CN102055536A - Reflector antenna delay measurement method - Google Patents

Abstract

The invention discloses a reflector antenna delay measurement method. Reflector antenna delay consists of feeder delay, feed source network delay and antenna aplanatism delay. The invention provides a vector network analyzer based measurement and calculation combined method for determining the reflector antenna delay; in the method, a vector network analyzer is used for measuring the feeder delay and the feed source network delay and calculating the aplanatism delay, and the feeder delay, the feed source network delay and the aplanatism delay are added to get antenna delay. The method disclosed by the invention is simple and feasible, is not only suitable for the measurement of the reflector antenna delay, but also suitable for the measurement of the characteristic that the delay varies with the change of temperature.

Description

Reflector antenna time delay assay method

Technical field

The present invention relates to a kind of reflector antenna time delay assay method in the space communication TT﹠C system.

Background technology

Reflector antenna is in space communication system, and as launching electromagnetic wave and reception electromagnetic wave signal, during emission, the power output of transmitter is by launching feeder line output by sky alignment space radiation; During reception, become radio frequency guided wave power transfer to give receiver the incident electromagnetic wave energy conversion in space.

In the space communication TT﹠C system, realize finding range by measuring time delay, so system's time delay null value measurement is considerable.And the time delay of reflector antenna itself is the part of system's time delay null value, so the reflector antenna latency measurement also is very important, and its certainty of measurement and stability thereof directly influence system's range accuracy.There is following limitation in traditional reflector antenna time-delay measuring method:

1, traditional antenna latency measurement is demarcated with system's time delay null value, needs to set up complicated far field test macro, testing expense costliness.

2, at the latency measurement of antenna own, traditional method of measurement is not suitable for measuring in the laboratory, and test environment is bigger to the measurement result influence.

3, traditional reflector antenna latency measurement can't realize that time delay varies with temperature feature measurement.

4, traditional antenna time-delay measuring method does not accurately provide the definition of reflector antenna time delay.

Summary of the invention

The objective of the invention is to avoid the weak point in the above-mentioned background technology and propose a kind of method of utilizing the vector network analyzer measurements and calculations to combine, determine the method for reflector antenna time delay.

A kind of reflector antenna time delay assay method, described reflector antenna time delay is made up of feeder time delay, feed network time delay and aplanatism time delay, is expressed as with following formula:

τ _ant＝τ _kx+τ _wl+τ _gc

In the formula: τ _AntThe time delay of-antenna;

τ _Kx-feeder line time delay;

τ _Wl-feed network time delay;

τ _Gc-aplanatism time delay.

The assay method of described feeder time delay is realized by vector network analyzer, at first do not receiving under the situation of surveying feeder line, test cable is straight-through, the radio frequency output of vector network analyzer directly connects its radio frequency input, lead directly to the calibration calibration, thereby vector network analyzer initial condition parameter is set; Then, connect feeder line to be measured, then vector network analyzer can directly be measured the size of feeder line time delay to be measured.

The assay method of described feed network time delay is realized by vector network analyzer, at first the test cable with standard horn is connected with the test cable of feed network is straight-through, vector network analyzer is led directly to calibration measure, and determine the time delay initial value of standard horn; Then, measure the time delay size in the whole loop of feed network and standard horn composition with vector network analyzer, deduction standard horn time delay initial value and standard horn promptly get the time delay of feed network to the propagation delay of the free space of distance between the Feed Horn phase center.

Described aplanatism time delay is an aplanatism distance and the ratio of the light velocity, and wherein the aplanatism distance is the distance that Feed Horn phase center to subreflector arrives primary reflection surface again, is expressed from the next:

$d=\frac{D_s}{2\sin {\mathrm{\θ}}_m}+\frac{{D-D}_s}{2\sin {\mathrm{\θ}}_{\mathrm{vm}}}$

In the formula: the d-aplanatism;

D-parabolic antenna interarea bore;

D _sThe secondary face bore of-parabolic antenna;

θ _m-feed phase the heart is to the half angle of secondary face;

θ _Vm-subreflector edge is to the half angle of interarea;

Apart from d, utilize following formula to calculate the aplanatism time delay by the aplanatism of calculating:

${\mathrm{\τ}}_{\mathrm{gc}}=\frac{d}{c}$

In the formula: c is the light velocity.

The present invention compares with background technology has following advantage:

1, utilize the method for vector network analyzer mensuration antenna time delay simply suitable.

2, can in the laboratory, finish the reflector antenna latency measurement, need not to measure in the outfield.

3, in the laboratory, finish the reflector antenna latency measurement, can reduce the influence of measurement environment, improved certainty of measurement measurement result.

