CN1254963A - Converter of linear polarized wave and circular polarized wave - Google Patents

Abstract

The linear/circular polarizing converter of the present invention uses an elliptical waveguide having elliptical cross-section which receives supply of a linearly polarized signal at one end of elliptical waveguide and outputs a circularly polarized signal from the other end of elliptical waveguide When the application frequency wavelength of polarized signal supplied to the elliptical waveguide is lambda<O>, length of elliptical waveguide is L, cutoff wavelength of polarizing plane in the long axis direction of polarized signal is lambda<CH>, cutoff wavelength of the polarizing plane in the short axis direction of polarized signal is lambda<CV>, phase of the basic mode polarization signal in the long axis direction for the polarized signal is theta<H>, phase of basic mode polarization in the short axis direction is theta<V> and phase difference of these phases theta<H> and theta<V> is DELTA<theta>.

Description

Linearly polarized wave, circularly polarized wave transducer

What the present invention relates to is linearly polarized wave, circularly polarized wave transducer, be particularly related to the oval waveguide pipe of using elliptical section with major axis and minor axis, and major axis dimension, minor axis dimension and the tube axial direction length of selecting oval waveguide pipe, to reach linearly polarized wave, the circularly polarized wave transducer that linearly polarized wave and circularly polarized wave can exchange.

The existing linearly polarized wave that the linearly polarized wave conversion of signals is become the circularly polarized wave signal, the circularly polarized wave transducer, well-known have following two kinds, they are: the inner radial of circular waveguide install with the input polarization corrugated of linearly polarized wave signal be 45 dielectric plate (below be called first kind of known linearly polarized wave, the circularly polarized wave transducer), with towards same circular waveguide inside, with the input polarization corrugated of linearly polarized wave signal be the outstanding some screw rods of 45 (below be called second kind of linearly polarized wave, the circularly polarized wave transducer).

Fig. 2 (a), Fig. 2 (b), Fig. 2 (c) represent the structural map of an example in first kind of known linearly polarized wave, the circularly polarized wave transducer, Fig. 2 (a) is the profile of length direction, the side view of Fig. 2 (b) for seeing to (being input one side) from A, the side view of Fig. 2 (c) for seeing to (being output one side) from B.

Arrive shown in Fig. 2 (c) as Fig. 2 (a), first kind of linearly polarized wave, circularly polarized wave transducer are to be the circular waveguide 21 of circle by section, form with the dielectric plate 22 that is assemblied in the circular waveguide inner radial, one end of circular waveguide 21 forms input 23, and the other end of circular waveguide 21 forms output 24.The linearly polarized wave face that dielectric plate 22 is mounted to the linearly polarized wave signal that sends from input 23 is 45, and cut into the deep 22a of portion that antireflection is used, 22b, this deep portion is for walk the dihedral that its cutting forms to the center more from input 23 and output 24 more darkly.

On first kind of linearly polarized wave, circularly polarized wave transducer, the linearly polarized wave signal that transmits from the input 23 of circular waveguide 21, when transmitting in the inside of circular waveguide 21 from input 23, make the polarization corrugated be transformed into circularly polarized wave by the dielectric plate 22 that is configured to be 45 by linearly polarized wave with the linearly polarized wave face, thus can be from output 24 output circularly polarized wave signals.In first kind of linearly polarized wave, circularly polarized wave transducer, carry out by the transformation of linearly polarized wave to circularly polarized wave.

Secondly, Fig. 3 (a), Fig. 3 (b), Fig. 3 (c) illustrate the structural map of second kind of linearly polarized wave, circularly polarized wave transducer one example, wherein, Fig. 3 (a) is the profile of length direction, the side view of Fig. 3 (b) for seeing to (being input one side) from A, the side view of Fig. 3 (c) for seeing to (being output one side) from B.

