel analog signal _Sc is:

${\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}<span\; class="notranslate">\; =</span>\left[\begin{array}{ccccc}{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}{\mathrm{<span\; class="notranslate">\; e</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; j</span>}\mathrm{<span\; class="notranslate">\; 2</span>}{\mathrm{<span\; class="notranslate">\; \&pi;f</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}\mathrm{<span\; class="notranslate">\; t</span>}}& {\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}{\mathrm{<span\; class="notranslate">\; e</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; j</span>}\mathrm{<span\; class="notranslate">\; 2</span>}{\mathrm{<span\; class="notranslate">\; \&pi;f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\mathrm{<span\; class="notranslate">\; t</span>}}& \mathrm{<span\; class="notranslate">\; ...</span>}& {\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}{\mathrm{<span\; class="notranslate">\; e</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; j</span>}\mathrm{<span\; class="notranslate">\; 2</span>}{\mathrm{<span\; class="notranslate">\; \&pi;f</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; t</span>}}& {\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}{\mathrm{<span\; class="notranslate">\; e</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; j</span>}\mathrm{<span\; class="notranslate">\; 2</span>}{\mathrm{<span\; class="notranslate">\; \&pi;f</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}\mathrm{<span\; class="notranslate">\; t</span>}}\end{array}\right]<span\; class="notranslate">\; ,</span>$

Wherein, S _a is the output signal of the digital-to-analog converter, m=0,1,2...M-2,M-1;

The band-pass filter is used to perform band-pass filter processing on the output signal of the secondary mixer, and takes out a signal waveform with a carrier frequency of _fv from a plurality of carrier frequency signal waveforms of each channel signal, and filters out For a signal waveform with a carrier frequency other than f _v , the multi-channel analog radio frequency signal Y=[β ₁ ,…β _m ,…,β _M-1 ], where f _v is the local oscillator carrier frequency of the up-converter, β _m It is the m-channel output signal of the secondary mixer Signal waveform obtained through bandpass filter processing.

As a preference, the antenna vibrator of the above-mentioned single-channel array transmitting antenna based on frequency precoding adopts a structure in which M rod-shaped metal tubes of the same size are arranged in parallel, and the length of each metal tube is L=k·λ, and the equal intervals are fixed at T-shaped Shaped support frame, where, λ is the signal wavelength, k is the coefficient, k=1/4 or k=1/2.

Compared with the prior art, the present invention has the following advantages:

1. Since the present invention is provided with a frequency modulator, the orthogonal subcarriers produced by the frequency modulator are used to modulate and aggregate the baseband digital signal to obtain a single-channel signal, which greatly reduces the electronic devices required for multi-channel processing, thereby reducing The volume and cost of the array transmitting antenna are reduced.

2. Since the present invention is provided with a frequency modulator and a frequency tracker, the multi-channel signal is modulated and aggregated into a single-channel signal by the orthogonal sub-carrier produced by the frequency modulator for processing, and the demodulation recovery signal by the frequency modulator can be easily It is a good solution to the problems of mutual coupling and amplitude-phase inconsistency among multiple channels.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is a schematic diagram of the real part of the signal waveform produced by the waveform generator in the present invention;

Fig. 3 is a schematic structural diagram of a frequency modulator in the present invention;

Fig. 4 is a schematic structural diagram of a frequency tracker in the present invention;

Fig. 5 is a schematic diagram of the output signal of the frequency modulator of the present invention;

Fig. 6 is the output signal schematic diagram of the frequency tracker of the present invention;

Fig. 7 is a structural diagram of the antenna vibrator in the present invention;

Fig. 8 is a layout and emission angle information map of the simulated array antenna of the present invention;

FIG. 9 is a schematic diagram of comparison of angular spectrums of signals transmitted by the present invention and conventional array antennas.

detailed description

Referring to FIG. 1 , the present invention includes: a waveform generator 1 , a frequency modulator 2 , a digital-to-analog converter 3 , an up-converter 4 , a low-noise amplifier 5 , a frequency tracker 6 and an antenna element 7 . Wherein: M frequency modulators 2 are connected between the output end of the waveform generator 1 and the input end of the digital-to-analog converter 3, the output end of the digital-to-analog converter 3 is connected to the input end of the up-converter 4, and the low-noise amplifier 5 is connected between the output end of the up-converter 4 and the input ends of M frequency trackers 6, and the output ends of the M frequency trackers 6 are connected to the input end of the antenna elements 7, where M is the number of antenna elements. The structure and working principle of each component are as follows:

The waveform generator 1 adopts, but is not limited to, a 33219A device, and its output signal is a multi-channel baseband digital signal. In this example, the number of channels is 10, and the multi-channel baseband digital signal is output to the frequency modulator 2. The baseband digital signal waveform is shown in Figure 2, where Figure 2(a) and Figure 2(c) are the signal waveforms output by the two edge channels, and Figure 2(b) is the signal waveform output by the center channel.