4, method of the present invention can realize that the antenna time delay varies with temperature feature measurement.

5, the present invention has the value of promotion and application preferably.

Description of drawings

Fig. 1 is a reflector antenna simple principle schematic diagram.

Fig. 2 is a feeder line latency measurement principle schematic of the present invention.

Fig. 3 is a feed network latency measurement principle schematic of the present invention.

Embodiment

The reflector antenna time delay is defined as the propagation time of electromagnetic wave by antenna, is made up of feeder time delay, feed network time delay and aplanatism time delay.The method of utilizing the vector network analyzer measurements and calculations to combine is determined the reflector antenna time delay.Reflector antenna is in case design finishes, and then the aplanatism time delay just can be calculated, and measures feeder line and feed network time delay with vector network analyzer then, just can determine the reflector antenna time delay.The reflector antenna time delay can be divided into antenna emission time delay and receive time delay.(the Feed Horn phase center is to subreflector to the emission time delay (comprising Feed Horn and feed network) of the emission feeder line propagation delay of antenna feed network input port, feed network and antenna aplanatism time delay by the transmitter delivery outlet for the emission time delay, reflex to the antenna interarea by secondary face reflecting surface, reflex to the electromagnetic wave propagation path delay of time of antenna actinal surface again by the antenna interarea).

Among Fig. 1, D is the bore of reflector antenna, D _sBe secondary face diameter, θ _mThe feed phase heart is to the half angle of secondary face, θ _VmSecondary face edge is to the half angle of interarea.

The propagation path of launching electromagnetic wave equals OM+MN+NP among Fig. 1) form; (the antenna actinal surface is to the antenna interarea by antenna aplanatism time delay for the antenna receive time delay, interarea reflexes to the antenna subreflector, reflex to the electromagnetic wave propagation path delay of time of the Feed Horn phase heart again by the secondary face of antenna, receive the electromagnetic wave propagation path among Fig. 1 and equal PN+NM+MO), the receive time delay (comprising Feed Horn and feed network) of feed network and receive feeder line time delay (the feed network delivery outlet is to the time delay of receiver input port) composition.Hence one can see that: no matter be antenna emission time delay or receive time delay, all form by feeder line time delay, feed network time delay and aplanatism time delay, can be represented by the formula into:

τ _ant＝τ _kx+τ _wl+τ _gc

In the formula: τ _AntThe time delay of-antenna;

τ _Kx-feeder line time delay;

τ _Wl-feed network time delay;

τ _Gc-aplanatism time delay.

The object of the present invention is achieved like this: reflector antenna feeder line time delay and feed network time delay null value utilize vector network analyzer to measure acquisition, and the aplanatism time delay obtains by calculating.Just can determine the reflector antenna time delay by the aplanatism time delay of measuring time delay and calculating.Then the reflector antenna time-delay measuring method is as follows:

Feeder line time delay τ _KxMeasurement: shown in the accompanying drawing 2, be feeder line latency measurement functional-block diagram.Its basic principle of measurement method is: according to the test macro of setting up shown in Figure 2, at first not receiving under the situation of surveying feeder line, that test cable is straight-through, the radio frequency output of vector network analyzer directly connects its radio frequency input, the vector network analyzer state parameter is set, and leads directly to the calibration calibration; Connect feeder line to be measured then, then vector network analyzer can directly be measured the size of feeder line time delay to be measured.

Feed network time delay τ _WlMeasurement: the feed network time delay is meant the time delay of antenna feed phase center to the network delivery outlet, and available vector network analyzer is demarcated, and its measuring principle block diagram is seen shown in the accompanying drawing 3.The basic principle of Feed Horn latency measurement is: according to the test macro of setting up shown in Figure 3, at first the test cable with standard horn is connected with the test cable of feed network is straight-through, vector network analyzer is led directly to calibration measure; Press then shown in the accompanying drawing 3 and connect, measure the time delay size in whole loop with vector network analyzer, deduct the propagation delay (distance of calculation delay is the distance of optical waveguide probe to the loudspeaker phase center) of standard horn time delay initial value and free space, promptly get the time delay size of Feed Horn.

Aplanatism time delay τ _GcCalculating: Feed Horn phase center to secondary face arrive the time delay of primary reflection surface again, available aplanatism condition, calculating electromagnetic wave propagation path, thus calculate the size of its time delay.Reflector antenna is in case design finishes, and then the aplanatism path can be calculated with following formula:

$d=\frac{D_s}{2\sin {\mathrm{\θ}}_m}+\frac{{D-D}_s}{{2\sin \mathrm{\θ}}_{\mathrm{vm}}}---\left(1\right)$

In the formula: the d-aplanatism;

D-parabolic antenna interarea bore;

D _sThe secondary face bore of-parabolic antenna;

θ _m-feed phase the heart is to the half angle of secondary face;

θ _Vm-secondary face edge is to the half angle of interarea.

