JP2010045464A - Phase-locked oscillator array and array antenna device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To supply many phase-locked oscillation signals without using a distributor. <P>SOLUTION: This phase-locked oscillator array outputs an oscillation signal of a four-phase same frequency, wherein the phase difference of the oscillation signal is 90°. The phase locked oscillator array includes: a plurality of ring resonators composed of a plurality of closed lines 21 to 23; differential oscillators 31a and 31b for making a connection between two adjacent ports 21b and 21c among four ports 21a to 21d disposed at positions obtained by performing 1/4 division of the total length of the closed line, and two adjacent ports 22a and 22d of the closed line 22 adjacent to the closed line 21 as negative resistance, respectively; and an excitation device 30 for exciting a signal having phase difference of 90 degrees to the two ports 21a and 21d with no differential oscillator connected thereto among the four ports of the closed line 21 in the closed line 21 arranged at least any end part. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a phase-locked oscillator array in which the phases of oscillation signals of a plurality of oscillators are synchronized, and an array antenna apparatus using the same. The present invention can be used to control the phase of a carrier wave to each antenna of a phased array antenna capable of variably controlling directivity.

  Patent Document 1 discloses a phased array antenna device. The phased array antenna apparatus has a plurality of transmission modules and varies the amplification and phase of a carrier wave. A carrier wave to be supplied to each antenna is generated by a single oscillator, distributed to each antenna system by a distributor, and then supplied to each antenna. By controlling the phase difference of the carrier wave supplied to each antenna, the directivity of the antenna can be changed.

  Non-Patent Document 1 discloses a push oscillator using a ring resonator. In this document, a ring resonator composed of a square microstrip line has two orthogonal resonance modes, and there are four oscillators that excite the ring resonator with four ports. It is disclosed that it is determined. Further, it is disclosed that an oscillation signal having a frequency of 4f0 can be obtained from the intersection of lines connecting the midpoints of the sides of the peripheral transmission line and intersecting in a cross shape by exciting the frequency f0 from the four oscillators. .

  Patent Document 2 discloses a circuit in which a plurality of oscillators are connected by a band rejection filter. This technology uses the reflection characteristics of the band-stop filter to oscillate in phase with the reflected signal and with the opposite phase to the transmitted signal, thereby synchronizing the frequency and phase of the oscillators interconnected by the band-stop filter. Is.

JP 2005-269569 A Patent No. 3861155 Hai Xiao, Takayuki Tanaka, Masayoshi Aikawa, "Basic Behavoir of Quadruple-Push Oscillator Using Ring Resonator." IEEE Trans. Electron., Vol. E88-C, No. 7, July 2005.

  However, in the phased array antenna device of Patent Document 1, there is one oscillator, and a signal output from this oscillator is distributed to the number of antenna systems, and the phase is changed by an amplifier or a phase shifter. In order to distribute the signal, the oscillator must generate a large amount of power. This causes not only a problem of increasing energy consumption but also a problem of heat dissipation. In addition, in order to distribute in-phase to the modules of each antenna system, it is necessary to make the length of the transmission path for supplying a carrier wave equal in each antenna system. It's not easy.

  In addition, with the introduction of SiGeIC, there is a possibility of high integration even at ultra-high frequencies such as millimeter waves. As a result, there is a possibility that the high-frequency circuit unit can be stored in one chip. In such a situation, each IC may be an IC including an oscillator, an amplifier, and a phase shifter. Then, by arranging these ICs in an array, a method of spatially synthesizing the output from the antenna has become realistic. However, this requires synchronization of the respective oscillators, but there is the above-mentioned problem in the distribution using the distributor. The present invention can be used for such applications.

  The technique described in Non-Patent Document 1 is a technique for attaching and oscillating four oscillators to one ring resonator. The ring resonator has two orthogonal modes of cosωt and sinωt, and the phases of the oscillation signals of the four oscillators are automatically shifted by 90 degrees. The phase of the oscillation signal at the four ports provided at the midpoint of each side of the square transmission path is 90 degrees in the counterclockwise direction, as opposed to the mode in which the phase advances 90 degrees in the clockwise direction. There is a mode in which the phase advances. However, this mode cannot be determined as either one, and is determined as one of the modes according to the initial phase when the oscillator is powered on. Therefore, the ring resonator disclosed in this non-patent document cannot be used for the array antenna device.

  In Non-Patent Document 1, since the number of signals obtained is limited to four, this method cannot be used when the number of antennas increases beyond this. Non-Patent Document 1 discloses that an oscillation signal having a frequency four times the oscillation frequency of the oscillator can be obtained from the center point of the square transmission path. An oscillation signal having a quadruple oscillation frequency cannot be supplied to the phased array antenna device without using a distributor. Therefore, also in this case, it is necessary to increase the output of the oscillator as described above, and there is a problem that power consumption and heat generation increase.

  Further, in the technique of Patent Document 2, the level of the transmitted signal is low and the coupling between adjacent oscillators is weak because the transmission signal of the band rejection filter is synchronized in the opposite phase. As a result, there is a problem that the synchronization of frequency and phase is not stable. In addition, with this technique, only a single waveform, that is, cosωt or sinωt can be obtained, making it difficult to configure a transmission / reception array antenna or a directivity control antenna.

The present invention has been made to solve the above-described problems, and its purpose is to use four types of signals having different phases by 90 degrees without using a distributor. It is to be able to supply a large number of phase-synchronized oscillation signals.
Another object of the present invention is to provide an oscillation device having a structure that can easily supply a carrier wave to an array antenna or a phased array antenna.

  According to the present invention, in a phase-locked oscillator array that outputs an oscillation signal having four phases and the same frequency with the phase difference of the oscillation signal being 90 degrees, a plurality of ring resonators composed of a plurality of closed lines and a total length of the closed line are set to 1 / Differential oscillator that connects two adjacent ports among the four ports provided at the four-divided positions and two adjacent ports of the closed line adjacent to the closed line as negative resistances, respectively And at least one of the four ports of the closed line in the closed line arranged at one end, the phase of the first port of one of the two ports to which the differential oscillator is not connected is And a resonance mode fixing means for fixing the orientation of the phase relationship between the first port and the second port so that the phase is relatively advanced by 90 degrees with respect to the phase of the second port. Synchronous oscillator It is an example.

