JP2013138356A - Planar line waveguide converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a planar line waveguide converter which widens a band width compared to conventional planar line waveguide converters thereby improving the manufacturing yield.SOLUTION: A planar line waveguide converter is composed of: a dielectric substrate 10 having a first surface closing a rectangular opening 21 of a waveguide block 2; a main matching element 6 and a sub matching element 7 which are formed in the opening 21 on the first surface of the dielectric substrate 10; a shorting bar 3 formed on a second surface of the dielectric substrate 10; and a microstrip line (MSL) 4 which is formed on the second surface of the dielectric substrate 10 and extends in a notch 3a of the shorting bar 3 so as to face the main matching element 6. The sub matching element 7 is disposed between a short side of the opening 21 of the waveguide block 2 and the main matching element 6. Lengths of the main matching element 6 and the sub matching element 7 differ from each other in a direction parallel with the short side of the opening 21.

Description

  The present invention relates to a planar line waveguide converter, and more particularly to an improvement of a planar line waveguide converter that mutually converts power transmitted by a planar line and power transmitted by a waveguide. .

  When connecting a planar line such as a microstrip line (MSL) and a waveguide (WG: Wave Guide), the power transmitted by the planar line and the power transmitted by the waveguide are mutually converted. A planar line waveguide converter that can be used is used (for example, Patent Document 1).

  14 and 15 are diagrams showing an example of a conventional planar line waveguide converter, in which an MSL-WG converter 200 having a matching element 213 is shown. 14 is a perspective view of the MSL-WG converter 200, and FIGS. 15A and 15B are plan views of the dielectric substrate 10 shown in FIG. The MSL-WG converter 200 is fixed so that the dielectric substrate 10 with the MSL 4 and the short-circuit plate 211 formed on the upper surface and the matching element 213 and the ground plate 214 formed on the lower surface blocks the opening of the waveguide block 2. ing. The ground plate 214 is formed so as to surround a closed region on the dielectric substrate 10 facing the opening of the waveguide block 2, and is in close contact with the end face of the waveguide block 2. The MSL 4 is formed in the cut 212 of the short-circuit plate 211. Matching element 213 is formed in the closed region, and is opposed to MSL 4 with dielectric substrate 10 interposed therebetween, so that they are electromagnetically coupled to each other.

  If an antenna pattern is formed on a dielectric substrate provided with such a planar line waveguide converter, a small and light planar antenna can be realized. However, since the MSL-WG converter 200 uses the matching element 213, there is a problem that the frequency band in which good conversion characteristics can be obtained is narrow. For example, in the frequency band where the reflection amount is (−20) dB or less, only about 3% of the band ratio can be secured. For this reason, there is a problem that the margin when the center frequency is shifted due to the influence of the processing accuracy during manufacturing is small, the manufacturing yield is lowered, and the manufacturing cost is increased. For example, an error corresponding to the processing accuracy at the time of forming the matching element 213 occurs in the center frequency of the planar line waveguide converter. However, if the bandwidth is narrow, a desired conversion characteristic is caused by a variation in processing accuracy. A plane-line waveguide converter that cannot be obtained easily occurs.

JP 2000-244212 A

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a broadband planar line waveguide converter. In particular, it is an object of the present invention to provide a planar line waveguide converter having an improved manufacturing yield by widening the bandwidth as compared with a conventional planar line waveguide converter.

  A planar line waveguide converter according to a first aspect of the present invention includes a dielectric substrate having a first surface that closes a rectangular opening of the waveguide, and the opening on the first surface of the dielectric substrate. A first matching element and a second matching element formed, a short-circuit plate formed on the second surface of the dielectric substrate, and formed on the second surface of the dielectric substrate, facing the first matching element. A planar line extending into the notch of the short-circuit plate, and a second matching element is disposed between the short side of the opening of the waveguide and the first matching element, The second matching elements are configured to have different lengths in a direction parallel to the short side of the opening.

  According to such a configuration, the planar line and the second matching element are electromagnetically coupled via the electromagnetic coupling between the planar line and the first matching element and the electromagnetic coupling between the first matching element and the second matching element. Can be combined. At this time, the first matching element and the second matching element can be resonated at different resonance frequencies. For this reason, the bandwidth of a planar line waveguide converter can be expanded compared with the conventional planar line waveguide converter.

  According to a second aspect of the present invention, in addition to the above-described structure, the planar line waveguide converter has the planar line extending across the long side of the opening, and the second matching element is formed on both sides of the rectangular first matching element. It is comprised so that it may be formed.

  According to such a configuration, it is possible to secure a large area as a resonance region related to the second matching element as compared with the case where the second matching element is formed only on one side of the first matching element. For this reason, the bandwidth of a planar line waveguide converter can be expanded reliably.

  A planar line waveguide converter according to a third aspect of the present invention is configured so that, in addition to the above configuration, the first matching element has a resonance whose element length in a direction parallel to the short side of the opening corresponds to the in-tube wavelength of the waveguide. The second matching element is configured such that the element length is shorter than the resonance length.

