CN203310914U - Low frequency antenna array phase measurement apparatus based on GPS and phase detection chip - Google Patents

Abstract

A low frequency antenna array phase measurement apparatus based on the GPS and a phase detection chip is disclosed. The hardware part of the apparatus comprises a GPS signal receiving module, a signal generation and control circuit, and a phase difference detection and comparison circuit, wherein the circuit data output end of the GPS signal receiving module is connected with the data receiving end of the signal generation and control circuit, a main control chip in the signal generation and control circuit is connected with the signal control end of a DDS, and a DDS signal output end is connected with the calibration signal input end of a receiving device. The output ends of the receiving device are grouped in a pairwise manner after transmitting through long electric cables, the pairwise output ends are connected with two analogue input ends of the phase difference detection and comparison circuit, and the direct current detection output end of the phase difference detection and comparison circuit is connected with the analogue output end of an AD collection board. The low frequency antenna array phase measurement apparatus based on the GPS and a phase detection chip is characterized by high efficiency, high precision, and experience value dependence-free property.

Description

A kind of device of the phase measurement of the low-frequency antenna battle array based on GPS and phase-detection chip

Technical field

The utility model is radio astronomy observation measuring method and device thereof, especially is applicable to the Digital Signal Analysis disposal route technical field of radio astronomy low-frequency antenna battle array.

Background technology

It is large that the low frequency radio antenna array has antenna volume, the characteristics that distribution area is wide, from each antenna element, receiving signal tentatively amplifies through low noise amplifier, by digital phase shifter, be weighted the formation synthesized pattern, then by long cable, multiple signals passed to point of fixity converges and carry out numeral and quantize.Wherein, be weighted and form the core that directional diagram is whole phased array by digital phase shifter, different weighting functions, make antenna array to observe different De Tian district.Fig. 5 is shown in by prior art process schematic diagram.

Weighing vector for the antenna array of N array element is:

$a\left(\mathrm{\θ}\right)=\left[\begin{array}{c}1\\ e^{j(\mathrm{kd}\sin \mathrm{\θ}+\mathrm{\δ})}\\ e^{2j(\mathrm{kd}\sin \mathrm{\θ}+\mathrm{\δ})}\\ \·\·\·\·\·\·\\ e^{(N-1)j(\mathrm{kd}\sin \mathrm{\θ}+\mathrm{\δ})}\end{array}\right]$

δ is phased array phase modulation parameter, and in the ideal case, we think the constant phase difference that every cable produces, and δ has forgiven two parts: 1. the phase differential δ caused by phase shifter _Shifter, this is that the antenna array phase modulation is needed, by changing δ _ShifterAdjusting antenna array points to; 2. the phase differential δ caused from long cable _CableIf under the constant condition of extraneous natural conditions, this phase differential is constant.

δ _tot=δ _shifter+δ _cable

But, due to temperature, humidity and the deformation impact on cable and other elements, δ _CableAnd non-constant, therefore:

δ _t' _ot=δ _shifter+δ _cable+Δδ _env

Wherein, Δ δ _envFor the impact that natural environment influence brings for whole antenna array weighing vector, must revise this parameter, otherwise can't obtain the desirable directional diagram of antenna array.

Traditional way is by measuring current temperature, and the information such as humidity, revise Δ δ by the empirical value of the situation of change of cable material under different temperatures, humidity _env, this method can't overcome all the other electronic components, for example: front-end amplifier, the impact that phase shifter and radio-frequency joint bring, and the error that empirical value is introduced also can't be eliminated.

Summary of the invention

The purpose of this utility model is exactly to reach long cable between the Back end data collector due to the change of temperature, humidity and the caused signal phase of pressure deformation for front end simulating signal in radio astronomy low-frequency antenna battle array, and the signal checking device is also fewer, so propose a kind of method and device thereof of the phase measurement of the low-frequency antenna battle array based on GPS and phase-detection chip.

The technical solution adopted in the utility model is:

A kind of device of the phase measurement of the low-frequency antenna battle array based on GPS and phase-detection chip, this device comprises the gps signal receiving circuit for hardware components, signal generation and control circuit and phase difference detection contrast circuit.

