EP1408577A1 - Band-pass filter - Google Patents
Band-pass filter Download PDFInfo
- Publication number
- EP1408577A1 EP1408577A1 EP20030255937 EP03255937A EP1408577A1 EP 1408577 A1 EP1408577 A1 EP 1408577A1 EP 20030255937 EP20030255937 EP 20030255937 EP 03255937 A EP03255937 A EP 03255937A EP 1408577 A1 EP1408577 A1 EP 1408577A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- substrate
- microstrip conductor
- band
- pass filter
- microstrip
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
- H01P1/00—Auxiliary devices
- H01P1/20—Frequency-selective devices, e.g. filters
- H01P1/201—Filters for transverse electromagnetic waves
- H01P1/203—Strip line filters
- H01P1/20327—Electromagnetic interstage coupling
- H01P1/20354—Non-comb or non-interdigital filters
- H01P1/20381—Special shape resonators
Definitions
- the present invention relates to a band-pass filter having microstrip conductors, and particularly to a band-pass filter having triangular microstrip conductors.
- band-pass filters having triangular microstrip conductors (sometimes called cymbal band-pass filters) are being studied.
- Fig. 4 is an exploded perspective view of a conventional cymbal band-pass filter, which includes a substrate 30 having two triangular microstrip conductors 31 and 32 formed on the upper surface thereof.
- the first microstrip conductor 31 and the second microstrip conductor 32 are shaped like isosceles triangles of the same size, and are disposed so that corresponding sides (bases) of the two microstrip conductors 31 and 32 are parallel to each other.
- the distance between the parallel bases and the sizes of the microstrip conductors determine characteristics such as the band-pass center frequency, bandwidth, loss, and skirt characteristics.
- the length W of each base is about 4.77 mm
- the distance G between the bases is 0.15 mm
- the height K from each base to the opposite apex is 0.6 mm.
- the thickness H of the substrate 30 is 0.25 mm.
- the substrate 30 has a first conductive line 33, a second conductive line 35, and an amplifier 34.
- the first conductive line 33 is connected to the apex opposite to the base of the first microstrip conductor 31.
- the input terminal (or output terminal) of the amplifier 34 is connected to the apex opposite to the base of the second microstrip conductor 32.
- the output terminal (or input terminal) of the amplifier 34 is connected to the second conductive line 35.
- the substrate 30 further includes a grounding conductor (not shown in Fig. 4) formed on its back surface.
- the conductive lines 33 and 35 have a characteristic impedance of, for example, 50 ohm.
- One of the conductive lines 33 and 35 is used for signal input and the other for signal output. Useful information about these band-pass filters can be found in non-patent document, IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 50. NO. 5, MAY 2002, P. 1431-1432, for example.
- the substrate 30 further includes bar conductors 36 and 37 along both sides of the first microstrip conductor 31 and the second microstrip conductor 32.
- the bar conductors 36 and 37 are connected to the grounding conductor on the back surface of the substrate 30 by means of conductive holes (not shown in Fig. 4).
- the band-pass filter includes a U-shaped shielding case 38 covering the first microstrip conductor 31 and the second microstrip conductor 32.
- the shielding case 38 has legs 38a and 38b soldered to the bar conductors 36 and 37, respectively.
- the apexes opposite to the bases of the two triangular microstrip conductors function as the input terminal and the output terminal of the band-pass filter, where the distance between the input and output terminals is about 1.35 mm.
- the band-pass filter has the amplifier as a peripheral circuit connected thereto, and therefore requires a certain area for the amplifier. This area for the amplifier adds to the footprint of the band-pass filter.
- an object of the present invention is to provide a band-pass filter requiring a smaller footprint while still including a peripheral circuit.
- a band-pass filter includes a first substrate having a first triangular microstrip conductor formed on one surface thereof and a grounding conductor formed on the other surface thereof; a second substrate having a second triangular microstrip conductor formed on one surface thereof and a grounding conductor formed on the other surface thereof; and a shielding case covering the first microstrip conductor.
- the shielding case includes a top plate and side plates, the side plates being connected to the first substrate.
- the second substrate is mounted on the inner surface of the top plate of the shielding case such that the second microstrip conductor faces the first substrate and does not overlap the first microstrip conductor in plan view.
- the first microstrip conductor is coupled with the second microstrip conductor, while a space for a peripheral circuit can be allocated on the first substrate, below the second microstrip conductor.
- the present invention can provide a compact band-pass filter which requires only a small footprint while still including a peripheral circuit.
- one side of the second microstrip conductor may be substantially directly above and parallel with one side of the first microstrip conductor.
- the two microstrip conductors can be sufficiently coupled with each other.
- An amplifier may be formed in an area of the first substrate, namely, the area facing the second substrate, such that the apex opposite to the side of the second microstrip conductor is connected to the input terminal or the output terminal of the amplifier.
- the present invention can provide a band-pass filter with an integrated amplifier.
- FIG. 1 is an exploded perspective view of the band-pass filter.
- Fig. 2 is a sectional view of a relevant part of the band-pass filter.
- Fig. 3 is a plan view illustrating the positional relationship between two microstrip conductors of the band-pass filter.
- a band-pass filter according to the present invention includes a first substrate 10, a second substrate 20, and a shielding case 18.
- the first substrate 10 includes a first isosceles-triangle-shaped microstrip conductor 11 formed on its upper surface, a peripheral circuit 12, such as an amplifier, adjacent to one side (base) of the first microstrip conductor 11, a first conductive line 13 connected to the apex opposite to the base of the first microstrip conductor 11, a second conductive line 14 connected to the input terminal (or output terminal) of the peripheral circuit 12, and a grounding conductor 17 formed on its entire lower surface.
- a peripheral circuit 12 such as an amplifier
- the first microstrip conductor 11 has a side (base) length W of about 4.77 mm and a distance (height) K between the base and the apex opposite to the base of about 0.6 mm.
- the first conductive line 13 and the second conductive line 14 extend away from each other.
- One of the conductive lines 13 and 14 is used for signal input and the other for signal output.
- the first substrate 10 further includes bar conductors 15 and 16 extending along both sides of the first microstrip conductor 11 and the peripheral circuit 12, that is, the two sides parallel to the direction in which the first microstrip conductor 11 and the peripheral circuit 12 are arranged.
- the grounding conductor 17 is connected to the bar conductors 15 and 16 by means of, for example, conductive holes (through-holes) (not shown in Figs. 1 to 3).
- the shielding case 18 is U-shaped, having a top plate 18a and two side plates 18b and 18c formed by bending the top plate 18a.
- the side plates 18b and 18c are soldered to the bar conductors 15 and 16, respectively, on the first substrate 10, in order to cover the first microstrip conductor 11 and the peripheral circuit 12.
- the second substrate 20 has a second isosceles-triangle-shaped microstrip conductor 21 formed on its lower surface and a grounding conductor 22 on its upper surface.
- the second microstrip conductor 21 has the same shape and size as the first microstrip conductor 11.
- the second substrate 20 is mounted on the shielding case 18 such that the grounding conductor 22 is in surface contact with the inner surface of the top plate 18a and one side (base) of the second microstrip conductor 21 is perpendicular to the surfaces of the side plates 18b and 18c. When mounted on the shielding case 18, the second substrate 20 occupies substantially half the area of the inner surface of the top plate 18a.
- the second microstrip conductor 21 does not overlap the first microstrip conductor 11 in plan view; the second microstrip conductor 21 is disposed above the peripheral circuit 12.
- the base of the first microstrip conductor 11 is aligned and parallel with the base of the second microstrip conductor 21 in plan view, the two microstrip conductors 11 and 21 being symmetrical with respect to the base line, as shown in Fig. 3.
- the vertical distance G (not shown in Figs. 1 to 3) between the first substrate 10 and the second substrate 20 is about 0.15 mm.
- the apex opposite to the base of the second microstrip conductor 21 is connected to the input terminal (or the output terminal) of the peripheral circuit 12 with a lead wire 23 such as a bonding wire.
- the first microstrip conductor 11 and the second microstrip conductor 21 are coupled with each other near their bases to function as a band-pass filter with a center frequency of 25 GHz.
- the footprint of the band-pass filter including the peripheral circuit 12 is small because the peripheral circuit 12 is formed on the first substrate 10 disposed below the second substrate 20.
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Control Of Motors That Do Not Use Commutators (AREA)
Abstract
Description
- The present invention relates to a band-pass filter having microstrip conductors, and particularly to a band-pass filter having triangular microstrip conductors.
- Nowadays, band-pass filters having triangular microstrip conductors (sometimes called cymbal band-pass filters) are being studied.
- Fig. 4 is an exploded perspective view of a conventional cymbal band-pass filter, which includes a
substrate 30 having twotriangular microstrip conductors first microstrip conductor 31 and thesecond microstrip conductor 32 are shaped like isosceles triangles of the same size, and are disposed so that corresponding sides (bases) of the twomicrostrip conductors substrate 30 is 0.25 mm. - Referring again to Fig. 4, the
substrate 30 has a firstconductive line 33, a secondconductive line 35, and anamplifier 34. The firstconductive line 33 is connected to the apex opposite to the base of thefirst microstrip conductor 31. The input terminal (or output terminal) of theamplifier 34 is connected to the apex opposite to the base of thesecond microstrip conductor 32. The output terminal (or input terminal) of theamplifier 34 is connected to the secondconductive line 35. Thesubstrate 30 further includes a grounding conductor (not shown in Fig. 4) formed on its back surface. Theconductive lines conductive lines - Referring again to Fig. 4, the
substrate 30 further includesbar conductors first microstrip conductor 31 and thesecond microstrip conductor 32. Thebar conductors substrate 30 by means of conductive holes (not shown in Fig. 4). The band-pass filter includes aU-shaped shielding case 38 covering thefirst microstrip conductor 31 and thesecond microstrip conductor 32. Theshielding case 38 haslegs bar conductors - In the band-pass filter described above, the apexes opposite to the bases of the two triangular microstrip conductors function as the input terminal and the output terminal of the band-pass filter, where the distance between the input and output terminals is about 1.35 mm. Furthermore, the band-pass filter has the amplifier as a peripheral circuit connected thereto, and therefore requires a certain area for the amplifier. This area for the amplifier adds to the footprint of the band-pass filter.
- Accordingly, an object of the present invention is to provide a band-pass filter requiring a smaller footprint while still including a peripheral circuit.
- In order to achieve the object described above, a band-pass filter according to an aspect of the present invention includes a first substrate having a first triangular microstrip conductor formed on one surface thereof and a grounding conductor formed on the other surface thereof; a second substrate having a second triangular microstrip conductor formed on one surface thereof and a grounding conductor formed on the other surface thereof; and a shielding case covering the first microstrip conductor. The shielding case includes a top plate and side plates, the side plates being connected to the first substrate. The second substrate is mounted on the inner surface of the top plate of the shielding case such that the second microstrip conductor faces the first substrate and does not overlap the first microstrip conductor in plan view. In this manner, the first microstrip conductor is coupled with the second microstrip conductor, while a space for a peripheral circuit can be allocated on the first substrate, below the second microstrip conductor. Thus, the present invention can provide a compact band-pass filter which requires only a small footprint while still including a peripheral circuit.
- Furthermore, one side of the second microstrip conductor may be substantially directly above and parallel with one side of the first microstrip conductor. Thus, the two microstrip conductors can be sufficiently coupled with each other.
- An amplifier may be formed in an area of the first substrate, namely, the area facing the second substrate, such that the apex opposite to the side of the second microstrip conductor is connected to the input terminal or the output terminal of the amplifier. Thus, the present invention can provide a band-pass filter with an integrated amplifier.
-
- Fig. 1 is an exploded perspective view of a band-pass filter according to the present invention;
- Fig. 2 is a sectional view of a relevant part of a band-pass filter according to the present invention;
- Fig. 3 is a plan view illustrating the positional relationship between a first microstrip conductor and a second microstrip conductor of a band-pass filter according to the present invention; and
- Fig. 4 is an exploded perspective view of a conventional band-pass filter.
-
- A band-pass filter according to the present invention is illustrated in Figs. 1 to 3. Fig. 1 is an exploded perspective view of the band-pass filter. Fig. 2 is a sectional view of a relevant part of the band-pass filter. Fig. 3 is a plan view illustrating the positional relationship between two microstrip conductors of the band-pass filter.
- Referring to Figs. 1 to 3, a band-pass filter according to the present invention includes a
first substrate 10, asecond substrate 20, and ashielding case 18. - The
first substrate 10 includes a first isosceles-triangle-shaped microstrip conductor 11 formed on its upper surface, aperipheral circuit 12, such as an amplifier, adjacent to one side (base) of thefirst microstrip conductor 11, a firstconductive line 13 connected to the apex opposite to the base of thefirst microstrip conductor 11, a secondconductive line 14 connected to the input terminal (or output terminal) of theperipheral circuit 12, and agrounding conductor 17 formed on its entire lower surface. - The
first microstrip conductor 11 has a side (base) length W of about 4.77 mm and a distance (height) K between the base and the apex opposite to the base of about 0.6 mm. The firstconductive line 13 and the secondconductive line 14 extend away from each other. One of theconductive lines - The
first substrate 10 further includesbar conductors 15 and 16 extending along both sides of thefirst microstrip conductor 11 and theperipheral circuit 12, that is, the two sides parallel to the direction in which thefirst microstrip conductor 11 and theperipheral circuit 12 are arranged. Thegrounding conductor 17 is connected to thebar conductors 15 and 16 by means of, for example, conductive holes (through-holes) (not shown in Figs. 1 to 3). - The
shielding case 18 is U-shaped, having atop plate 18a and twoside plates top plate 18a. Theside plates bar conductors 15 and 16, respectively, on thefirst substrate 10, in order to cover thefirst microstrip conductor 11 and theperipheral circuit 12. - The
second substrate 20 has a second isosceles-triangle-shaped microstrip conductor 21 formed on its lower surface and agrounding conductor 22 on its upper surface. Thesecond microstrip conductor 21 has the same shape and size as thefirst microstrip conductor 11. Thesecond substrate 20 is mounted on theshielding case 18 such that thegrounding conductor 22 is in surface contact with the inner surface of thetop plate 18a and one side (base) of thesecond microstrip conductor 21 is perpendicular to the surfaces of theside plates shielding case 18, thesecond substrate 20 occupies substantially half the area of the inner surface of thetop plate 18a. - Referring to Figs. 2 and 3, with the
shielding case 18 mounted on thefirst substrate 10, thesecond microstrip conductor 21 does not overlap thefirst microstrip conductor 11 in plan view; thesecond microstrip conductor 21 is disposed above theperipheral circuit 12. The base of thefirst microstrip conductor 11 is aligned and parallel with the base of thesecond microstrip conductor 21 in plan view, the twomicrostrip conductors first substrate 10 and thesecond substrate 20 is about 0.15 mm. - The apex opposite to the base of the
second microstrip conductor 21 is connected to the input terminal (or the output terminal) of theperipheral circuit 12 with alead wire 23 such as a bonding wire. - According to the structure described above, the
first microstrip conductor 11 and thesecond microstrip conductor 21 are coupled with each other near their bases to function as a band-pass filter with a center frequency of 25 GHz. - The footprint of the band-pass filter including the
peripheral circuit 12 is small because theperipheral circuit 12 is formed on thefirst substrate 10 disposed below thesecond substrate 20.
Claims (3)
- A band-pass filter comprising:a first substrate including:a first triangular microstrip conductor formed on one surface thereof; anda grounding conductor formed on the other surface thereof;a second substrate including:a second triangular microstrip conductor formed on one surface thereof and coupled with the first triangular microstrip conductor; anda grounding conductor formed on the other surface thereof; anda shielding case covering the first microstrip conductor, the shielding case including:a top plate; andside plates connected to the first substrate,
- The band-pass filter according to claim 1, wherein a first side of the second microstrip conductor is substantially directly above and parallel with a first side of the first microstrip conductor.
- The band-pass filter according to claim 2, further comprising an amplifier formed in an area of the first substrate, the area facing the second substrate, wherein the apex opposite to the first side of the second microstrip conductor is connected to an input terminal or an output terminal of the amplifier.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2002098099 | 2002-10-10 | ||
JP2002298099A JP2004135102A (en) | 2002-10-10 | 2002-10-10 | Bandpass filter |
Publications (1)
Publication Number | Publication Date |
---|---|
EP1408577A1 true EP1408577A1 (en) | 2004-04-14 |
Family
ID=32025574
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP20030255937 Withdrawn EP1408577A1 (en) | 2002-10-10 | 2003-09-23 | Band-pass filter |
Country Status (2)
Country | Link |
---|---|
EP (1) | EP1408577A1 (en) |
JP (1) | JP2004135102A (en) |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4210881A (en) * | 1978-11-09 | 1980-07-01 | The United States Of America As Represented By The Secretary Of The Navy | Millimeter wave microstrip triplexer |
US6304156B1 (en) * | 1993-08-24 | 2001-10-16 | Toshio Ishizaki | Laminated dielectric antenna duplexer and a dielectric filter |
-
2002
- 2002-10-10 JP JP2002298099A patent/JP2004135102A/en not_active Withdrawn
-
2003
- 2003-09-23 EP EP20030255937 patent/EP1408577A1/en not_active Withdrawn
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4210881A (en) * | 1978-11-09 | 1980-07-01 | The United States Of America As Represented By The Secretary Of The Navy | Millimeter wave microstrip triplexer |
US6304156B1 (en) * | 1993-08-24 | 2001-10-16 | Toshio Ishizaki | Laminated dielectric antenna duplexer and a dielectric filter |
Non-Patent Citations (1)
Title |
---|
STRASSNER B ET AL: "NEW WIDE-BAND DC-BLOCK CYMBAL BANDPASS FILTER", IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, IEEE INC. NEW YORK, US, vol. 50, no. 5, May 2002 (2002-05-01), pages 1431 - 1432, XP001113444, ISSN: 0018-9480 * |
Also Published As
Publication number | Publication date |
---|---|
JP2004135102A (en) | 2004-04-30 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6587015B2 (en) | Transmission/reception unit with improved antenna gain | |
US4703291A (en) | Dielectric filter for use in a microwave integrated circuit | |
EP1056133A1 (en) | Rf circuit module | |
JPH0653733A (en) | Resonator antenna | |
GB2234399A (en) | Dielectric filter | |
US6683572B2 (en) | Chip antenna device and method | |
US7098531B2 (en) | Jumper chip component and mounting structure therefor | |
TW200405617A (en) | Enclosed antenna in system and portable terminals installed with the antenna | |
EP1408577A1 (en) | Band-pass filter | |
JPH11330298A (en) | Package provided with signal terminal and electronic device using the package | |
JPS6033604Y2 (en) | strip line filter | |
EP1408576A1 (en) | Band-pass filter | |
JP3794874B2 (en) | Transmission / reception unit | |
US6977559B2 (en) | Nonreciprocal circuit element with notch part in yoke | |
JP3425702B2 (en) | Antenna duplexer | |
US7132748B2 (en) | Semiconductor apparatus | |
JP3444246B2 (en) | Dielectric resonator device, dielectric duplexer, and communication device | |
JP2001203519A (en) | Antenna system for transmission reception module | |
JPH0565102U (en) | Balance-unbalance converter | |
US6930566B2 (en) | Small nonreciprocal circuit element that can be easily wired | |
JPS5921525Y2 (en) | Microwave strip line connection structure | |
US6796840B2 (en) | Surface mounting type non-reversible circuit element having superior productivity | |
JPS632406A (en) | Microwave module | |
JPH02207470A (en) | Connector for printed wiring board | |
JP3660316B2 (en) | Non-reciprocal circuit element |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PT RO SE SI SK TR |
|
AX | Request for extension of the european patent |
Extension state: AL LT LV MK |
|
17P | Request for examination filed |
Effective date: 20040320 |
|
17Q | First examination report despatched |
Effective date: 20040524 |
|
GRAP | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOSNIGR1 |
|
AKX | Designation fees paid |
Designated state(s): DE FR GB |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN |
|
18D | Application deemed to be withdrawn |
Effective date: 20050323 |