JPS59221018A - Composite lc filter - Google Patents

Abstract

PURPOSE:To simplify the manufacturing process and to reduce the production cost by forming capacitor blocks of >=2 LC filters on a sheet of dielectric substrate and using a common electrode at the earth sides of LC filters. CONSTITUTION:The plus side earth electrodes 2 and 3 of capacitors C1 and C2 of an LPF-A and a common electrode 6 of capcitors C3-C5 of a BPF-B are printed on the surface of a dielectric substrate 10. While an earth side common electrode 11 between an earth side common electrode of the capacitors C1 and C2 and an earth side electrode of a capacitor C5 is printed on the rear side of the substrate 10 together with plus side electrodes 7 and 8 of capacitors C3 and C4 respectively. A coil L1 of the LPF-A is connected between electrodes 2 and 3, and a coil L2 of the BPF-B is connected between electrodes 6 and 11. Then lead- out terminals a, b, c (f), d and e are connected to electrodes 2, 3, 11, 7 and 8 respectively. Thus terminals (a) and (b) serve as the input and output terminals of the LPF-A respectively. The terminals (d) and (e) serve as the input and output terminals of the BPF-B. While a terminal c(f) functions as a common earth terminal of both filters.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a composite LC filter in which two or more LC filters are included in one panpackage.

(Prior art) - Generally, LC filters include low-pass filters, high-pass filters, and i? There are many types of filters such as bandpass filters and bandstop filters.

A conventional low-pass filter has, for example, the circuit configuration shown in FIG. 1 (A), and is configured like the 11th sword (B).

In Figures 1 (a) and (b), the + side electrode 2 of capacitor C1 and the + side electrode 3 of capacitor C2 are printed on the surface (front side of the page) of one dielectric substrate l, and the dielectric substrate The capacitor C and the ground-side common electrode 4 of the capacitor C2 are printed on the back side of 1 (on the front side of the paper).

Then, the positive side of capacitor C1, pole 2 and capacitor C
A coil L is connected between the + side electrode 3 of 2, and further,
External lead terminals a, b, and c are connected to the + side electrodes 2 and 38 and the ground side common electrode 4, respectively, where a is an input terminal, b is an output terminal, and C is a ground terminal.

Further, a conventional bandpass filter has, for example, the circuit configuration shown in FIG. 2(A) and is configured as shown in FIG. 2(B). In the 21st peeling (a) and (b), one dielectric-L substrate 5
The common electrode 6 of capacitor C3, capacitor C7+, and capacitor C5 is printed on the surface of the capacitor C3, and the + side 11 of capacitor C3 [pole 7 and capacitor C4] is printed on the back surface of dielectric substrate 5.
The + side electrode 8 of the capacitor C5 and the ground side electrode 9 of the capacitor C5 are printed.

Then, the common electrode 6 and the ground side electrode 9 of the capacitor C5
A coil L2 is connected between them, and the + side electrodes 7 and 8 and the earth side electrode 9 have external lead terminals -d, e, and
f is connected, d is an input terminal, e is an output terminal f, and f is a ground terminal.

For example, when such low-pass filters and bandpass filters are used in signal processing circuits for televisions and VTRs, the signal processing systems are usually different, so conventionally, two or more LC filters such as low-pass filters and bandpass filters are used. Each filter was manufactured separately and shipped separately to the signal processing system customer. Therefore, when two or more LC filters are used in a conventional signal processing circuit, etc., the manufacturing cost is high because the LC filters are manufactured individually, and for example, when applying exterior dip painting, individual dip painting is required. ,
There was a problem in that both I and I had to do it individually.

(1-1 of 1-1) This invention is an attempt to solve such conventional problems, and by combining two or more 1- LC filters into one pangeage, it simplifies the manufacturing step 1. Reduces manufacturing costs, requires only one dip coating, and only one telegraph connection to signal processing circuits, etc.
We aim to provide composite LC filters that require only
1 target.

