JPH02188001A - Circular to linear polarized wave converter - Google Patents

Abstract

PURPOSE:To eliminate a mechanical movable element and to handle a clockwise and a counterclockwise polarized wave by providing a movable phase shifter whose phase shift quantity is switched between a state wherein the phase is shifted by (2n-1)pi/2 from the phase of an electric field component of a circular polarized wave perpendicular to a dielectric substrate where (n) is an integer larger than 1 and a state wherein the phase is further shifted equivalently by pi. CONSTITUTION:Between a microstrip line 23 and the tube-axis side end parts of a couple of extremely small antennas 251 and 252, p-n junction diodes 24-1 and 24-2 which are selected as semiconductor switching elements are connected as external components on a substrate. Here, the couple of diodes 24-1 and 24-2 are connected in series and in the same direction through a connection point on the microstrip line 23. Among respective-part pattern constitution and a pair of the diodes 24-1, 24-2 a single extremely small antenna 22 constitute an input antenna part 31, the microstrip line 23 including a reverse-surface conductor pattern 26 and the couple of diodes 24-1 and 24-2 constitute a variable phase shifter 32 which is variable in phase shifting quantity and the couple of extremely small antennas 25-1 and 25-2 constitute an output antenna part.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates generally to a converter used in the microwave region for converting circularly polarized waves into linearly polarized waves, and in particular to converters that use mechanically movable elements. Instead, only by an electrical switching signal, both the right-handed circularly polarized wave and the left-handed circularly polarized wave incident on the opening at one end of the waveguide are converted into linearly polarized waves in the same plane. This invention relates to an improvement to enable output to the end side.

[Conventional technology] If you just convert circularly polarized waves to linearly polarized waves, conventionally,
Generally, a method is adopted in which a dielectric plate is inserted into the waveguide. In other words, among the electric field components (electric field vectors) of the circularly polarized wave input into the waveguide, the component parallel to the dielectric substrate is delayed, so this is the electric field component perpendicular to this at the output end of the dielectric substrate. When combined, it becomes a linearly polarized wave.

However, there are two types of circularly polarized waves: clockwise and counterclockwise. In the near future, both clockwise and counterclockwise polarized waves will be used in satellite broadcasting and the like.

As shown above, the phase of the electric field component perpendicular to the electric field component parallel to the dielectric plate differs by exactly π or 1π between right-handed circularly polarized waves and left-handed circularly polarized waves. For,
As described above, the planes of polarization of the linearly polarized waves vector-combined at the output end of the dielectric plate are ultimately orthogonal to each other.

Therefore, in order to process converted linearly polarized waves based on both right-handed circularly polarized waves and left-handed circularly polarized waves in a single receiving system, the planes of polarization must be mutually π/2 (or 3π/2) so that it can be selectively tuned to either linearly polarized wave with a rotation angle difference of 3π/2), or a means for mechanically rotating the micro antenna, or further adjusting either linearly polarized wave plane by π. If you rotate it by /2, or if you rotate one linear polarization plane clockwise by π/4, for example,
An electrical means is required to rotate the other linearly polarized wave plane counterclockwise by π/4.

The former method of mechanically rotating a small antenna, generally called a polar rotor, has fairly satisfactory electrical characteristics considering its classical nature.

However, there are problems with the use of mechanically movable elements, and there is a high risk of failure due to the nature of the wood.In particular, the rotation of the micro antenna is usually performed by a motor, so the device as a whole is quite expensive. Becomes large,
Power consumption is also large and costs are high.

Therefore, it has been possible to convert both right-handed and left-handed circularly polarized waves into linearly polarized waves in the same plane through electrical processing without using such mechanical moving parts. In order to achieve this, a device was proposed that utilizes the Faraday effect due to the presence of a ferrite core, following the last method mentioned above. It has also been a long time since this was put into practical use.

The present invention particularly relates to the improvement of a type of circularly polarized wave to linearly polarized wave converter that eliminates mechanically moving parts, so the schematic configuration of this conventional type using a ferrite core is shown in FIG. List them and provide explanations.

In order to avoid any particular hindrance to understanding, electric field components that are originally defined as vector quantities or complex numbers are simply expressed in scalar notation in the figures, but for example, in Figure 12 (A), the counterclockwise rotation is shown. When the input wave (red component E+), which is a circularly polarized wave, enters the waveguide 10, a waveguide is installed in the waveguide 10, whose length is in the tube axis direction, and in the direction orthogonal thereto. An electric field component E+(//) parallel to the surface of the dielectric plate 11 having a predetermined thickness and an electric field component E1(↓) perpendicular to the surface of the dielectric plate 11 having a width and a predetermined thickness are at a distance of π from each other when incident on the dielectric plate 11. A phase difference of /2 is set.

However, the electric field component parallel to the dielectric plate 11 (hereinafter simply referred to as a parallel electric field component) E+ (//) is delayed due to the influence of the dielectric plate 11, whereas the electric field perpendicular to the dielectric plate 11 Since the component (hereinafter simply the vertical electric field component) El (↓) is almost not affected by the dielectric plate 11, the dielectric plate 11 can be At the output end where the length ends, these parallel electric field components E
A condition can be created in which l(//) and the vertical electric field component E+(↓) are aligned in the same plane, and therefore the direction of the plane of polarization due to the resultant vector is also as shown by the arrow E with respect to the electric field. It is possible to obtain linearly polarized waves as shown by .

Of course, the electric field component E of this linearly polarized wave. is dielectric plate 1
The rotation angle is π/4 (45°) around the tube axis with respect to the main surface of 1.

The electric field component is arrow E. The linearly polarized wave (hereinafter, the linearly polarized wave itself may be expressed using the symbol Eo) is then incident on the ferrite core 12 inserted into the waveguide.

When an external magnetic field is applied, the ferrite core 12 latches the direction of its own internal magnetic field in a direction corresponding to the direction of the external magnetic field. As a result of flowing, ferrite core 12
is biased above the critical magnetic field value along its hysteresis curve, and even after removing the excitation current,
Assume that a magnetic field is applied to the ferrite core 12 in the direction of the arrow H0.

In such a state, as shown in the relationships shown in FIGS. 12(B) to 12(C), by communicating the physical constants and geometric dimension parameters of the ferrite core 12,
In the presence of the magnetic field Ho, the electric field component whose polarization plane direction is indicated by the arrow Eo at the input end rotates clockwise by a predetermined angle θ at the output end at the other end of the ferrite core, for example, as shown in the figure. If the electric field component after rotation is expressed as Eo (θ), then
Generally, the predetermined angle θ is chosen to be π/4.

On the contrary, the direction of the current applied to the coil 13 is reversed to the first direction, and the internal magnetic field direction of the ferrite core 12 is set in the opposite direction -■. When latched, the electric field component E after rotation passing through the ferrite core 12. The rotation angle θ of (θ) is −π/4.

Therefore, by selecting the direction of the magnetic field applied to the ferrite core 12, the micro antenna (probe) fixedly aligned in the direction of the electric field component EO (θ) in FIG. 146), both the signal component due to left-handed circular polarization and the signal component due to right-handed circular polarization,
These can be extracted together.

To be more specific, if the circularly polarized wave incident on the waveguide lO is not the left-handed circularly polarized wave described above but the right-handed circularly polarized wave, the incident circularly polarized wave on the dielectric plate 11 Dielectric plate 1 at the end
The relative phase relationship between the electric field component E+ (top) perpendicular to 1 is:
The phase is advanced or delayed by π with respect to that of the left-handed circularly polarized wave, and as a result, as shown particularly well in FIG. 12(B), the synthesis at the output end of the dielectric plate 11 is The electric field component EO' of the linearly polarized wave thus obtained is in a plane orthogonal to the electric field component E0 of the linearly polarized wave when the left-handed circularly polarized wave is incident.

Therefore, when trying to extract Eo from among the electric field components Eo and Eo', the ferrite core 1
2, the direction of the internal magnetic field to be latched is set to Ho, and as shown in FIG.
If the electric field component EO(θ) is obtained by rotating the coil 13 by
The internal magnetic field latched by the core 12 may be set in the opposite direction -Ho as shown in FIG. 12(A). This makes the ferrite core! The plane of polarization of the electric field component passing through 2 is rotated counterclockwise by π/4 (by -π/4 clockwise), and the electric field component Eo(θ) with the same polarization plane as before is obtained.