Arrive shown in Fig. 3 (c) as Fig. 3 (a), second kind of linearly polarized wave, circularly polarized wave transducer, be to be the circular waveguide 31 of circle by section, form with the some screw rods 32 that protrude in circular waveguide 31 inner radial, one end of circular waveguide 31 forms input 33, and the other end of circular waveguide 31 promptly forms output 34.Some screw rod 32 outstanding settings, be 45 with (the linearly polarized wave signal) the linearly polarized wave face that transmits from input 23, simultaneously for preventing that thus some screw rods 32 produce reflection, make the structure that its outstanding length (from the centre) shortens successively to input 23 and output 24.

On second kind of linearly polarized wave, circularly polarized wave transducer, the linearly polarized wave signal that transmits from the input 33 of figure waveguide pipe 31, when in circular waveguide 31, transmitting from input 33, by being 45 and outstanding some screw rods 32 with the linearly polarized wave face, the polarization corrugated is promptly changed circularly polarized wave into by linearly polarized wave, and can be from output 34 output circularly polarized wave signals.Like this, in second kind of linearly polarized wave, circularly polarized wave transducer, carried out by the conversion of linearly polarized wave to circularly polarized wave.

First kind of linearly polarized wave, circularly polarized wave transducer, be in circular waveguide 21, to install dielectric plate 22, dielectric plate 22 is transformed into circularly polarized wave with linearly polarized wave whereby, so, it is too much to have produced the part number, thereby unitary construction is complicated, be difficult to guarantee problem such as stability shortcoming reliability during running.

Again, second kind of linearly polarized wave, circularly polarized wave transducer, be outstanding some screw rods 32 in circular waveguide 31, some screw rods 32 are transformed into circularly polarized wave with linearly polarized wave whereby, so the same with first kind of linearly polarized wave, circularly polarized wave transducer, it is too much to produce the part number, the unitary construction complexity, thus be difficult to guarantee problem such as stability shortcoming reliability during running.

The present invention proposes for addressing these problems.Its objective is in minimizing part number when structure is oversimplified, provides running to have good stability, and can obtain linearly polarized wave, the circularly polarized wave transducer of height reliability.

For achieving the above object, linearly polarized wave of the present invention, circularly polarized wave transducer have adopted oval waveguide pipe, and the major axis dimension a of its oval waveguide pipe, minor axis dimension b and tube axial direction size l will so select so that following formula is set up:

[formula 1]

Δθ＝|θ _V-θ _H| $=\frac{2\mathrm{\&pi;}l}{{\mathrm{\&lambda;}}_0}|\sqrt{1-{\left(\frac{{\mathrm{\&lambda;}}_0}{{\mathrm{\&lambda;}}_{\mathrm{CV}}}\right)}^2}-\sqrt{1-{\left(\frac{{\mathrm{\&lambda;}}_0}{{\mathrm{\&lambda;}}_{\mathrm{CH}}}\right)}^2}|$

＝90°

Wherein: the wavelength of the polarized wave signal institute frequency of utilization of being supplied with by oval waveguide pipe is made as λ ₀, the length of oval waveguide pipe is made as l, and the cut square wavelength of polarized wave signal on long axis direction polarization corrugated is made as λ _CH, the intercept wavelength of polarized wave signal on short-axis direction polarization corrugated is made as λ _CV, with respect to the polarized wave signal, the phase place of the basic mode polarized wave of long axis direction is made as θ _H, and the phase place of short-axis direction basic mode polarization is made as θ _V, and the phase difference of establishing wherein is Δ θ.

Linearly polarized wave of the present invention, circularly polarized wave transducer, be utilize the long axis direction polarization corrugated of oval waveguide pipe to cut square wavelength and short-axis direction polarization corrugated to cut the square wavelength variant, different with short-axis direction polarization velocity of wave propagation these two characteristics with long axis direction polarization velocity of wave propagation, select major axis dimension a, the minor axis dimension b of oval waveguide pipe and the length l of tube axial direction, so that the phase difference between long axis direction basic mode polarization and short-axis direction basic mode polarization becomes 90 ° of angles.

According to above-mentioned means, because linearly polarized wave, circularly polarized wave transducer are made of separately oval waveguide pipe, need not be equipped with dielectric plate or some screw rods in waveguide pipe inside, so can make the part number reduce, unitary construction is simple, thereby can obtain the reliability of the good and height of action stability.