Annexation between each discrete parts hardware is as follows:

1.GPS the signal receiving circuit data output end produces with signal and the data receiver of control circuit is connected,

Signal produce and control circuit in main control chip and DDS(AD9852) the signal controlling end be connected; The DDS signal output part is connected with the rate-aided signal input end of receiver;

3. the receiver output terminal is after long cable transmission, is one group of two analog input end with the phase difference detection contrast circuit in twos

Be connected;

4. the direct current of phase difference detection contrast circuit detection output terminal is connected with the analog output of AD collection plate.

Use the method for said apparatus as follows: the antenna array receiver to be done as a whole, as the initial control signal of giving the array element rate-aided signal, made each antenna element input simultaneously synchronous coherent signal by gps time signal; After the whole reception analog link of this signal experience, by phase detection, incite somebody to action the phase difference δ between link in twos and be converted into voltage difference delta v, gather this voltage difference by high-accuracy data collection card, in software, be converted into potential difference (PD).Deduct original phase differential δ ₀, know that namely the phase differential caused due to conditions such as temperature, humidity and deformation now changes, thereby can revise at software or phase shifter place.

The method feature also is:

1) utilize the initial control signal of gps clock signal as the relevant output of each array element calibration information source, make respectively calibrate information source can be in the same time, same-phase output, for the detection of rear end provides coherent;

2) using center antenna as the phase standard antenna, with all the other antenna link signals, try to achieve by comparison the phase differential of link in twos, the whole receiver of array element is made to as a whole its phase differential that calculates;

3) utilize advanced phase difference detection chip AD8302, will be converted into corresponding with it DC voltage through the phase differential of the calibration source signal of the array element in twos of receiver and transmission feeder, be conducive to accurately measuring phase differential;

4) utilize the 4 Channel Synchronous 100Ksps speed collections of the high-accuracy data collection card NI921516bit of U.S. national instrument company quantified precision.Collect the phase voltage signal, by computing machine LABVIEW software, recovering the phase differential of link in twos.

The method is exported at feeder line, the employing phase detecting circuit phase differential of the output signal of rate-aided signal after different receivers in twos is converted into voltage, the antenna array center cell of take is reference, can infer and obtain the phase differential of each antenna array element with respect to center cell by the voltage difference situation.

Effect of the present utility model is: the utility model solves each parts in the low-frequency antenna battle array and is subjected to natural environment influence, thus the non-constant difficult problem that affects Antenna Array Pattern of each array element phase differential of generation.The utility model also has efficiently, high precision and do not need to rely on the advantages such as empirical value.1. adopt GPS to control calibration information source precision and can reach 10 nanosecond, the coherent signal of make the rate-aided signal of many array elements become in the same time, same-phase being exported; 2. by the phase-detection chip, incite somebody to action the phase differential of signal in twos and be converted into voltage difference, facilitate data acquisition and analysis, and do not rely on empirical value, overcoming need to be to the problem of physical environment understanding.

The accompanying drawing explanation

Fig. 1 is that the utility model information source control section connects block diagram;

Fig. 2 is that the utility model phase-detection partly connects block diagram;

Fig. 3 is the utility model information source control section program flow chart;

Fig. 4 is the connection block diagram between the utility model three part hardware;

Fig. 5 is the process schematic diagram of art methods;

Fig. 6 is AD8302 phase detection principle figure.

Specific implementation method

A kind of device of the phase measurement of the low-frequency antenna battle array based on GPS and phase-detection chip, this device comprises the gps signal receiving circuit for hardware components, signal generation and control circuit and phase difference detection contrast circuit.

Annexation between each discrete parts hardware is as follows:

1.GPS the signal receiving circuit data output end produces with signal and the data receiver of control circuit is connected,

Signal produce and control circuit in main control chip and DDS(AD9852) the signal controlling end be connected; The DDS signal output part is connected with the rate-aided signal input end of receiver;

3. the receiver output terminal, after long cable transmission, is in twos one group and is connected with two analog input ends of phase difference detection contrast circuit;

4. the direct current of phase difference detection contrast circuit detection output terminal is connected with the analog output of AD collection plate.