Referring to Fig. 3, each frequency modulator 2 includes a primary oscillator 21, a primary mixer 22 and an aggregation transmission module 23;

The primary oscillator 21 is composed of a first transistor G1, a first positive feedback network circuit C1 and a first frequency selection network circuit S1, wherein both the first positive feedback network circuit C1 and the first frequency selection network circuit S1 use resistors , capacitance, and reactance, the output terminal of the first positive feedback network circuit C1 is connected to the input terminal of the first transistor G1, and the signal output by the first positive feedback network circuit C1 controls the first transistor G1 to perform signal output, the first The output terminal of the transistor G1 is connected to the input terminal of the first frequency selection network S1, the subcarrier is selected for the output signal of the first transistor G1 through the first frequency selection circuit S1, and the subcarrier F _cm is output to the first-stage mixer 22 Perform frequency mixing processing, the subcarrier F _cM is: $f_{cm}=\left\{\begin{array}{cccccc}{e}^{j2{\mathrm{\&pi;f}}_{0}t}& e^{j2{\mathrm{\&pi;f}}_{1}t}& \mathrm{...}& e^{j2{\mathrm{\&pi;f}}_{m}t}& \mathrm{...}& e^{j2{\mathrm{\&pi;f}}_{m-1}t}\end{array}\right\},$ Among them, f _m is the subcarrier frequency, f _m =f _c +m·Δf, m=0,1,2...M-2,M-1, M is the number of antenna elements, f _c is the reference carrier frequency, Δf is Subcarrier frequency step length;

The first-stage mixer 22 is constructed by the first electric bridge, capacitor, resistor, and reactance, and its input end is connected to the output end of the first-stage oscillator 21, and the subcarrier generated by the first-stage oscillator 21 makes the first stage A bridge is in the on or off state, and is used to modulate the output signal of the waveform generator 1, and the modulated signal is:

$\begin{array}{c}\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; =</span>\left\{\begin{array}{ccc}{\mathrm{<span\; class="notranslate">\; \&Gamma;\&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}\mathrm{<span\; class="notranslate">\; 2</span>}{\mathrm{<span\; class="notranslate">\; \&pi;f</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}\mathrm{<span\; class="notranslate">\; t</span>}}& {\mathrm{<span\; class="notranslate">\; \&Gamma;\&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; \&Delta;</span>}\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; t</span>}}& \mathrm{<span\; class="notranslate">\; ...</span>}\end{array}\right.\\ \left.\begin{array}{ccc}{\mathrm{<span\; class="notranslate">\; \&Gamma;\&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; \&CenterDot;</span>\mathrm{<span\; class="notranslate">\; \&Delta;</span>}\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; t</span>}}& \mathrm{<span\; class="notranslate">\; ...</span>}& {\mathrm{<span\; class="notranslate">\; \&Gamma;\&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; \&Delta;</span>}\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; t</span>}}\end{array}\right\}\end{array}<span\; class="notranslate">\; ,</span>$

Among them, Γ is the signal amplitude value, ω _m is the baseband transmit signal waveform, m=0,1,2...M-2,M-1;

The aggregation transmission module 23 is connected to the digital-to-analog converter 3 at its output end, and the module is composed of a logic circuit B1 and a second transistor G2, wherein the logic circuit C1 is constructed using resistance, capacitance, and reactance, and is output through the control logic circuit B1 current and voltage, so that the second transistor G2 is turned on or off, so as to realize the gating aggregation of multiple signals, and the aggregation signal S _aggr is: The aggregated signal waveform is shown in Figure 5.

The digital-to-analog converter 3 adopts, but is not limited to, a device of the AD5755 type. The output signal of the frequency modulator 2 is decoded and summed by the digital-to-analog converter 3 to obtain an analog signal, and the analog signal is output to the up-converter 4 .

The up-converter 4 adopts, but is not limited to, a MAX2044 device. The analog signal output by the digital-to-analog converter 3 is mixed by the up-converter 4 to obtain a radio frequency signal, and the radio frequency signal is output to the low-noise amplifier 5 .

The low-noise amplifier 5 adopts but is not limited to a device of the LMP7711 type. The signal output by the up-converter 4 is amplified by the low-noise amplifier 5 to obtain a gain amplified signal, and the amplified signal is output to the frequency tracker 6 .