  The differential oscillator can be connected between adjacent closed line ports by connecting the gate / base of the transistor constituting the oscillator to the closed line port via a capacitor, or by the drain / collector or source of the transistor. / There is a method of connecting an emitter to each port of a closed line via a capacitor or an inductor. In addition, the transistors constituting the oscillator and the closed line may be electromagnetically coupled by capacitive coupling or inductive coupling. In short, it is only necessary that the oscillator and the closed line are electromagnetically coupled so that the resonance frequency and the resonance characteristic are determined by the circuit constant of the oscillator and the resonance characteristic and circuit constant of the closed line. The bonding method is arbitrary. That is, a negative resistance by a differential oscillator may be connected between the ports of adjacent closed lines.

  The resonance mode fixing means is two ports to which a differential oscillator is not connected among four ports of a closed line (hereinafter referred to as “first closed line”) provided at an end of a plurality of closed lines. Connected to the first port and the second port. The resonance mode fixing means fixes the orientation of the phase relationship between the first port and the second port so that the phase of the first port is a leading phase of 90 degrees relative to the phase of the other second port. To do. The direction of phase relationship refers to the phase advance or delay relationship between ports.When the phase relationship is fixed, the phase relationship between ports is always unique regardless of whether the device power is on or off. It means to be fixed. By this fixing, the phase relationship of each of the four ports when the closed line is in a resonance state is uniquely fixed. As a result, the phase relationship between the ports of the other plurality of closed lines is also uniquely fixed.

The following means can be adopted as the resonance mode fixing means.
First, the resonance mode fixing unit includes an oscillator that outputs two signals having a phase difference of 90 degrees, and inputs the signal having the advanced phase to the first port and the other signal to the second signal. It is a means to make it input into a port. Two signals having a phase difference of 90 degrees are generated from the output of the oscillator that oscillates at the same frequency as the resonance frequency of the closed line. For this, a 90-degree delayed phase shifter, a 90-degree delayed phase shifter, a 90-degree advanced phase shifter, or the like can be used. Of course, a signal whose phase is advanced by π / 4 with respect to the output signal of the oscillator and a signal whose phase is delayed by π / 4 may be generated. Of the two signals, the signal with the phase advanced may be input to the first port, and the signal with the phase delayed may be input to the second port. Even in this case, the resonance mode fixing means supplies a signal to the first port and the second port. At this time, the signal propagating through the closed line is connected to the first port and the first port via the resonance mode fixing means. In order to prevent bypassing between the two ports, a propagation direction limiting circuit that transmits a signal only from the oscillator to the first port between the oscillator and the first port, and between the oscillator and the second port, It is desirable to provide a propagation direction limiting circuit for transmitting a signal only from the oscillator toward the second port. In this way, the resonance mode fixing means can be prevented from affecting the resonance characteristics of the closed line, and the Q value can be improved. The propagation direction limiting circuit can be composed of an amplifier, a directional coupler, a circulator, an isolator, and the like.

Secondly, the resonance mode fixing means includes, as a negative resistance, an oscillator connected to the first port, a delayed phase shift circuit that delays the phase of the output signal of the oscillator by 90 degrees, and outputs the delayed signal to the second port. Can be configured.
Thirdly, the resonance mode fixing means includes, as a negative resistance, an oscillator connected to the second port, an advanced phase shift circuit that advances the phase of the output signal of the oscillator by 90 degrees, and outputs it to the first port; Can be configured.
The oscillator is connected to the first closed line so that the resonance frequency and the resonance characteristic are determined by the circuit constant of the oscillator, the resonance characteristic of the closed line, and the circuit constant. Are connected. That is, this oscillator is an oscillator configured to oscillate at the resonance frequency of the closed line while being connected to the first closed line.

  The resonance mode fixing means preferably has a propagation direction limiting circuit for propagating a signal only from the oscillator toward the port between the oscillator and the first port or the second port. The oscillator that provides the negative resistance oscillates at the resonance frequency of the closed line while being connected to the port to which the propagation direction limiting circuit is not connected. The propagation direction limiting circuit prevents the port to which the propagation direction limiting circuit is connected from affecting the oscillator. Therefore, since the oscillator oscillates when connected to one port, the oscillation mode can be limited to one. As the propagation direction limiting circuit, an amplifier, a directional coupler, a circulator, an isolator, or the like can be used.

  Further, the resonance mode fixing means may be a phase shifter that generates a 90-degree phase that connects the first port and the second port. In this case, resonance in the first closed line is caused by a differential oscillator connected thereto. The voltage of the first port is delayed by 180 degrees with respect to the phase of the voltage of the port having a positional relationship of 180 degrees with the port. Similarly, the second port is also delayed by 180 degrees with respect to the phase of the voltage of the port having a positional relationship of 180 degrees with the port. At this time, the resonance mode fixing means operates to advance the phase of the voltage of the first port by 90 degrees with respect to the phase of the voltage of the second port, and to change the phase of the first port to the phase of the second port. The phase is always fixed so that the phase advances by 90 degrees.

  The resonance mode fixing means includes, for example, a 90-degree delay line, a 90-degree delay phase shifter, and a 90-degree advance phase shifter. When the resonance mode fixing means is a 90-degree delay line or a 90-degree delay phase shifter, a differential oscillator connected to a port having a positional relationship of 180 degrees with the first port is connected to the second port and 180 degrees. The differential oscillator connected to the ports having the positional relationship is first turned on to oscillate. As a result, an excitation mode in which the first port has the maximum amplitude and the second port has the zero amplitude is excited in the first closed line. Then, the phase of the voltage signal of the first port is delayed by 90 degrees by the resonance mode fixing means and input to the second port. In this way, the second port can be resonated with the phase always delayed by 90 degrees with respect to the first port.

  Conversely, when the resonance mode fixing means is a 90-degree lead phase shifter, the differential oscillator connected to the port having a positional relationship of 180 degrees with the second port is connected to the first port with 180 degrees. The differential oscillator connected to the ports in the positional relationship is first turned on to oscillate. As a result, an excitation mode in which the second port has the maximum amplitude and the first port has the zero amplitude is excited in the first closed line. The phase of the voltage signal of the second port is advanced by 90 degrees by the resonance mode fixing means and is input to the first port. In this way, the closed line can be resonated with the first port always being 90 degrees ahead of the second port.