Use the method for said apparatus as follows: the antenna array receiver to be done as a whole, as the initial control signal of giving the array element rate-aided signal, made each antenna element input simultaneously synchronous coherent signal by gps time signal; After the whole reception analog link of this signal experience, by phase detection, incite somebody to action the phase difference δ between link in twos and be converted into voltage difference delta v, gather this voltage difference by high-accuracy data collection card, in software, be converted into potential difference (PD).Deduct original phase differential δ ₀, know that namely the phase differential caused due to conditions such as temperature, humidity and deformation now changes, thereby can revise at software or phase shifter place.

The method feature also is:

1. utilize the initial control signal of gps clock signal as the relevant output of each array element calibration information source, make respectively calibrate information source can be in the same time, same-phase output, for the detection of rear end provides coherent;

2. using center antenna as the phase standard antenna, try to achieve by comparison the phase differential of link in twos with all the other antenna link signals, the whole receiver of array element is made to as a whole its phase differential that calculates;

3. utilize advanced phase difference detection chip AD8302, will be converted into corresponding with it DC voltage through the phase differential of the calibration source signal of the array element in twos of receiver and transmission feeder, be conducive to accurately measuring phase differential;

4. utilize the 4 Channel Synchronous 100Ksps speed collections of the high-accuracy data collection card NI921516bit of U.S. national instrument company quantified precision.Collect the phase voltage signal, by computing machine LABVIEW software, recovering the phase differential of link in twos.

The method is exported at feeder line, the employing phase detecting circuit phase differential of the output signal of rate-aided signal after different receivers in twos is converted into voltage, the antenna array center cell of take is reference, can infer and obtain the phase differential of each antenna array element with respect to center cell by the voltage difference situation.

Implementation process: the utility model adopts the GPS time service to control many array element calibration source signals, makes it to reach the purpose of coherent source; Adopt the phase-detection chip, the phase differential of signal in twos is converted to corresponding with it voltage, obtain phase differential by data collection and analysis.

1. at first each array-element antenna calibration information source control panel is connected with the GPS receiving circuit, and control panel reads and analyze the temporal information that GPS receives signal.By the preset calibration time on control panel, the GPS receiving circuit plays the effect into the time service of information source control panel.Adopt DDS chip AD9852 to produce chip as information source, when the calibration time arrives, each information source control panel writes and initially sends phase place and frequency parameter to signal source circuit, and while enabling signal source, like this under the synchro control of GPS, the calibration information source of each array element has been sent same-phase in the same time, the same frequency signal;

2. the signal received of each array-element antenna and calibration source signal are by selectable being linked in front end LNA of microwave switch, and microwave switch is connected aerial signal when observing, and microwave switch is selected the input of calibration information source when calibrating;

3. in the rear end of every array-element antenna receiver, with two power splitters, combiner is accessed on a road, and microwave switch is all accessed on another road;

4. by the selection of microwave switch, select two input signals to carry out phase differential relatively at every turn, adopt the core of phase-detection chip AD8302 as phase detection, phase signal is converted into to corresponding voltage signal with it.

5. simultaneously by the rate-aided signal of center array element as a reference, calculate every array element receiver with respect to center array element phase differential, the phase differential that this phase differential deducts two array elements under current weighting condition is namely the phase differential that produced by effect of natural conditions.

Claims (1)

1. the device of the phase measurement of the low-frequency antenna battle array based on GPS and phase-detection chip, is characterized in that, the hardware components of this device comprises gps signal receiver module, signal generation and control circuit, phase difference detection contrast circuit;

Annexation between each discrete parts hardware is as follows:

1) the circuit data output terminal of gps signal receiver module is connected with the data receiver of signal generation and control circuit,

2) in signal generation and control circuit, main control chip is connected with the signal controlling end of DDS; The DDS signal output part is connected with the rate-aided signal input end of receiver;

3) the receiver output terminal, after long cable transmission, is in twos one group and is connected with two analog input ends of phase difference detection contrast circuit;

4) direct current of phase difference detection contrast circuit detection output terminal is connected with the analog output of AD collection plate.

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