JPH0460361B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a DC circuit breaker formed in microstrips.

[Conventional technology]

Figure 6 shows, for example, IEEE TRANSACTION ON
MICROWAVE THEORY AND
TECHNIQUES, AUGUST 1972 P555 Octave
-Band Microstrip DC Blocks is a diagram showing a conventional DC circuit breaker, and FIG. 5 is a partially enlarged view of the above-mentioned FIG. 6. In the figure, 1 is a dielectric substrate on which a metal film 2 serving as a ground conductor is formed on the back surface. On the surface of the substrate 1, strip line conductors 3a and 3b, which serve as first and second busbars, are formed.The first strip conductor has a finger-like piece, that is, a strip electrode 4a, and the second strip conductor has a finger-shaped piece, that is, a strip electrode 4a. There is also a finger-like piece or strip electrode 4.
b are arranged close to each other. If an alumina substrate with a thickness of 0.635 mm is used as the dielectric substrate, the line width will be 0.6 mm in order to set the characteristic impedance of the microstrip line conductor, which becomes the first and second busbars, to 50Ω. It is determined. Furthermore, the finger-like pieces or strip electrodes 4a and 4b are EVEN
MODE impedance Zoe130ohm, ODD
MODE impedance Zoo24 ohm, characteristic impedance Zo = Zoe - Zoo / Z = 130 - 24 / 253 ohm, conductor width W = 0.16 mm, in order to match with the characteristic impedance of 50 ohm of the microstrip line conductor which becomes the bus bar. Conductor spacing S=
It is provided so that it is 0.025mm. Further, the length is 1/4 wavelength of the wavelength at the center frequency of the frequency used. Next, the operation will be explained. Although the DC signal applied to one of the microstrip line conductors 3a or 3b serving as the first or second busbars is obvious, it is not clear that the first and second busbars 3a and 3b are DC-blocked. Since it is cut off in shape, it will not be transmitted. However, similarly applied high frequency signals are efficiently transmitted from one side to the other due to the electrode coupling between the finger or strip electrodes 4a, 4b.

[Problem that the invention seeks to solve]

As mentioned above, the conventional interdigital microstrip DC circuit breaker has a conductor width W = 0.16mm and a conductor spacing S = 0.025mm, and the strip electrodes are generally formed by etching the conductor on a dielectric substrate. Depending on the conductor spacing S=
Accurately forming 0.025 mm requires extreme difficulty as side etching cannot be avoided, and minute side etching has a large effect on electrical characteristics, particularly reducing the transmission efficiency of high frequency signals. .

This invention was made to solve the above-mentioned problems, and it widens the conductor spacing, makes it easier to form microstrip lines by etching, and reduces the influence of side etching on electrical characteristics. In particular, the object of the present invention is to obtain an interdigital microstrip DC breaker that can reduce the drop in transmission efficiency of high frequency signals.

[Means for solving problems]

The interdigital microstrip DC breaker according to the present invention has two comb-shaped electrodes arranged so as to fit into each other from the bus bar, and also arranged so as to protrude toward the other comb-shaped electrode, and each Finger-like pieces are connected by a conductor in the square-shaped electrode part.

[Effect]