  The phase relationship between the four ports of the first closed line is always fixed even when the power of the device is turned on / off. Since the phase relationship of the two output terminals of the differential oscillator connecting between the ports of the adjacent closed lines is fixed, the phase relationship of the four ports of all other closed lines is always fixed. Become.

  The resonance mode fixing means preferably has a propagation direction limiting circuit that limits the propagation direction of the signal between the first port and the second port to one direction. In this case, when the resonance mode fixing means is not connected, the propagation direction limiting circuit outputs the signal only in the direction from the port where the signal is excited to the port where the signal is not excited in the first closed line. The direction is restricted so as to propagate. Thereby, orthogonal two-mode excitation can be effectively realized.

  In all the above inventions, the number of ports in one closed line is four, and the phase difference between the ports is π / 2 with respect to the fundamental oscillation frequency. As the closed line, a microstrip line or a coplanar line can be used, but it is desirable that the closed line is composed of a microstrip line having an entire circumference of one wavelength in the tube having an oscillation frequency.

  The number of closed lines is arbitrary as long as it is plural. As many oscillation signals as necessary can be obtained. For example, if the number of array antennas is n, the number of closed lines is n. The differential oscillator connects two ports with opposite phases. Two sets of ports of adjacent closed lines are connected by two sets of differential amplifiers. These two sets of differential amplifiers are preferably configured with the same element characteristics.

In addition, in the second closed line at the other end, a port not connected to the other closed line is connected to an impedance-matched termination resistor, an open end, or a negative resistance. As an example, an oscillator may be connected.
In the present invention, in a plurality of oscillation signals obtained at corresponding ports of a plurality of closed lines, the phases may be fixedly synchronized or may be synchronized by changing a phase difference. Therefore, when obtaining an oscillation signal that changes the phase, it is desirable to provide a phase shifter that shifts the phase in a line that connects two ports of adjacent closed lines.

  The plurality of closed lines may be two-dimensionally arranged. This array arrangement makes it easy to supply signals to the array antenna.

  The shape of the closed line is arbitrary, such as a circle, an ellipse, a square, a rhombus, a rectangle, a parallelogram, a regular triangle, a regular pentagon, a regular hexagon, a regular octagon, and a regular polygon. In the case of a polygon, the position where the port is provided may be an apex angle or a side. The line length between the provided ports is 1/4 of the guide wavelength of the fundamental frequency. When the closed lines are arranged one-dimensionally in one direction, two ports in two adjacent closed lines are connected in opposite phases. There are two sets of this antiphase connection in the adjacent closed line. When the closed lines are two-dimensionally arranged, the closed lines are connected in opposite phases by two sets of differential oscillators in two orthogonal directions.

  The closed line is composed of a peripheral line provided with a port, and an internal line that connects the central point of the closed line and the peripheral line at an equicentral angle, and outputs a frequency four times the oscillation frequency from the central point. It is also good. In this case, a frequency four times the oscillation fundamental frequency can be output from the center point.

  In these cases, even when a one-dimensional array or a two-dimensional array is used, the coupling of the two closed paths is the same as that described above. In the case of a polygon, the position where the oscillator is coupled may be the apex angle or the side of the closed line. Further, in the case where the closed line is constituted by a regular polygon or a circle, a differential oscillator may be coupled to the intersection of the peripheral line and the internal line, or the differential oscillator may be on a peripheral line other than the intersection. It may be provided at an arbitrary quadrant. When four differential oscillators are connected to one closed line, the differential oscillators are closed at any point where the distances between the four differential oscillators and their intersections are all equal because of symmetry. Connect the track. This is true even when the closed track is square. That is, the differential oscillator and the closed line may be coupled at a square corner, a midpoint of each side, or a point on each side that is equal in distance from each corner.

  Further, the closed line may be composed of a peripheral line composed of a square whose length of one side is ¼ of one wavelength of the oscillation frequency, and an internal line that connects the midpoint of each side and the center point of the square. . In this case, a frequency four times the oscillation frequency can be output from the center point. At this time, the port for connecting the differential oscillator may be provided at the midpoint of each side of the square, or may be provided at the corner of the square. This configuration may be a one-dimensional array or a two-dimensional array.

  It is also possible to configure an array antenna apparatus using the phase-locked oscillator array having the above configuration. In this case, an antenna element, an oscillator, a closed line, and other transmission circuits can be formed on one substrate. Similarly, an array antenna apparatus using a phase-locked oscillator array, in which a transmission circuit and an antenna element are formed at the center point of a closed line, may be used.

  Further, a phase shifter that shifts the phase of the output signal of each port by nθ, where n is a natural number, may be provided. In this case, directivity can be controlled in the array antenna.

  According to the present invention, between the two adjacent ports among the four ports provided at the position obtained by dividing the total length of the closed line by 1/4, and between the two adjacent ports of the closed line adjacent to the closed line, A differential oscillator is connected as a negative resistance. Therefore, each closed line is synchronized in frequency and phase, and four stable oscillation signals having different phases by 90 degrees can be obtained from the four ports of each closed line. Further, in the closed line disposed at least at one of the ends, the phase of the first port of one of the two ports not connected to the differential oscillator among the four ports of the closed line is changed to the other Since the resonance mode fixing means for fixing to the lead phase of 90 degrees with respect to the phase of the second port is provided, the oscillation mode in the closed line has a phase in a direction determined by the resonance mode fixing means. Then, the mode is sequentially rotated. As a result, a signal in which the phase relationship between adjacent ports is 90 degrees and the phase relationship between advance and delay is fixed is obtained from each port of each closed line even if the power of the apparatus is turned on / off.

  Further, by arranging a plurality of closed lines such as a one-dimensional array and a two-dimensional array, application to an array antenna becomes possible. Also, by providing a plurality of closed lines, such as a one-dimensional array and a two-dimensional array, and providing a phase shifter on a line connecting adjacent closed lines, the phase of the obtained oscillation signal can be variably controlled. . Therefore, directivity control of the phased array antenna device can be easily performed. Also, directivity control of the phased array antenna device is facilitated by providing a phase shifter that provides a phase difference of nθ for each stage of the oscillation signal output from each port of the closed line of each stage. Can be done.