  According to such a configuration, a resonance path longer than the resonance length can be formed in the first matching element, and a resonance path shorter than the resonance length can be formed in the second matching element. For this reason, compared with the case where only the matching element whose element length is about the resonance length is formed, the bandwidth of the planar line waveguide converter can be sufficiently widened.

  A planar line waveguide converter according to a fourth aspect of the present invention is configured such that, in addition to the above configuration, the first matching element and the second matching element are arranged apart from each other. According to such a configuration, the resonance path can be separated between the first matching element and the second matching element. For this reason, two different resonance frequencies between the first matching element and the second matching element can be easily realized.

  A planar line waveguide converter according to a fifth aspect of the present invention has a first matching element and a second matching element having a length in a direction parallel to the short side of the opening in addition to the above-described configuration. It is configured to be connected to each other via a short neck region.

  According to such a configuration, it is possible to suppress the influence of the resonance path formed between the first matching element and the second matching element via the neck region. For this reason, the first matching element and the second matching element can be resonated at different resonance frequencies.

  According to the present invention, the bandwidth of a planar line waveguide converter can be widened as compared with a conventional planar line waveguide converter. For this reason, even if the processing accuracy at the time of manufacturing greatly fluctuates, good conversion characteristics can be obtained, so that it is possible to provide a wideband planar line waveguide converter with improved manufacturing yield.

It is the expansion | deployment perspective view which showed the MSL-WG converter 1 by Embodiment 1 of this invention. It is a top view of the MSL-WG converter 1 of FIG. It is sectional drawing which showed the cut surface at the time of cut | disconnecting the MSL-WG converter 1 of FIG. 2 by the AA cut line. It is sectional drawing which showed the cut surface at the time of cut | disconnecting the MSL-WG converter 1 of FIG. 2 by a BB cutting line. FIG. 5 is a diagram showing an example of the arrangement of the MSL 4, the main matching element 6 and the sub matching element 7 with respect to the opening 21 of the waveguide block 2. It is the figure which showed the measurement result which measured the amount of reflection in the MSL-WG converter 1 of FIG. FIG. ₂ is a diagram illustrating an example of a relationship between element lengths B ₁ and B ₂ and resonance frequencies f ₁ and f ₂ of a main matching element 6 and a sub matching element 7 in the MSL-WG converter 1 of FIG. Is a diagram showing an example of the relationship between the position d ₂ and the reflection characteristic and the fractional bandwidth characteristics W1 of the insertion length d ₁ and the sub-matching element 7 of MSL4 in MSL-WG converter 1 of FIG. Is a diagram showing an example of the relationship between the dimension L ₁ of Semakabe 22b in the waveguide block 2 of Figure 1 and the reflection characteristics and the resonance frequency characteristics. FIG. 10 is a diagram showing another example of the arrangement of the MSL 4, the main matching element 6 and the sub matching element 7 with respect to the opening 21 of the waveguide block 2. FIG. 5 is a diagram illustrating another configuration example of the MSL-WG converter 1 and illustrates a case where sub-matching elements 7 a and 7 b having different element lengths are formed on both sides of the main matching element 6. FIG. 5 is a diagram illustrating a configuration example of an MSL-WG converter 1 according to a second embodiment of the present invention, in which a main matching element 6 and a sub-matching element 7 are connected to each other via a neck region 9. FIG. 5 is a diagram showing a configuration example of an MSL-WG converter 1 according to Embodiment 3 of the present invention, in which a sub-matching element 7 is formed only on one side of the main matching element 6. It is the perspective view which showed the conventional MSL-WG converter 200 which has the matching element 213. It is a top view of the conventional MSL-WG converter 200 of FIG.

Embodiment 1 FIG.
1 to 5 are diagrams showing a configuration example of the MSL-WG converter 1 according to the first embodiment of the present invention. 1 is a developed perspective view, FIG. 2 is a plan view, FIG. 3 is a sectional view taken along the line AA in FIG. 2, and FIG. 4 is a sectional view taken along the line BB in FIG. ing. FIG. 5 shows an example of the arrangement of the MSL 4, the main matching element 6, and the sub matching element 7 with respect to the opening 21 of the waveguide block 2.

  This MSL-WG converter 1 is a resonance type planar line waveguide converter composed of a dielectric substrate 10, a short plate 3, an MSL 4, a ground plate 5, a main matching element 6 and a sub matching element 7. It is used by being fixed to the opening of the waveguide block 2. In the MSL-WG converter 1 according to the present embodiment, the bandwidth is widened by causing the main matching element 6 and the sub-matching element 7 to resonate at different resonance frequencies.