[Problem to be Solved by the Invention] Although the circularly polarized wave to linearly polarized wave converter using this ferrite core 12 also has a somewhat large loss in terms of electrical characteristics, it is tolerable and has the same characteristics as described above. It is put into practical use as in

However, as is particularly clear from the structural diagram of FIG.
The insertion part of 1 and the ferrite core part that selectively rotates the polarization plane converted into a linearly polarized wave by ±π/4 around the tube axis each require a required geometric length, and therefore The length of the waveguide 1o becomes long, and when viewed as a whole, there is a disadvantage that the device becomes considerably large.

In addition, although it is not necessary to constantly supply current to the coil 13, it is necessary to supply a fairly large current during the latching operation that reverses the direction of the magnetic field held by the ferrite core 12, and the power supply for this is necessary. Necessary peripheral circuit systems such as circuits end up becoming a factor in increasing the size and cost of this type of device as a whole.

In view of these conventional circumstances, the present invention can handle both right-handed circularly polarized waves and left-handed circularly polarized waves, has no mechanically movable elements, is small and simple, and can also be used to select left and right circularly polarized waves. The present invention aims to provide a circularly polarized wave to linearly polarized wave converter based on a new principle that does not require a large current.

[Means for Solving the Problems] In order to achieve the above object, the present invention has the following features: 0. A predetermined waveguide inserted into a waveguide and having a length in the tube axis direction of the waveguide and a width in a direction orthogonal thereto. a dielectric substrate having a thickness; (1) having a conductor pattern formed on the dielectric substrate, which is parallel to the surface of the dielectric substrate with respect to the electric field of the circularly polarized wave incident on one end of the waveguide; an input antenna section that captures electric field components; (1) an output antenna section that has a conductor pattern formed on the dielectric substrate and re-radiates electric field components parallel to the dielectric substrate into the waveguide; (2) It has a conductor pattern formed on the dielectric substrate and a semiconductor switching element that is selectively turned on and off by an external electric signal,
Due to the switching operation of the semiconductor switching element,
The phase of the electric field component parallel to the dielectric substrate captured by the input antenna section is changed to the electric field perpendicular to the dielectric substrate of the circularly polarized wave until the re-radiation into the waveguide at the output antenna section. Variable to switch the amount of phase shift between a state in which the phase of the component is shifted by (2n-1)π/2, where n is an integer greater than or equal to 1, and a state in which the phase is further equivalently shifted by π. A circular to linear polarization converter is provided, comprising: a phase shifter;

Furthermore, the present invention not only satisfies the above-mentioned basic constituent requirements ■ to ■, but also
In contrast, we also propose a circularly polarized wave to linearly polarized wave converter with the following limiting conditions (1) to (2).

That is, ■ The conductor bars and turns of either the input antenna part or the output antenna part are on a dielectric substrate and are in a pattern that constitutes a single micro antenna perpendicular to the waveguide tube axis, and The conductor pattern is a pattern that constitutes a pair of micro antennas that are on the dielectric substrate and extend independently and in opposite directions while being orthogonal to the tube axis.

■ Also, as a result of propagating the electric field component parallel to the dielectric substrate from one end to the other, the conductor pattern in the variable phase shifter always has a phase difference of (2n-1)π/2 with respect to the phase of the vertical electric field component.
A microstrip line is used that delays the phase by .

■ Either the one end or the other end of this microstrip line is connected to the single micro antenna so as to be constantly conductive, and the other end is connected to the semiconductor in the phase shifter. It is connected to one of the pair of microantennas through a switching element so as to be selectively conductive.

In addition to this configuration, among the above limiting conditions ■ to ■, circularly polarized wave to linear polarized wave conversion where condition ■ is the same but the above ■ and ■ are changed to the following limiting conditions ■ and ■. We can also suggest utensils. In other words, in this case, the basic configuration ■～■
However, the limiting conditions ■, ■, and ■ are added.

■ The above conductor pattern in the variable phase shifter has an input terminal and an output terminal, and when the other two terminals other than this input terminal and output terminal are constantly grounded or constantly opened, The pattern constitutes a four-terminal hybrid circuit in which the signal applied to the input terminal is steadily phase-shifted by (2n-1)π/2 and is expressed at the output terminal.

■ On top of that, one of the input terminals and output terminals of this hybrid circuit is connected to a single micro antenna so that it is constantly conductive, and the other is connected to a pair of micro antennas via a semiconductor switching element. Connect to one side of the antenna so that it is selectively conductive.

However, the above limitations ■, ■, ■, or ■
, ■ and ■, in the end, in a phase shifter with a variable phase shift amount that satisfies the constitutional requirement ■ among the basic constitutional requirements ■ to ■ of the present invention, the parallel electric field component is changed to the vertical electric field component by (2n −
1) The mechanism for further equivalently shifting the phase by π from a state in which the phase has been shifted by π/2 is based on selectively switching a pair of micro antennas in the input antenna section or the output antenna section using a semiconductor switching element.

However, if the following limitations ■~[phase] are adopted, both the input antenna section and the output antenna section can be modified to consist of a single micro antenna.
That is, (1) The conductor patterns of the input antenna section or the output antenna section are both formed on a dielectric substrate and are a single minute antenna pattern orthogonal to the tube axis.

■ On the other hand, the conductor pattern in the variable phase shifter has an input terminal and an output terminal, and the voltage applied to the input terminal can be applied by selectively grounding or opening the other two terminals other than the input and output terminals. Shift the phase of the signal by (2n-1)π/2, or equivalently shift the phase by (2n+1)π/2, which corresponds to a state in which the phase is further shifted by π, and display it on the above output terminal. The line pattern of a four-terminal hybrid circuit is configured.

(2) The input terminal of the hybrid circuit is connected to the single micro antenna of the input antenna section, and the output terminal is connected to the single micro antenna of the output antenna section, respectively, so as to be constantly conductive.

[Phase] Furthermore, the semiconductor switching element in the variable phase shifter selectively grounds the remaining two terminals other than the input and output terminals of the hybrid circuit only when it is in the on state. Connect for continuity.

In addition, when the circularly polarized wave to linearly polarized wave converter of the present invention is configured using a hybrid circuit as described above, depending on the convenience of the circuit configuration, the input antenna part and the input terminal of the hybrid circuit, and the hybrid A microstrip line may be provided between the output terminal of the circuit and the output antenna section. However, in that case, the length of each of the microstrip lines is set so that the sum of the phase shifts of signals propagating through them is π, where k is an integer greater than or equal to 1.

A steady phase shift of an integer multiple of π (phase lead or lag of π or 1 π) produces the same result as no phase shift at all in terms of the plane of polarization, but it is difficult to actually commercialize it. This is meaningful, and is effective, for example, when it is not possible to connect directly between the micro antenna of the input antenna section or the output antenna section and the input/output terminal of the hybrid circuit due to the circuit configuration.

[Function] In the present invention, the dielectric substrate serves as a support substrate for each of the constituent elements (1) to (2).

The input antenna section (2) extracts only the electric field component parallel to the dielectric substrate.

The extracted parallel electric field component is expressed as (2n-1), where n is an integer greater than or equal to 1, when the semiconductor switching element is first placed in either the on or off state by the phase shifter ■.
The phase is shifted (phase advanced or phase delayed) by π/2.

For the sake of simplicity, and in practice, n = 1 is often chosen for miniaturization of circuit devices, so this will be considered in the following explanation, and (2n-1)π/2 will simply be π/2. shall be treated as such.

Of course, the slow phase of π/2 is the leading phase of 3π/2 or −π/
Leading phase of 2, leading phase of π/2 is lag phase of 3π/2 or 1π/
It can be considered as a lag phase of 2, and leading and lag relationships with a phase difference of 2π are all equivalent.

