JPS6036124B2 - Parallel feedback microwave oscillator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a structure in which first and second distributed constant lines are formed on the main surface of a dielectric substrate, and a dielectric substrate on which the first and second distributed constant lines are formed. , a field effect transistor connects its gate terminal to the first distributed constant line and its drain terminal (
The field effect transistor's drain terminal (or source terminal) and gate terminal are connected to the second distributed constant line, the source terminal (or drain terminal) is connected to the ground, and the drain terminal (or source terminal) and gate terminal of the field effect transistor are connected to the second distributed constant line. The present invention relates to an improvement in a parallel feedback microwave oscillator having a configuration in which the microwave oscillator is coupled in parallel.

A conventional parallel feedback microwave oscillator of this type has first and second main surfaces 1 and 2 facing each other, as shown in FIGS. On the main surface 1 of the dielectric substrate 4 on which the ground conductor 3 is formed, distributed constant lines 5 and 6 are formed by microstrip lines, and on the main surface 1 of the dielectric substrate 4, gate terminals G and drain terminals are formed. A field effect transistor T having a terminal D and a source terminal S has its gate terminal G connected to one end 5a of the distributed constant line 5 using a line 7, and the drain terminal D connected to one end 6a of the distributed constant line 6 using a line 8. , a lead wire 9 connecting the source terminals S at one end, a conductor 10 formed in advance on the main surface 2 of the dielectric substrate 1 to which the other end of the lead wire 9 is connected, and a conductor 10 at one end. The field effect transistor T is connected to the ground conductor 3 via a shorting conductor 11 which extends across the thickness of the dielectric substrate 4 and whose other end is connected to the ground conductor 3. The distributed constant line 12 is a microstrip line formed in such a manner that the drain terminal ○ and the gate terminal G can extend from one end 5a of the distributed constant line 5 on the main surface 1 of the dielectric substrate 4, and the distributed constant line 12 of the dielectric substrate 4. A distributed constant line 13 formed by a microstrip line is formed on the main surface 1 so as to extend from one end 6a of the distributed constant line 6, and electrodes 14a and 1 are formed on the opposing surfaces.
4b, its electrode 14a is electromechanically connected to the free end 12a of the distributed constant line 12, and the electrode 14b is connected to the free end 13a of the distributed constant line 13 via the wire 15. They are coupled through a feedback circuit 17 composed of a DC blocking/feedback capacitive element 16 disposed on a dielectric substrate 4, and a detailed explanation thereof is omitted, but as shown in FIGS. 1 and 2. It is generally assumed that the configuration is represented by an equivalent circuit as shown in FIG. 3, in which the same reference numerals are given to corresponding parts.

According to the configuration of such a parallel feedback microwave oscillator,
Since the drain terminal ○ and gate terminal G of the field effect transistor T are coupled through the feedback circuit 17, the feedback constant of the feedback circuit 17 (the characteristic impedance of the distributed constant lines 12 and 13, the capacitive element for DC blocking and feedback) 16), and by appropriately selecting the characteristic impedance of the distributed constant lines 5 and 6 in advance, the required direct current (not shown) can be generated between each of the distributed constant lines 5 and 6 and the ground conductor 3. By connecting a bias power supply, a microwave oscillator is obtained, and its oscillation output can be led out between the distributed constant line 6 and the ground conductor 3. However, the drain terminal of the field effect transistor T A feedback circuit 17 that connects ○ and the gate terminal G is connected to the distributed constant line 5.
and 6, and a DC blocking/feedback capacitive element 16 connected between the equally distributed constant lines 12 and 13 via a line 15. This makes it a stable microphone.

In addition to not being able to obtain wave oscillations, this method has drawbacks such as the overall structure becoming large due to the direct current blocking/feedback capacitive element 16 that constitutes the feedback circuit 17. Therefore, the present invention aims to propose a novel parallel feedback type microwave oscillator which can effectively avoid the above-mentioned drawbacks, which will become clear from the detailed description below.

4 and 5 show an example of a parallel feedback microwave oscillator according to the present invention, and corresponding parts to those in FIGS. 1 and 2 are given the same reference numerals, and detailed explanation thereof will be omitted. 1st
The feedback circuit 16 in the configuration described above in FIGS.
The distributed constant lines 5 and 6 are respectively connected to the distributed constant line 1.
2 and 13 and the line 1 between the equally distributed constant lines 12 and 13
A ground conductor 3 formed on the main surface 2 of the dielectric substrate 4 has a distributed constant when viewed from the main surface 2 side. A sixth line, in which corresponding parts to those in FIGS. 4 and 5 are denoted by the same reference numerals, has a distributed constant line 21 which is a circular slot line formed with a size that intersects the lines 5 and 6. As shown in the figure, a transformer 24 on the side of the drain terminal D and gate terminal G of the field effect transistor T is connected by a series circuit of an inductance 22 and a capacitor 23 on the drain terminal D and gate terminal G of the field effect transistor T.
It has the same structure as that described above in FIGS. 1 and 2, except that it is configured to be represented by an equivalent circuit formed by coupling through 25 and 25.