  The waveguide block 2 is a hollow rectangular waveguide having a hollow portion 23 communicating with a rectangular opening 21, and can transmit power with low loss. The hollow portion 23 is surrounded by a tube wall 22 including a wide wall 22a and a narrow wall 22b narrower than the wide wall 22a, and can propagate electromagnetic waves in the tube axis direction. The wavelength of electromagnetic waves that can be propagated is defined by the dimensions of the wide wall 22a. Such a waveguide block 2 is manufactured, for example, by cutting a conductive metal block. The cross-sectional shape orthogonal to the propagation direction of the hollow portion 23 is a rectangle composed of a long side corresponding to the wide wall 22a and a short side corresponding to the narrow wall 22b.

  The dielectric substrate 10 is a rectangular substrate made of a dielectric, and the opening 21 of the waveguide block 2 is closed by the lower surface of the dielectric substrate 10. The short-circuit plate 3 and the MSL 4 are formed on the upper surface of the dielectric substrate 10, and the ground plate 5, the main matching element 6 and the sub-matching element 7 are formed on the lower surface of the dielectric substrate 10.

  The short-circuit plate 3 is an electrode plate that constitutes a short-circuit surface that terminates the waveguide block 2 and includes a conductor layer. This short circuit board 3 consists of a rectangular-shaped metal thin film, and is arrange | positioned so that the opening 21 may be covered. The short-circuit plate 3 is formed with a linear cut 3a for disposing the MSL 4. The cut 3 a is formed from the side parallel to the long side of the opening 21 toward the inside.

  The MSL 4 is a linear planar line made of a metal thin film, and extends into the cut 3 a of the short-circuit plate 3 in parallel with the short side of the opening 21. The MSL 4 crosses the long side of the opening 21 vertically, and one end thereof reaches a closed region 8 described later. The other end of the MSL 4 is drawn to the outside of the short-circuit plate 3. Further, the MSL 4 is arranged at a certain distance from the short-circuit plate 3 in the cut 3 a, and faces the ground plate 5 through the dielectric substrate 10 outside the closed region 8.

  The ground plate 5 is an electrode plate that is brought into contact with the end face of the waveguide block 2 and is made of a conductor layer. The ground plate 5 is made of a rectangular metal thin film and is formed so as to surround the closed region 8 facing the opening 21 of the waveguide block 2. The closed region 8 is a rectangular region on the short-circuit plate 3 for closing the opening 21 and has substantially the same shape and size as the opening 21. The main matching element 6 and the sub matching element 7 are formed in the closed region 8.

  The dielectric substrate 10 and the ground plate 5 are both wider than the short-circuit plate 3, and the shape and size of the outer edge coincide with the outer edge of the waveguide block 2. The short-circuit plate 3 and the ground plate 5 are electrically connected to each other through a plurality of through holes 11 formed in the dielectric substrate 10, and the lower surface of the ground plate 5 is brought into close contact with the upper surface of the waveguide block 2. When the MSL-WG converter 1 is fixed to the waveguide block 2, the same potential as that of the waveguide block 2 is maintained.

  The through hole 11 is formed, for example, by providing a minute through hole in the dielectric substrate 10 and filling the through hole with a conductive material, and is disposed so as to surround the closed region 8. Such a conduction structure using a large number of through holes 11 can suppress power loss in the dielectric substrate 10.

  The main matching element 6 and the sub-matching element 7 are matching elements that are formed apart from the inner edge of the ground plate 5 so as not to be electrically connected to the ground plate 5, and each includes a conductor layer. The main matching element 6 is arranged in the vicinity of the center of the opening 21 so as to face one end of the MSL 4 with the dielectric substrate 10 interposed therebetween. That is, the MSL 4 extends into the cut 3 a of the short-circuit plate 3 so that the tip thereof faces the main matching element 6.

  The sub-matching element 7 is not opposed to the MSL 4 and is disposed between the short side of the opening 21 and the main matching element 6. The sub matching element 7 has a rectangular shape and is formed on both sides of the rectangular main matching element 6. That is, the sub-matching element 7, the main matching element 6, and the sub-matching element 7 are arranged in this order in the direction parallel to the long side of the opening 21.

  By forming the sub-matching element 7 on both sides of the main matching element 6, it is possible to secure a wide area as a resonance region related to the sub-matching element 7 as compared with the case where it is formed only on one side. Here, a matching element disposed near the center of the opening 21 and facing the MSL 4 is called a main matching element, and a matching element not facing the MSL 4 is called a sub-matching element.

  The short-circuit plate 3, the MSL 4, the ground plate 5, the main matching element 6 and the sub-matching element 7 are formed as, for example, a conductive metal thin film pattern. These thin film patterns are formed by forming a thin film such as copper on the entire surface of the dielectric substrate 10 by a thermocompression bonding method, a sputtering method, a vapor deposition method or the like and then patterning the thin film by a photoetching method.

  In this specification, a direction parallel to the long side of the opening 21 is referred to as a longitudinal direction of the opening 21, and a direction parallel to the short side of the opening 21 is referred to as a short direction of the opening 21. The MSL 4 and the main matching element 6 are generally arranged at the center of the long side of the opening 21. In the rectangular waveguide, only the electric field in the short direction of the opening 21 exists, and the electric field strength is maximized at the center of the long side of the opening 21. With this arrangement, the conversion efficiency can be improved. .

