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

Abstract

The invention discloses a kind of single channel array emitter antenna based on frequency precoding, mainly solve the amplitude phase unbalance problem that conventional arrays sending antenna structure is complicated, size is large, price is high and multichannel causes.It comprises: waveform generator (1), frequency modulator (2), digital to analog converter (3), upconverter (4), low noise amplifier (5), frequency tracker (6) and antenna oscillator (7).The multiple signals that waveform generator produces aggregate into single channel signal by frequency modulator modulation, this signal amplifies through digital to analog converter formal transformation, upconverter mixing, low noise amplifier successively, obtain analog radio-frequency signal, this analog radio-frequency signal is by exporting multi channel signals after frequency tracker quadrature demodulation and filtering, and this multi channel signals is by launching after antenna element signal formal transformation.Structure of the present invention is simple, size is little, cost is low, and antenna amplitude-phase consistency is good, can reach the performance index identical with conventional arrays transmitting antenna.

Description

Based on the single channel array emitter antenna of frequency precoding

Technical field

The invention belongs to antenna technical field, particularly single channel array emitter antenna, particularly a kind of single channel array emitter antenna being realized multi channel signals by orthogonal frequency modulation polymerization and demodulation recovery, can be used for communication and Radar Signal Processing.

Background technology

Antenna is widely used in the radio art such as communication, radar, navigation, broadcast, TV, and it, by radio wave radiation and reception transmission of information effectively, is a requisite device in radiotechnics equipment.Along with the development of microwave integrated circuit, the array antenna be made up of high-frequency electron device is more and more subject to people's attention, and its main feature is band-wise processing, namely utilizes multiple parallel circuit to multiple signals parallel processing.Multichannel is the main feature that array emitter antenna is different from mechanical trigger antenna.Array emitter antenna utilizes the antenna element of each passage to transmit respectively, realizes the synthesis of power in space.Due to the multichannel signal of array emitter antenna transmission, it is made to have the beam shape higher than mechanical trigger antenna and the control ability of beam position.But in practical engineering application, because the high-frequency element forming each passage exists disturbing mutually between inevitable trueness error and device, by causing that signal to noise ratio is low, amplitude phase unbalance, mutual coupling problem, actual array manifold is caused often to occur deviation to a certain degree or disturbance, now, common signal processing algorithm performance meeting severe exacerbation, even lost efficacy.

Another major obstacle that array emitter antenna carries out applying is the requirement to cost, size, weight and power.Because each passage of conventional arrays transmitting antenna includes the devices such as upconverter, DAC, memory and an amplifier, therefore for expensive high performance electronics, a large amount of uses directly enhances the cost of array emitter antenna, and huge cost has become its bottleneck promoted the use of.Moreover large metering device, in the use of each passage, makes its volume, weight become the major constraints of conventional arrays transmitting antenna extensibility, the region being particularly useful for dispelling the heat is very limited.

Summary of the invention

The object of the invention is to the deficiency for above-mentioned prior art, a kind of single channel array emitter antenna based on frequency precoding is proposed, to launch multiple signals by single channel, thus realize the reduction to antenna size and cost, improve passage amplitude-phase consistency and signal to noise ratio.

For achieving the above object, the present invention includes: waveform generator, digital to analog converter, upconverter, low noise amplifier, antenna oscillator, is characterized in that:

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

Be connected with M frequency tracker between low noise amplifier and antenna oscillator, for generation of orthogonal sub-carriers, carry out demodulation process with the single channel signal exported low noise amplifier, obtain multi-channel analog radiofrequency signal.

As preferably, each frequency modulator of the above-mentioned single channel array emitter antenna based on frequency precoding comprises one-level oscillator, one-level frequency mixer and aggregation transfer module;

Described one-level oscillator, for generation of subcarrier F _cM, to modulate the output signal frequency of waveform generator, the expression of this subcarrier is: $F_{cM}=\left\{\begin{array}{cccccc}{e}^{j2{\mathrm{\πf}}_{0}t}& e^{j2{\mathrm{\πf}}_{1}t}& \mathrm{...}& e^{j2{\mathrm{\πf}}_{m}t}& \mathrm{...}& e^{j2{\mathrm{\πf}}_{M-1}t}\end{array}\right\},$ 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, for modulating the output signal of waveform generator, obtaining the signal after modulating is:

$\begin{array}{c}S=\left\{\begin{array}{ccc}{\mathrm{\Γ\ω}}_0{e}^{j2{\mathrm{\πf}}_{c}t}& {\mathrm{\Γ\ω}}_1{e}^{j2\mathrm{\π}(f_c+\mathrm{\Δ}f)t}& \mathrm{...}\end{array}\right.\\ \left.\begin{array}{ccc}{\mathrm{\Γ\ω}}_m{e}^{j2\mathrm{\π}(f_c+m\·\mathrm{\Δ}f)t}& \mathrm{...}& {\mathrm{\Γ\ω}}_m{e}^{j2\mathrm{\π}(f_c+(M-1)\mathrm{\Δ}f)t}\end{array}\right\}\end{array},$

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

Described aggregation transfer module, for being polymerized the output signal of one-level frequency mixer, obtains aggregate signal S _aggrfor: $S_{aggr}=\underset{m=0}{\overset{M-1}{\Σ}}{\mathrm{\Γ\ω}}_m{e}^{j2{\mathrm{\πf}}_{m}t}.$

As preferably, each frequency tracker of the above-mentioned single channel array emitter antenna based on frequency precoding comprises secondary oscillator, secondary frequency mixer and band pass filter;

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

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

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

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

Described band pass filter, for carrying out bandpass filtering treatment to the output signal of secondary frequency mixer, 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, β _mfor the m multi-channel output signal of secondary frequency mixer through the signal waveform that band pass filter process obtains.

As preferably, the antenna oscillator of the above-mentioned single channel array emitter antenna based on frequency precoding, 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, equidistantly be fixed on T-shaped bracing frame, wherein, λ is signal wavelength, k is coefficient, k=1/4 or k=1/2.

The present invention compared with prior art tool has the following advantages:

1, the present invention is owing to being provided with frequency modulator, the orthogonal sub-carriers utilizing frequency modulator to produce carries out modulation polymerization to baseband digital signal, obtain single channel signal, considerably reduce the electronic device needed for band-wise processing, thus reduce volume and the cost of array emitter antenna.

2, the present invention is owing to being provided with frequency modulator and frequency tracker, multi channel signals modulation is aggregated into single channel signal and processes by the orthogonal sub-carriers produced by frequency modulator, and by frequency modulator demodulation restoring signal, can be good at the problem of mutual coupling and the amplitude phase unbalance existed between Solving Multichannel.

Accompanying drawing explanation

Fig. 1 is structural representation of the present invention;

Fig. 2 is that in the present invention, waveform generator produces signal waveform real part schematic diagram;

Fig. 3 is the frequency modulator structural representation in the present invention;

Fig. 4 is the frequency tracker structural representation in the present invention;

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

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

Fig. 7 is the antenna oscillator structure chart in the present invention;

Fig. 8 is that the present invention emulates array antenna layout and emission angle hum pattern;

Fig. 9 is the angular spectrum contrast schematic diagram of the present invention and conventional arrays antenna transmission signal.

Embodiment

With reference to Fig. 1, the present invention includes: waveform generator 1, frequency modulator 2, digital to analog converter 3, upconverter 4, low noise amplifier 5, frequency tracker 6 and antenna oscillator 7.Wherein: M frequency modulator 2 is connected between the output of waveform generator 1 and the input of digital to analog converter 3, the output of digital to analog converter 3 is connected with the input of upconverter 4, low noise amplifier 5 is connected between the output of upconverter 4 and the input of M frequency tracker 6, the output of M frequency tracker 6 is connected to the input of antenna oscillator 7, wherein, M is antenna oscillator number.The structure and working principle of each parts is as follows:

Described waveform generator 1, adopts but is not limited to the device of 33219A model, and its signal exported is multichannel baseband digital signal, and it is 10 that this example gets port number, and this multichannel baseband digital signal exports to frequency modulator 2.As shown in Figure 2, wherein Fig. 2 (a) and Fig. 2 (c) are the signal waveform that two edge gateways export to baseband digital signal waveform, the signal waveform that centered by Fig. 2 (b), passage exports.