In an embodiment of the present invention, used linearly polarized wave, circularly polarized wave transducer, be that oval waveguide pipe by the elliptical section with major axis and minor axis constitutes, end input linearly polarized wave signal or circularly polarized wave signal from oval waveguide pipe, from the device of the other end of oval waveguide pipe output circularly polarized wave signal or linearly polarized wave signal, as the wavelength of establishing the polarized wave signal institute frequency of utilization that is supplied to oval waveguide pipe is λ ₀, the length of oval waveguide pipe is l, section square wavelength of polarized wave signal on long axis direction polarization corrugated is λ _CH, section square wavelength of polarized wave signal on short-axis direction polarization corrugated is λ _CV, with respect to the polarized wave signal, the phase place of the basic mode polarized wave of long axis direction is θ _H, and the phase place of short-axis direction basic mode polarization is θ _V, long axis direction basic mode polarization phase theta _HPhase theta with the short-axis direction basic mode polarization _VBetween phase difference when being Δ θ, then choose major axis dimension a, minor axis dimension b and the tube axial direction length dimension l of oval waveguide pipe by the principle that makes following numerical expression set up.

[formula 1]

Δθ＝|θ _V-θ _H| $=\frac{2\mathrm{\&pi;}l}{{\mathrm{\&lambda;}}_0}|\sqrt{1-{\left(\frac{{\mathrm{\&lambda;}}_0}{{\mathrm{\&lambda;}}_{\mathrm{CV}}}\right)}^2}-\sqrt{1-{\left(\frac{{\mathrm{\&lambda;}}_0}{{\mathrm{\&lambda;}}_{\mathrm{CH}}}\right)}^2}|$

＝90°

In an object lesson of the embodiment of the invention, its linearly polarized wave, circularly polarized wave transducer are such: the polarized wave signal wavelength that is supplied to the low-limit frequency in the oval waveguide pipe frequency bandwidth is made as λ ₁, then by itself and section square wavelength X of polarized wave signal on long axis direction polarization corrugated _CHBetween relational expression λ _CH≈ 1.1 λ ₁Set up such condition and select the minor axis dimension b of oval waveguide pipe.

In embodiments of the present invention in the another one object lesson, its linearly polarized wave, circularly polarized wave transducer are such, are promptly making the minor axis dimension b that becomes the relation of (a/b) ≈ 1.2 between major axis dimension a and the minor axis dimension b and select oval waveguide pipe on the oval waveguide pipe.

According to embodiments of the invention, linearly polarized wave, the circularly polarized wave transducer is made of separately oval waveguide pipe, as selecting the major axis dimension of oval waveguide pipe in a manner described, the length of minor axis dimension and tube axial direction, then the inside of oval waveguide pipe does not need to be equipped with building blocks such as any dielectric plate or some screw rods, therefore, linearly polarized wave, the component part number of circularly polarized wave transducer can reduce, unitary construction is extremely simple, thereby linearly polarized wave, the running stability of circularly polarized wave transducer can reach good degree, and its reliability can increase substantially.

With reference to the accompanying drawings embodiments of the invention are illustrated.

Fig. 1 (a), Fig. 1 (b), Fig. 1 (c) are the composition diagram of an embodiment of linearly polarized wave of the present invention, circularly polarized wave transducer;

Fig. 2 (a), Fig. 2 (b), Fig. 2 (c) are the composition diagram of existing linearly polarized wave, circularly polarized wave transducer one example;

Fig. 3 (a), Fig. 3 (b), Fig. 3 (c) are the composition diagram of existing linearly polarized wave, the other example of circularly polarized wave transducer.

Fig. 1 (a) is the profile of length direction, the side view of Fig. 1 (b) for seeing from A direction (being input one side), the side view of Fig. 1 (c) for seeing from B direction (being output one side).