Referring to Fig. 4, each frequency tracker 6 comprises a secondary oscillator 61, a secondary mixer 62 and a bandpass filter 63;

The secondary oscillator 61 is composed of a third transistor G3, a second positive feedback network circuit C2 and a second frequency selection network circuit S2, wherein both the second positive feedback network circuit C2 and the second frequency selection network circuit S2 use resistors , capacitance, and reactance are built, the output end of the second positive feedback network circuit C2 is connected to the input end of the third transistor G3, and the signal output by the second positive feedback network circuit C2 controls the third transistor G3 to perform signal output, and the third The output terminal of the transistor G3 is connected to the input terminal of the second frequency selection network S2, and the subcarrier is selected for the output signal of the third transistor G3 through the second frequency selection circuit S2, and the subcarrier F _cdeM is output to the secondary mixer 62 performs frequency mixing processing, and the subcarrier F _cdeM is the same as the subcarrier F _cM generated by the primary oscillator 21, that is, F _cdeM =F _cM ;

The secondary mixer 62 is constructed by a second electric bridge, a capacitor, a resistor, and a reactance, and its input terminal is connected to the output terminal of the secondary oscillator 61, and the subcarrier generated by the secondary oscillator 61 controls the second The state of the second electric bridge is used to modulate the output signal of the digital-to-analog converter 5, and the modulated signal obtained is: $S_c=\left[\begin{array}{ccccc}{S}_a{e}^{-j2{\mathrm{\&pi;f}}_{0}t}& S_a{e}^{-j2{\mathrm{\&pi;f}}_{1}t}& \mathrm{...}& S_a{e}^{-j2{\mathrm{\&pi;f}}_{m-2}t}& S_a{e}^{-j2{\mathrm{\&pi;f}}_{m-1}t}\end{array}\right],$ Wherein, S _a is the output signal of the digital-to-analog converter 5, m=0, 1, 2...M-2, M-1, and M is the number of antenna dipoles.

The band-pass filter is used to perform band-pass filter processing on the output signal of the secondary mixer, and takes out a signal waveform with a carrier frequency of _fv from a plurality of carrier frequency signal waveforms of each channel signal, and filters out The signal waveform whose carrier frequency is not f _v is to obtain multi-channel analog radio frequency signal Y=[β ₁ ,...β _m ,...,β _M-1 ] and output to the antenna oscillator 7, where f _v is the local frequency of the up-converter 4 Vibration carrier frequency, β _m is the m-channel output signal of the second-stage mixer Signal waveform obtained through bandpass filter processing. In this example, M=10, the waveform of the multi-channel analog RF signal is shown in Figure 6, where Figure 6(a) and Figure 6(c) are the output signal waveforms of the two edge channels, and Figure 6(b) is the center channel output signal waveform.

Referring to FIG. 7 , the antenna vibrator 7 is composed of M rod-shaped hollow metal tubes of the same size, where M≥2, and M=10 in this example. These metal tubes are arranged at equal intervals in parallel and fixed on the T-shaped support rod; the length of each metal tube is L=k·λ, where λ is the signal wavelength, k is the coefficient, k=1/4 or k=1/2 , the cavity of each metal tube is connected with a sensor unit, and the input end of the sensor unit is connected with the output end of a frequency tracker 6 . The entire antenna vibrator 7 is placed in an open space without shelter, and the electrical signal output by the frequency tracker 6 is converted into an electromagnetic wave signal by the sensor unit and then input to the port of the metal tube for emission.

The effect of the present invention can be further verified by the following simulation.

1. Experimental scene:

As shown in Figure 8, it is the layout of the simulation array antenna of the present invention and the information map of the emission angle. The position coordinates of the antenna of the present invention and the conventional array transmission antenna are all (0,0) km, and the array antenna is provided with 10 antenna elements. The transmit beam pointing angle in the scene is set to +45°.

2. Experimental content and results:

The transmitting signals at different positions are obtained by scanning the airspace with the antenna, and the scanning airspace ranges from -90° to +90°. Carry out beamforming with conventional array transmitting antenna and the transmitting signal of these two kinds of antennas of the present invention respectively, obtain angle power spectrum graph, as shown in Figure 9, wherein the dotted line in Figure 9 is the angle power spectrum of conventional array antenna, the angle power spectrum of Figure 9 The solid line is the angular power spectrum of the present invention.

Through the comparison of the dotted line in Figure 9 and the solid line in Figure 9, it can be seen that the present invention can achieve the same accuracy as conventional array antennas in controlling the emission direction under the circumstances of simplified structure, smaller volume, reduced components, and reduced cost. And can achieve the same beam resolution.