With reference to Fig. 3, each frequency modulator 2 comprises one-level oscillator 21, one-level frequency mixer 22 and aggregation transfer module 23;

This one-level oscillator 21, by the first transistor G1, first positive feedback lattice network C1 and the first frequency-selective network circuit S1 forms, wherein, first positive feedback lattice network C1 and the first frequency-selective network circuit S1 all adopts resistance, electric capacity, reactance builds, the output of the first positive feedback lattice network C1 is connected with the input of the first transistor G1, the signal controlling the first transistor G1 exported by the first positive feedback lattice network C1 carries out signal output, the output of the first transistor G1 is connected with the input of the first frequency-selective network S1, carry out subcarrier by the first frequency selection circuit S1 to the output signal of the first transistor G1 to choose, and export subcarrier F _cMfrequency mixing processing is carried out, this subcarrier F to one-level frequency mixer 22 _cMfor: $F_{cM}=\left\{\begin{array}{cccccc}{e}^{j2{\mathrm{\πf}}_{0}t}& e^{j2{\mathrm{\πf}}_{1}t}& \mathrm{...}& e^{j2{\mathrm{\πf}}_{m}t}& \mathrm{...}& e^{j2{\mathrm{\πf}}_{M-1}t}\end{array}\right\},$ 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;

This one-level frequency mixer 22, built formed by the first electric bridge, electric capacity, resistance, reactance, its input is connected to the output of one-level oscillator 21, by the subcarrier that one-level oscillator 21 produces, the first electric bridge is made to be in the state of being turned on or off, for modulating the output signal of waveform generator 1, obtaining the signal after modulating is:

$\begin{array}{c}S=\left\{\begin{array}{ccc}{\mathrm{\Γ\ω}}_0{e}^{j2{\mathrm{\πf}}_{c}t}& {\mathrm{\Γ\ω}}_0{e}^{j2\mathrm{\π}(f_c+\mathrm{\Δ}f)t}& \mathrm{...}\end{array}\right.\\ \left.\begin{array}{ccc}{\mathrm{\Γ\ω}}_{m-1}{e}^{j2\mathrm{\π}(f_c+m\·\mathrm{\Δ}f)t}& \mathrm{...}& {\mathrm{\Γ\ω}}_{M-1}{e}^{j2\mathrm{\π}(f_c+(M-1)\mathrm{\Δ}f)t}\end{array}\right\}\end{array},$

Wherein, Γ is signal amplitude value, ω _mfor base band transmit waveform, m=0,1,2 ... M-2, M-1;

This aggregation transfer module 23, its output is connected with digital to analog converter 3, this module is made up of logical circuit B1 and transistor seconds G2, wherein logical circuit C1 employing resistance, electric capacity, reactance build, the electric current exported by control logic circuit B1 and voltage, transistor seconds G2 is made to be in the state of being turned on or off, to realize the gating polymerization of multiple signals, aggregate signal S _aggrfor: aggregate signal waveform as shown in Figure 5.

Described digital to analog converter 3, adopts but is not limited to the device of AD5755 model, and the output signal of frequency modulator 2 is by obtaining analog signal after the decoding summation process of digital to analog converter 3, and this analog signal output is to upconverter 4.

Described upconverter 4, adopt but be not limited to the device of MAX2044 model, the analog signal that digital to analog converter 3 exports is by the Frequency mixing processing of upconverter 4, and obtain radiofrequency signal, this radiofrequency signal outputs to low noise amplifier 5.

Described low noise amplifier 5, adopt but be not limited to the device of LMP7711 model, the signal that upconverter 4 exports is by the amplification process of this low noise amplifier 5, and obtain gain amplifying signal, this amplifying signal outputs to frequency tracker 6.

With reference to Fig. 4, each frequency tracker 6 comprises secondary oscillator 61, secondary frequency mixer 62 and band pass filter 63;

This secondary oscillator 61, by third transistor G3, second positive feedback lattice network C2 and the second frequency-selective network circuit S2 forms, wherein, second positive feedback lattice network C2 and the second frequency-selective network circuit S2 all adopts resistance, electric capacity, reactance builds, the output of the second positive feedback lattice network C2 is connected with the input of third transistor G3, the signal controlling third transistor G3 exported by the second positive feedback lattice network C2 carries out signal output, the output of third transistor G3 is connected with the input of the second frequency-selective network S2, carry out subcarrier by the second frequency selection circuit S2 to the output signal of third transistor G3 to choose, and by subcarrier F _cdeMexport to secondary frequency mixer 62 and carry out Frequency mixing processing, this subcarrier F _cdeMthe subcarrier F produced with one-level oscillator 21 _cMidentical, i.e. F _cdeM=F _cM,