MSL4 the line width is w, the insertion length for opening 21 is _{d 1.} The insertion length d ₁ is the distance between the long side of the opening 21 and the tip of the MSL 4. By adjusting the line width w and the insertion length d ₁ of MSL4, impedance can be matched. Sub-matching element 7 is disposed at a position _{d 2} relative to the MSL4. The position d ₂ is a distance between the centers of the sub-matching element 7 and the MSL 4 in the longitudinal direction of the opening 21.

The AA cutting line in FIG. 2 is a straight line that passes through the MSL 4 and is parallel to the short direction of the opening 21. In FIG. 3, the MSL 4 overlaps with the main matching element 6 only partly through the dielectric substrate 10, and the ground plate 5 sandwiches the dielectric substrate 10 outside the wide wall 22 a of the waveguide block 2. Opposite. Dimension _{L 1} of Semakabe 22b is the length of the short side of the opening 21.

A BB cutting line in FIG. 2 is a straight line that passes through the center of the short side of the opening 21 and is parallel to the longitudinal direction of the opening 21. In FIG. 4, the short-circuit plate 3 is opposed to the main matching element 6 and the sub-matching element 7 through the dielectric substrate 10 and is electrically connected to the ground plate 5 through the through hole 11. Dimension _{L 2} of the wide wall 22a is the length of the long sides of the opening 21.

In FIG. 5, the main matching element 6 and the sub-matching element 7 in the opening 21 are arranged apart from each other, and both are arranged away from the inner edge of the ground plate 5. That is, one main matching element 6 and two sub matching elements 7 are arranged in an island shape in the closed region 8. With this configuration, the MSL 4 and the sub-matching element 7 are electromagnetically coupled via the electromagnetic coupling between the MSL 4 and the main matching element 6 and the electromagnetic coupling between the main matching element 6 and the sub-matching element 7. Can be made. At that time, the resonance paths P ₁ and P ₂ can be separated between the main matching element 6 and the sub-matching element 7.

The sub-matching elements 7 arranged on both sides of the main matching element 6 are both shorter in the short direction of the opening 21 than the main matching element 6. That relates to the short-side direction of the opening 21, the length of the main matching element 6 and the element length B _1, if the length of the sub-matching element 7 and element length B _2, is a B _1> B _2. Each sub-matching element 7 is arranged at the center of the opening 21 with respect to the short direction of the opening 21. In this example, for each sub-matching element 7, it is largely matched element length B _2.

Since the main matching element 6 and the sub-matching element 7 have different lengths in the short direction of the opening 21, resonance paths P ₁ and P ₂ having different path lengths in the electric field direction are formed. 6 and the sub-matching element 7 can resonate at different resonance frequencies.

The main matching element 6 and the sub matching element 7, for example, longer than the resonant length L ₀ of the element length B ₁ is corresponding to the guide wavelength λg waveguide block 2, element length B ₂ is shorter than the resonant length L ₀ Formed to be. The in-tube wavelength λg is a spatial wavelength in the tube axis direction of the electric field distribution in the waveguide, and can be expressed by using the wavelength λ in free space and the cutoff wavelength λc = L ₂ × 2. The resonance length L ₀ is an element length defined by the guide wavelength λg. With this configuration, the resonance path P ₁ having a resonance length longer than the resonance length L ₀ is formed in the main matching element 6, and the resonance path P ₂ having a resonance length shorter than the resonance length L ₀ is formed as the sub-matching element. 7 can be formed.

If the length of the matching element in the longitudinal direction of the opening 21 is called an element width, the element width of the main matching element 6 is A ₁ , and the element width of the sub-matching element 7 is A ₂ . The length of the gap between the main matching element 6 and the sub matching element 7 is A _3. Also relates to the short-side direction of the opening 21, the length of the overlap region between the main matching element 6 and MSL4 it is d _3.

The parameters w, d _{1 to} d ₃ , A ₁ , A ₂ , B ₁ , B ₂ described above are the conversion characteristics and frequency characteristics of the MSL-WG converter 1 along with the dimensions L ₁ , L ₂ of the waveguide block 2. Greatly affects. Here, as an example, the dielectric substrate 10 has a relative dielectric constant of 2.17 and a thickness relative to the waveguide block 2 made of an aluminum plate having a thickness of 6 mm and having L ₁ = 1.65 mm and L ₂ = 5.0 mm. The short-circuit plate 3, the MSL4, the ground plate 5, the main matching element 6 and the sub-matching element 7 are made of 9 μm thick copper foil, and w = 0.3 mm and d ₁ = 0.28 mm. _{, d 2 = 1.37mm, a 1} = 1.2mm, a 2 = 1.34mm, B 1 = 1.18mm, is MSL-WG converter 1 is B 2 = 1.08 mm are used. In this MSL-WG converter 1, A ₃ = 0.1 mm and d ₃ = 0.04 mm.

