CN218416335U - Miniaturized LTCC band-pass filter with multiple transmission zeros - Google Patents

Abstract

The utility model discloses a miniaturized LTCC band pass filter with a plurality of transmission zeros, including integrated input inductance L1, coupling inductance L2, ground connection inductance L3, ground connection inductance L4, coupling inductance L5, output inductance L6, condenser C3, condenser C4 and condenser C5 on ceramic substrate, ceramic substrate still table pastes condenser C1 and condenser C2, and band pass filter sensor adopts symmetrical structure to connect. The utility model discloses with each inductor in symmetrical structure's the circuit, condenser C2, C3, C4 and C5 are integrated to ceramic substrate to surface mounting resonance electric capacity C1 at the substrate surface, when utilizing the LTCC technique to reduce the product size, the design increases a plurality of transmission zero points, further improves loss, bandwidth, selectivity isoelectric point index circuit of product, the reliability is better. Isoelectric properties.

Description

Miniaturized LTCC band-pass filter with multiple transmission zeros

Technical Field

The utility model relates to a miniaturized LTCC band pass filter with a plurality of transmission zero belongs to common mode filter inductor technical field.

Background

Electronic components are now widespread in various electronic devices, are the most basic parts of electronic devices, and have a decisive influence on the electronic devices and information systems. And with the higher integration level of electronic equipment, the market demand for miniaturization of electronic components cannot be resisted. Miniaturization of electronic devices is a future development direction and trend of the entire electronic device technology.

LTCC (low temperature co-fired ceramic) low temperature co-fired ceramic has become a mainstream technology for passive integration. The new material technology is that low temperature sintered ceramic powder is made into dense green ceramic tape with precise thickness, required circuit pattern is made on the green ceramic tape by means of laser drilling, micropore grouting, precise conductor slurry printing and other technological process, several passive components are embedded into multilayer ceramic base board and then laminated together, and the inner and outer electrodes are sintered at 900 deg.c with silver, copper, gold and other metal separately to form three-dimensional non-interfering high-density circuit or three-dimensional circuit base board with built-in passive elements.

A bandpass filter is an important passive component in microwave circuits, and is a device that allows waves in a particular frequency band to pass through while suppressing shielding in other frequency bands. Meanwhile, transmission zero points are added, so that the selective electric performance of the filter can be greatly improved. The design of miniaturized, high-performance, and high-reliability bandpass filters has become an important research and mainstream development direction today.

The traditional LC band-pass filter has large size and poor reliability in a 225MHz frequency band. The electric properties of loss, bandwidth, selectivity and the like can not meet the market demand gradually. Especially, the requirement for small size is higher and higher at present, and the size of the band-pass filter in the conventional technology is difficult to further reduce.

Disclosure of Invention

The to-be-solved technical problem of the utility model is: the miniaturized LTCC band-pass filter with the transmission zeros is provided to solve the problems in the prior art.

The utility model adopts the technical proposal that: the utility model provides a miniaturized LTCC band pass filter with a plurality of transmission zeros, including integrated input inductance L1 on the ceramic substrate, coupling inductance L2, ground inductance L3, ground inductance L4, coupling inductance L5, output inductance L6, condenser C3, condenser C4 and condenser C5, the ceramic substrate still table pastes condenser C1 and condenser C2, resonant capacitor C1 and ground inductance L3 are connect to coupling inductance L2 both ends, the middle tap of input output inductance L2, a condenser C4 is connected in parallel to input inductance L1 both ends, condenser C5 is connected in parallel to output inductance L6 both ends, ground inductance L3 connects gradually ground inductance L4 and output inductance L6, be connected with coupling inductance L5 between output inductance L6 and the ground inductance L4, ground connection between ground inductance L3 and the ground inductance L4, coupling inductance L2 and coupling inductance L5 are respectively through condenser C1 and condenser C2 ground connection, condenser C3 both ends are connected to LTCC band pass filter's input/output terminal.

The utility model has the advantages that: compared with the prior art, the utility model discloses with each inductor in symmetrical structure's the circuit, condenser C2, C3, C4 and C5 are integrated to the ceramic substrate to in the substrate surface table subsides resonance electric capacity C1 (surperficial black cuboid, as in fig. 1), when utilizing the LTCC technique to reduce the product size, the design increases a plurality of transmission zero points, further improves the loss, bandwidth, selectivity and other performance index circuit of product, and the reliability is better. Isoelectric properties.

Drawings

FIG. 1 is a diagram of an LTCC bandpass filter;

FIG. 2 is a circuit diagram of a filter;

FIG. 3 is a diagram of a filter simulation waveform;

FIG. 4 is a diagram of integrated inductors L1 and L2;

FIG. 5 is a diagram of integrated inductors L1 and L3;

FIG. 6 is a diagram of the inductors L1, L2, L3 connecting vias;

FIG. 7 is an integrated capacitor C2 diagram;

fig. 8 is an integrated capacitor C3 diagram.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and specific embodiments.