In the output antenna section ■, the phase shifter ■ first converts π/
The electric field components that are phase advanced or delayed by 2 can be re-radiated into the waveguide.

Therefore, in this output antenna section, initially, the π that was between the parallel electric field component and the perpendicular electric field component in the input antenna section
Since the phase difference of /2 is eliminated and both become vector components within the same plane, linearly polarized waves can be obtained based on their combination.

However, if the phase shifter simply performs fixed phase advancement or lag by π/2 as described above, a counterclockwise circularly polarized wave will be incident at the input antenna position. When a right-handed circularly polarized wave is incident, the directions of the electric field components perpendicular to the dielectric substrate are opposite to each other, and π
Or, in order to set a phase difference of -π, the linear polarization plane as a result of combining the parallel electric field component parallel to the dielectric substrate and phase advanced or delayed by π/2 as described above is the waveguide axis. They end up existing in different orthogonal planes that have a rotation angle of π/2 around each other.

Therefore, in the present invention, the phase shifter (2) is not constructed as a means for fixing the amount of phase shift, but according to the state of the semiconductor switching element.
The amount of phase shift is set to π/2, and the phase shifter is configured as a variable phase shifter that can further shift the phase by at least equivalently π.

Therefore, when a left-handed circularly polarized wave is incident, for example, the direction of the polarization plane of the composite linearly polarized wave at the output antenna section obtained by keeping the semiconductor switching element off and not causing the above-mentioned π phase shift operation. On the other hand, even when a right-handed circularly polarized wave is incident, which would otherwise result in a linearly polarized wave plane rotated by π/2 around the tube axis, the converter of the present invention turns on the semiconductor switching element. By this,
By equivalently shifting the phase of the parallel electric field components by roughly π, the linearly polarized wave plane resulting from the combination of the parallel electric field components and the perpendicular electric field component of the right-handed circularly polarized wave can also be converted into a linearly polarized wave plane due to the combination of the parallel electric field components and the vertical electric field component of the right-handed circularly polarized wave. can be assumed to exist in the same plane as the linearly polarized wave plane generated by .

Of course, depending on whether the circularly polarized wave to be received is counterclockwise or clockwise, it is necessary to turn on or turn off the semiconductor switching element. When a pair of switching elements is used, the on/off relationship between them is determined by the design of each specific circuit.

Furthermore, for example, in addition to the basic structural requirements of the present invention, the limiting conditions of When a microstrip line is used as a phase shifting means, the semiconductor switching element is in either an on or off state to conduct one of the pair of microantennas and the microstrip line,
In other states, by switching the line so that the other microantenna and the microstrip line are electrically connected, the microstrip line constantly maintains the parallel electric field component whose phase is delayed by π/2. It is possible to decide or select whether to radiate from the output antenna section or to further equivalently shift the phase by π and radiate.

In this case, when the input antenna section is composed of a pair of micro antennas and one of them is selected, the amount of phase shift of π/2 that the micro strip line shifts, Furthermore, the equivalent phase shift of π is performed in advance before the input to the microstrip line, and the output antenna section is composed of a pair of micro antennas, one of which is a semiconductor switching When selected by the element, the microstrip line is constantly π/2
The amount of phase shifted by π is then selectively further shifted by π, and then radiated from the output antenna section.

However, in either case, a common point is that the parallel electric field component incident on the input antenna part undergoes a phase shift of π/2 or π/2±π before being radiated from the output antenna part.

Furthermore, while the above condition (■) is the same, if condition (2) and condition (2) are replaced with the conditions (2) and (2) described above, in other words, it is possible to constantly obtain a phase shift of π/2 using a microstrip line. Instead, the effect is similar even when a four-terminal hybrid circuit is used to constantly obtain a phase shift of π/2 between its input and output terminals.

In other words, when the semiconductor switching element is in either the on or off state and selectively conducts between the hybrid circuit and one of the pair of micro antennas provided in the input antenna section or the output antenna section. In this case, the parallel electric field component whose phase is constantly shifted by π/2 by the hybrid circuit is radiated as is from the output antenna part, whereas the semiconductor switching element is in another state,
When the hybrid circuit is connected to the other of the pair of micro antennas, the parallel electric field component whose phase is steadily shifted by π/2 in the hybrid circuit is further equivalently shifted by π, and then the output antenna It becomes more radiated.

This means that regardless of whether the circularly polarized wave is clockwise or counterclockwise, the planes of polarization of the converted linearly polarized wave lie in the same plane, just as in the case of using the microstrip line mentioned above. It means that it can be done like this.

Also, whether the input antenna section or the output antenna section is composed of a pair of micro antennas, the operation when the input antenna section is composed of a pair of micro antenna sections, and the output antenna section is composed of a pair of micro antennas. The explanation for the case where the micro-strip line is used can be applied as is to the operation when the micro-strip line is used.

On the other hand, in these configuration examples, whether a microstrip line or a hybrid circuit is used, whether or not a signal whose phase is "steadily" shifted by π/2 is shifted by π or not. Although the pair of micro antenna configurations and their switching means are provided separately, they can also be configured with a substantially single circuit component.

In such a case, the limited conditions ■ for the above basic configurations ■～■
This is a configuration in which ~ [phase] is added.

As is clear, in this configuration, the two terminals other than the input/output terminals of the four-terminal hybrid circuit are not "constantly" fixed to either ground or open, but are "selectively" fixed using semiconductor switching elements. “We are trying to make sure that we are grounded. This also means that it can be selectively opened.

Therefore, due to the phase shifting operation of a four-terminal hybrid circuit, which is known per se, when the semiconductor switching element selectively, for example, grounds the two terminals in question of the hybrid circuit, this hybrid circuit receives a signal applied to its input terminal. If the phase of the hybrid circuit is advanced by π/2 and sent to the output terminal, when the state of the semiconductor switching element is reversed and the two terminals of the hybrid circuit are open, the hybrid circuit will now advance -π/2, The phase of the input signal is advanced and displayed at the output terminal.

As mentioned above, the phase advance of −π/2 is equivalently 3π/2
However, depending on the state of the semiconductor switching element, the signals passing through such a hybrid circuit can have a relative phase difference of π.

In this way, it can be seen that even if a hybrid circuit in which the phase shift amount is equal in absolute value but variable in steps of π/2 in positive and negative directions is used as a variable phase shifter, the basic principle of the present invention is satisfied in exactly the same way.

When using a hybrid circuit, whether the amount of phase shift is fixed or variable, in principle, the input antenna section should be directly connected to the input terminal of the hybrid circuit, and the output terminal should also be connected directly to the output antenna section. However, in reality, it is difficult to realize such a circuit configuration with an actual conductor pattern structure, so there are A micro strip line may be provided for each.

In that case, if the propagation phase difference of the signals through these microstrip lines is set to kπ for an integer k of 1 or more, the design is easy and the operation is not affected. When k is an even number, it is an integer multiple of the phase difference 2π, so it is equivalently the same as when there is no phase difference π, and even if k is an odd number, the plane of the linearly polarized wave plane to be synthesized after the output antenna section is simply stationary. Basically 90@, it just rotates.

[Embodiment] FIG. 1 shows a schematic configuration of a first embodiment of a circularly polarized wave to linearly polarized wave converter constructed in accordance with the present invention.

In the illustrated case, the waveguide 20 is a general circular waveguide, and the circularly polarized wave E is incident on one end thereof. In the figure, only left-handed circularly polarized waves are illustrated. Inside the circular waveguide 20, there is a suitable thickness having a length along the tube axis direction and a width in the direction orthogonal to the waveguide. A dielectric substrate 21 is inserted.

On one surface of the dielectric substrate 21, a conductive pattern 22 constituting a single micro antenna 22 extending from one end located on the tube axis toward the protruding end of the Φ end in a direction orthogonal to the tube axis;
One end of the micro antenna 22 is connected to one end on the tube axis, and a conductor pattern 23 forming a micro strip line 23 extends on the tube axis toward the other end, and one end on the tube axis or close to the tube axis. Conductive patterns 25-1, 2s-2 are formed, which constitute a pair of micro antennas 25-1, 25-2, each extending in a direction perpendicular to the tube axis toward the other free end, and extending in opposite directions. A conductor pattern 26 is provided on the back surface of the substrate 21 as a back surface conductor pattern for configuring the micro-strip line 23, which may be formed uniformly over a certain area.