FIG. 6 is a diagram showing the frequency characteristics of the reflection amount and the transmission amount in the MSL-WG converter 1 of FIG. The reflection amount and the transmission amount are values obtained as the scattering parameters S11 and S21, and a normalized frequency (f / f ₀ ) normalized by the center frequency f ₀ is used on the horizontal axis. Solid lines R1 and T1 in the figure are characteristic curves showing the reflection amount and the transmission amount of the MSL-WG converter 1 of FIGS. On the other hand, broken lines R2 and T2 are characteristic curves respectively showing the reflection amount and the transmission amount of the conventional MSL-WG converter 200 shown in FIGS. The center frequency f ₀ is the resonance frequency in the conventional MSL-WG converter 200, that is, the frequency of the transmission wave.

Each dimension of the MSL-WG converter 1 used for this measurement is as follows. As the dielectric substrate 10, a fluororesin substrate having a thickness of 0.127 mm and a relative dielectric constant of 2.17 was used. The main matching element 6 was formed such that the element width A ₁ was 1.2 mm, the element length B ₁₀ was 1.18 mm, and the resonance frequency f ₁ was slightly lower than the center frequency f ₀ = 76 GHz.

The sub-matching element 7 has an element width A ₂ of 1.34 mm, an element length B ₂₀ of 1.08 mm, a position d ₂₀ of 1.37 mm, and the resonance frequency f ₂ is slightly higher than the center frequency f ₀ = 76 GHz. Formed as follows. The MSL 4 was formed so that the line width w was 0.3 mm and the insertion length d ₁₀ to the closed region 8 was 0.28 mm.

Waveguide block 2 uses an aluminum plate having a thickness of 6 mm, the dimension _{L 20} of the wide wall 22a is 5.0 mm, the dimension _{L 10} of Semakabe 22b is formed to have a 1.65 mm. 6 to 9 show values normalized with respect to these dimensions when displaying parameter values and measured values.

Comparing the amount of transmission in the vicinity of the center frequency f ₀ , both the transmission characteristics T1 and T2 are approximately (−1) dB or less, and the transmission characteristic T1 according to the present embodiment is almost the same as the conventional transmission characteristic T2. It can be said that they are equivalent. On the other hand, if the bandwidths W1 and W2 at which the reflection amount is (−20) dB or less are compared, the ratio band (W1 / f ₀ ) is 8.2% in the reflection characteristic R1, and the ratio band (W2 / w) in the reflection characteristic R2. f ₀ ) is 3.2%, and it can be seen that the bandwidth of the reflection characteristic R1 according to the present embodiment is more than twice that of the conventional reflection characteristic R2. That is, the bandwidth of the reflection characteristic R1 is greatly improved without substantially deteriorating the transmission characteristic T1. In the reflection characteristic R1, the resonance frequency f ₁ = 0.98 and the resonance frequency f ₂ = 1.03.

The frequency characteristics of the conventional MSL-WG converter 210 are such that the transmission amount is maximum and the reflection amount is minimum at the center frequency f ₀ corresponding to the resonance frequency of the matching element 213. Further, the transmission characteristic T2, compared to gently changes according to the frequency, the reflection characteristic R2 is steeply changed in the vicinity of the center frequency f _0. For this reason, the frequency band in which both the reflection amount and the transmission amount are good is determined by the reflection characteristic R2, and only a relatively narrow bandwidth can be secured.

On the other hand, the MSL-WG converter 1 according to the present embodiment has two slightly different resonance frequencies f ₁ and f ₂ , so that the band of the reflection characteristic R 1 is not significantly deteriorated without significantly deteriorating the transmission characteristic T 1. Widening. That is, by resonating at two resonance frequencies f ₁ and f ₂ corresponding to different resonance paths P ₁ and P ₂ of the main matching element 6 and the sub-matching element 7, the steep reflection characteristic R 2 in the conventional device is made in the frequency axis direction Thus, the reflection characteristic R1 is obtained such that the two are overlapped with each other.

Here, the resonance frequencies f ₁ and f ₂ can be adjusted independently. The resonance frequency f ₁ can be adjusted by the element length B ₁ of the main matching element 6. On the other hand, the resonance frequency f ₂ can be adjusted by the element length B ₂ of the sub-matching element 7. For this reason, the bandwidth W1 can be widened by making these resonance frequencies f ₁ and f ₂ slightly different.

Further, in order to widen the bandwidth W1 of the MSL-WG converter 1, the resonance frequencies f ₁ and f ₂ are frequencies that sandwich the center frequency f ₀ , and a desired frequency is present between the resonance frequencies f ₁ and f _2. It is necessary that the conversion characteristics of In Figure 6, as the difference between the two resonance frequencies _f 1, _{f 2} becomes about 5% in bandwidth ratio, the resonance frequency _{f 1} is lower than the center frequency _{f 0,} than the resonance frequency _{f 2} is the center frequency _{f 0} The MSL-WG converter 1 adjusted to be higher is also used.

The MSL− adjusted so that the resonance frequency f ₁ is higher than the center frequency f ₀ and the resonance frequency f ₂ is lower than the center frequency f ₀ by making the element length B ₂ longer than the element length B _1. The WG converter 1 may be used.

