TWI220085B - Multi-layer bandpass filter with the characteristic of harmonic-suppression - Google Patents

Abstract

Disclosed a multi-layer bandpass filter with the characteristic of harmonic-suppression that mostly using a emending three-stage comb-line filter having a coupled capacitance connecting between input port and output port for having the characteristic of high-attenuation in low-side skirt, and having grounding inductance with the characteristic of harmonic-suppression in high-side skirt.

Description

1220085

V. Description of the invention (1) [Technical field to which the invention belongs] 1 Ming is related to a kind of multi-layer band-pass filter that can suppress the spectral wave and reduce in the low-pass band skirt, especially suitable for all wireless front = Circuits, such as: Supervisory tooth (Bluet00th), wireless LAN distance (, Antenna), telephone handset (Handset). Special device. …… Prior technology】 To drive Lu Liangying 5 Need to construct the use of crystal ig In recent years, with the popularity of portable mobile phones, and for the convenience of ▼, reducing the size and weight of communication devices has become a trend of improving efforts. On the other hand, filters are often used in high-end In frequency, 'has become an important key part in communication devices. However, in addition to the advantages of reducing and reducing the weight of an excellent filtering component, it is also based on allowing necessary signals to pass and unnecessary signals. Therefore, how to reduce the insertion loss and increase the attenuation outside the passband has become a major issue. For example, U.S. Patent No. 4, 1 66, 258 discloses a surface acoustic wave Element (Surface Acoustic Wave) SAW's smart filter (fi 1 ters), if it is generally used below iGHz7, its small size and weight reduction do have great advantages, but if the frequency is higher than 1 GHz In this case, the surface acoustic wave element is basically an interdigital electrode (IDT) formed by an interd 1 tal conductor with aluminum as the main component on the surface of a piezoelectric substrate. And increase the difficulty of process technology. For example, US Patent No. 6, 2 43, 564 B1 is disclosed

1220085 — 91H891R Rev. V. Description of the invention (2) " = A filter formed by coupling coaxial resonators made of electrical materials with each other: ', is already a very mature product, so in wireless mobile phones or The RF transceiver part of the wireless LAN card can often find this kind of crying application; "m, in general, its frequency of use is still limited to 500MHz to 6GHz, because high-dielectric materials are used (Generally, there are two families of materials with dielectric constants 38 and 90) The ~ 1/4 wavelength resonant cavity is greatly reduced. In addition, the use of low-temperature co-fired ceramic LTCC thick-film technology has developed very rapidly in recent years, such as US Patent No. 5,332,98 and U.S. Patent No. 5,489,881 are disclosed, which mainly uses ceramics as the circuit substrate material, and the internal and external electrodes can be silver, copper, and gold, respectively. Other metals: In a sintering furnace with a temperature of about 85 to 900 degrees Celsius, passive components such as filters are sintered in a parallel printing and coating process to form integrated ceramic components. Among them, ceramics are very close to Shi Xi, so they are suitable. versus The chip is connected and / or has the advantages of saving space and reducing costs. Its operating frequency is between 90 MHz and 5 GHz. However, it has shrinking gas characteristics. It is intended to be used for this purpose. As an external layer, the LTCC is difficult to sinter when the temperature is controlled below 900 degrees, and it is still made in a stacked manner, which is easy to increase the number of electricity. Therefore, it is necessary to use three degrees in design. The space electromagnetic mode is assisted, so the program is quite complicated. The design of the filter often has different considerations due to different regulations. = National Patent US · patent No. 5,523, 72 No. 9 sets the filter, and its characteristic response is Near the low-pass band skirt, a transmission zero point will be generated. If used, for example, USPatent No. 6,0 64,68 No. 1

1220085 __Case No. 92118916__ Year Month Revision_ V. Multilayer Filter Designed by the Structure of Invention Description (3) ’Its characteristic response will also appear near the low-pass band skirt near the transmission zero. In addition, if a multilayer filter is designed using an architecture such as US Patent No. 6,114, 925, its characteristic response is on both sides of the center frequency of the design, such as near the high-pass skirt and the low-pass skirt. Each transmission zero will appear; however, in order to comply with the characteristics of mobile communication band-pass filters, "high attenuation characteristics are generated in the low-pass band skirt, and attenuation characteristics can also be generated in the high-pass band skirt (that is, transmission with adjustable position can be generated). Zero point) "cannot be met. As for the multilayer filter manufactured by the method of US Patent No. 5,373,271, although it has a characteristic frequency adjustment "adjusting frequency characteristic", however, it only produces a high attenuation characteristic when the low-pass band skirt, and The effect of harmonics cannot be erased when using a high-pass belt skirt. It can be seen that there are still many shortcomings in the existing conventional solutions, which are not a good designer, and need to be improved. In view of various shortcomings derived from the above-mentioned conventional knowledge system, the inventor of this case has been eager to improve and innovate. After years of painstaking research, he has successfully completed the case. [Summary of the Invention] The main purpose of this and the present is to provide / a kind of laminated belt that can suppress harmonics, and its system b at the same time in the low-pass band skirt (l0w — side skirt) attenuation characteristics and A high _side skirt can suppress high frequency harmonics.

1220085 Case No. 92118916 V. Description of the invention (4) Chip-type components that are very suitable for multi-layers on laminated belts that can suppress harmonics are light, thin, short, and small. The design is mainly based on modified filters.) That is, in the input port to achieve a low-pass band skirt (and use ground inductance to achieve the purpose of filtering high-frequency harmonics) Another object of the present invention is to provide a pass filter, where the component is being designed, Therefore, a chip with a small size can be produced, which can fully meet the requirements of today's communication equipment. In order to achieve the above purpose, the present invention adds a coupling capacitor between the comb-line and the output port of the third-order comb filter The low-side skirt has a high attenuation characteristic and is used in a high-side skirt: [Embodiment] The present invention mainly provides a laminated band-pass filter capable of suppressing harmonics. The low-pass band skirt (10w-side has high attenuation characteristics) and high-frequency harmonics can be suppressed at the same time. In order to achieve the above-mentioned object, it is important for the present invention The point is that the actual chip is mounted on the metal pad mV of the printed circuit board (shown in the second figure). 'The metal pad (Pad) and the PCB ground plane (PCB ground) The connection is achieved by using metal perforations (... This can reduce the complexity of the design of the multi-layer architecture. 嗖 Ϊ See the first figure, which is a trial of the present invention-the preferred embodiment ": ___ Its main system Including C12, C20, C23 and TL1, TL2, Page 9 1220085

TL3 is connected in parallel to form three transmission lines. Among them, one mountain is connected in series through C10, and the C2o is connected in series through C30, and it is transmitted through Cl0 panel door /// 243 \ several 3 times. Pom, the unconnected ends each lead to the transmission end point (li / u rort), and the transfer wheel enters Leiqi ci3, and the j-a han (I / 〇Po) is connected in parallel through the coupling port C1 3 another From the other ends of the two transmission lines, an L is passed. The ground inductance L can be connected through the printed circuit board to form a load = ⑽ (Vla) 3 and the printed electrical circuit = (connection: shown). The connection is now "" I refer to the second figure 仫 Π · ί: In the concept of the description, in the design of multilayer chip-type band-pass filter system can be interspersed into a structure without ground inductance L (such as the third (Shown in the figure), its embodiment reveals a multi-layered frame consisting of 9 layers of Leyerl ~ Leyer, which constitutes the three transmission lines tli, τ [2, TL3 in the special-effect circuit of the figure. line), and the ground part is connected to the component chip guound of Layer 9 using metal vias 3. Among them, Layer4 is used as the component ground plane (chip gu〇und). 俾 This Layer4 can be defined as a boundary line and divided into upper and lower parts. The lower part is composed of

Layer4 'Lay er5' Layer6, Layer7, to achieve the connection of C12, C23, C20 and some CIO, C30; the upper part is composed of Layerl 'Layer2, Layer3, Layer4, to achieve the connection of C13 and some CIO, C30'俾 Layerl, Layer4,

Ground planes 4 are formed on the upper ends of Layer 7 and Layer 9 respectively, and transmission endpoints (ι / ο Portl, I / O Port 2) are formed on both ends of Layer 3 and Layer 5 and separated by Layer 4.

Page 10 1220085

皇 舞 91Π8916 V. Description of the invention (6) As shown in the fourth figure, it is private ^ ^ \ \ 明 明 明 (including the printed circuit board 金属 (the frequency of the metal pad 2 (Pad) invites C CB)) Sheng Huishi Λ ώΒ 'should. The right uses the grounding inductance L (see the curve of △ in the fourth figure), that is, the maximum attenuation of Yugu, s / A TBJ high-si Ρ skirt can reach ~ 7ηΗ k ^. (〇dB ' Therefore, high-frequency harmonics can be eliminated in the high-pass band skirt; if you lose 瑝 β ^ ^ ^ ^ ^ C13 (see the curve of △ in the fourth figure, σ α _ _ τ • ',, go u. margin), that is, the low-side skirt reaches (-80dB) swallowing and ^^ > ^ 0 ^ ^ ^ i ±. The moon dagger ^ in 纟 Shiwa, and high-frequency harmonics can be suppressed in the high-pass belt skirt.,; Can be individually layered to design, so the design complexity is greatly reduced, non- ^ ρ ^ ηπ, ^, ^ It is very commercially competitive; and the structure size of the present invention is very small, which is extremely suitable for the reduction of communication systems. [Features and functions of the present invention, other conventional technologies 1, its system can attenuate special effects In addition to surface 2, structure rule-type: 3, can be listed in detail, but it should be far from the technical effect of the present invention] The mutual comparison provided is at the same time low, In-frequency harmonics. Inch is small, 1 element. The design of the reduction is detailed. The example is not a multilayer bandpass filter that suppresses harmonics. It also has the following advantages: A high-side wave device (with its rt) and a skir with a high t) can be made into a small chip type (Ch ip

Specifically, the complexity that is not contained in this book. Regarding one of the feasible implementations of the present invention, equivalent implementations or changes to limit the patent scope of the present invention are

1220085 Amendment _ Case No. 92118916 V. Description of invention (7) in the patent scope. To sum up, this case is not only technically innovative, but also enhances the above-mentioned multiple effects over conventional items. It should have fully met the requirements for novel and progressive statutory invention patents, and filed an application in accordance with the law. We ask your office to approve this. Application for invention patents, to encourage invention, to the utmost.

Page 12 1220085 _Case No. 92118916_ Year, Month, and Day Amendment Brief Description of Drawings [Simplified Description of Drawings] The first drawing is an equivalent circuit of a preferred embodiment of the present invention. The second figure is a structure including a ground inductance L in a multi-layer chip-type band-pass filter implemented in the present invention. The third figure is a structure that does not include the ground inductance L in the multi-layer chip-type band-pass filter implemented in the present invention. The fourth graph is a frequency response diagram of a metal pad including a printed circuit board of the present invention.

1gb # The main branch of the symbol table is rL 1…… printed circuit board 1… PCB ground 2… metal pad 3… metal via 4… ground plane (Ground Plane)

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Claims (1)

1220085 _Case No. 92118916_ Modified on __ Month, Day and Day__ Patent Application Scope 1. A multilayer bandpass filter capable of suppressing harmonics, including: A filter formed by a multilayer chip element, which is provided with several layers on both sides A multi-layer with a transmission end point and a ground plane of several layers of components, wherein a coupling capacitor is added between an input port and an output port in the transmission end point; a printed circuit board having a metal pad (pad) at one end, the A metal via is formed on the metal pad, so that the ground plane of several layers of the chip element is connected to the ground plane of the printed circuit board through the metal via to form a ground inductor. 2. A multilayer bandpass filter capable of suppressing harmonics as described in item 1 of the scope of patent application, wherein the filter is a modified third-order comb-line filter (comb-line filter) 〇3, The multilayer bandpass filter capable of suppressing harmonics as described in item 1 of the scope of the patent application, wherein at least one component ground plane is used as a separation boundary area. 4. The multilayer bandpass filter capable of suppressing harmonics as described in item 1 of the scope of patent application, wherein the transmission line of the transmission end point is realized by a strip line (strip-1 ine). Page 14