Shown in Fig. 1 (a), Fig. 1 (b), Fig. 1 (c), the linearly polarized wave of present embodiment, circularly polarized wave transducer, section is oval, length (diameter) a by long axis direction, the length of short-axis direction (diameter) b, the oval waveguide pipe 1 that the length l of tube axial direction etc. form constitutes, and an end of oval waveguide pipe 1 is an input 2, and the other end of oval waveguide pipe becomes output 3.

In the present embodiment, when the polarized wave signal transmits in the inside of oval waveguide pipe 1, section square wavelength X on the long axis direction polarization corrugated of oval waveguide pipe 1 _CHWith section square wavelength X on the short-axis direction polarization corrugated _CVAnd different, and long axis direction polarized wave speed and short-axis direction polarized wave speed are also inequality, present embodiment utilizes this two different place to carry out work.

Establishing the wavelength of polarized wave signal frequency on free space herein, is λ ₀, establishing the wavelength of polarized wave signal frequency in waveguide pipe is λ _g, then the phase theta at the polarized wave signal of waveguide pipe internal communication can be expressed as following formula:

[formula 2] $\mathrm{\&theta;}=\frac{2\mathrm{\&pi;}}{{\mathrm{\&lambda;}}_g}l,{\mathrm{\&lambda;}}_g=\frac{{\mathrm{\&lambda;}}_0}{\sqrt{1-{\left(\frac{{\mathrm{\&lambda;}}_0}{{\mathrm{\&lambda;}}_C}\right)}^2}}$

As previously mentioned, l represents the length of waveguide pipe tube axial direction.

In addition, under oval waveguide pipe situation, as the phase place of establishing long axis direction polarized wave signal is θ _H, the phase place of short-axis direction polarized wave signal is θ _V, the phase theta of long axis direction polarized wave signal then _HPhase theta with short-axis direction polarized wave signal _VCan be expressed as following formula respectively:

[formula 3] ${\mathrm{\&theta;}}_H=\frac{2\mathrm{\&pi;}}{{\mathrm{\&lambda;}}_{\mathrm{gH}}}l,{\mathrm{\&theta;}}_V=\frac{2\mathrm{\&pi;}}{{\mathrm{\&lambda;}}_{\mathrm{gV}}}l$

λ in the following formula _GHFor the employed optional frequency of long axis direction polarized wave signal at guided wave wavelength in pipe, λ _GVFor the employed optional frequency of short-axis direction polarized wave signal at the guided wave wavelength in pipe.

The condition that linearly polarized wave, circularly polarized wave transducer use that can be used as of oval waveguide pipe 1 is obtained in examination now, in other words, i.e. and the phase theta of the long axis direction polarized wave signal of polarized wave signal on output 3 _HPhase theta with short-axis direction polarized wave signal _VBetween phase difference θ be 90 ° condition.This condition is:

[formula 1]

Δθ＝|θ _V-θ _H| $=\frac{2\mathrm{\&pi;}l}{{\mathrm{\&lambda;}}_0}|\sqrt{1-{\left(\frac{{\mathrm{\&lambda;}}_0}{{\mathrm{\&lambda;}}_{\mathrm{CV}}}\right)}^2}-\sqrt{1-{\left(\frac{{\mathrm{\&lambda;}}_0}{{\mathrm{\&lambda;}}_{\mathrm{CH}}}\right)}^2}|$

＝90°

Yet, as previously mentioned, on oval waveguide pipe 1, section square wavelength X on its long axis direction polarization corrugated _CHSection square wavelength X with short-axis direction polarization corrugated _CVBetween λ is arranged _CH≠ λ _CVRelation, in addition, as previously mentioned, long axis direction polarization corrugated cut the square wavelength X _CHSection square wavelength X with short-axis direction polarization corrugated _CV, when the long axis direction length of establishing oval waveguide pipe 1 is a, and its short-axis direction length also has following relationship to exist when being b:

λ _CH≈3.41·(b/2)

λ _CV≈3.41·(a/2)

And then, be λ as if the low-limit frequency free space wavelength in the frequency band of establishing the polarized wave signal ₁, then should satisfy cutting between the square wavelength of itself and long axis direction polarization corrugated and form following relationship, that is: λ _CH〉=λ ₁, be preferably λ _CH≈ 1.1 λ ₁Condition select the short-axis direction length b of oval waveguide pipe 1.