FIG. 7 is a diagram showing an example of the relationship between the element lengths B ₁ and B ₂ of the main matching element 6 and the sub matching element 7 and the resonance frequencies f ₁ and f _{2 in} the MSL-WG converter 1 of FIG. A plurality of MSL-WG converters 1 having different element lengths B ₁ and B ₂ are manufactured, and the measurement results of the respective reflection characteristics are shown.

The (a) of the figure, normalized normalized matching element length by the element length B ₁₀ on the horizontal axis _(B 1 _/ B _10), using a normalized frequency on the vertical axis, the element of the main matching element 6 when varying the length B ₁ is shown. This figure shows measurement results when the normalized matching element length is changed from 0.98 to 1.04 about every 0.02.

According to this measurement result, when the normalized matching element length is increased within the above range, the resonance frequency f ₂ is substantially constant within the range of 1.02 to 1.03, whereas the resonance frequency f ₂ f ₁ is greatly reduced from 1.02 to 0.93. That is, it can be seen that the resonance frequency f ₁ can be controlled by the element length B ₁ of the main matching element 6.

The (b) in FIG, normalized normalized matching element length by the element length B ₂₀ on the horizontal axis _(B 2 _/ B _20), using a normalized frequency on the vertical axis, the element of the sub-matching element 7 when varying the length B ₂ is shown. This figure shows the measurement results when the normalized matching element length is changed from 0.96 to 1.02 by about 0.02.

According to this measurement result, when the normalized matching element length is increased within the above range, the resonance frequency f ₁ is substantially constant within the range of 0.97 to 1.00, whereas the resonance frequency f ₁ f ₂ is greatly reduced from 1.06 to 1.00. That is, it can be seen that the resonance frequency f ₂ can be controlled by the element length B ₂ of the sub-matching element 7.

FIG. 8 is a diagram showing an example of the relationship between the insertion length d 1 of the MSL ₄ and the position d ₂ of the sub-matching element 7 and the reflection characteristics and the ratio band characteristics W 1 in the MSL-WG converter 1 of FIG. to prepare a plurality of MSL-WG converter 1 of different lengths d ₁ and position d _2, are measured to determine their reflection characteristic and the fractional bandwidth characteristics W1 results are shown. In FIG. 8, the normalized line insertion length at which the ratio band reaches a peak is 1.

The (a) of the figure, the normalized line insertion length normalized by the insertion length _{d 10} on the horizontal axis with _(d 1 _{/ d 10),} is the case of changing the insertion length _{d 1} of MSL4 shown ing. This figure shows the measurement results when the normalized line insertion length is changed from 0.85 to 1.15 every about 0.05.

According to this measurement result, when the normalized line insertion length is increased within the above range, the resonance frequency f ₂ is substantially constant, whereas the resonance frequency f ₁ has a normalized line insertion length of 0. The amount of reflection is greatly reduced in the vicinity of .92. On the other hand, the specific band characteristic W1 has the widest band characteristic when the normalized line insertion length is around 1.0.

(B) in the figure shows a case where the position d ₂ of the sub-matching element 7 is changed using the normalized matching element position (d ₂ / d ₂₀ ) normalized by the position d _{20 on the} horizontal axis. Has been. This figure shows the measurement results when the normalized matching element position is changed from 0.2 to 2.2 every about 0.3.

According to this measurement result, if the normalized matching element position is long within the above range, the resonance frequency f ₁ has a large drop in the reflection amount near the normalized matching element position of 0.7, and the resonance frequency f ₁ frequency f ₂ is the normalized matching element position is depressed large reflection amount in the vicinity of 1.3. On the other hand, the specific band characteristic W1 is 7.3 to 8.2% in the range where the normalized matching element position is 0.7 to 1.8, and a wide band characteristic is obtained. That is, it can be seen that if the normalized matching element position is within the range of 0.7 to 1.3, the MSL-WG converter 1 having a wide band and good reflection characteristics can be obtained. It can also be seen that the gap A ₃ between the main matching element 6 and the sub matching element 7 is sufficiently smaller than the lengths A ₁ and A ₂ .

Figure 9 is a diagram showing an example of the relationship between dimension L ₁ and the reflection characteristic and resonant frequency characteristics of Semakabe 22b in the waveguide block 2 of FIG. 1, a plurality of different waveguides block dimensions L ₁ 2 shows the measurement results obtained by measuring the reflection characteristics and resonance frequency characteristics of the MSL-WG converter 1 for each of the two.

In the figure, the case where the dimension L ₁ is changed using the normalized narrow wall dimension (L ₁ / L ₁₀ ) normalized by the dimension L _{10 on the} horizontal axis is shown. This figure shows the measurement results when the normalized narrow wall size is changed from 0.8 to 1.1 every about 0.03.