  In addition, when four rotationally symmetric internal lines are provided and a signal having a frequency four times the fundamental frequency is obtained from the center point, the resonance frequency of the ring resonator is lower than the frequency used. Compared with the case where resonance is made at the operating frequency, a high Q value can be obtained, which is effective.

  When these phase-locked oscillator arrays are used in an array antenna apparatus including a phased array antenna, the power consumption can be reduced because a distributor is not used. Also, there is little heat generation. Further, the antenna element and the circuit can be integrated on one substrate. Furthermore, the gain of the ring resonator can be determined by the number of differential oscillators, and the capacity of the differential oscillator can be reduced in obtaining a constant output. In addition, when the length of each line for supplying a signal to each antenna system is distributed by a distributor using a single oscillator, it is necessary to adjust the transmission phase at each antenna because it is not equal. However, in the present invention, it is possible to eliminate various adverse effects due to such non-uniformity of the line length.

  In addition, since a plurality of closed lines are provided, it is possible to provide an array antenna apparatus according to the required level with the same configuration by selecting the closed line to be used according to the performance required for the array antenna. Become. For example, when the search range is long, or the directivity is narrowed to increase the direction resolution, the number of closed lines to be operated is increased, the search range is shortened, the directivity If the width is widened to reduce the direction resolution, the number of closed lines to be operated may be reduced.

  Hereinafter, specific examples of the present invention will be described with reference to the drawings. However, the present invention is not limited to the examples.

  FIG. 1 is a plan view of a phase-locked oscillator array, and FIG. 2 is a cross-sectional view showing one of the ring resonators. On the substrate 10, a circular closed line 22 made of a microstrip line and an IC made up of differential oscillators 31a, 31b, 32a, 32b are arranged. A ground conductor 12 is disposed on the back surface 11 of the substrate. The total length a of the circular closed line is the guide wavelength λ of the oscillation fundamental frequency. The four equally divided points around the closed line 22 constitute four ports 22a, 22b, 22c and 22d to which the gates / bases of the differential oscillators 31a, 32a, 32b and 31b are respectively connected.

  FIG. 3 shows a specific circuit of the differential oscillators 31 a and 31 b that connect the closed line 21 (first closed line) and the closed line 22. The transistors constituting the differential oscillator are composed of transistors having the same configuration and the same element characteristics. A differential oscillator 31 a is connected between the port 21 b of the closed line 21 and the port 22 a of the closed line 22. That is, the gates / bases of the two transistors Tr1 and Tr2 constituting the differential oscillator 31a are connected to the port 21b and the port 22a, respectively. In addition, a differential oscillator 31 b is connected between the port 21 c of the closed line 21 and the port 22 d of the closed line 22. That is, the gates / bases of the two transistors Tr3 and Tr4 constituting the differential oscillator 31b are connected to the port 21c and the port 22d, respectively. Between the other closed lines 22 and 23, a differential oscillator 32a for connecting the respective ports 22b and 23a and a differential oscillator 32b for connecting the respective ports 22c and 23d are arranged. Further, differential oscillators 33a and 33b are connected to the port 23b and the port 23c of the closed line (hereinafter referred to as “second closed line”) 23 at the other end. In FIG. 1, only three closed lines are illustrated, but actually, a necessary number of closed lines are connected by a differential oscillator according to the number of necessary signals.

  The resonance mode fixing device 30 is connected to the ports 21a and 21d to which the differential oscillator in the first closed line 21 at the end is not connected. The resonance mode fixing device 30 includes an oscillator 27, a 90-degree delay line 29, and an amplifier 28 constituting a propagation direction limiting circuit. The port 21d is connected to the gate / base of the transistor Tr5 of the oscillator 27 via a resistor r. The port 21a is connected to the gate / base of the transistor Tr5 of the oscillator 27 via the amplifier 28, the 90-degree delay line 29, and the resistor r that propagate the oscillation signal only from the point B1 to the point A1 (port 21d to port 21a). It is connected to the. As the propagation direction limiting circuit, in addition to the amplifier 28, a directional coupler, an isolator, a circulator, or the like can be used as long as it can propagate an electromagnetic wave in one direction. When the excitation signal at point B1 is cosωt, the excitation signal at point A1 is a signal sinωt whose phase is delayed by 90 degrees. As described above, when the port 21d is excited by cosωt and the port 21a is excited by sinωt, the electric field becomes a clockwise rotating electric field, and the voltages of the ports 21a, 21b, and 21c with respect to the signal cosωt of the port 21d are sequentially The signal is delayed by 90 degrees in phase.

  The amplifier 28 prevents the signal from propagating from the second port to the oscillator side. In other words, the amplifier 28 is for causing the oscillator 27 to oscillate at the resonance frequency only by the characteristics of the first port without the characteristics of the second port affecting the oscillator 27.

  In FIG. 1, the signal excited from the port 21d does not appear at the ports 21a and 21c, but appears only at the port 21b with a phase difference of 180 degrees. On the other hand, the signal excited from the port 21a does not appear at the ports 21b and 21d but appears only at the port 21c with a phase difference of 180 degrees. When excitation is performed with a phase difference of 90 degrees from the port 21a and the port 21d, the closed line 21 rotates in a direction from the port where the excitation phase is advanced toward the port where the excitation phase is delayed. A rotating electric field is generated, which rotates at an angular velocity ω of the fundamental frequency.

  Since the adjacent closed line ports are connected by a differential oscillator, the signal of the port 21b is different from the signal of the port 22a by 180 degrees. Similarly, the signal of the port 21c and the signal of the port 22d are 180 degrees out of phase. The signals at the port pairs of the ports 22b and 22c of the closed line 22 and the ports 23a and 23d of the closed line 23 are 180 degrees out of phase. When the excitation state in the first closed line 21 at the end is determined, the rotating electric field is also excited in the other closed lines coupled by the differential oscillator in the direction determined by the rotating direction of the electric field.

In this way, according to the present embodiment, it is possible to obtain the oscillation signals having the frequency f that is phase-synchronized with the number of closed lines, without using a distributor. Further, four oscillation signals having different phases by 90 degrees can be obtained from the four ports in each closed line.
In the present embodiment, the gate / base of the transistor of the differential oscillator is connected to the closed line. However, the drain / collector or the source / emitter may be connected to the closed line via a capacitor or inductor. The line through which the oscillation signal flows and the closed line may be coupled by electromagnetic coupling such as capacitive coupling or inductive coupling. Further, in the second closed line, the differential oscillators 33a and 33b are connected to ports not connected to other closed lines, but this port may be open or terminated with a matching resistor. good.

  In the above embodiment, the arrangement relationship between the amplifier 28 and the 90-degree delay phase shifter 29 may be reversed. That is, the amplifier 28 may be disposed on the side close to the oscillator 27, and the 90-degree delay phase shifter 29 may be disposed on the side close to the second port 21a. In the above embodiment, the amplifier 28 is connected in series to the 90-degree delay phase shifter 29. However, as shown in FIG. 4, the amplifier 28 is connected to the side where the 90-degree delay phase shifter 29 is not provided. You may provide in the direction which transmits a signal to the 1st port side in the track | line, ie, the track | line connected to the 1st port 21d. In this case, the oscillator 27 oscillates at a frequency determined by the negative resistance, the 90-degree delay phase shifter 29, and the characteristics of the closed line viewed from the second port 21a. The oscillation frequency of the oscillator 27 is input to the first port 21d. Even in this way, the voltage phase of the first port 21d can always be advanced by 90 degrees with respect to the voltage phase of the second port 21a.

  In FIG. 1, a phase shifter advanced by 90 degrees and an amplifier that propagates a signal only in the direction toward the first port 21d are connected to the side connected to the first port 21d, and the second port 21a is connected to the second port 21a. The output of the oscillator 27 may be input as it is. In this case, the oscillator 27 oscillates at a frequency determined by its negative resistance and the characteristics of the closed line viewed from the second port 21a, and the oscillation signal advances 90 degrees and passes through the phase shifter. Input to 1 port 21d. This also makes it possible to always fix the voltage phase of the first port 21d to a state advanced by 90 degrees with respect to the voltage phase of the second port 21a. Similar to the concept of the configuration of FIG. 4, only a 90-degree advance phase shifter is connected to the line connected to the first port 21d, and the signal connected only to the direction is connected to the line connected to the first port 21a. Only an amplifier for propagation may be provided. In this case, the oscillator 27 oscillates at a frequency determined by its negative resistance, a 90-degree advance phase shifter, and the characteristics of the closed line viewed from the first port 21d. The oscillation frequency of the oscillator 27 is input to the second port 21a. Even in this way, the voltage phase of the first port 21d can always be advanced by 90 degrees with respect to the voltage phase of the second port 21a.

  In the first embodiment, the resonance mode fixing device 30 is configured such that the oscillator 27 oscillates at a frequency based on the single peak characteristic due to the negative resistance of the oscillator 27 and the characteristics of the closed line viewed from one port. . The second embodiment uses an independent oscillator 26 as shown in FIG. That is, the oscillator 26 that oscillates at the resonance frequency of the closed line is used although it is not affected by the circuit constant of the first closed line 21. Using the 90-degree delay phase shifter 29, the phase of the oscillation signal of the oscillator 26 is delayed by 90 degrees. In this case, since the circuit characteristic of the closed line 21 does not affect the oscillation characteristic of the oscillator 26, an amplifier that is a propagation direction limiting circuit is not used. Of course, a 90-degree lead phase shifter may be provided on the line connected to the first port 21d, and the output of the oscillator 26 may be directly input to the second port 21a. In any case, the phase of the voltage of the first port 21d can be fixed to a state advanced by 90 degrees with respect to the phase of the voltage of the second port 21a.

  In the case of the present embodiment, the oscillator 26 is an oscillator that oscillates regardless of the closed line 21. Therefore, even if the oscillator 26 and the closed line 21 are directly connected, the characteristics of the closed line 21 affect the oscillator 26. Never give. However, a path that bypasses the closed line 21 is formed between the first port 21d and the second port 21a by the line into which the 90-degree delay phase shifter and the 90-degree advance phase shifter are inserted. For this reason, the resonance characteristics of the closed line 21 are affected. Therefore, as shown in FIG. 6, an amplifier 28a for propagating a signal only in the direction of the second port 21a is provided on the line connected to the second port 21a, and the first line is connected to the first port 21d. An amplifier 28b that propagates a signal only in the direction of the port 21d may be provided. Thereby, the resonance characteristics can be improved. Similarly, when a 90-degree lead phase shifter is used, each amplifier can be used for each path.

  As shown in FIG. 7, in the third embodiment, the resonance mode fixing device 130 is a 90-degree delay phase shifter 29 (λ / 4 delay) connected via a capacitor between the first port 21d and the second port 21a. Track). In the case of this configuration, the differential oscillator 31a connected to the port 21b having a 180 ° positional relationship with the first port 21d is connected to the port 21c having a 180 ° positional relationship with the second port 21a. The differential oscillator 31b is activated before the closed line 21 is excited from the port 21b. When excitation is performed from the port 21b with cosωt, the voltage of the first port 21d is −cosωt having a phase difference of 180 degrees with respect to the excitation signal. This excitation signal does not appear in the second port 21a and the port 21c, and the voltage of these ports is zero. A signal appearing at the first port 21d is input to the second port 21a via the 90-degree delay phase shifter 29. Then, the second port 21a is excited by −sinωt. By exciting with an excitation signal having a phase difference of 90 degrees from the two ports, the electric field distribution of the closed line 21 is excited from the first port 21d with a phase delay of 90 degrees by the above-described explanation. It becomes a rotating electric field that rotates in the direction toward. Accordingly, the voltage phase of the first port 21d can be fixed to a state advanced by 90 degrees relative to the voltage phase of the second port 21a regardless of whether the power of the apparatus is on or off. As a result, the voltage phase at each port in the other closed line can also be fixed at a phase different by 90 degrees.

When the differential oscillator 31b connected to the port 21c having a positional relationship of 180 degrees with the second port 21a is activated before the differential oscillator 31a, the voltage phase of the second port 21a is changed to the first port. The phase advances by 90 degrees from the voltage phase of 21d, and the rotation direction of the electric field is also counterclockwise. As described above, the phase relationship between the ports of the closed line can be uniquely fixed by the starting order of the differential oscillators 31a and 31b connected to the first closed line 21.
Further, instead of the 90-degree delay phase shifter 29, a 90-degree advance phase shifter may be used. In this case, the differential oscillator 31b is started before the differential oscillator 31a. By doing so, the voltage phase of the first port 21d can be fixed at a state advanced by 90 degrees with respect to the voltage phase of the second port 21a.