Secondly, formation (a/b) ≈ 1.2 such relations are selected the long axis direction length a of oval waveguide pipe 1 between the short-axis direction length b of the long axis direction length a that should satisfy oval waveguide pipe 1 and this pipe.

Just constitute the method for designing of oval waveguide pipe 1 of linearly polarized wave, the circularly polarized wave transducer of present embodiment below, enumerate an example narration.

At first, if will use oval waveguide pipe 1 to carry out the conversion of linearly polarized wave, must make bandwidth (the low-limit frequency f of linearly polarized wave signal to circularly polarized wave _lWith highest frequency f _h).

Next is from section square wavelength X on long axis direction polarization corrugated _CH, oval waveguide pipe 1 long axis direction length a, low-limit frequency free space wavelength λ ₁, and low-limit frequency f _lBetween following relational expression determine the short-axis direction length b of oval waveguide pipe 1:

λ _CH≈ 3.41 (b/2)=1.1 λ ₁=1.1 (C/f _l) (C is a ray velocity herein)

Then, determine the long axis direction length a of oval waveguide pipe 1 from the following relationship formula between the short-axis direction length b of the long axis direction length a of oval waveguide pipe 1 and oval waveguide pipe 1:

(a/b)≈1.2

Next step is to determine the tube axial direction length l of oval waveguide pipe 1 by following formula, thereby the ask shape of oval waveguide pipe 1 is obtained.

[formula 1]

Δθ＝|θ _V-θ _H| $=\frac{2\mathrm{\&pi;}l}{{\mathrm{\&lambda;}}_0}|\sqrt{1-{\left(\frac{{\mathrm{\&lambda;}}_0}{{\mathrm{\&lambda;}}_{\mathrm{CV}}}\right)}^2}-\sqrt{1-{\left(\frac{{\mathrm{\&lambda;}}_0}{{\mathrm{\&lambda;}}_{\mathrm{CH}}}\right)}^2}|$

＝90°

In the linearly polarized wave of present embodiment, circularly polarized wave transducer, if supply with the frequency of utilization wavelength X for the input 2 of oval waveguide pipe 1 with above-mentioned structure ₀The linearly polarized wave signal, then this linearly polarized wave signal will transmit in oval waveguide pipe 1.At this moment, because the long axis direction length a of oval waveguide pipe 1, short-axis direction length b, and the size of tube axial direction length l etc. is all selected under above-mentioned each relational expression situation from satisfying, so supply with the linearly polarized wave signal of input 2, at output 3, its polarization corrugated converts circularly polarized wave to from linearly polarized wave, so can take out the circularly polarized wave signal from output 3, thereby form linearly polarized wave, the circularly polarized wave transducer that can convert circularly polarized wave to from linearly polarized wave.In addition, if supply with circularly polarized wave for input 2, also can take out linearly polarized wave from output 3.

In the case, the linearly polarized wave of present embodiment, the circularly polarized wave transducer, owing to constitute separately by oval waveguide pipe 1, so as long as major axis dimension a of this oval waveguide pipe 1, minor axis dimension b and tube axial direction length l are selected in a manner described, then in the inside of oval waveguide pipe 1, need not to be equipped with the structure element of dielectric plate or some screw rods etc., so linearly polarized wave, the structure element of circularly polarized wave transducer can reduce, thereby its unitary construction is extremely simple, in addition, there is no other parts beyond oval waveguide pipe 1, so linearly polarized wave, having good stability of circularly polarized wave transducer action can increase substantially its reliability.