According to the present invention, since the electromagnetic coupling part is a comb-shaped electrode, the conductor spacing can be widened, making it easy to form a microstrip substrate by etching, etc., and reducing the influence of side etching. Furthermore, by connecting the finger-like pieces in each wedge-shaped electrode portion with a conductor, the problem that the conductor width becomes narrow and the transmission efficiency decreases due to resonance occurring at a certain frequency is solved.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, numeral 1 is a dielectric substrate on which a metal film 2 serving as a ground conductor is formed on the back surface, and strip line conductors 3a and 3b serving as first and second busbars are formed on the front surface of the substrate 1. The first strip conductor is provided with finger-shaped pieces, ie, strip electrodes 4f and 4d, and the second strip conductor is provided with similarly shaped electrodes 4e and 4c, respectively. Each finger or strip electrode has a width W, and the fingers are spaced apart from each other by a distance S. Further, each finger-like piece forming each wedge-shaped electrode is connected by a conductor 5. This is generally bonded by thermocompression bonding or ultrasonic bonding. In this example, if an alumina substrate with a thickness of 0.635 mm is used as the dielectric substrate in 1 above, the width of the microstrip line conductor serving as the first and second busbars has a characteristic impedance of 50 ohms. It is set to 0.6mm in order to Also, finger-like pieces or strip electrodes 4
f, 4d, 4e, 4c are EVEN MODE impedance Zoe 130 ohm, ODD MODE impedance Zoo 24 ohm, and characteristic impedance.
The conductor width W is set so that Zo=Zoe-Zoo/2=130-24/253 ohm can be matched with the characteristic impedance of 50 ohm of the microstrip line that becomes the bus bar.
= 0.06mm, and the conductor spacing S = 0.04mm. Further, the length is 1/4 wavelength of the wavelength at the center frequency of the frequency used.

Figure 3 shows the characteristics of an interdigital microstrip DC breaker when conductor 5 is removed from the above configuration. The horizontal axis represents the center frequency o, the operating frequencies L to H, and the vertical axis represents The axis shows the voltage standing wave ratio (VSWR) at that frequency. In this figure, the voltage standing wave ratio (VSWR) is approximately within 1.3 within the operating frequency. However, in the case of frequency a in part A, the voltage standing wave ratio is 1.4 or more, which indicates a decrease in the transmission efficiency of high frequency signals. These are the fingers or strip conductors 4f, fd, fe, 4c.
This is because resonance occurs due to the narrowing of the In the present invention, a metal conductor 5 is further connected between the finger-like pieces 4c and 4e and between 4d and 4d.
FIG. 4 shows finger-like pieces 4c and 4e formed by the metal conductor 5.
The characteristics of the interdigital type microstrip DC breaker according to the present invention are shown in the case of connecting between 4d and 4f. Although the DC signal is obvious, it is not transmitted because the first and second busbars are disconnected in terms of DC.
Similarly, the applied high frequency signal is efficiently transmitted from one side to the other due to the electromagnetic coupling between the finger-shaped strip electrodes 4c, 4e, 4d, and 4f.

In the above example, the thickness of the substrate is 0.635 mm.
Although the alumina substrate is used, the thickness is not limited to 0.635 mm, and other thicknesses may be similarly determined, for example, the width of the microstrip line serving as the bus bar. Further, the same effect can be obtained even if the substrate is made of another material, such as a Teflon substrate.

〔Effect of the invention〕

As described above, according to the present invention, two comb-shaped electrodes are arranged so as to fit into each other, and are arranged so that they each protrude toward the other comb-shaped electrode, and each comb-shaped electrode part has a finger-like shape. Since the pieces are connected by conductors,
The conductor spacing can be widened, making it easier to form a microstrip line by etching, etc., and the effect of side etching can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a detailed view of the electrode section of the microstrip DC breaker according to the present invention, Fig. 2 is an overall view of the microstrip DC breaker of the invention, and Fig. 3 is a microstrip DC breaker. Characteristic diagram of the vessel, 4th
The figure is a characteristic diagram of the microstrip DC breaker of the present invention, Figure 5 is a detailed diagram of the electrode section of a conventional microstrip DC breaker, and Figure 6 is a diagram of the conventional microstrip DC breaker. This is an overall diagram. In the figure, 1 is a dielectric substrate, 2 is a metal conductor serving as a ground conductor, 3 is a bus bar, and 4 is a finger-like piece or strip electrode 5 is a metal conductor. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] 1 A dielectric substrate with a ground conductor adhered to the back surface,
A first strip electrode consisting of a plurality of finger-like pieces extending in a comb shape from a first generatrix provided on the surface of the dielectric substrate, and a comb formed from a second generatrix provided on the surface of the dielectric substrate. a second strip electrode consisting of a plurality of finger-like pieces extending in a shape and facing the first finger-like pieces at regular intervals; and a strip on each of the first and second strip electrodes. A microstop DC circuit breaker comprising a conductor connecting the electrode fingers to each other.