  In the third embodiment, when the first port 21 d is excited, the signal does not appear at the position of the second port 21 a on the closed line 21. Therefore, even if the voltage signal at the position of the first port 21a is extracted and delayed by 90 degrees and input from the second port 21a to the closed line 21, it does not affect the other oscillation modes. However, since a path that bypasses the closed line 21 is formed between the first port 21d and the second port 21a, the oscillation characteristics of the closed line 21 are affected. Therefore, as shown in FIG. 8, an amplifier 28 that restricts the propagation direction only in the direction in which a signal having a phase of 90 degrees is propagated may be provided in the direction from the first port 21d to the second port 21a. In this case, the level of the signal branched to the 90-degree delay phase shifter 29 side is lowered at the first port 21d, amplified by the amplifier 28, and input to the second port 21a, whereby the closed line 21 The oscillation characteristics are not impaired. The above configuration is the same when a 90-degree advance phase shifter is used instead of the 90-degree delay phase shifter 29.

  In this embodiment, the initial phase of the oscillation signal of the closed line at each stage is set to 0, θ, 2θ in the phase-locked oscillator array of the first embodiment shown in FIG. The phase difference between them is θ. The phase difference θ can be variably set.

  As shown in FIG. 9, a phase shifter 51 a is provided between the differential oscillator 31 a connecting the closed lines and the port 22 a of the closed line 22, and between the differential oscillator 31 b and the port 22 d of the closed line 22. A phase shifter 51b is provided, a phase shifter 52a is provided between the differential oscillator 32a and the port 23a of the closed line 23, and a phase shifter 52b is provided between the differential oscillator 32b and the port 23d of the closed line 23. It is a feature. As a result, four signals of cos ωt, -cos ωt, sin ωt, and -sin ωt are obtained from the closed line 21, and four signals whose phases are delayed by θ in the four signals from the second closed line 22. From the third stage closed line 23, four signals having phases delayed by 2θ are obtained from the third stage closed line 23. Similarly, by providing many closed lines, cos [ωt- (n-1) θ], -cos [ωt- (n-1) θ], sin [ωt- Four oscillation signals (n-1) θ] and -sin [ωt- (n-1) θ] are obtained. With such a configuration, the apparatus of the present embodiment can be used for a carrier wave generator of a phased array antenna apparatus that can control directivity in a one-dimensional direction.

  9 uses the configuration of FIG. 1 of the first embodiment as the resonance mode fixing device 30, but the resonance mode fixing device 30 has a configuration according to the modification of the first embodiment shown in FIG. 5, a configuration using the independent oscillator of the second embodiment shown in FIG. 5, a configuration according to a modification of the second embodiment shown in FIG. 6, a 90-degree delay phase shifter of the third embodiment shown in FIG. A configuration in which a phase shifter is connected between the first port and the second port, and a configuration according to a modification of the third embodiment shown in FIG. 8 can be adopted.

  In this embodiment, as shown in FIG. 10, closed lines are two-dimensionally arranged. That is, the one-dimensional array in the x direction according to the first embodiment is repeated in the y direction perpendicular to the x direction, and the closed lines of each x system are coupled also in the y axis direction. The first system arranged in the x-direction composed of the closed lines 21, 22, and 23 is the same as that of the first embodiment. The second system arranged in the x direction, which includes the closed line 61, the differential oscillators 61a and 61b, the closed line 62, the differential oscillators 62a and 62b, and the closed line 63, has the same configuration as that of the first embodiment. The point that the differential oscillators 63a and 63b are connected to the ports not connected to the differential oscillators 62a and 62b of the second closed line 63 at the end of the second system is the same as that of the first system.

  In the present embodiment, the first system closed line 21 and the second system closed line 61 are connected by differential oscillators 31c and 31d, and the first system closed line 22 and the second system closed line 62 are connected. Are connected by differential oscillators 32c and 32d, and a closed line 23 of the first system and a closed line 63 of the second system are connected by differential oscillators 33c and 33d. The output of each oscillation signal has a similar relationship. Thus, the number of signals can be increased by arranging the closed line and the differential oscillator two-dimensionally.

  Also in the fifth embodiment, phase shifters 51a, 51b, 52a, and 522b of the phase shift amount θ shown in FIG. 9 of the fourth embodiment may be provided in each row in the x-axis direction. Thereby, a sine wave and a cosine wave having a number of phases of nθ can be generated. Further, in each column in the y-axis direction, a phase shifter having a phase amount φ is provided between the differential oscillators 31d, 31c, 32d, 323c, 33d, and 33c and the ports of the closed lines 61, 62, and 63. Also good. In this way, cos [ωt- (n-1) θ], -cos [ωt- (n-1) θ], sin [ωt- (n-1) θ], -sin [ωt- ( n-1) θ], cos [ωt- (n-1) φ], -cos [ωt- (n-1) φ], sin [ωt- (n-1) φ], -sin [ωt- ( n-1) φ], cos [ωt- (n-1) θ- (n-1) φ], -cos [ωt- (n-1) θ- (n-1) φ], sin [ωt- (n-1) θ- (n-1) φ] and -sin [ωt- (n-1) θ- (n-1) φ] can be generated.

  Also in the present embodiment, similarly to the fourth embodiment, the resonance mode fixing device 30 includes the resonance mode fixing device 30 used in the first embodiment, the second embodiment, the third embodiment, and modifications thereof. Can be used.

In the sixth embodiment, a frequency 4f ₀ that is four times the frequency f ₀ of the oscillator is generated. As shown in FIG. 11, the configuration of the first embodiment shown in FIG. 1 is characterized in that the closed lines 21, 22, and 23 are provided with an internal line 200 that crosses the cross. It has a cross-shaped internal line 200 that connects each midpoint between the ports of the peripheral line 210 of each closed line and the center of the circle.

The closed line 21 will be described. The lengths of the peripheral lines 210 between the four ports 21a to 21d are equal. Accordingly, the phase of the harmonic of the frequency 4f ₀ at the four intersections of the peripheral line 210 and the internal line 200 is the same phase. Moreover, the four ports 21a to 21d, harmonic phase frequency 4f ₀ is in phase, the oscillation signal becomes cos (4ωt). However, ω = 2πf ₀ . Further, since the distance between the center point R11 and each port is the same, the phase of the signal at the center point R11 is delayed by the same constant phase amount with respect to the signal phase of each port. Therefore, the signal at the center point R11 is cos (4ωt−α).