(Structure of the Invention) Therefore, the feature of the composite LC filter of the present invention is that each capacitor block of two or more LC filters is formed on one dielectric substrate, and the ground side tw 8 of each LC filter is
The reason lies in the fact that the i is the same.

(Example) Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIGS. 3(A) and 3(B) are a circuit diagram and a configuration diagram, respectively, in the case where two LC filters are combined as an example of the composite type LC filter of the first embodiment. In the figure, A corresponds to the low-pass filter shown in FIGS. 1(a) and 2(b), and B corresponds to the bandpass filter shown in FIGS. 2(a) and 2(b).

On the surface of one dielectric substrate 10, the + side electrodes 2 and 3 of the capacitors C1 and C2 of the low-pass filter A, and the capacitors C3, C, , C of the bandpass filter B.

A common type 8i6 is printed, and on the back side there is a ground side common electrode 11 that shares the ground side common electrode of the capacitors C1 and 02 of the low-pass filter A and the ground side common electrode of the capacitor C5 of the bandpass filter B. The + side electrodes 7 and 8 of capacitors C-I and C4 of bandpass filter B are printed.

The coil L1 of the low-pass filter A is connected between the + side electrodes 2 and 3 of the capacitors C1 and C2, and the coil L2 of the bandpass filter B is connected between the common electrode 6 and the earth side common electrode II. Then, + side' city poles 2 and 3, earth side common terminal %
11, + side electrodes 7 and 8 respectively have external lead terminals a
, b, c (f), d, and e are connected, a and b are the input terminal and output terminal of low-pass filter A, respectively. (
f) is the common ground terminal of low-pass filter A and band-pass filter B. Below-1 is an example in which two LC filters, low-pass filter A and band-pass filter B, are combined, but three LC filters u-1 ，
Similarly, when combining LC filters, it is possible to form each capacitor block of each LC filter on one dielectric substrate and make the ground side pole of each L'C filter common. It should be obvious. In addition, multiple LC
The filters are not electrically connected to each other.

(Effects of the Invention) As explained above, according to the composite LC filter of the present invention, each capacitor block of two or more LC filters is formed on one dielectric substrate, and the capacitor blocks of each LC filter are Since the earth side electrode is shared and the L package is used, there is no need to test the winding height of the coil and the characteristics of each LC filter σ for two or more other than the number of LC filters to be combined. Compared to the case where LC filters are individually manufactured and ordered, the following various effects can be obtained.

That is, (1) 1 takt time is required for the production, reducing manufacturing costs.

(2) Only one transparent C body substrate is required.

(3) The electrode purification 1 of the rTi[l:% plate only needs to be applied once.

(4) Only one ground terminal is required, reducing the number of lead terminals.

(5) Miniaturized.

(6) Reduction in equipment used such as signal processing circuits (= J x L number will be removed).

(7) Installation space can be narrowed down.

(8) Management costs as parts are also reduced.

(9) The above effect becomes more significant as the number of LC filters to be combined increases.

[Brief explanation of drawings]

Figures 1 (a) and (b) are a circuit diagram and a configuration diagram of a conventional low-pass filter, respectively, Figures 2 (a) and (b) are a circuit diagram and a configuration diagram of a conventional bandpass filter, respectively, and Figure 3 (a) and (b) are the composite form L of this invention, respectively.
3 is a circuit diagram and a configuration diagram of an example of a C filter. FIG. A...Low pass filter, B...Band filter, C3~
C2...Capacitor, L, L2...Coil, 2゜3...+ side electrode, 6...Common electrode, 7,8...+
side electrode, 10... dielectric body board, 11... earth side common terminal, a, d... input terminal, b, e... output terminal, C(f)... common Earth terminal. 18th cb Figure 2 (a)
(B)de Figure 3 (B)

Claims (1)

[Claims] A composite LC filter in which capacitor blocks of two or more LC filters are formed on one dielectric substrate, and each LC filter has a common ground electrode.