This secondary frequency mixer 62, built formed by the second electric bridge, electric capacity, resistance, reactance, its input is connected to the output of secondary oscillator 61, by the subcarrier that secondary oscillator 61 produces, control the state of the second electric bridge, output signal for logarithmic mode transducer 5 is modulated, and obtains the signal after modulating to be: $S_c=\left[\begin{array}{ccccc}{S}_a{e}^{-j2{\mathrm{\πf}}_{0}t}& S_a{e}^{-j2{\mathrm{\πf}}_{1}t}& \mathrm{...}& S_a{e}^{-j2{\mathrm{\πf}}_{M-2}t}& S_a{e}^{-j2{\mathrm{\πf}}_{M-1}t}\end{array}\right],$ Wherein, S _afor the output signal of digital to analog converter 5, m=0,1,2 ... M-2, M-1, M are antenna oscillator number.

Described band pass filter, for carrying out bandpass filtering treatment to the output signal of secondary frequency mixer, 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] export to antenna oscillator 7, wherein, f _vfor the local oscillator carrier frequency of upconverter 4, β _mfor the m multi-channel output signal of secondary frequency mixer through the signal waveform that band pass filter process obtains.This example gets M=10, and as shown in Figure 6, wherein Fig. 6 (a) and Fig. 6 (c) are the signal output waveform of two edge gateways to this multi-channel analog radiofrequency signal waveform, multi-channel output signal waveform centered by Fig. 6 (b).

With reference to Fig. 7, described antenna oscillator 7, the shaft-like hollow metal tube identical by M size forms, and wherein, M >=2, this example gets M=10.The parallel equidistant arrangement of these metal tubes, is fixed on T-shaped support bar; The length L=k λ of each metal tube, wherein, λ is signal wavelength, and k is coefficient, k=1/4 or k=1/2 is all connected with sensor unit in the cavity of each metal tube, and the input of sensor unit is connected with the output of a frequency tracker 6.Whole antenna oscillator 7 is placed on without there being the clearing blocked, and the signal of telecommunication that frequency tracker 6 exports is converted to through sensor unit the port being input to metal tube after electromagnetic wave signal and launches.

Effect of the present invention is verified further by following emulation.

1. experiment scene:

As shown in Figure 8, it is that the present invention emulates array antenna layout and emission angle hum pattern, and the position coordinates of inventive antenna and conventional arrays transmitting antenna is all (0,0) km, array antenna is provided with 10 antenna oscillators, and in simulating scenes, launching beam orientation angle is set to+45 °.

2. experiment content and result:

Obtain transmitting of diverse location by antenna scanning spatial domain, this scan sector scope is-90 ° ~+90 °.Wave beam forming is carried out respectively with conventional arrays transmitting antenna and transmitting of these two kinds of antennas of the present invention, obtain angular power spectrogram, as shown in Figure 9, the dotted line wherein in Fig. 9 is the power azimuth spectrum of conventional arrays antenna, and the solid line of Fig. 9 is power azimuth spectrum of the present invention.

Can be seen by the contrast of Fig. 9 dotted portion and Fig. 9 bold portion: when the present invention reduces at designs simplification, smaller volume, device, cost reduces, can reach same with conventional arrays antenna accurate to launching the control pointed to, and same beam resolution can be reached.

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:

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

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:

$\begin{array}{c}S=\{\begin{array}{ccc}{\mathrm{\Γ\ω}}_0{e}^{j2{\mathrm{\πf}}_{c}t}& {\mathrm{\Γ\ω}}_1{e}^{j2\mathrm{\π}(f_c+\mathrm{\Δ}f)t}& \mathrm{...}\end{array}\\ \begin{array}{ccc}{\mathrm{\Γ\ω}}_m{e}^{j2\mathrm{\π}(f_c+m\·\mathrm{\Δ}f)t}& \mathrm{...}& {\mathrm{\Γ\ω}}_{M-1}{e}^{j2\mathrm{\π}(f_c+(M-1\left)\mathrm{\Δ}f\right)t}\end{array}\},\end{array}$

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: $S_{aggr}=\underset{m=0}{\overset{M-1}{\Σ}}{\mathrm{\Γ\ω}}_m{e}^{j2{\mathrm{\πf}}_{m}t}.$

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:

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

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.