According to this measurement result, when the normalized narrow wall dimension is increased within the above range, the reflection characteristic Rf _{2 at} the resonance frequency f ₂ gradually decreases, whereas the reflection characteristic Rf at the resonance frequency f ₁ is decreased. _{No. 1} is greatly depressed when the normalized narrow wall size is around 0.97. Further, the resonance frequency _{f 2,} compared to a generally constant in the range of 1.00 to 1.03, the resonance frequency _{f 1} is gradually increased from 0.88 to 1.03. That is, it can be seen that if the normalized narrow wall dimension is in the range of 0.97 to 1.05, the MSL-WG converter 1 having a wide band and good reflection characteristics can be obtained.

  According to the present embodiment, the main matching element 6 and the sub-matching element 7 can resonate at different resonance frequencies, and the bandwidth of the MSL-WG converter 1 compared to the conventional MSL-WG converter. Can be spread. In particular, compared to the case where the sub-matching element 7 is formed only on one side of the main matching element 6, a large area can be secured as a resonance region related to the sub-matching element 7, and the bandwidth can be surely widened.

In addition, with such a wide band, it is possible to prevent the conversion characteristics of the MSL-WG converter 1 from being significantly deteriorated due to the influence of processing accuracy during manufacturing. For example, an error corresponding to the patterning accuracy in forming the main matching element 6 occurs in the resonance frequency f ₁ . Similarly, the resonance frequency f ₂ error corresponding to the processing accuracy of the sub-matching element 7 occurs. However, by causing resonance at two different resonance frequencies f ₁ and f ₂ , even if some error occurs in one or both of these resonance frequencies f ₁ and f ₂ , the conversion characteristics at the frequency of the transmission wave are remarkable. It will not deteriorate. Therefore, variation in frequency characteristics can be suppressed. As a result, the manufacturing yield can be improved and the manufacturing cost can be reduced.

Further, a resonance path P ₁ having a resonance length longer than the resonance length L ₀ is formed in the main matching element 6, and a resonance path P ₂ having a resonance length shorter than the resonance length L ₀ is formed in the sub-matching element 7. Therefore, the bandwidth of the MSL-WG converter 1 can be sufficiently widened as compared with the case where only the matching element whose element length is about the resonance length L ₀ is formed in the closed region 8. Further, since the resonance path is separated between the main matching element 6 and the sub-matching element 7, two different resonance frequencies f ₁ and f ₂ can be easily realized between the main matching element 6 and the sub-matching element 7. .

  In the present embodiment, an example in which the sub-matching element 7 has a rectangular shape including a side parallel to the long side of the opening 21 and a side parallel to the short side of the opening 21 has been described. The invention does not limit the shape of the sub-matching element 7 to this. For example, the sub-matching element 7 having a diamond shape or a circular shape is also included in the present invention.

  FIG. 10 is a diagram showing another example of the arrangement of the MSL 4, the main matching element 6, and the sub matching element 7 with respect to the opening 21 of the waveguide block 2. (A) in the figure shows a diamond-shaped sub-matching element 7 having a diagonal line parallel to the short side of the opening 21, and (b) shows a circular-shaped sub-matching element 7. Further, (c) shows a parallelogram-shaped sub-matching element 7 in which a pair of sides parallel to the long side of the opening 21 are displaced from each other in the longitudinal direction.

In sub-matching element 7 (a), the length of the diagonal line is an element length B _2, in the sub-matching element 7 (b), is a device length B ₂ length to diameter. In sub-matching element 7 (c), the length of the parallelogram hypotenuse is an element length B _2. Even if the sub-matching element 7 has such a shape, the bandwidth of the MSL-WG converter 1 can be increased.

  In the present embodiment, an example in which the sub-matching element 7 is formed in only one pattern on both sides or one side of the main matching element 6 has been described. However, the sub-matching element 7 includes a plurality of different patterns. You may comprise so that it may be formed from. For example, the present invention includes a configuration in which two sub-matching elements having different element lengths are formed on both sides of the main matching element 6, respectively.

  FIG. 11 is a diagram illustrating another configuration example of the MSL-WG converter 1 and illustrates a case where sub-matching elements 7 a and 7 b having different element lengths are formed on both sides of the main matching element 6. Yes. In the MSL-WG converter 1, two sub-matching elements 7 a and 7 b are formed between the main matching element 6 and the short side of the opening 21. Even if the sub-matching element 7 is formed of such a plurality of different patterns, the bandwidth of the MSL-WG converter 1 can be increased.

Embodiment 2. FIG.
In the first embodiment, the example in which the main matching element 6 and the sub matching element 7 are arranged apart from each other has been described. In the present embodiment, the case where the main matching element 6 and the sub-matching element 7 are connected to each other via a region in which the length of the opening 21 in the short direction is shorter than the matching elements 6 and 7 will be described. To do.