On the other hand, for the fundamental wave of frequency f ₀ , the phase of the signal at each port is 0, π / 2, π, 3π / 2, and at the center point R11, these phases have the same phase lag amount. This is the sum of cosine waves whose phase is the value obtained by subtracting β. This is zero. Similarly, in the case of the second harmonic 2f ₀ , it is the sum of cosine waves whose phase is a value obtained by subtracting the phase delay amount γ due to the internal line to the phase of each port of 0, π, 0, π. This sum is also zero due to symmetry. In the case of the third harmonic 3f ₀ , the sum of cosine waves whose phase is a value obtained by subtracting the phase delay η due to the internal line in common with the phase of each port of ₀ , 3π / 2, π, and π / 2. It becomes. Also in this case, the third harmonic component at the center point R11 is zero because of the symmetry of the phase. Eventually, only the fourth harmonic component appears at the center point R11.

  In this way, an oscillation signal of cos (4ωt) is obtained from each central point R11 of each closed line 21, 22, 23. This configuration may be adopted in the configuration of the fourth embodiment shown in FIG. In this case, a signal of cos [4ωt−4 (n−1) θ] can be obtained. Also, by providing m closed lines having these configurations in the y direction, m oscillation signals having n phase differences 4θ can be obtained. Thereby, the phased array antenna apparatus which can change directivity to a one-dimensional direction can be comprised.

  Moreover, it can also be employ | adopted as a structure at the time of arranging the closed line of Example 5 of FIG. 10 two-dimensionally. Further, in the configuration of FIG. 10, the configuration of the present embodiment can be adopted as a configuration using a phase shifter that changes the phase of a signal by θ in the x direction and φ in the y direction. In that case, cos [4ωt-4 (n-1) θ] cos [4ωt-4 (n-1) φ], cos [4ωt-4 (n-1) θ-4 (n-1) φ] The signal can be generated.

Thus, by configuring the closed line in a two-dimensional arrangement of m rows and n columns, the antenna elements can also be configured in m rows and n columns, and the radiated power can be increased. In this embodiment, the oscillation frequency in the ring resonator is f _{0 and} the frequency of the oscillation signal to be used is 4f ₀ . Therefore, since the resonance frequency is lower than the signal used, the resonance Q value can be increased. Also in the present embodiment, with respect to the resonance mode fixing device 30, the resonance mode fixing device 30 used in the first, second, and third embodiments and modifications thereof can be employed.

The present embodiment is an array antenna apparatus that uses the phase-locked oscillator array of the first embodiment for directivity control of a phased array antenna.
As shown in FIG. 12, four signals, cosωt, cos (ωt−π / 2), cos (ωt−π), and cos (ωt−3π / 2) are respectively transmitted from the closed lines 22, 23, and 24. Is output. In FIG. 12, these signals are represented by phase angles 0, 90, 180, and -90 with the leading phase being positive at the port from which they are output. The first closed line 21 is connected to the resonance mode fixing device 30 of the above-described embodiment. To the closed line 22, mixers 52a, 52b, 52c, and 52d are connected in order to shift the phase of these signals. The mixers 53a to 53d and 54a to 54d are similarly connected to the other closed lines 23 and 24. Symbols a, b, c, and d in the code represent mixers that process signals having phase angles of 0, −90, 180, and 90 degrees, respectively. Further, for the system of the closed line 22, an adder 62a for adding the output of the mixer 52b and the output of the mixer 52c, a subtractor 62b for subtracting the output of the mixer 52b from the output of the mixer 52c, the output of the mixer 52a and the mixer An adder 62c for adding the outputs of 52d and a subtractor 62d for subtracting the output of the mixer 52d from the output of the mixer 52a are provided. An adder 63a that adds the output of the mixer 53a and the output of the mixer 53d to the system of the closed line 23, a subtracter 63b that subtracts the output of the mixer 52b from the output of the mixer 52a, the output of the mixer 53b, and the output of the mixer 53c An adder 63c for adding outputs and a subtractor 63d for subtracting the output of the mixer 53b from the output of the mixer 53c are provided. For the system of the closed line 24, an adder 64a that adds the output of the mixer 54b and the output of the mixer 54c, a subtractor 64b that subtracts the output of the mixer 54b from the output of the mixer 54c, the output of the mixer 54a, and the output of the mixer 54d And an adder 64c for subtracting the output of the mixer 54d from the output of the mixer 54a.

  To the mixers 52a, 52b, 52c, and 52d, cosφ, −sinθ, −cosθ, and sinφ are input to shift the phase of the oscillation signal by θ and φ, respectively. Cos 2θ, −sin 2φ, −cos 2φ, and sin 2θ are input to the mixers 53a, 53b, 53c, and 53d, respectively, in order to shift the phase of the oscillation signal by θ and φ. Further, cos 3φ, −sin 3θ, −cos 3θ, and sin 3φ are input to the mixers 54a, 54b, 54c, and 54d, respectively, in order to shift the phase of the oscillation signal by θ and φ, respectively. As a result, in the system of the closed line 22, cos (ωt + θ) from the adder 62a, cos (ωt−θ) from the subtractor 62b, and cos (ωt + φ), from the adder 62c. From the subtractor 62d, cos (ωt−φ) is output. Further, in the system of the closed line 23, cos (ωt + 2θ) is added from the adder 63a, cos (ωt−2θ) is added from the subtractor 63b, and cos (ωt + 2φ) is subtracted from the adder 63c. Cos (ωt−2φ) is output from the device 63d. In the system of the closed line 24, cos (ωt + 3θ) is added from the adder 64a, cos (ωt−3θ) is added from the subtractor 64b, and cos (ωt + 3φ) is subtracted from the adder 64c. Cos (ωt−3φ) is output from the unit 64d. ,

  As described above, since the signals that decrease and increase with the phases nθ and nφ are obtained, as shown in FIG. 12, by supplying signals that change in phase to the transmitting and receiving antennas T1 to T3 and K1 to K3, The directivity of transmission and reception can be controlled in the θ direction and the φ direction.