Example 1: as shown in fig. 1 to 8, a miniaturized LTCC band pass filter with multiple transmission zeros includes an input inductor L1, a coupling inductor L2, a ground inductor L3, a ground inductor L4, a coupling inductor L5, an output inductor L6, a capacitor C3, a capacitor C4 and a capacitor C5 integrated on a ceramic substrate, the ceramic substrate is further attached with the capacitor C1 and the capacitor C2, two ends of the coupling inductor L2 are connected to the resonant capacitor C1 and the ground inductor L3, the input and output inductors are connected to a center tap of the coupling inductor L2, two ends of the input inductor L1 are connected in parallel to the capacitor C4, two ends of the output inductor L6 are connected in parallel to the capacitor C5, the ground inductor L3 is sequentially connected to the ground inductor L4 and the output inductor L6, the coupling inductor L5 is connected between the output inductor L6 and the ground inductor L4, the ground inductor L3 and the ground inductor L4 are connected to the ground, the coupling inductor L2 and the coupling inductor L5 are respectively connected to the input and the output of the LTCC band pass filter, and two ends of the capacitor C3 are connected to the input and output terminals of the LTCC band pass filter.

The L1 and L6 inductors are standing waves of the input and output adjustable filter of the filter, the L2 and L5 inductors generate coupling to form the center frequency of the resonance adjustable filter with the capacitors C1 and C2, and the L3 and L4 inductors are grounded to adjust the loss of the filter. The input end and the output end of the parallel capacitor C3 can generate a zero point and a zero point respectively, and the performance index of the filter can be improved. The capacitors C4 and C5 connected in parallel with L1 and L6 can generate a second zero point at the right end to improve the performance index of the filter.

As shown in the following figure 1, the low temperature co-fired ceramic (LTCC) technology is adopted, a circuit adopts a symmetrical structure on a 225MHz frequency band, traditional inductors L1, L2 and L3 and capacitors C2 and C3 are integrated into a ceramic substrate, a resonant capacitor C1 (a black cuboid on the surface) is attached to the surface of the substrate, the LTCC technology is used for reducing the size of a product, meanwhile, a plurality of transmission zero points are designed and added, the electrical performance index of the product is further improved, a circuit diagram of a filter is shown in the following figure 2, and a simulation waveform is shown in the following figure 3.

1. The integrated inductor of the band-pass filter adopting the LTCC process has three symmetrical inductors, namely an input-output inductor L1, a coupling inductor L2 and a grounding inductor L3, wherein two ends of the coupling inductor are connected with a resonant capacitor C1 and the grounding inductor L3 of an LTCC substrate. The input and output inductors are connected with the middle tap of the coupling inductor L2, as shown in FIG. 4 and FIG. 5. They are connected by vias as in figure 6,

2. the integrated capacitor C2 of the band-pass filter adopting the LTCC process has two ends respectively connected to two ends of the input and output inductor L1 in parallel, and can generate a transmission zero at the right end, as shown in fig. 7.

3. An integrated capacitor C3 of the band-pass filter adopting the LTCC process, wherein two ends of the capacitor are respectively connected to the input inductor L1 and the output inductor L1, so as to generate a transmission zero point on the left and right, as shown in fig. 8.

The above description is only the specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art can easily think of the changes or substitutions within the technical scope of the present invention, and all should be covered within the protection scope of the present invention, therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims (1)

1. A miniaturized LTCC band pass filter with a plurality of transmission zeros, characterized in that: the low-temperature co-fired ceramic band-pass filter comprises an input inductor L1 integrated on a ceramic substrate, a coupling inductor L2, a grounding inductor L3, a grounding inductor L4, a coupling inductor L5, an output inductor L6, a capacitor C3, a capacitor C4 and a capacitor C5, wherein the capacitor C1 and the capacitor C2 are further attached to the surface of the ceramic substrate, two ends of the coupling inductor L2 are connected with the resonant capacitor C1 and the grounding inductor L3, the input inductor and the output inductor are connected with a middle tap of the coupling inductor L2, two ends of the input inductor L1 are connected with the capacitor C4 in parallel, two ends of the output inductor L6 are connected with the capacitor C5 in parallel, the grounding inductor L3 is sequentially connected with the grounding inductor L4 and the output inductor L6, the coupling inductor L5 is connected between the output inductor L6 and the grounding inductor L4, the grounding inductor L3 and the grounding inductor L4 are grounded, the coupling inductor L2 and the coupling inductor L5 are respectively grounded through the capacitor C1 and the capacitor C2, and two ends of the capacitor C3 are connected to the input end and the output end of the LTCC band-pass filter.

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