Each of these conductor patterns may be formed by an etching method similar to the method for forming a line pattern on a normal printed wiring board, or by attaching a separately cut and cut conductor pattern, or by other appropriate methods such as vapor deposition. Good by. This point also applies to all other embodiments described later.

Micro strip line 23 and a pair of micro antennas 2
Between the tube axis side ends of L, 25-, and 25-, respectively, there are pn junction diodes 2L, which are simply shown as circuit diagram symbols in the figure, and are selected as semiconductor switching elements.
, 2L2 are connected as external components on the board, but,
These pair of diodes 24-124-3 are connected in series in the same direction via a connection point on the microstrip line 23.

In other words, the diode 24-2 shown below in the figure
has its anode connected to the micro antenna 25-2 and the cathode microstrip line 23, and the diode 24-0 shown above has its anode connected to the microstrip line 23 and its cathode connected to the other side. It is connected to the micro antenna 25-0.

Such a pattern configuration of each part and a pair of diodes 24-
+, 24-2, in this embodiment, the micro antenna 22 at - is the input antenna section 3 mentioned in the gist of the present invention.
1, a microstrip line 23 including a back conductor pattern 26 and a pair of diodes 2Ll, 2L2 form a variable phase shifter 32 with a variable phase shift amount, and a pair of micro antennas 2
5-1 and 212 constitute the output antenna section 33.

FIG. 2 is a diagram of the polarization converter of the present invention shown in FIG. 1, viewed from the input opening side of the waveguide 20. The wave is a wave, and the input antenna section 31 or the micro antenna 2 on the dielectric substrate 21
2, if the electric field component parallel to the dielectric substrate 21 is captured by the micro antenna 21 in the direction shown by the arrow El (//) in FIG.
As shown by the solid arrow E+ (top), the electric field component perpendicular to this is along the direction of propagation of the radio wave and has a phase difference of π/2.
is placed.

However, it is captured by the micro antenna 22 patterned on the dielectric substrate, and the micro strip line 2
3, that is, the electric field component E+(//) parallel to the dielectric substrate 21, the phase of the electric field component E + (//) parallel to the dielectric substrate 21 is delayed as it progresses, and therefore, due to the length of the microstrip line 23, the dimensions of the dielectric substrate, and the physical When various parameters known in this field such as constants are used, the electric field component E+ (//) parallel to the dielectric substrate becomes relatively π at the output of the microstrip line 23. /
As a result, a condition can be created in which the vertical electric field component E+ (top), which has been delayed by π/2, is aligned in the same plane (plane of drawing paper) orthogonal to the tube axis.

Therefore, at this time, for example, the ground potential is applied to the micro strip line 23 so that only the diode 24-1 shown in the upper part of FIG. When a predetermined negative potential is applied to both, 1. Since the diode 24-2 becomes reverse biased and becomes cut off, the microstrip line 2 is connected only to the micro antenna 25-1 in the output antenna section 33.
3 is output, and the parallel electric field component E+(//) is re-radiated into the waveguide 20 from there.

Therefore, at this minute antenna 25-3, the parallel electric field component El (//) and the vertical electric field component E I (1), whose phases are matched with each other, are created by their vector composition as shown in FIG. 2 (B). As shown in the figure, a linearly polarized wave E having a polarization plane within a plane rotated clockwise by π/4 with respect to the dielectric substrate 21, for example. generate.

On the other hand, if the circularly polarized wave input to the waveguide 20 is now a right-handed circularly polarized wave, at the input antenna section 31 or the micro antenna 22 on the dielectric substrate 21, the dielectric substrate 21 The parallel electric field component is captured by the micro antenna 21 in the direction shown by the imaginary arrow E+ (//) in Fig. 2 (^), as in the case of the left-handed circularly polarized wave. perpendicular to and along the direction of radio wave propagation, the phase difference π/
The vertical electric field component where 2 is placed is, as shown by the imaginary arrow E r (JL)' in Figure 2 (A), relative to the vertical electric field component E + (↓) when a counterclockwise circularly polarized wave is incident. is only π,
They are in a lagging or leading phase relationship.

However, it is captured by the micro antenna 21 patterned on the dielectric substrate, and the micro strip line 2
The electric field component propagating through the dielectric substrate 21, that is, the electric field component E+(//) parallel to the dielectric substrate 21, is delayed in phase as it progresses, just as described above regarding the incident of left-handed circularly polarized waves. At the output end of the microstrip line 23, the phase is relatively delayed by π/2, and as a result, the phase difference in the traveling direction from the vertical electric field component E+(1), which was either delayed or advanced by π/2, is It is possible to create a condition where it becomes zero.

However, as mentioned above, the vertical electric field component E+(1).

Since there is a phase difference of π from that when the left-handed circularly polarized wave is incident, this time the diode 24-3 shown at the top in FIG. 1 is blocked, and the diode shown at the bottom is 24-2 is made conductive.

For example, even if the microstrip line 23 is kept at the ground potential as before, the pair of micro antennas 2
This can be achieved by applying a predetermined positive potential to both 5-+ and 25-2.

In this way, when the micro antenna 25-2 becomes more effective in the output antenna section 33, the relationship between the parallel and perpendicular electric field components in its output becomes as shown in FIG. 2(C). Parallel electric field component 1//) and vertical electric field component E in the output antenna section 33 when the left-handed circularly polarized wave is incident as described above
The output electric field component in Fig. 2 (B) is a vector combination of the parallel electric field component E + (//)' and the vertical electric field component E + (1) degree, which have 8 phases of + (upper) by π, respectively. E.

A linearly polarized wave E with a phase difference of π, but whose electric field component polarization planes lie within the same plane. ° can be obtained.

As described above, according to the present invention, both left-handed circularly polarized waves and right-handed circularly polarized waves are linearly polarized waves E whose electric field components are located in the same plane after the output antenna section 33. Alternatively, the microwave can be re-radiated into the waveguide 20 as EO', and therefore, this microwave is detected by the probe 40 fixedly installed so as to match the plane of polarization, and as shown by the arrow 50. , for example, can be sent out to a coaxial line or the like.

However, the method of extracting the signal EO or Eoo that is converted into a linearly polarized wave and re-radiated within the waveguide 20 is not limited to this, and the method of extracting the signal EO or Eoo that is converted into a linearly polarized wave and re-radiated within the waveguide 20 is not limited to this. In addition to being taken out to a coaxial line via a tube-to-coaxial line converter, the output of the waveguide 20 may be further introduced into a rectangular waveguide or the like using a known existing method.

In particular, this type of polarization converter usually has an LNB in its subsequent stage.
A low-noise block-down converter, abbreviated as It is sufficient if the output end of the waveguide 20 used can be matched to this. These points are also the same in each of the embodiments described below.

FIG. 3 shows a dielectric substrate 21 in this first embodiment.
and a conductor pattern configuration example thereon, especially a diode 2LI as a semiconductor switching element in the variable phase shifter 32,
An example line configuration providing selective switching bias to 2L2 is shown in more detail.

In this case, the back conductor 26 of the microstrip line 23 formed on the dielectric substrate 21 is also used as a common ground conductor for the diode switching circuit.

Of course, the part where the pair of micro antennas 25-, 25-2 forming the output antenna part 33 and the micro antenna pattern 22 for configuring the input antenna part whose one end is connected to the input part of the micro-strip line 23 are provided. There is no conductor pattern on the back side of the dielectric substrate.

Surface side of dielectric substrate or micro strip line 2
A high frequency choke 27 composed of a λ/4 micro strip line with one end open, for example, is patterned in the blank area of the board on the same side as 3. A predetermined DC level, for example, a steady ground level, is applied to the microstrip line 23.

On the other hand, a pair of micro antennas 2 constituting the output antenna section
5-, , 2s-2 are fine-width wiring paths 2L, I, 2! that also serve as high-frequency choke functions. Continuity is established between L2 and the through hole to a conductor surface 26 on the back side of the board, and a predetermined positive level B0 or negative A predetermined level B- is selectively provided.

For example, when applying a negative predetermined voltage B- to the back conductor 26,
Among the pair of diodes 24-+ and 24-2, only the diode 24-+ shown at the top in the figure is forward biased, and the other is reverse biased, so the output end of the microstrip line 23 is A pair of micro antennas 25
-, , 25-, only the upper micro antenna 25 is electrically conductive, in other words, the other micro antenna 25-2 is substantially disabled at this time. The operation associated with this state corresponds to the case already described with respect to FIG. 2(B).

On the other hand, when a predetermined positive potential is applied to the back conductor 26, only the diode 24-2 shown at the bottom of the figure among the pair of diodes 2L, 2L becomes forward biased, and the other is reverse biased, so the micro-
The output end of the strip line 23 is a pair of micro antennas 2L.
, , 25-2 is electrically conductive only to the lower micro antenna 25-2, and the operation at that time corresponds to the case described with respect to FIG. 2(C).

Even when general pn junction diodes 2L+ and 24-2 are used as semiconductor switching elements as shown in the figure, it is clear from the above-mentioned operation required of these diodes that depending on the bias application relationship, The connection method and polarity can be arbitrarily adopted.

For example, as shown in FIG. 4 (8), when the anodes of a pair of diodes 24-+ and 24-2 are connected to the microstrip line 23 in common, there is a steady state in the microstrip line 23. A predetermined positive power supply potential B″″ is applied to each diode 24-+,
If one of the pair of minute output antennas 25-, 25-, connected to each cathode of 24-2 is selectively connected to the ground as schematically shown by the switch 30, the left The pair of micro antennas can be selected depending on either circularly polarized waves or right-handed circularly polarized waves.

On the other hand, as shown in FIG. 4(B), the cathodes of the diodes 2LI and 2L2 are commonly connected to the microstrip line 23, and each anode is connected to a pair of micro antennas 2L, 25-2. It is also possible to adopt a circuit configuration in which they are connected to each other.

In this case, of course, the microstrip line 23 is constantly grounded, and the pair of micro antennas 25-
, , 25-2 may be selectively applied with a positive predetermined level bias potential B4 via a switch 30, which is also schematically shown, depending on the rotational direction of the circularly polarized wave to be received. .

However, in both cases of Figure 4 (A) and (B), microwaves should not enter the closed circuit side of the DC bias power supply via such diodes. In order to prevent the diode from being grounded with low impedance, it is recommended to insert a high-frequency choke 27 in series at an appropriate location in the diode bias DC loop, as shown in Figure 3. . These various bias methods and considerations can also be similarly adopted in each of the embodiments shown in the fifth figure and thereafter.

In FIG. 5, unlike the previous embodiments, the input antenna section 31 is connected to a pair of micro antennas 2L.

22-2, and the output antenna section 33 is a micro-
An embodiment is shown in which a single minute antenna 25 is connected to the output end of a strip line 23 through a continuous conductor pattern.

Of course, such a conductor pattern structure is formed on the telephone body substrate 21 as in the previous embodiment, and is housed within the waveguide 20 as shown in the first figure. For simplification of the drawing, illustration of the power visiting body substrate 21 is omitted in FIG. 5.

The pair of micro antennas in the input antenna section 31 are also connected to the micro strip line 23 via general pn junction diodes 2L, 2L2, and therefore, as before, for example, the back conductor 26 By constantly grounding the fine width wiring path pattern 2L,
, 2L, and a pair of micro antennas 2L+, 22-2 that are electrically connected to this back conductor 26 via a through hole.
When a predetermined positive potential B+ is applied to the microstrip line 23 through the fine width wiring path 28 having the high frequency choke 27 while both are connected to the ground potential steadily, the diode 24-1 is Further, when a predetermined negative potential B- is applied, the diode 24-2 can be turned on, and thereby one of the effective micro antennas can be selected and determined.

As is clear, in the embodiment shown in FIG. Parallel electric field component E+ (//) with
or E+(//)' is selectively extracted.

Therefore, for example, when selecting a left-handed circularly polarized wave, the minute antenna 2
2-1 is enabled, the parallel electric field component 1//) in the direction shown in FIG. When the phase is shifted by π/2 and re-radiated into the waveguide 20 from the single minute antenna 25 constituting the output antenna section 33, the relationship as shown in FIG. 2(B) is obtained. Assuming that a linearly polarized wave E0 can be obtained, when selecting a right-handed circularly polarized wave, the micro antenna 22- in the input antenna section 31
3 is enabled, this means that the parallel electric field component El(//)' shown in FIG. 2(C) has been selected in advance at the input antenna section 31, so Even if the direction in which the output antenna extends is opposite to that shown in Fig. 2 (C), the vector synthesis associated with re-radiation from the output antenna section will behave as if it were the situation shown in Fig. 2 (C). The linearly polarized wave E is equivalently equal and the plane of polarization related to the electric field component exists in the same plane as when receiving the left-handed circularly polarized wave. (//)' can be obtained.

Therefore, in the case of the fifth illustrated embodiment, the variable phase shifter 32 referred to in the gist of the present invention includes the microstrip line 23, the pair of semiconductor switching elements 24-,
, 242, and also a pair of micro antennas 2L+,
The pattern structure of 22-2 is satisfied, and depending on the case, it may be considered that the pattern structure is further configured by adding a wiring path and a bias power source to provide a selective bias relationship.

However, if we only look at the microstrip line 23 that is commonly used in each of the above embodiments, this is a means for constantly shifting the phase of the propagation signal by π/2. can be changed to other steady phase shift means with a fixed phase shift amount.

The most numerical example of such a circuit is the so-called four-terminal hybrid circuit. Therefore, the present invention also proposes the adoption of such a four-terminal hybrid circuit.

For example, in the embodiment shown in FIG. 6, a so-called branch line type hybrid circuit 51 is used as a four-terminal hybrid circuit that constantly performs the B phase of π/2.

In the figure, the same reference numerals used in each of the embodiments described so far indicate the same components. A pattern, a branch line, a conductive pattern constituting the type hybrid circuit 51, and a conductive pattern constituting the output antenna section 33 consisting of a pair of micro antennas 25-+ and 25-2 are formed, The micro antenna 22 is conductor-connected to one terminal portion TI of the branch line type hybrid circuit 51.

On the other hand, another terminal T2 of the branch line type hybrid circuit 51 is connected to a pair of pn junction diodes 2L, .
2L, a pair of micro antennas 25-, .

25-2, and the remaining two terminals T5.
T4 is schematically shown as a ground symbol in Figure 6, but
Both are connected to the conductor pattern 26 formed on the back surface of the dielectric substrate 21 via the through-hole structure as described above.

As is well known, the branch line type hybrid circuit 51 is a square arrangement of conductor lines each having a length of 1/4 of the working frequency λ, and as described above, one terminal T1 is an input terminal and the other terminal is an input terminal. If T2 is considered as an output terminal, the remaining two terminals T
When , , and T are both grounded, the phase of the input signal can be steadily advanced by π/2, and when opened, it is possible to advance the phase of the input signal by π/2.
2. It can be delayed.

In this embodiment, since the terminals T, , and Tj are both grounded as described above, the parallel electric field component captured by the micro antenna 22 of the input antenna section 31 and input to the input terminal T of the hybrid circuit 51 Regardless of whether it accompanies left-handed circularly polarized waves or right-handed circularly polarized waves, both of them are phase-advanced by π/2 and appear at the output terminal T2.

Therefore, as can be understood from the description of the first to fifth illustrated embodiments, whether the left-handed circularly polarized wave is incident or the right-handed circularly polarized wave is incident, the output terminal T2 of the hybrid circuit 51 Output antenna section 33 via
In this case, the accompanying parallel electric field components can be aligned in the same plane as the perpendicular electric field components.
, As explained in accordance with (C), the vertical electric field component E+(
(Top), Et (Top).