Apart from d, utilize following formula to calculate the aplanatism time delay by the aplanatism of calculating:

${\mathrm{\τ}}_{\mathrm{gc}}=\frac{d}{c}$

In the formula: c is the light velocity.

Illustrate embodiment below:

Known reflector antenna bore is 13 meters, and secondary face diameter is 1.3 meters, and the feed phase center is 16.94 ° to the half angle of secondary face, and secondary face edge is 79.611 ° to the half angle of interarea, and then the aplanatism distance of being calculated by formula (1) is:

$d=\frac{130}{2\×\sin 16.94}+\frac{1300-130}{2\×\sin 79.611}=817.834\left(\mathrm{cm}\right)$

The time delay of the aplanatism distance of being calculated by formula (2) is 27.261ns.

When frequency is 6075MHz, with vowing that the transmit waveguide feeder line time delay that net is measured is 95.508ns

When frequency is 6075MHz, with vowing that the feed network time delay that net is measured is 12.375ns

Then 13 meters reflector antennas are when tranmitting frequency is 6075MHz, and the time delay of reflector antenna is:

τ _ant＝τ _kx+τ _wl+τ _gc＝95.508+12.375+27.261＝135.144ns

Operation principle of the present invention is as follows:

The present invention proposes the method for utilizing the vector network analyzer measurements and calculations to combine and determine the method for reflector antenna time delay.

The reflector antenna time delay is made up of feeder line time delay, feed network time delay and aplanatism time delay.

Feeder line time delay and Feed Horn time delay are utilized vector network analyzer to measure and are obtained, and the aplanatism time-delay calculation obtains, and by the aplanatism time delay of calculating and the feeder line and the feed network time delay of measurement, just can determine the size of reflector antenna time delay null value.

Indoor at environmental experiment, but utilize method Measurement Network of the present invention and feeder line time delay to vary with temperature characteristic.

Claims (4)

1. reflector antenna time delay assay method, it is characterized in that: described reflector antenna time delay is made up of feeder time delay, feed network time delay and aplanatism time delay, is expressed as with following formula:

τ _ant＝τ _kx+τ _wl+τ _gc

In the formula: τ _AntThe time delay of-antenna;

τ _Kx-feeder line time delay;

τ _Wl-feed network time delay;

τ _Gc-aplanatism time delay.

2. reflector antenna time delay assay method according to claim 1, it is characterized in that: the assay method of described feeder time delay is realized by vector network analyzer, at first do not receiving under the situation of surveying feeder line, test cable is straight-through, the radio frequency output of vector network analyzer directly connects its radio frequency input, lead directly to the calibration calibration, thereby vector network analyzer initial condition parameter is set; Then, connect feeder line to be measured, then vector network analyzer can directly be measured the size of feeder line time delay to be measured.

3. reflector antenna time delay assay method according to claim 1 and 2, it is characterized in that: the assay method of described feed network time delay is realized by vector network analyzer, at first the test cable with standard horn is connected with the test cable of feed network is straight-through, vector network analyzer is led directly to calibration measure, and determine the time delay initial value of standard horn; Then, measure the time delay size in the whole loop of feed network and standard horn composition with vector network analyzer, deduction standard horn time delay initial value and standard horn promptly get the time delay of feed network to the propagation delay of the free space of distance between the Feed Horn phase center.

4. reflector antenna time delay assay method according to claim 3, it is characterized in that: described aplanatism time delay is an aplanatism distance and the ratio of the light velocity, wherein the aplanatism distance is the distance that Feed Horn phase center to subreflector arrives primary reflection surface again, is expressed from the next:

$d=\frac{D_s}{2\sin {\mathrm{\θ}}_m}+\frac{{D-D}_s}{2\sin {\mathrm{\θ}}_{\mathrm{vm}}}$

In the formula: the d-aplanatism;

D-parabolic antenna interarea bore;

D _sThe secondary face bore of-parabolic antenna;

θ _m-feed phase the heart is to the half angle of secondary face;

θ _Vm-subreflector edge is to the half angle of interarea;

Apart from d, utilize following formula to calculate the aplanatism time delay by the aplanatism of calculating:

${\mathrm{\τ}}_{\mathrm{gc}}=\frac{d}{c}$

In the formula: c is the light velocity.

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