JPS6027441B2 - amplitude equalizer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses a circulator variable attenuator and a coaxial line between them to obtain flat vibration characteristics or desired vibration characteristics in the microwave band, quasi-millimeter wave band, and millimeter wave band. This invention relates to a vibration equalizer constructed from a variable Q resonator.

As a conventional vibration equalizer, there is one shown in the diagram of FIG. 1, for example.

In Fig. 1, the cavity 7 is inserted through the circulator 5.
2, the attenuation characteristic diagram shown in FIG. 2 is obtained. By changing the frequency Na, it is possible to obtain positive linear characteristic A, negative linear characteristic C, and negative quadratic characteristic as shown in the characteristic diagram in Fig. 3 in the range of Na to Na2. I can do it.
However, since the characteristics shown in FIG. 3 become constant depending on the Q of the capacitance 7, the required vibration characteristics cannot be obtained at the required amount of attenuation. Furthermore, there is a drawback that it is not possible to equalize positive quadratic characteristics, third-order characteristics, fourth-order characteristics, and even higher-order characteristics. The purpose of the present invention is to eliminate these drawbacks by using a circulator, a variable attenuator, and a coaxial multiple-tuned resonance system, and by changing the attenuation amount and Q, the amplitude can be equalized even for high-order characteristics. The purpose is to provide an equalizer.

The drawings will be explained in detail below.

FIG. 4 is a block diagram of an embodiment of the present invention.

Reference numeral 1 denotes a variable attenuator having a coaxial structure, in which a radio wave absorber 12 is inserted into the open end side of a central conductor 11 whose one end is open.

The radio wave absorber 12 is movable in the axial direction, and by moving the radio wave absorber 12, the amount of attenuation can be varied. 2 and 4 are coaxial resonators, each with one end open and a capacitive coaxial line 2 with an electrical equivalent length of 1/4 wavelength or less.
1, 41, and a conductive coaxial line 22, 42 which is open at one end and has an electrical equivalent length of 1/4 wavelength or more and 1/2 wavelength or less.

Dielectrics 23, 43, 24, 44 are inserted into the openers of the lines 21, 41, 22, 42, respectively, and by moving these dielectrics in all directions, the capacitance of 21 and 41 and the capacity of 2
The inductance of 2 and 42 can be varied. The electrical equivalent length between coaxial resonators 2 and 4 is 1/4
A wavelength coaxial line 3 is inserted. 1, 2, 3 and 4
is connected to one terminal C of the circulator 5 by the coaxial line 6.
It is connected to the.

D indicates an input terminal, B indicates an output terminal, and A and B indicate the positions of the coaxial resonators 2 and 4 on the coaxial line, respectively. FIG. 5 is an equivalent circuit of FIG. 4. Points A, B, C, and D correspond to points with the same symbols in FIG. 4, respectively. Next, the operation of this equalizer will be explained.

The admittance of 1 at point A changes as shown in the Smith diagram in FIG. 6 depending on the amount of insertion of the heavy wave absorber 12. In this case, there is a slight phase change as shown in the figure, but this is equivalent to connecting a capacitive or inductive element in parallel to the attenuator, so it is corrected by resonator 2. be able to. Next, when the admittance of resonator 2 is added at point x in FIG. 6, the total admittance of 1 and 2 changes depending on the frequency as shown by the solid line in the Smith diagram of FIG. 7. H' is the highest frequency, × is the center frequency, L
corresponds to the lowest frequency. If we insert 23 and subtract 24 here, we can expand the change range of admittance while keeping the real part constant, that is, we can increase the Q of the resonator and at the same time change the center frequency of the resonator. is also possible. Of course, it is possible to lower the Q of the resonator by performing the opposite operation. Furthermore, when the admittance of 1 and 2 is viewed from point B, it looks like the chain line in FIG. Day corresponds to H', X to X', and L to L'. The admittance of 4 is the solid line K-L of the Smith diagram in Figure 8 at point B.
- Changes like M.

Here, as in case 2, by operating 43 and 44, it is possible to vary the Q and the center frequency of the resonator. Since the total admittance of 1 and 2 at point B is as shown by the chain line in FIG. 8, the total admittance of 1, 2 and 4 is as shown by the solid line FX'-G in FIG. If this is converted into an attenuation amount, the characteristic diagram shown in FIG. 9 will be obtained. By moving the variable attenuator 1 and the coaxial resonators 2 and 4, they can be changed as shown in the respective Smith diagrams of FIGS. 10, 11, and 12. The attenuation characteristics between the terminals D and E of the circulator shown in FIG. 4 are inversely proportional to the distance from the center on the Smith diagram, so they change as shown in FIG. 13. With this structure, by utilizing this effect and moving the inductive side and capacitive side of resonator 2 and resonator 4, the primary, secondary, and tertiary order can be adjusted as shown in Figure 14. , fourth-order attenuation characteristics can be obtained. As explained above, by using a circulator, two variable Q resonators with 1/4 skin length spacing, and a variable attenuator, the vibration characteristics having first, second, third, and fourth order characteristics can be equalized. , and can very easily obtain flat or desired characteristics during vibration.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of a conventional vibration equalizer, Figure 2 is a reflection characteristic diagram of the cavity of a conventional vibration equalizer, and Figure 3 is the required band limit when changing the center frequency. ,~Na2
Fig. 4 is a cross-sectional view of the vibration equalizer according to the embodiment of the present invention, Fig. 5 is an equivalent circuit of Fig. 4, Fig. 8 is from Fig. 6, and Fig. 12 is from Fig. 10. A Smith diagram showing the operation of the vibration equalizer, and FIGS. 9, 13, and 14 are attenuation characteristic diagrams, respectively. In the figure, 1... variable attenuator, 2, 4... coaxial resonator,
3, 6... Coaxial line, 5... Circulation line, 7. ．．・．． ．．・Cavity, 11...
Center conductor, 12... Radio wave absorber, 21, 41...
...capacitive coaxial line, 22, 42... inductive coaxial line, 23, 24, 43, 44... dielectric. Chrysanthemum drawing number' drawing younger brother Z drawing favorite drawing name 4 drawing many drawings 7th leopard 8th leopard? Illustration Leopard 'o Illustration Leopard

Claims (1)

[Claims] 1. Two terminals of a three-terminal circulator are input/output terminals,
Two variable Q resonators are provided on the coaxial line connected to the other terminal of the circulator at 1/4 wavelength intervals or at odd multiples of 1/4 wavelength, and further, the tip of the coaxial line An amplitude equalizer constructed by providing a coaxial variable attenuator as a terminator. 2. The coaxial variable attenuator is constructed of a coaxial line with one end open, in which a radio wave absorber that can be moved in the axial direction is inserted into an opener, and at least one of the variable Q resonators is further provided with a dielectric that can be moved in the axial direction. The amplitude equalizer according to claim 1, which comprises a coaxial line with both ends open inserted into the open end.