WO2007029853A1 - Bandpass filter and resonator - Google Patents
Bandpass filter and resonator Download PDFInfo
- Publication number
- WO2007029853A1 WO2007029853A1 PCT/JP2006/317947 JP2006317947W WO2007029853A1 WO 2007029853 A1 WO2007029853 A1 WO 2007029853A1 JP 2006317947 W JP2006317947 W JP 2006317947W WO 2007029853 A1 WO2007029853 A1 WO 2007029853A1
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- WO
- WIPO (PCT)
- Prior art keywords
- transmission line
- distributed transmission
- bandpass filter
- stub
- resonators
- Prior art date
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Classifications
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- 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
- H01P1/2039—Galvanic coupling between Input/Output
Definitions
- the present invention relates to a bandpass filter suited to be applied to a UWB wireless communication system.
- UWB ultra wideband
- a signal transmitted in the UWB wireless communication system possibly interferes with a signal of an existing communication service since the signal includes a wideband frequency component .
- it is necessary to use a bandpass filter in the UWB wireless communication system so as to extract the indispensable frequency range.
- Bandpass filters available in a high frequency region such as a region of microwave band have been conventionally proposed as disclosed in Japanese Patent Application Laid-Open No. 2000-357903.
- bandpass filters each of which exhibits wide passband characteristics and steep attenuation characteristics near a passband so as to be applicable to the UWB wireless communication system have been proposed conventionally.
- no bandpass filter characteristics of which can be easily adjusted has been conventionally proposed. In these circumstances, there is an urgent need for a bandpass filter suited to be applied to the UWB wireless communication system.
- the present invention has been achieved to solve the conventional problems, and an object of the invention is to provide a bandpass filter that exhibits wide passband characteristics and steep attenuation characteristics near a passband.
- the inventors of the present invention have discovered that by connecting a plurality of resonators, each configured by connecting a tap formed by a distributed transmission line to a side surface of a stub formed by another distributed transmission line to one another in multistages by yet another distributed transmission line, parameters such as characteristic impedances, line lengths, and line widths of the distributed transmission lines are changed. It is thus possible to control a passband width and a position of an attenuation pole near a passband.
- a bandpass filter for outputting only a signal in a desired frequency band from an output terminal among a plurality of signals input to an input terminal, the bandpass filter including: a first distributed transmission line connecting the input terminal to the output terminal; and a resonatorincludingatap formedbya seconddistributedtransmission line connected to the first distributed transmission line and a stub formed by a third distributed transmission line connected to the second distributed transmission line in a region other than both ends of the stub.
- Fig. 5 is a schematic diagram of the configuration of the modification of the bandpass filter according to the embodiment of the present invention
- Fig. 6 is a schematic diagram of the configuration of the modification of the bandpass filter according to the embodiment of the present invention,-
- Fig.7 is a schematic diagram of a configuration of a bandpass filter according to another embodiment of the present invention,- and
- Fig. 8 shows attenuation characteristics and reflection characteristics of the bandpass filter shown in Fig. 7.
- a bandpass filter according to one embodiment has a multilayer structure including a ground substrate and a dielectric substrate.
- a GND member formed on the dielectric substrate is connected to the ground substrate through a via hole formed in the dielectric substrate.
- abandpass filter 1 includes a dielectric substrate 2 formed on the ground substrate, distributed transmission lines 5a, 5b, 5c connecting an input transmission line 3 and an output transmission line 4 formed on the dielectric substrate 2 to each other, and a plurality of resonators.
- the resonators include taps 6a, 6b, 6c, 6d formed by distributed transmission lines, one ends of which are connected to the distributed transmission lines 5a, 5b, 5c, and stubs 7a, 7b, 7c, 7d formed by distributed transmission lines connected to the taps 6a, 6b, 6c, 6d in regions other than both ends of each of the stubs 7a, 7b, 7c, 7d, respectively.
- the bandpass filter 1 outputs onlya signal ina desired frequencyband fromthe output transmission line 4 bymaking the resonators resonate at a frequencycorresponding to a passbandwhenever each signal is input to the input transmission line 3.
- Each of the distributed transmission lines 5a, 5b, 5c, and the distributed transmission lines that respectively constitute the taps 6a, 6b, 6c, 6d and the stubs 7a, 7b, 7c, 7d can be formed by, for example, a microstrip line, a coplanar line, or a strip line formed in a triplate structure of the dielectric substrate 2.
- the four resonators are provided in the bandpass filter 1.
- the number of the resonators provided in the bandpass filter of the present invention is not limited to four but can be appropriately set according to passband characteristics of the bandpass filter 1.
- both ends of the stub 7a are opened and the stub 7a is connected to the tap 6a, thereby constituting a both-end-open-type tap-connection resonator.
- one end of each of the other stubs 7b, 7c, 7d is grounded to GMD members 8a, 8b, 8c, the stubs 7b, 7c, 7d are connected to the taps 6b, 6c, 6d, respectively, thereby constituting one-end-grounded-type tap-connection resonators, respectively.
- the bandpass filter 1 can control aposition of an attenuation pole to be located near the passband and realize steep attenuation characteristics by changing parameters such as characteristic impedances, line lengths, and line widths of the tap 6a and the stub 7a that constitute the both-end-open-type tap-connection resonator and those of the distributed transmission lines 5a, 5b, 5c .
- Fig.2 shows simulation results of attenuation characteristics and reflection characteristics of the bandpass filter 1 by a solid line and a broken line, respectively.
- attenuation poles are formed near frequency positions of 2.5 [GHz] and 10 [GHz] , respectively, and wide passband characteristics and steep attenuation characteristics near the passband are realized.
- stubs 7a, 7b, 7c, 7d are linear stubs as shown in Fig. 1, they can be bent as similarly to the stub 7a shown in Fig.3.
- the bandpass filter 1 can be downsized.
- Fig. 4 shows simulation results of attenuation characteristics and reflection characteristics of the bandpass filter 1 shown in Fig.3 by a solid line and a broken line, respectively.
- attenuation poles are formed near frequency positions o " f f L (2.5 [GHz]) and f H (4.5. [GHz]), respectively, and wide passband characteristics and steep attenuation characteristics near the passband are realized.
- stubs 7a, 7b, 7c, 7d are linear stubs as shown in Fig. 1, they can be stepped. As shown in Fig. 5, all the resonators in the bandpass
- filter 1 can be both-end-grounded-type tap-connection resonators by grounding both ends of all the stubs 7a, 7b, 7c, 7d to GND members
- a bandpass filter that exhibits the wide passband characteristics and the steep attenuation characteristics near the passband can be realized.
- a bandpass filter can be configured as follows. A configuration of a bandpass filter according to another embodiment of the present invention will be explained below with reference to the accompanying drawings .
- a bandpass filter 11 includes a dielectric substrate 12 formed on a ground substrate (not shown) , an LC circuit 15 and distributed transmission lines 16a, 16b, 16c connecting an input transmission line 13 and an output transmission line 14 formed on the dielectric substrate 12 to each other, and a plurality of resonators.
- the resonators include taps 17a, 17b, 17c formed by distributed transmission lines connected to the distributed transmission lines 16a, 16b, 16c on one end of each of the taps, stubs 18a, 18b, 18c formed by distributed transmission lines connected to the taps 17a, 17b, 17c, 17d in regions other than both ends of each of the stubs, and distributed transmission lines 20a, 20b, 20c, respectively.
- Three resonators are multistage-connected (multistage-coupled) by the distributed transmission lines 16a, 16b, 16c between the input transmission line 13 and the output transmission line 14.
- one ends of the distributed transmission lines 20a, 20b, 20c are connected to the distributed transmission lines 16a, 16b, 16c so as to oppose connection points between the taps 17a, 17b, 17c and the distributed transmission lines 16a, 16b, 16c, respectively.
- other ends of the distributed transmission lines 20a, 20b, 20c are grounded to GMD members (grounding members) 19a, 19b, 19c, respectively.
- the bandpass filter 11 outputs only a signal in a desired frequency band from the output transmission line 14 by making the resonators resonate at a frequency corresponding to a passband whenever each signal is input to the input transmission line 13.
Abstract
A bandpass filter includes a distributed transmission line (5a, 5b, 5c) connecting an input transmission line (3) and an output transmission line (4) formed on a dielectric substrate to each other, and four resonators each including a tap (6a, 6b, 6c, 6d) formed by a distributed transmission line, one end of which is connected to the distributed transmission line, and a stub formed by a distributed transmission line (7a, 7b, 7c, 7d) connected to the tap in a region other than both ends of the stub. The four resonators are multistage-connected by a distributed transmission line between the input transmission line and the output transmission line.
Description
DESCRIPTION
BANDPASS FILTER AND RESONATOR
TECHNICAL FIELD
The present invention relates to a bandpass filter suited to be applied to a UWB wireless communication system.
BACKGROUND ART Inrecentyears, activeconsiderationhasbeengiventoputting an ultra wideband (UWB) wireless communication system for realizing communication speed as high as several hundreds of megabits per second, into practical application. A signal transmitted in the UWB wireless communication systempossibly interferes with a signal of an existing communication service since the signal includes a wideband frequency component . In these circumstances , it is necessary to use a bandpass filter in the UWB wireless communication system so as to extract the indispensable frequency range.
DISCLOSURE OF INVENTION
Bandpass filters available in a high frequency region such as a region of microwave band have been conventionally proposed as disclosed in Japanese Patent Application Laid-Open No. 2000-357903. However, not many bandpass filters each of which exhibits wide passband characteristics and steep attenuation characteristics near a passband so as to be applicable to the UWB wireless communication system have been proposed conventionally. In addition, no bandpass filter characteristics of which can be
easily adjusted has been conventionally proposed. In these circumstances, there is an urgent need for a bandpass filter suited to be applied to the UWB wireless communication system.
The present invention has been achieved to solve the conventional problems, and an object of the invention is to provide a bandpass filter that exhibits wide passband characteristics and steep attenuation characteristics near a passband.
After dedicated studies, the inventors of the present invention have discovered that by connecting a plurality of resonators, each configured by connecting a tap formed by a distributed transmission line to a side surface of a stub formed by another distributed transmission line to one another in multistages by yet another distributed transmission line, parameters such as characteristic impedances, line lengths, and line widths of the distributed transmission lines are changed. It is thus possible to control a passband width and a position of an attenuation pole near a passband.
According to one aspect of the present invention attained from the above knowledge, there is provided a bandpass filter for outputting only a signal in a desired frequency band from an output terminal among a plurality of signals input to an input terminal, the bandpass filter including: a first distributed transmission line connecting the input terminal to the output terminal; and a resonatorincludingatap formedbya seconddistributedtransmission line connected to the first distributed transmission line and a stub formed by a third distributed transmission line connected to the second distributed transmission line in a region other than both ends of the stub.
BRIEF DESCRIPTION OF DRAWINGS
Fig.1 is a schematic diagram of a configuration of a bandpass filter according to an embodiment of the present invention; Fig. 2 shows attenuation characteristics and reflection characteristics of the bandpass filter shown in Fig. 1;
Fig. 3 is a schematic diagram of a configuration of a modification of the bandpass filter according to the embodiment of the present invention,- Fig. 4 shows attenuation characteristics and reflection characteristics of the bandpass filter shown in Fig. 3,-
Fig. 5 is a schematic diagram of the configuration of the modification of the bandpass filter according to the embodiment of the present invention,- Fig. 6 is a schematic diagram of the configuration of the modification of the bandpass filter according to the embodiment of the present invention,-
Fig.7 is a schematic diagram of a configuration of a bandpass filter according to another embodiment of the present invention,- and
Fig. 8 shows attenuation characteristics and reflection characteristics of the bandpass filter shown in Fig. 7.
BEST MODE FOR CARRYING OUT THE INVENTION A configuration of a bandpass filter according one embodiment of the present invention will be explained below with reference to the drawings . A bandpass filter according to one embodiment has a multilayer structure including a ground substrate and a
dielectric substrate. A GND member formed on the dielectric substrate is connected to the ground substrate through a via hole formed in the dielectric substrate.
As shown inFig.1, abandpass filter 1 according to thepresent embodiment includes a dielectric substrate 2 formed on the ground substrate, distributed transmission lines 5a, 5b, 5c connecting an input transmission line 3 and an output transmission line 4 formed on the dielectric substrate 2 to each other, and a plurality of resonators. The resonators include taps 6a, 6b, 6c, 6d formed by distributed transmission lines, one ends of which are connected to the distributed transmission lines 5a, 5b, 5c, and stubs 7a, 7b, 7c, 7d formed by distributed transmission lines connected to the taps 6a, 6b, 6c, 6d in regions other than both ends of each of the stubs 7a, 7b, 7c, 7d, respectively. Four resonators are multistage-connected (multistage-coupled) by the distributed transmission lines 5a, 5b, 5c between the input transmission line 3 and the output transmission line 4. The bandpass filter 1 outputs onlya signal ina desired frequencyband fromthe output transmission line 4 bymaking the resonators resonate at a frequencycorresponding to a passbandwhenever each signal is input to the input transmission line 3.
Each of the distributed transmission lines 5a, 5b, 5c, and the distributed transmission lines that respectively constitute the taps 6a, 6b, 6c, 6d and the stubs 7a, 7b, 7c, 7d can be formed by, for example, a microstrip line, a coplanar line, or a strip line formed in a triplate structure of the dielectric substrate 2. In the present embodiment, the four resonators are provided in the bandpass filter 1. However, the number of the resonators
provided in the bandpass filter of the present invention is not limited to four but can be appropriately set according to passband characteristics of the bandpass filter 1. Furthermore, in the present embodiment, both ends of the stub 7a are opened and the stub 7a is connected to the tap 6a, thereby constituting a both-end-open-type tap-connection resonator. On the other hand, one end of each of the other stubs 7b, 7c, 7d is grounded to GMD members 8a, 8b, 8c, the stubs 7b, 7c, 7d are connected to the taps 6b, 6c, 6d, respectively, thereby constituting one-end-grounded-type tap-connection resonators, respectively. By providing the resonators the stubs of which are grounded, it is possible to improve cutoff characteristics of the bandpass filter with respect to a DC component of each input signal and frequency components near the DC component. The bandpass filter 1 can control aposition of an attenuation pole to be located near the passband and realize steep attenuation characteristics by changing parameters such as characteristic impedances, line lengths, and line widths of the tap 6a and the stub 7a that constitute the both-end-open-type tap-connection resonator and those of the distributed transmission lines 5a, 5b, 5c . Fig.2 shows simulation results of attenuation characteristics and reflection characteristics of the bandpass filter 1 by a solid line and a broken line, respectively. As evident from Fig. 2, attenuation poles are formed near frequency positions of 2.5 [GHz] and 10 [GHz] , respectively, and wide passband characteristics and steep attenuation characteristics near the passband are realized.
In the present embodiment, while the stubs 7a, 7b, 7c, 7d are linear stubs as shown in Fig. 1, they can be bent as similarly
to the stub 7a shown in Fig.3. With such configuration, the bandpass filter 1 can be downsized. Fig. 4 shows simulation results of attenuation characteristics and reflection characteristics of the bandpass filter 1 shown in Fig.3 by a solid line and a broken line, respectively. As evident from Fig.4, attenuation poles are formed near frequency positions o"f fL (2.5 [GHz]) and fH (4.5. [GHz]), respectively, and wide passband characteristics and steep attenuation characteristics near the passband are realized.
Furthermore, according to the present embodiment, while the stubs 7a, 7b, 7c, 7d are linear stubs as shown in Fig. 1, they can be stepped. As shown in Fig. 5, all the resonators in the bandpass
•filter 1 can be both-end-grounded-type tap-connection resonators by grounding both ends of all the stubs 7a, 7b, 7c, 7d to GND members
8 (8a to 8i) . Moreover, alternatively, as shown in Fig. 6, both-end-grounded-type tap-connection resonators and both-end-open-type tap-connection resonators can be provided together in the bandpass filter 1.
In this manner, the bandpass filter that exhibits the wide passband characteristics and the steep attenuation characteristics near the passband can be realized. However, there is a limit to reducing the lengths of the distributed transmission lines that constitute the stubs and the taps to realize the wide passband characteristics and the steep attenuation characteristics near the passband. Therefore, it is difficult to configure abandpass filter that can simultaneously satisfy the wide passband characteristics, the steep attenuation characteristics near the passband, and the downsizing. A bandpass filter can be configured as follows. A configuration of a bandpass filter according to another embodiment
of the present invention will be explained below with reference to the accompanying drawings .
As shown in Fig. 7, a bandpass filter 11 according to the other embodiment includes a dielectric substrate 12 formed on a ground substrate (not shown) , an LC circuit 15 and distributed transmission lines 16a, 16b, 16c connecting an input transmission line 13 and an output transmission line 14 formed on the dielectric substrate 12 to each other, and a plurality of resonators. The resonators include taps 17a, 17b, 17c formed by distributed transmission lines connected to the distributed transmission lines 16a, 16b, 16c on one end of each of the taps, stubs 18a, 18b, 18c formed by distributed transmission lines connected to the taps 17a, 17b, 17c, 17d in regions other than both ends of each of the stubs, and distributed transmission lines 20a, 20b, 20c, respectively. Three resonators are multistage-connected (multistage-coupled) by the distributed transmission lines 16a, 16b, 16c between the input transmission line 13 and the output transmission line 14. In the bandpass filter 11, one ends of the distributed transmission lines 20a, 20b, 20c are connected to the distributed transmission lines 16a, 16b, 16c so as to oppose connection points between the taps 17a, 17b, 17c and the distributed transmission lines 16a, 16b, 16c, respectively. In addition, other ends of the distributed transmission lines 20a, 20b, 20c are grounded to GMD members (grounding members) 19a, 19b, 19c, respectively. The bandpass filter 11 outputs only a signal in a desired frequency band from the output transmission line 14 by making the resonators resonate at a frequency corresponding to a passband whenever each signal is input to the input transmission line 13.
Each of the distributed transmission lines 16a, 16b, 16c and the distributed transmission lines that respectively constitute the taps 17a, 17b, 17c, the stubs 18a, 18b, 18c, and the distributed transmission lines 20a, 20b, 20c can be formed by, for example, a microstrip line, a coplanar line, or a strip line formed in a triplate structure of the dielectric substrate 12. In the present embodiment, the bandpass filter 11 is configured to include three stages. However, the number of stages of the bandpass filter is not limited to three but can be appropriately set according to passband characteristics of the bandpass filter 11. Furthermore, while the stub 18b is a linear stub, it can be bent similarly to the stubs 18a and 18c . With this configuration, the bandpass filter 11 can be downsized.
The bandpass filter 11 can control the position of an attenuation pole to be located near the passband and realize steep attenuation characteristics by changing parameters such as characteristic impedances, line lengths, and line widths of the distributed transmission lines 16a, 16b, 16c, the taps 17a, 17b, 17c, the stubs 18a, 18b, 18c, and the distributed transmission lines 20a, 20b, 20c. It is to be noted, however, that discontinuity of the characteristic impedance is secured between the taps 17a, 17b, 17c and the distributed transmission lines 20a, 20b, 20c by making the taps 17a, 17b, 17c and the distributed transmission lines 20a, 20b, 20c differ in characteristic impedance. With this configuration, steep attenuation characteristics can be realized even on a low frequency-band side near the passband since the LC circuit 15 is provided between the input transmission line 13 and the output transmission line 14. Furthermore, the
distributed transmission lines 20a, 20b, 20c, which, function as inductors on the low frequency-band side, contribute to attenuation characteristics in regions other than the passband. Moreover, the resonators including the taps 17a, 17b, 17c, the stubs 18a, 18b, 18c, and the distributed transmission lines 20a, 20b, 20c, respectively. act as quarter-wavelength resonators. Therefore, there is no need for the taps 17a, 17b, 17c to act as the inductors on the low frequency-band side. It is thus possible to reduce the line lengths of the taps 17a, 17b, 17c and the stubs 18a, 18b, 18c, and to downsize the bandpass filter 11 (about 10x10 mmx2) .
Fig. 8 shows simulation results of the attenuation characteristics and the reflection characteristics of the bandpass filter 11 bya solid line andabroken line, respectively. As evident from Fig. 8, attenuation poles are formed near frequency positions of 2.5 [GHz] and 4.5 [GHz], respectively, and wide passband characteristics and steep attenuation characteristics near the passband are realized.
While the embodiment of the present invention has been describedabove, the invention is not limitedto the above embodiment and changes and modifications can be made within the scope of the gist of the present invention.
This application is based upon and claims the benefit of priority from prior Japanese Patent Application
P2005-256600 filedon September 5,2005, andprior Japanese Patent Application P2006-061572 filedonMarch.7, 2006; the entire contents of which are incorporated by reference herein.
INDUSTRIAL APPLICABILITY
According to the bandpass filter of the present invention, widepassbandcharacteristics andsteepattenuationcharacteristics near a passband can be realized.
Claims
1. A bandpass filter for outputting only a signal in a desired frequency band from an output terminal among a plurality of signals input to an input terminal, the bandpass filter comprising: a first distributed transmission line connecting the input terminal to the output terminal; and a resonator including a tap formed by a second distributed transmission line connected to the first distributed transmission line, and a stub formed by a third distributed transmission line connected to the second distributed transmission line in a region other than both ends of the stub.
2. The bandpass filter according to claim 1, comprising at least one resonator in which the both ends of the stub are opened.
3. The bandpass filter according to claim 1 or 2, comprising a plurality of resonators, wherein the stub of at least one of the resonators is grounded.
4. A bandpass filter for outputting only a signal in a desired frequency band from an output terminal among a plurality of signals inputtoaninput terminal, thebandpass filtercomprisingaplurality of resonators each constitutedby connecting a tap formedbya second distributed transmission line to a side surface of a stub formed by a first distributed transmission line, wherein the resonators are multistage-connected by a third distributed transmission line.
5. A bandpass filter for outputting only a signal in a desired frequency band from an output terminal among a plurality of signals input to an input terminal, the bandpass filter comprising: a first distributed transmission line connecting the input terminal to the output terminal; and a resonator connected to the first distributed transmission line, wherein the resonator includes : a tap formed by a second distributed transmission line, one end of the second distributed transmission line being connected to the first distributed transmission line; a stub formed by a third distributed transmission line connected to the second distributed transmission line in a region other than both ends of the stub; and a fourth distributed transmission line, one end of the fourth distributed transmission line being connected to the first distributed transmission line so as to oppose a connection point between the first distributed transmission line and the tap, and otherendof the fourthdistributedtransmissionlinebeinggrounded.
6. The bandpass filter according to claim 5, wherein a characteristic impedance of the second distributed transmission line differs from a characteristic impedance of the fourth distributed transmission line.
7. A resonator connected to a first distributed transmission line for connecting an input terminal and an output terminal of a bandpass filter to each other, comprising: a tap formed by a second distributed transmission line, one end of the second distributed transmission line being connected to the first distributed transmission line; a stub formed by a third distributed transmission line connected to the second distributed transmission line in a region other than both ends of the stub; and a fourth distributed transmission line, one end of the fourth distributed transmission line being connected to the first distributed transmission line so as to oppose a connection point between the first distributed transmission line and the tap, and otherendof the fourthdistributedtransmissionlinebeinggrounded.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2005-256600 | 2005-09-05 | ||
| JP2005256600A JP2007074123A (en) | 2005-09-05 | 2005-09-05 | Band-pass filter |
| JP2006061572A JP2007243462A (en) | 2006-03-07 | 2006-03-07 | Band-pass filter and resonator |
| JP2006-061572 | 2006-03-07 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2007029853A1 true WO2007029853A1 (en) | 2007-03-15 |
Family
ID=37400986
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/JP2006/317947 WO2007029853A1 (en) | 2005-09-05 | 2006-09-05 | Bandpass filter and resonator |
Country Status (1)
| Country | Link |
|---|---|
| WO (1) | WO2007029853A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2202840A1 (en) * | 2008-12-25 | 2010-06-30 | Fujitsu Limited | Filter, communication module, and communication apparatus |
| CN106848503A (en) * | 2017-03-24 | 2017-06-13 | 中国振华集团云科电子有限公司 | Film filter and film filter manufacture method |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4264881A (en) * | 1973-10-17 | 1981-04-28 | U.S. Philips Corporation | Microwave device provided with a 1/2 lambda resonator |
| US4513263A (en) * | 1981-12-24 | 1985-04-23 | U.S. Philips Corporation | Bandpass filters |
| EP1239541A1 (en) * | 2001-03-09 | 2002-09-11 | Thales | Lightning protection printed circuit and method for its manufacture |
-
2006
- 2006-09-05 WO PCT/JP2006/317947 patent/WO2007029853A1/en active Application Filing
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4264881A (en) * | 1973-10-17 | 1981-04-28 | U.S. Philips Corporation | Microwave device provided with a 1/2 lambda resonator |
| US4513263A (en) * | 1981-12-24 | 1985-04-23 | U.S. Philips Corporation | Bandpass filters |
| EP1239541A1 (en) * | 2001-03-09 | 2002-09-11 | Thales | Lightning protection printed circuit and method for its manufacture |
Non-Patent Citations (2)
| Title |
|---|
| BRIAN J. MINNIS: "CLASSES OF SUB-MINIATURE MICROWAVE PRINTED CIRCUIT FILTERS WITH ARBITRARY PASSBAND AND STOPBAND WIDTHS", IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUE, vol. 30, no. 11, November 1982 (1982-11-01), USA, pages 1893 - 1900, XP002408548 * |
| G.L. MATTHAEI ET AL: "MICROWAVE FILTERS, IMPEDANCE MATCHING NETWORKS AND COUPLING STRUCTURES", 1980, USA, pages 11,360-363,374,375, XP002408547 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2202840A1 (en) * | 2008-12-25 | 2010-06-30 | Fujitsu Limited | Filter, communication module, and communication apparatus |
| US9876479B2 (en) | 2008-12-25 | 2018-01-23 | Fujitsu Limited | Filter |
| CN106848503A (en) * | 2017-03-24 | 2017-06-13 | 中国振华集团云科电子有限公司 | Film filter and film filter manufacture method |
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