In addition, the linearly polarized wave of present embodiment, circularly polarized wave transducer, special superior place is, for the polarized wave in oval waveguide pipe 1, what its transmission loss increased the most rapidly is the low-limit frequency band of frequency bandwidth, section square wavelength X on the long axis direction polarization corrugated of its low-limit frequency free space wavelength λ 1 and oval waveguide pipe 1 _CHBetween, make its constituent relation formula λ _CH〉=λ ₁, be preferably λ _CH≈ 1.1 λ ₁, select the long axis direction length a of oval waveguide pipe 1 like this for use, just can avoid the increase rapidly of above-mentioned transmission loss on lowest band.

Further, the linearly polarized wave of present embodiment, circularly polarized wave transducer, owing to the short-axis direction size b that selects oval waveguide pipe 1 between long axis direction size a that makes oval waveguide pipe 1 and the short-axis direction size b for the relational expression of (a/b) ≈ 1.2, so singly do not avoided the oversize of oval waveguide pipe 1, avoided producing simultaneously unnecessary higher mode yet.

As mentioned above, according to the present invention, linearly polarized wave, circularly polarized wave transducer can constitute individually with oval waveguide pipe, owing to need not to be equipped with element such as dielectric plate or some screw rods in oval waveguide pipe inside, so the number of the building block of linearly polarized wave, circularly polarized wave transducer can reduce.Unitary construction is very simple, simultaneously, can make that the action stability of linearly polarized wave, circularly polarized wave transducer is good, and can increase substantially its reliability.

Claims (3)

1. a linearly polarized wave, circularly polarized wave transducer, it is characterized in that, this transducer is made of the oval waveguide pipe with elliptic jet (major axis and minor axis are arranged), above-mentioned oval waveguide pipe is when the one end is supplied with linearly polarized wave signal or circularly polarized wave signal, can be from the other end output circularly polarized wave signal of above-mentioned oval waveguide pipe or the device of linearly polarized wave signal, the major axis dimension a of the above-mentioned oval waveguide pipe of selecting for use, minor axis dimension b and tube axial direction length l should make following formula set up:

[formula 1]

Δθ＝|θ _V-θ _H| $=\frac{2\mathrm{\&pi;}l}{{\mathrm{\&lambda;}}_0}|\sqrt{1-{\left(\frac{{\mathrm{\&lambda;}}_0}{{\mathrm{\&lambda;}}_{\mathrm{CV}}}\right)}^2}-\sqrt{1-{\left(\frac{{\mathrm{\&lambda;}}_0}{{\mathrm{\&lambda;}}_{\mathrm{CH}}}\right)}^2}|$

＝90°

Wherein, the wavelength of establishing the polarized wave signal frequency of utilization that is supplied to above-mentioned oval waveguide pipe is λ ₀, the length of establishing above-mentioned oval waveguide pipe is l, establish on the long axis direction polarization corrugated of above-mentioned polarized wave signal to cut a square wavelength be λ _CH, establish on the short-axis direction polarization corrugated of above-mentioned polarized wave signal to cut a square wavelength be λ _CV, the phase place of establishing the long axis direction basic mode polarization of corresponding above-mentioned polarized wave signal is θ _H, the phase place of establishing above-mentioned short-axis direction basic mode polarization is θ _V, the phase theta of establishing above-mentioned long axis direction basic mode polarization _HPhase theta with above-mentioned short-axis direction basic mode polarization _VBetween phase difference be Δ θ.

2. linearly polarized wave as claimed in claim 1, circularly polarized wave transducer is characterized in that, the polarized wave signal of establishing the low-limit frequency in the frequency bandwidth that is supplied to above-mentioned oval waveguide pipe is λ at the wavelength of free space ₁The time, when selecting the minor axis dimension b of above-mentioned oval waveguide pipe, should satisfy λ ₁With λ _CHBetween relational expression be λ _CH≈ 1.1 λ ₁, wherein, λ _CHBe section square wavelength on the long axis direction polarization corrugated of above-mentioned polarized wave signal.

3. linearly polarized wave as claimed in claim 2, circularly polarized wave transducer is characterized in that, when selecting above-mentioned oval waveguide pipe major axis dimension a, should satisfy following relationship formula between the major axis dimension a of above-mentioned oval waveguide pipe and the minor axis dimension b: (a/b) ≈ 1.2.

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