FIG. 12 is a diagram showing a configuration example of the MSL-WG converter 1 according to the second embodiment of the present invention, in which the main matching element 6 and the sub-matching element 7 are connected to each other via the neck region 9. . The neck region 9 is a region in which the length d ₄ in the short direction of the opening 21 is shorter than the element lengths B ₁ and B _{2. The} main matching element 6, the neck region 9, and the sub-matching element 7 define the opening 21. Concave portions that are opposed from both sides in the short direction are formed. That is, with respect to the outer edge on one long side of the opening 21, a recess is formed by the outer edge of the main matching element 6, the outer edge of the sub-matching element 7, and the outer edge of the neck region 9, and the other length of the opening 21. Concerning the outer edge on the side, a recess is formed by the outer edges of the main matching element 6, the sub-matching element 7, and the neck region 9. The neck region 9 is made of, for example, the same conductor layer as the main matching element 6 and the sub matching element 7.

In this example, the sub-matching elements 7 arranged on both sides of the main matching element 6 are all connected to the main matching element 6 via the neck region 9. Of the resonance paths formed between the main matching element 6 and the sub-matching element 7 via the neck region 9, if the influence of the resonance path whose path length is close to the resonance paths P ₁ and P ₂ is small, the bandwidth can be increased. is there. For this reason, the length d ₄ of the neck region 9 may be shorter than the element lengths B ₁ and B _{2 of} the main matching element 6 and the sub-matching element 7, but for example, between the main matching element 6 and the sub-matching element 7 it is desirable that less than the distance A _3.

Even with such a configuration, the bandwidth of the MSL-WG converter 1 can be increased. That is, the main matching element 6 and the sub-matching element 7 may be electrically connected to each other as long as they can be electromagnetically coupled and resonance paths P ₁ and P ₂ having different path lengths can be formed. .

Embodiment 3 FIG.
In the first embodiment, an example in which the sub-matching element 7 is arranged on both sides of the main matching element 6 has been described. On the other hand, in the present embodiment, a case where the sub-matching element 7 is arranged only on one side of the main matching element 6 will be described.

  FIG. 13 is a diagram illustrating a configuration example of the MSL-WG converter 1 according to the third embodiment of the present invention, and the sub-matching element 7 is formed only on one side of the main matching element 6. In this example, the sub-matching element 7 is formed only on the right side of the main matching element 6. Even with such a configuration, the bandwidth of the MSL-WG converter 1 can be increased.

  In the first to third embodiments, an example in which the planar line is the MSL4 has been described. However, the present invention does not limit the planar line connected to the waveguide via the converter to the MSL4. For example, a strip line having a structure in which a conductive layer formed inside a dielectric substrate is sandwiched between conductive layers formed on the first and second surfaces of the dielectric substrate, or a conductive layer formed on the surface of the dielectric substrate The present invention can also be applied to a converter using a coplanar waveguide having a structure in which a linear gap is provided in the gap and a linear conductor layer is formed in the gap as a planar line.

  In the first to third embodiments, an example in which the MSL 4 extends in parallel with the short side of the opening 21 across the long side of the opening 21 of the waveguide block 2 has been described. The present invention can also be applied to a transducer configured to extend across the side and parallel to the long side of the opening 21.

  In the first to third embodiments, an example in which the main matching element 6 has a rectangular shape has been described. However, a shape other than the main matching element 6, for example, a circle or a rhombus is also included in the present invention. included.

DESCRIPTION OF SYMBOLS 1 MSL-WG converter 10 Dielectric substrate 11 Through hole 3 Short-circuit board 3a Cut 4 MSL
5 grounding plate 6 main matching element 7, 7a, 7b auxiliary matching element 8 closed region 9 neck region second waveguide blocks 21 opening 22a wide wall 22b Semakabe 23 hollow section _B 1, _{B 2} element length _{d 1} insertion distance _{d 2} Sub-matching element position f ₀ Center frequency f ₁ , f ₂ Resonance frequency L ₁ Narrow wall dimension L ₂ Wide wall dimension w Line width

Claims (5)

A dielectric substrate having a first surface for closing the rectangular opening of the waveguide;
A first matching element and a second matching element formed in the opening on the first surface of the dielectric substrate;
A short-circuit plate formed on the second surface of the dielectric substrate;
A planar line formed on the second surface of the dielectric substrate and extending into the notch of the shorting plate so as to face the first matching element;
The second matching element is disposed between the short side of the opening of the waveguide and the first matching element,
The planar line waveguide converter, wherein the first matching element and the second matching element have different lengths in a direction parallel to the short side of the opening. The planar track extends across the long side of the opening,
2. The planar line waveguide converter according to claim 1, wherein the second matching element is formed on both sides of the rectangular first matching element. The first matching element has an element length in a direction parallel to the short side of the opening longer than a resonance length corresponding to the waveguide wavelength of the waveguide,
3. The planar line waveguide converter according to claim 1, wherein the second matching element has an element length shorter than the resonance length. 4.   The planar line waveguide converter according to claim 1, wherein the first matching element and the second matching element are spaced apart from each other.   2. The first matching element and the second matching element are connected to each other via a neck region whose length in a direction parallel to the short side of the opening is shorter than each matching element. The planar line waveguide converter in any one of -3.

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