  As the resonance mode fixing device 30, all of the above-described embodiments and modifications thereof can be used in this embodiment. In FIG. 1 of the first embodiment, the oscillation frequency can be changed by changing the values of the capacitors of the oscillation devices 27 and 26 of the resonance mode fixing device 30, thereby realizing a radar antenna using FMCW. I can do it. Further, as shown in FIG. 13, by changing the bias voltage of the first closed line 21 and the reverse bias diodes D1 to D4 connected between the ground, the capacitance is changed and the oscillation frequency is changed. Can do. Therefore, an FMCW radar antenna apparatus can be realized also by this method. Also, in FIG. 13, unlike FIG. 12, the phase shift system of φ is also a phase shift system of θ, so that a signal having four phase differences of ± θ and ± 2θ from one closed line 23 is obtained. Can be output. Further, from one closed line 24, signals having four phase differences of ± 3θ and ± 4θ can be output.

  The present invention can be used for a phased array antenna apparatus capable of controlling directivity.

1 is a circuit diagram showing a phase-locked oscillator array according to a specific example 1 of the present invention. FIG. 3 is a cross-sectional view showing the structure of the phase-locked oscillator array of the first embodiment. 1 is a circuit diagram showing details of a phase-locked oscillator array oscillation device according to a first embodiment. The circuit diagram which showed the 1st closed line and resonance mode fixing device which concern on the deformation | transformation of Example 1. FIG. The circuit diagram which showed the phase-locked oscillator array which concerns on the specific Example 2 of this invention. The circuit diagram which showed the phase-locked oscillator array which concerns on the modification of the specific Example 2 of this invention. FIG. 6 is a circuit diagram showing a phase-locked oscillator array according to a specific example 3 of the invention. The circuit diagram which showed the phase-locked oscillator array which concerns on the modification of the specific Example 3 of this invention. The circuit diagram which showed one closed line of the phase-locked oscillator array which concerns on the specific Example 4 of this invention. FIG. 10 is a circuit diagram showing a phase-locked oscillator array according to a specific example 5 of the invention. FIG. 10 is a circuit diagram showing a phase-locked oscillator array according to a specific example 6 of the invention. FIG. 10 is a circuit diagram showing a phase-locked oscillator array according to a seventh embodiment of the invention. The circuit diagram which showed the phase-locked oscillator array which concerns on the modification of the specific Example 7 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 21 ... 1st closed line 23 ... 2nd closed line 22, 61, 62, 63 ... Closed line 30 ... Resonance mode fixing device 26, 27 ... Oscillator 29 ... 90 degree | times delay phase shifter 28 ... Amplifier 31a, 31b, 32a, 32b, 61a, 61b, 62a, 62b ... differential oscillator 21d ... first port 21a ... second port 21b, 21c, 22a-22d, 23a-23 ... port 51a, 51b, 52a, 52b ... phase shifter

Claims (16)

In a phase-locked oscillator array that outputs an oscillation signal having the same frequency of four phases with an oscillation signal phase difference of 90 degrees,
A plurality of ring resonators comprising a plurality of closed lines;
Negative resistance between two adjacent ports among the four ports provided at a position obtained by dividing the total length of the closed line by ¼, and two adjacent ports of the closed line adjacent to the closed line, respectively. As a differential oscillator to be connected,
At least one of the four ports of the closed line in the closed line arranged at one end of the closed line has a phase of the first port of the two ports to which the differential oscillator is not connected. And a resonance mode fixing means for fixing a direction of a phase relationship between the first port and the second port so that the phase is a relative advance of 90 degrees with respect to the phase of the second port. Oscillator array.   The resonance mode fixing means has an oscillator that outputs two signals having a phase difference of 90 degrees, and inputs the signal having the advanced phase to the first port and the other signal to the second port. The phase-locked oscillator array according to claim 1, wherein   The resonance mode fixing means is provided between the oscillator and the first port and between the oscillator and the second port, respectively, from the oscillator to the first port side and from the oscillator to the second port side. The phase-locked oscillator array according to claim 2, further comprising a propagation direction limiting circuit for limiting a propagation direction of the signal.   The resonance mode fixing means includes, as a negative resistance, an oscillator connected to the first port and a delayed phase shift circuit that delays the phase of the output signal of the oscillator by 90 degrees and outputs the delayed signal to the second port. The phase-locked oscillator array according to claim 1.   The resonance mode fixing means includes, as a negative resistance, an oscillator connected to the second port, and an advanced phase shift circuit that advances the phase of the output signal of the oscillator by 90 degrees and outputs the signal to the first port. The phase-locked oscillator array according to claim 1.   The resonance mode fixing unit includes a propagation direction limiting circuit for propagating a signal only from the oscillator toward the port between the oscillator and the first port or the second port. The phase-locked oscillator array according to claim 4 or 5.   2. The phase-locked oscillator array according to claim 1, wherein the resonance mode fixing unit is a phase shifter that generates a phase of 90 degrees connecting the first port and the second port. 3.   8. The phase-locked oscillator array according to claim 7, wherein the resonance mode fixing unit includes a propagation direction limiting circuit that limits a propagation direction of a signal between the first port and the second port to one direction.   9. The phase-locked oscillator array according to claim 1, wherein the closed line is formed of a microstrip line having an entire circumference of one wavelength having an oscillation frequency.   10. The differential oscillator according to claim 1, wherein each transistor of the differential oscillator is coupled to each of two ports of the adjacent closed line. The phase-locked oscillator array described.   The phase-locked oscillator array according to any one of claims 1 to 10, wherein the plurality of closed lines are two-dimensionally arranged.   12. The phase-locked oscillator array according to claim 1, further comprising a phase shifter that shifts a phase in a line that connects two ports of the adjacent closed lines.   The closed line is composed of a peripheral line in which the port is provided, and an internal line connecting the central point of the closed line and the peripheral line at an equicentral angle, and outputs a frequency four times the oscillation frequency from the central point. The phase-locked oscillator array according to claim 1, wherein the phase-locked oscillator array is provided.   14. The phase-locked oscillator array according to claim 1, further comprising a phase shifter that shifts a phase of an output signal of the port by nθ, where n is a natural number.   An array antenna apparatus using the phase-locked oscillator array according to claim 1.   The array antenna apparatus according to claim 15, wherein a transmission circuit and an antenna element are formed at a center point of the closed line.

Images