The above is an example of the configuration of the parallel feedback type microwave oscillator according to the present invention. According to such a configuration, the electric field is Since the drain terminal D and gate terminal G of the effect transistor T are coupled through the feedback circuit 17, the feedback constant (determined by the characteristic impedance, length, etc. of the distributed constant circuit 21) of the feedback circuit 17, the distributed constant The characteristic impedances, etc. of the lines 5 and 6 are set appropriately in advance as in the case of FIGS. By connecting a necessary DC bias power supply (not shown) between the ground conductor 3 and the ground conductor 3, micro oscillation can be obtained as in the case of Figs. 1 and 2, and the oscillation output can be distributed. It is clear that it can be derived from between the constant line 6 and the ground conductor 3.

However, according to the embodiment of the present invention described above, the feedback circuit 17 for coupling the drain terminal ○ and the gate terminal G of the field effect transistor T is formed in the annular shape formed on the ground conductor 3 on the main surface 2 of the dielectric substrate 4. It has a simple configuration consisting of only the distributed constant line 21 formed by a slot line, so that stable microwave oscillation can be obtained, and the feedback circuit 17 is as described above in FIGS. 1 and 2. Since it does not include a direct current blocking/feedback capacitive element that increases the size of the entire configuration as in the conventional case, it has great features such as the ability to downsize the entire configuration.

In the above description, the gate terminal G of the field effect transistor T
7 and 8, in which corresponding parts to those in FIGS. 4 and 5 are designated with the same reference numerals, have been described above. As shown in FIG. 4 and FIG. 5, in the configuration described above, the distributed constant line 5 is of a terminal short-circuit type in which the distributed constant line 5 is terminated and short-circuited by a short-circuit conductor 31 that can be extended across the thickness of the dielectric substrate 4. It will be obvious that, except for this, it is possible to obtain the same effects as those described above with reference to FIGS. 4 and 5 using the same configuration as that shown in FIGS. 4 and 5.

Further, in the above description, the field effect transistor T has a structure in which its gate terminal G, drain terminal D, and source terminal S are arranged on a plane common to them, and thus the field effect transistor When T is arranged on the dielectric substrate 4 in such a manner that the surface facing the surface on which the gate terminal G, drain terminal D and source terminal S are arranged is arranged on the dielectric substrate 4. However, as shown in FIGS. 9 and 10, in which parts corresponding to those in FIGS. 4 and 5 are denoted by the same reference numerals, the configuration described above in FIGS. , the field effect transistor T has its gate terminal G
and a drain terminal D are disposed on a surface common to them, a source terminal S is arranged on a gate terminal G, and a drain terminal D is disposed on a common plane.
On the other hand, a hole 32 is formed in the dielectric substrate 4, and a field effect transistor T is placed in the hole 32 with its gate terminal connected to the dielectric substrate 4. G
and the drain terminal D are connected to the distributed constant lines 5 and 6 using wires 7 and 8, respectively, and the source terminal S is connected to the ground conductor 3.
4 and 5 except that it is connected to the dielectric substrate 4 and arranged on the dielectric substrate 4, and the same operation and effect can be obtained as described above in FIGS. It is obvious that you can do something similar.

Furthermore, in the above, one of the field effect transistors is used, and the distributed constant line to which the gate terminal and drain terminal of the field effect transistor are connected is a distributed constant line formed of a microstrip line, and further feedback is generated. Although we have described the case where the distributed constant lines constituting the circuit are configured with slot lines, as shown in FIGS.
Strip line 43 and slots 44 and 45 on both sides
Distributed constant lines 48 and 49 formed by a coupled slot line constituted by conductors 46 and 47 arranged through the
Distributed constant lines 58 and 59 are connected to each other by coupled slot lines, which are constituted by a strip line 53 that can be extended in connection with the strip line 43, and conductors 56 and 57 arranged on both sides of the strip line 53 through slots 54 and 55. Field effect transistors TI and T2 are formed on the crown surface 42 of the dielectric substrate 41 and have a gate terminal G, a drain terminal D, and a source terminal S, respectively. Connect the drain terminal D to the conductors 56 and 57 using wires 76 and 77, respectively, and the source terminal S to the strip lines 43 and 53 using wires 63 and 73, respectively. The drain terminals D and gate terminals G of the field effect transistors TI and T2 are arranged on the other main surface 82 opposite to the main surface 42 of the dielectric substrate 41. A strip line section formed in such a manner that it extends across the distributed constant lines 48 and 49 when viewed from the main surface 82 side, between the side position of the conductor 46 facing the conductor 56 and the side position of the conductor 47 facing the conductor 57. 91 and
Similarly, on the main surface 82, when viewed from the main surface 82 side, there is a mode in which the conductor 56 is extended across the distributed constant lines 58 and 59 between the side position of the conductor 56 facing the conductor 46 and the side position of the conductor 57 facing the conductor 47. The strip line section 92 thus formed and one electrode 93a are connected on the conductor 46 using a wire 94 at a position corresponding to one free end of the strip line section 91 described above, and the other electrode 93b is conductor 5
6, a coupling capacitive element 95 connected at a position corresponding to one free end of the strip line section 92 mentioned above.
One electrode 96a is connected to the conductor 47 using a wire 97 at a position corresponding to the other free end of the above-mentioned strip line section 91, and the other electrode 96b is connected to the conductor 57 at a position corresponding to the other free end of the above-mentioned strip line section 91. A feedback circuit 100 is configured with a distributed constant line 99 having a ring resonator configuration and a coupling capacitance element 98 connected at a position corresponding to the other idler of the section 92. The circuits are combined and are represented by an equivalent circuit similar to the equivalent circuit described above in FIG. 6 as shown in FIG. 13, in which the corresponding parts in FIGS. Therefore, two field effect transistors TI and T
2, and the distributed constant lines 48 and 49 to which the gate terminal G and drain terminal ○ of the field effect transistors TI and T2 are connected; Furthermore, the distributed constant line 99 constituting the feedback circuit 100 is configured to have a ring resonator configuration, so that the same effects as described above in FIGS. 4 and 5 can be obtained. It is also possible.