In view of each direction, as already explained in accordance with FIG. 3.4, by selectively making only one of the diodes 24-+ and 24-1 conductive, Either one of the micro antennas 25-1
Alternatively, if 25-2 is selected, the linearly polarized wave E has a plane of polarization in the same plane both when the left-handed circularly polarized wave is incident and when the right-handed circularly polarized wave is incident. Or you can get Eoo.

This mechanism is based on the terminal Ts of the hybrid circuit 51.
, T4 is changed from the steady grounded state shown in the figure to the steady open state, the result is substantially the same.

When the terminals Ts and T4 are opened, the parallel electric field component 1//) incident on the input terminal TI becomes constant π/
While the phase was advanced by 2, the phase is steadily delayed by π/2, but regarding these parallel electric field components,
The directions of the vertical electric field components E+ (top) and El (↓) degrees that align in the same plane at the output terminal T2 are shown in Figure 2 (B).
It is sufficient to simply think in the opposite direction in (C), and in the end, the plane of polarization of the linearly polarized waves to be synthesized is as shown in Figure 2 ( B),
(C) This is the plane in which the linearly circularly polarized waves Eo' and E exist.

Quite similarly, in this sixth illustrated embodiment, a pair of output antenna sections 25-1 in output antenna section 33.

25-2 with a diode switch, as shown in the fifth illustrated embodiment, the conductor pattern in the input antenna section 31 is replaced by a pair of minute antennas 2Ll,
2L2, and if these are selectively connected to the input terminal T of the hybrid circuit 51 by switching them with a pair of diodes 2Ll and 2L2, almost the same effect as explained with reference to FIG. 5 will be obtained. , the effect can be obtained.

However, as described above, when the hybrid circuit 51 constitutes a steady π/2 phase shift means, the back conductor 26 is conversely attached to the input antenna section 31 and the output antenna section 33 where it should not be present. It is desirable to directly connect the input terminal TI and output terminal T2 of the hybrid circuit 51 that require the back conductor 2B, since the edges of the back conductor 26 will have an influence on the input/output antenna sections 31 and 33. Therefore, it is actually better to connect them via micro-strip lines 53, 53 of appropriate length.

In this case, the pair of microstrip lines 53
, 53 is set to be kπ for an integer k greater than or equal to 1. In particular, if k is chosen to be an even number, the signal phase relationship is exactly the same as when they are not provided. Therefore, the above explanation regarding the vector composition relationship can be applied as is, and the design is also simplified.

Even in the case of an odd number, the parallel electric field component E+(
//) to El(//)' and El(//)" to El(//
/).

This is because there is a constant phase difference of π between them.

In general, of course, as a case where the design can be simplified the most, the input antenna section 31 and the hybrid circuit input terminal T
, and the microstrip line 53 between the hybrid circuit output terminal T2 and the output antenna section 33, so that a steady phase of π/2 or π occurs in both. A total phase amount of π or 2π is obtained.

In the case of this embodiment, the variable phase shifter 32 referred to in the gist of the present invention constantly shifts the input signal to π/2 or -π/
A hybrid circuit 51 with 8 phases and a pair of diodes 21L, 21L as semiconductor switching elements.
4-2, and a pair of micro antennas 25-1 and 25-2 in the output antenna section 33 (or a pair of micro antennas 2L+ and 22-2 in the input antenna section).

As is clearer, the branch line type hybrid circuit 51 shown in FIG. 6 can be replaced with other types of known hybrid circuits.

One example is a so-called rat race type hybrid circuit 52 as shown in FIG.

In this hybrid circuit 52, the terminals facing each other in the diametrical direction are terminals T+ and T4 in the sixth illustrated embodiment, and
By setting the terminal at a position π/3 counterclockwise rotated from the terminal T as the terminal T3, and the terminal at a position roughly π/3 counterclockwise rotated from there as the output terminal T2, the terminal Ts, By constantly grounding T4 or, contrary to the case shown, by constantly opening it, the signal applied to the input terminal T can be constantly advanced or delayed by π/2. output terminal T.

Therefore, instead of the hybrid circuit 51 shown in FIG. 6, a pattern of this rat race type hybrid circuit 52 may be formed on the dielectric substrate 21.

However, in view of the illustrated embodiment 6.7, it will be understood that the present invention may include further modifications.

This is because, in the above description, two terminals T5. When T4 is constantly grounded and when it is constantly opened, there is a difference in whether the signal input to the input terminal Tl is advanced or delayed by π/2; This is because there is a phase difference of π between the case where the phase is delayed and the case where the phase is delayed.

Looking at the previous embodiments, we find that not only the hybrid circuits 51 and 52 but also the microstrip line 23 as in the first to fifth illustrated embodiments are used.
These means are used as means for "regularly" advancing or retarding the phase of the parallel electric field component E+(//) captured by the input antenna section 31 by π/2, and the parallel electric field component E+
The means for selectively advancing or retarding the phase of (//) by roughly π consists of semiconductor diodes 2L, , 2L, and a pair of micro antennas 22-+, 22-z or 25-, , 2.
It was composed of 5-2.

However, as mentioned above, the two terminals T3 of the hybrid circuit
, If it is possible to obtain a signal with a phase difference of π by grounding or opening T4, then the two terminals T4
Rather than "regularly" grounding or opening s and Ta, semiconductor switching elements are connected to them, and whether they are "selectively" grounded or opened is determined by an external electric signal (voltage signal). ), either the input antenna section 31 or the output antenna section 33 should be replaced with a pair of micro antennas 2L, 22-2 or 25-1, 2.
5-2, both of them are composed of a single minute antenna, and the fixed input/output antenna patterns are constantly connected to the input/output terminals Tt, T2 of the hybrid circuits 51, 52. Even if a conductor pattern is formed, the input parallel electric field component El (
//) can be outputted by giving a phase difference of π/2, or by giving a phase difference of π equivalently to this.

The embodiment shown in Figure 8 shows such a case.

As the hybrid circuit, a pattern example of the branch line type hybrid circuit 51 shown in the sixth illustrated embodiment is shown, but in this embodiment, the terminals T3. The cathodes of diodes 2Ll and 2L2 are connected to the terminal T4, respectively, and the anodes of these diodes 2tl and 2L2 are schematically shown with a ground symbol, but in reality they are connected to the back conductor 26 through a through hole or the like. It is designed to be connected to.

On the other hand, the input terminal T1 of the hybrid circuit 51 is connected to the input antenna section 31 composed of a single micro antenna 22 via a micro-strip line 53, which is provided as necessary for the reasons described above, and similarly The output terminal T2 is also a micro strip line 5 provided as necessary.
3, it is connected to an output antenna section 33 composed of a single micro antenna 25.

Therefore, either the DC potential of the back conductor 26 is set to a predetermined potential B0 higher than the DC potential of the conductor pattern on the hybrid circuit side, or the DC potential of the conductor pattern on the hybrid circuit side is set lower than the DC potential of the back conductor 26. Diode switch 2 is connected to a predetermined potential B-.
By turning on both L1 and 2L2, both terminals T3 and T4 of the hybrid circuit 51 can be grounded together. In this case, the micro strip line 53 is connected from the micro antenna 22 in the input antenna section 31. It is possible to give a phase advance of π/2 to the parallel electric field component E plate (〃) inputted to the terminal T1 via the parallel electric field component E and send it out to the output terminal T2.

On the other hand, if a bias relationship is generated that turns off both the diode switches 2L, 2L, the parallel electric field component El(//) applied to the input terminal T,
It is possible to give a phase delay of 2 (a phase advance of -π/2), and for the previous phase advance of π/2, a phase relationship further equivalently shifted by π can be given and sent to the output terminal T2. Can be done.

Even if this is done, in principle, the same mechanism as explained with reference to FIG. Again, at the output antenna section 33, there is a vertical electric field component E+(1) or E with no phase difference in the traveling direction.
+ (1) A linearly polarized wave E whose plane of polarization lies in the same plane as a result of composition with (1)°. Or E. ° can be obtained.

Of course, the DC bias line for selective switching of each diode 2L, 2L2 and the high frequency choke necessary therefor are constructed by appropriate pattern formation, etc. with reference to the illustrated embodiment in Section 3.5. The hybrid circuit 51 shown in FIG.
It may be replaced with the race-type hybrid circuit 52 or with other known existing hybrid circuits.

In addition, in the case of such a configuration, the variable phase shifter 32 referred to in the gist of the present invention is connected to the hybrid circuit,
A pair of diodes 2t, 2t selectively ground or open the two terminals Ts and T4 by an external electric signal (voltage signal or minute current signal).

(It may be considered to include a peripheral bias circuit).

However, in the examples so far, even if hybrid circuits are used, branch line type or rat type
We have shown examples of so-called planar hybrid circuits such as lace type hybrid circuits, but as well-known existing hybrid circuits,
As is well known, there is also a so-called distributed coupling type.

In the present invention, such a distributed coupling type hybrid circuit can be adopted as well, so the embodiment shown in FIG. 9 will be described to serve as proof of this.

As is well known in itself, a distributed coupling type hybrid circuit uses a pair of distributed coupling line patterns sandwiching a dielectric member of an appropriate thickness and appropriate permittivity from the front and back sides. In the illustrated embodiment, a power generation substrate 21 is used as the dielectric member, and a pair of distributed coupling line portions 5 are provided on the front and back surfaces of the substrate 21, respectively, so as to face each other with the substrate 21 in between.
By patterning Ll and 5L2, such a distributed coupling hybrid circuit 55 is constructed.

In this hybrid circuit 55, one lower end of the distributed coupling line section 54-1 shown by a solid line on the front side corresponds to the input terminal T1 of the hybrid circuits 51 and 52 in each of the embodiments described above. Terminal T is connected via a microstrip line 53 to one end of an input antenna 22 consisting of a single micro antenna pattern.

On the other hand, the other end of the line portion 54-1 corresponds to the terminal T of the hybrid circuit in the embodiments up to FIG.
It is connected to a conductive surface pattern 26-2 formed on the same substrate surface side via a diode 24-8 connected to the same substrate.

This conductor surface pattern 26-2 on the front side forms the opposing conductor surface of the microstrip line 53 on the back surface, and therefore, on the back surface of the dielectric substrate 21, there is a conductor surface pattern 26-2 at the center of the length direction of the dielectric substrate 21. Regarding the axis perpendicular to the tube axis, a similar pattern is formed axially symmetrically to the structure on the front surface side.

That is, one end T2 of the distributed coupling line section 54-2 on the back surface side is connected to the output antenna section 33 consisting of a single micro antenna 25 via the micro strip line 53, and the other end of the line section 54-3 is The end T4 is a diode 24-2 whose cathode is similarly connected to the line portion 54-2.
The conductor surface pattern 26-, which is on the back side and constitutes the back conductor of the micro-strip line 53 on the front side of the substrate,
Connected to 4.

Of course, for the reasons already mentioned, the conductor surface pattern 2a is
-, ze-, are not provided as if cut out.

The micro-strip lines 53 and 53 provided on the front and back surfaces of the substrate, respectively, have fine-width wiring paths 2LI,
2L2 and high frequency chokes 27-1 and 27-2,
A bias power source can be applied to selectively turn on and off the diodes 24-+ and 24-2.

Therefore, although its operation is probably self-evident, the parallel electric field component Et (//) input from the input antenna 22 to the input terminal TI of the hybrid circuit 55 is caused by the conductor surface pattern za-t, 26-2. Micro strip lines 53, 53 or distributed coupling lines 54-+, 54
-2, when the DC potential is biased to be higher than the forward ON voltage of the diodes 2L, 2t2, the two terminals TS of the distributed coupling hybrid circuit 55
, T4 are both grounded AC, so π
/2 and is sent to the output terminal T2, and conversely, the conductor surface patterns 2Ll, 212 are biased below the forward ON voltage and the terminals T3. When T is equivalently opened, it receives a lag phase of π/2 (a phase advance of -π/2 or 3π/2) and is sent to the output terminal T2.

Therefore, in the output antenna section 33 consisting of the single micro antenna 25, regardless of whether the electromagnetic wave input to the input antenna section 31 or the micro antenna 22 is a left-handed circularly polarized wave or a right-handed circularly polarized wave. , diode switch 24-
+, 24-2, the vertical electric field component E+ (↓
) or E+(upper)°, it is possible to obtain a linearly polarized wave E(1 or E.″) having a plane of polarization in the same plane.

Going back a little bit, as in the embodiments shown in Figures 3 to 5, the hybrid circuit is constantly exposed to the parallel electric field component E+(//
), this distributed coupling type hybrid circuit 55 is also used instead of the planar type.
You can also use

Of course, the dielectric substrate 21 in each of the embodiments shown in the sixth to eighth figures is used by being housed within the waveguide 20, along with each component thereon, in exactly the same manner as in the first embodiment.

As described above, according to each embodiment constructed based on the present invention, the diode 2 as a semiconductor switching element
4-+, 24-, and 24-, only by applying an electric signal as a phase shift amount switching signal, and only by an electric signal which may be a voltage signal or a minute current signal, can the counterclockwise rotation that has entered the input end of the waveguide 20 be detected. It can be seen that both circularly polarized waves and right-handed circularly polarized waves can be re-radiated as linearly polarized waves having their plane of polarization in the same plane, but in reality, it may be necessary to adjust the amount of phase shift slightly.

In such a case, the conductor pattern provided on the dielectric substrate, especially the part of the microstrip line 53 which is the relay line part, has a phase difference as shown in FIGS. 10(^) to (D). It would be good to provide adjustment means.

The phase fine adjustment means shown in FIG. 1O(A) is exemplified as a modification of the microstrip line 53 connected to the single micro antenna 22 constituting the input antenna section. It comprises a narrow inductance forming portion 56 and a varactor diode 57 having a cathode connected to the inductance forming portion 56 and an anode connected to the back conductor 26 via a through hole.

As is well known, the equivalent circuit of such a structure is a T-type filter circuit consisting of an inductor 56 and a variable capacitor 57, as shown in FIG. Depending on the degree of
The overall amount of phase shift can be varied and adjusted.

Therefore, if you want to make this adjustable band wider, as shown in FIG.
First and second inductance forming portions 56-, , se-, on both sides of the line 5B, and varactor diodes SL, , sy- associated with each of them.

It is only necessary to make it possible to tune each stage in multiple stages, such as by providing .

Furthermore, although it is somewhat special, as shown in Figure 1θ (0), even if a ferrite plate 59 is provided on the microstrip line 53 and the DC bias magnetic field IDC applied to it is made variable, the phase shift The amount can be adjusted. In this case as well, unlike the conventional example using the ferrite core 12 described at the beginning with reference to FIG. The significance of is not compromised.

Incidentally, in the circularly polarized wave to linearly polarized wave converter of the present invention, the input opening side of the waveguide 20 is actually connected to an electromagnetic horn such as a conical horn, and the other end opening side is connected to the LNB described above. However, considering such uses, it is also possible to incorporate the device of the present invention integrally inside the horn.

The embodiment shown in FIG.
A dielectric substrate 21 is provided along the internal length direction so as to rest on the diameter thereof.

In FIG. 11, the configuration of the first illustrated embodiment mentioned above is provided on the dielectric substrate 21, and the corresponding reference numbers of each part are also shown.

However, any other embodiments of the present invention derived from those described with reference to FIGS. 3 to 10 may be constructed on the dielectric substrate 21 within the horn 60. .

As can be seen, such an arrangement is extremely advantageous.

In fact, in the case of the 11th illustrated embodiment, the length conventionally required for the horn and the subsequent polarization plane converter can be reduced to a length that is not much different from the length of only the horn or only the converter. For example, when viewed as a satellite broadcast receiving system as a whole, it can be extremely small. In addition to being inexpensive, it also greatly improves work efficiency by reducing the number of parts to be assembled.

In each of the embodiments of the present invention described above, ordinary pn junction diodes 2LI and 2L2 were used as semiconductor switching elements.

It is true that this is the cheapest, simplest, and most reliable method, but it is not limited to this in principle. Triggered and also turns
Any device that can be turned off can be used in place of the pn junction diodes 2Ll and 2L2.

[Effects] In the present invention, both left-handed circularly polarized waves and right-handed circularly polarized waves can be converted into linearly polarized waves having polarization planes in the same plane by electric signals without using specific moving members. can be converted.

Moreover, compared to polarization converters that use conventional ferrite cores, the electrical signal required as the phase shift switching signal does not require as much energy as a power signal, and is generally represented by a diode. A voltage signal or a minute current signal that can selectively turn on and off the available semiconductor switching elements is sufficient, and the peripheral circuitry becomes extremely simple and inexpensive.

Additionally, unlike conventional ferrite core-based models, there is no separate part for generating linearly polarized waves and a part for selectively further rotating the generated linearly polarized waves, so the overall size is also greatly reduced. .

Furthermore, if necessary, an integrated configuration with an electromagnetic horn can be adopted, and the overall microwave receiving system can be greatly downsized, simplified, and reduced in cost.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view of a first embodiment of a circular polarization to linear polarization converter constructed according to the present invention. FIG. 2 is an explanatory diagram of the operation of each embodiment constructed according to the present invention, including the first illustrated embodiment. FIG. 3 is a schematic diagram of the main parts of a second embodiment of the present invention. FIG. 4 is an explanatory diagram of a modified example of the bias relationship for switching a pn junction diode selected as a semiconductor switching element. FIG. 5 is a schematic diagram of the main part of still another embodiment of the present invention, which is modified so that a pair of small antennas are provided in the input antenna section and used by switching between them. FIG. 6 is a schematic diagram of the main part of an embodiment in which a branch line type hybrid circuit is used as the phase shift means with a fixed phase shift amount. FIG. 7 is an explanatory diagram showing an example of another hybrid circuit that can be adopted instead of the branch line type. FIG. 8 is a schematic configuration diagram of the main parts of an embodiment in which the hybrid circuit itself is provided with a variable phase shift function in combination with a semiconductor switching element. FIG. 9 is a schematic diagram of the main part of an embodiment in which the hybrid circuit having a variable phase shift function in the embodiment shown in FIG. 8 is replaced with a distributed coupling type hybrid circuit. FIG. 10 is an explanatory diagram of a steady phase shift amount fine adjustment means. FIG. 11 is a schematic configuration diagram of main parts when each embodiment of the present invention is incorporated inside an electromagnetic horn. Figure 12 shows a conventional circularly polarized wave versus linearly polarized wave constructed using a telephone body plate that constantly delays only the parallel electric field component and a ferrite core that rotates the polarization plane of the composite linearly polarized wave as a whole. A schematic configuration diagram of a wave converter. It is. In the figure, 20 is a waveguide, 21 is a dielectric substrate, 22 is a single minute input antenna, 2L+, 22-2 is a pair of minute input antennas, 23 is a microstrip line, 2Ll
, 24-2 is a diode as a semiconductor switching element, 25 is a small output antenna, 25-, , 25-
2 is a pair of small output antennas, 26 is a back conductor of a micro strip line, 26-1, 2L2 is a pair of conductor surfaces, 27 is a high frequency choke, 28.2L, 2L,
. 29, 29-129-2 is a fine width wiring path, 31 is an input antenna section, 32 is a variable phase shifter, 33 is an output antenna section, 51° 52 is a hybrid circuit configured in a planar type,
53 is a micro strip line, 54-+, 54
-z is a distributed coupling line section, 55 is a distributed coupling type hybrid circuit, 56 is an inductance forming section, and 57 is a varactor.
58 is a λ/4 line portion, 59 is a ferrite plate, and 60 is an electromagnetic horn. Figure 1 So Kamiba Application Person Unison Co., Ltd.

Claims (5)

[Claims] (1) A dielectric substrate inserted into a waveguide and having a length in the tube axis direction of the waveguide and a width in a direction orthogonal thereto; and a dielectric substrate formed on the dielectric substrate. an input antenna portion having a conductor pattern and capturing an electric field component parallel to the surface of the dielectric substrate with respect to a circularly polarized electric field incident on one end of the waveguide; an output antenna section having a conductor pattern formed on the dielectric substrate and re-radiating electric field components parallel to the dielectric substrate into the waveguide; and a semiconductor switching element that is turned on and off automatically, and by the switching operation of the semiconductor switching element, the phase of the electric field component parallel to the dielectric substrate captured by the input antenna section is changed to the phase of the electric field component parallel to the dielectric substrate in the output antenna section. Before the re-radiation into the wave tube, the phase of the electric field component perpendicular to the dielectric substrate of the circularly polarized wave is shifted by (2n-1)π/2, where n is an integer of 1 or more. , and a variable phase shifter that switches the amount of phase shift between this and a state in which the phase is further equivalently shifted by π; and a circularly polarized wave to linearly polarized wave converter. (2) The conductor pattern of either the input antenna section or the output antenna section constitutes a single micro antenna on the dielectric substrate and perpendicular to the tube axis of the waveguide. , the other conductor pattern constitutes a pair of minute antennas that are on the dielectric substrate and extend independently from each other in opposite directions while being perpendicular to the tube axis; and the conductor pattern in the variable phase shifter is , as a result of propagating the electric field component parallel to the dielectric substrate from one end to the other, its phase is constantly changed to (2n-1)π/2 with respect to the phase of the electric field component perpendicular to the dielectric substrate. a microstrip line whose phase is retarded by a phase delay of , selectively connected to one of the pair of microantennas via the semiconductor switching element in the phase shifter depending on the on/off state of the semiconductor switching element; 1. The Enbi wave to linear polarization converter according to 1. (3) The conductor pattern of either the input antenna section or the output antenna section constitutes a single micro antenna on the dielectric substrate and perpendicular to the tube axis of the waveguide. , the other conductor pattern constitutes a pair of minute antennas that are on the dielectric substrate and extend independently from each other in opposite directions while being perpendicular to the tube axis; and the conductor pattern in the variable phase shifter is , has an input terminal and an output terminal, and the other two terminals other than the input terminal and the output terminal are constantly grounded or constantly released,
A four-terminal hybrid circuit is configured in which a signal applied to the input terminal is steadily phase-shifted by (2n-1)π/2 and is expressed at the output terminal; One of the antennas is connected to the single micro antenna so as to be constantly conductive, and the other is connected to the pair of antennas according to its on/off state via the semiconductor switching element in the phase shifter. The circularly polarized wave to linearly polarized wave converter according to claim 1, wherein the circularly polarized wave to linearly polarized wave converter is connected to one end of the micro antenna so as to be selectively conductive. (4) The conductor patterns of the input antenna section or the output antenna section are both formed on the dielectric substrate and constitute a single micro antenna perpendicular to the tube axis; while the variable phase shifter The conductive pattern inside has an input terminal and an output terminal, and the signal applied to the input terminal is controlled by selectively grounding or opening the other two terminals other than the input terminal and the output terminal. 2n-1) A four-terminal hybrid circuit represented at the output terminal with a phase shift of (2n+1)π/2, which corresponds to a state in which the phase is shifted by π, or (2n+1)π/2, which corresponds to a state in which the phase is further equivalently shifted by π. The input terminal of the hybrid circuit is connected to the single micro antenna of the input antenna section, and the output terminal of the hybrid circuit is connected to the single micro antenna of the output antenna section so as to be constantly conductive, respectively; ; The semiconductor switching element in the variable phase shifter selectively connects the remaining two terminals other than the input terminal and output terminal of the hybrid circuit to ground only when the semiconductor switching element is in the on state. The circularly polarized wave to linearly polarized wave converter according to claim 1, wherein the circularly polarized wave to linearly polarized wave converter is connected as follows. (5) A microstrip line is provided between the input antenna section and the input terminal of the hybrid circuit, and between the output terminal of the hybrid circuit and the output antenna section, and a microstrip line is provided between the input side of the hybrid circuit and the input terminal of the hybrid circuit. The length of each of the microstrip lines connected to the output side is set so that the sum of the phase shifts of the signals propagating through them is kπ, where k is an integer of 1 or more; The circularly polarized wave to linearly polarized wave converter according to claim 3 or 4.