Claims (3)

1. the single channel array emitter antenna based on frequency precoding, comprise: waveform generator (1), digital to analog converter (3), upconverter (4), low noise amplifier (5) and antenna oscillator (7), is characterized in that:

M frequency modulator (2) is connected with between waveform generator (1) and digital to analog converter (3), for generation of orthogonal sub-carriers, frequency modulation(FM) is carried out with the signal exported waveform generator (1), and positive crosslinking polymerization process is carried out to the signal after modulation, wherein, M is antenna oscillator number;

M frequency tracker (6) is connected with between low noise amplifier (5) and antenna oscillator (7), for generation of orthogonal sub-carriers, carry out demodulation process with the single channel signal exported low noise amplifier (5), obtain multi-channel analog radiofrequency signal;

Each frequency modulator (2) comprises one-level oscillator (21), one-level frequency mixer (22) and aggregation transfer module (23);

Described one-level oscillator (21), for generation of subcarrier F _cM, to modulate the output signal frequency of waveform generator (1), the expression of this subcarrier:

$F_{cM}=\left\{\begin{array}{cccccc}{e}^{j2{\mathrm{\&pi;f}}_{0}t}& e^{j2{\mathrm{\&pi;f}}_{1}t}& \mathrm{...}& e^{j2{\mathrm{\&pi;f}}_{m}t}& \mathrm{...}& e^{j2{\mathrm{\&pi;f}}_{M-1}t}\end{array}\right\},$

Wherein, f _mfor sub-carrier frequencies, f _m=f _c+ m Δ f, m=0,1,2 ... M-2, M-1, M are antenna oscillator number, f _cfor reference carrier frequency, Δ f is sub-carrier frequency stepping length;

Described one-level frequency mixer (22), for modulating the output signal of waveform generator (1), obtaining the signal after modulating is:

$\begin{array}{c}S=\{\begin{array}{ccc}{\mathrm{\&Gamma;\&omega;}}_0{e}^{j2{\mathrm{\&pi;f}}_{c}t}& {\mathrm{\&Gamma;\&omega;}}_1{e}^{j2\mathrm{\&pi;}(f_c+\mathrm{\&Delta;}f)t}& \mathrm{...}\end{array}\\ \begin{array}{ccc}{\mathrm{\&Gamma;\&omega;}}_m{e}^{j2\mathrm{\&pi;}(f_c+m\&CenterDot;\mathrm{\&Delta;}f)t}& \mathrm{...}& {\mathrm{\&Gamma;\&omega;}}_{M-1}{e}^{j2\mathrm{\&pi;}(f_c+(M-1\left)\mathrm{\&Delta;}f\right)t}\end{array}\},\end{array}$

Wherein, Γ is signal amplitude value, ω _mfor the baseband signal waveform that waveform generator (1) produces, m=0,1,2 ..., M-1;

Described aggregation transfer module (23), for being polymerized the output signal of one-level frequency mixer (22), obtains aggregate signal S _aggrfor: $S_{aggr}=\underset{m=0}{\overset{M-1}{\&Sigma;}}{\mathrm{\&Gamma;\&omega;}}_m{e}^{j2{\mathrm{\&pi;f}}_{m}t}.$

2. the single channel array emitter antenna based on frequency precoding according to claim 1, it is characterized in that, each frequency tracker (6) comprises secondary oscillator (61), secondary frequency mixer (62) and band pass filter (63);

The raw device (61) of described secondary vibration, for generation of subcarrier F _cdeM, to carry out frequency modulation(FM) to the output signal of low noise amplifier (5), this subcarrier F _cdeMthe subcarrier F produced with one-level oscillator (21) _cMidentical, i.e. F _cdeM=F _cM;

Described secondary frequency mixer (62), carries out mixing with the output signal of low noise amplifier (5) respectively for the subcarrier exported by secondary oscillator (61), obtains the multichannel analog signals S after mixing _cfor:

$S_c=\left[\begin{array}{ccccc}{S}_a{e}^{-j2{\mathrm{\&pi;f}}_{0}t}& S_a{e}^{-j2{\mathrm{\&pi;f}}_{1}t}& \mathrm{...}& S_a{e}^{-j2{\mathrm{\&pi;f}}_{M-2}t}& S_a{e}^{-j2{\mathrm{\&pi;f}}_{M-1}t}\end{array}\right],$

Wherein, S _afor the output signal of low noise amplifier (5), m=0,1,2 ... M-2, M-1;

Described band pass filter (63), for carrying out bandpass filtering treatment to the output signal of secondary frequency mixer (62), from multiple CF signal waveforms of each channel signal, take out carrier frequency is f _vsignal waveform, filter out carrier frequency for f _vsignal waveform, obtain multi-channel analog radiofrequency signal Y=[β ₁... β _m..., β _m-1], wherein, f _vfor the local oscillator carrier frequency of upconverter (4), β _mfor the m multi-channel output signal of secondary frequency mixer (62) the signal waveform obtained is processed through band pass filter (63).

3. the single channel array emitter antenna based on frequency precoding according to claim 1, it is characterized in that, described antenna oscillator (7), the structure that the metal, rod-shaped pipe adopting M size identical is arranged in parallel, the length L=k λ of each metal tube, is equidistantly fixed on T-shaped support bar, wherein, λ is signal wavelength, and k is coefficient, k=1/4 or k=1/2.