In this example, by connecting a DC bias power source between the conductor 43 and each of the conductors 46 and 47, and between the conductor 53 and each of the conductors 56 and 57, the conductor 53 and the conductor 46 or 47 are connected. It is possible to obtain microwave oscillation output from between. Further, as shown in FIG. 14, in the configuration described above in FIGS. 11 and 12, the free ends of the strip line 43 constituting the distributed constant lines 48 and 49 are connected to the conductor 46 by short-circuiting conductors 101 and 102. It is also possible to connect the distributed constant lines 48 and 47 to terminals 47 and 47 to configure the distributed constant lines 48 and 49 to have short-terminated terminals, thereby obtaining the same effect as in the embodiment described above in FIGS. 11 and 12. It is something.

Furthermore, as shown in FIGS. 15 and 16, in the configuration described above in FIGS. 11 and 12, the field effect transistors TI and T2 have their gate terminals G and drain terminals D separately connected to each other. On the surface common to them, source terminal S
and the field effect transistors TI and TI are integrated in such a manner that the gate terminal G and the drain terminal D are arranged as common terminals on another surface opposite to the surface on which the gate terminal G and the drain terminal D are arranged, and the field effect transistors TI and Source terminal S of T2 (as a common terminal)
11 and 12 except that the strip lines 43 and 53 are connected to the connection position of the strip lines 43 and 53 formed on the main surface 42 of the dielectric substrate 41. It is also possible to obtain the same effect as that of the embodiment described above with reference to FIG.

In each embodiment of the present invention described above, the "source terminal"
It is also possible to replace the "drain terminal" with "drain terminal" and the "drain terminal" with "source terminal," and various other modifications and changes may be made without departing from the spirit of the present invention.

[Brief explanation of the drawing]

Fig. 1 is a schematic plan view showing a conventional parallel feedback type microwave oscillator, Fig. 2 is a sectional view taken along line D-0, Fig. 3 is its equivalent circuit diagram, and Fig. 4 is a parallel parallel feedback oscillator according to the present invention. FIG. 5 is a schematic plan view showing an example of a feedback microwave oscillator, FIG. 5 is a sectional view taken along line V-V, FIG. 6 is an equivalent circuit diagram thereof, and FIG. 7 is a schematic diagram showing another example of the present invention. A linear plan view, FIG. 8 is a sectional view taken along the field line, FIG. 9 is a schematic plan view showing still another example of the present invention, and FIG. 10 is a sectional view taken along the line X-X. FIG. 11 is a schematic plan view showing still another example of the present invention, FIG. 12 is a sectional view on the cutting line, FIG. 13 is an equivalent circuit diagram thereof, and FIG. 14 is a further example of the present invention. FIG. 15 is a schematic plan view showing still another example of the present invention, and FIG. 16 is a cross-sectional view taken along the line XW-XW. In the figure, 1 and 2 are the main south, 3 is the ground conductor, 4 is the dielectric substrate,
T, TI and T2 are field effect transistors, 5, 6, 2
1, 48, 49, 58, 59 and 99 are distributed constant lines,
11, 31, 101 and 102 are short circuit conductors, 17 and 1
00 indicates a feedback circuit. Figure 2 Figure 1 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16

Claims (1)

[Claims] 1. First and second distributed constant lines are formed on the main surface of a dielectric substrate, and a field effect transistor on the dielectric substrate has its gate terminal connected to the first distributed constant line, and its drain terminal (or source terminal) is connected to the second distributed constant line, and the source terminal (or drain terminal) is connected to ground, and the drain terminal (or source terminal) and gate terminal of the field transistor are coupled through a feedback circuit. In a parallel feedback microwave oscillator with a configuration of
The feedback circuit includes a third distributed constant line formed on another main surface of the dielectric substrate opposite to the main surface to be coupled to the first and second distributed constant lines. A parallel feedback microwave oscillator characterized by: