JPH0575309A - Dielectric filter - Google Patents

Abstract

PURPOSE:To enhance the mount efficiency of a printed circuit board by inserting an antenna to a coupling hole and forming the filter such that the neighboring of an open end of the hole is in contact with a conductor wire of the antenna when the antenna is used while being extended. CONSTITUTION:Plural holes are made in the direction of a height (h) to a hexahedron dielectric block 10 whose height (h) is nearly lambdag/4 with respect to an effective wavelength lambdag and the inner face of the holes 11, 12 and five sides except one outer face of the block are metallized. The transmission reception branching device filter 1 to which the metallized transmission filter 11 and the metallized reception filter 12 are integrated is provided with antenna coupling hollow holes 2 comprising holes used to couple the filter 11 and an antenna 20 whose inner side is metallized and whose one end is opened and holes used to couple the filter 12 and the antenna 20 whose inner side is metallized and whose one end is opened. Then the neighboring of the open end of the holes 2 is in contact with the conductor wire of the antenna 20 and the antenna 20 and the filter 1 are in continuity with each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connection structure for a filter of a transmitting / receiving duplexer of a portable radio telephone and an antenna coupling circuit for coupling an antenna of the filter.

[0002]

2. Description of the Related Art As shown in FIG. 4, a transmission filter TxFil of a transmission / reception duplexer of a conventional portable radio telephone and its antenna coupling circuit are connected to each other.
The common antenna terminal of RxFil and the filter for reception is connected to the antenna ANT via the wiring of the printed board and the antenna coupling fitting.
When the antenna was pulled out, it was connected to the antenna coupling circuit. As shown in FIG. 5, the internal structure of the filter of the transmission / reception duplexer of FIG. 4 is that each of the λg / 4 resonators for transmission and reception is connected to the open end by a metal wire that comes from a coupling capacitor C. Was connected to the antenna ANT by wiring on the printed board.

[0003]

The above-mentioned conventional technique is
Not only does the output loss of the transmitter and NF deterioration of the receiver occur due to transmission loss in the wiring that connects the filter consisting of each λ / 4 resonator for transmission and reception and the antenna ANT, and on the printed board. However, there is a problem that the mounting space of the printed board is wasted due to the wiring. The object of the present invention is to eliminate unnecessary wiring from the filter Fil of the transmission / reception demultiplexer to the antenna ANT, not to reduce the output of the transmitter or deteriorate the NF of the receiver, and to improve the mounting efficiency of the printed circuit board. It is to realize a dielectric filter having a structure in which a filter of a transmission / reception demultiplexer and an antenna coupling circuit thereof are integrated.

[0004]

According to the present invention for achieving this object, a filter Fil of a transmission / reception duplexer is connected to an antenna AN.
The antenna ANT is attached to the filter Fil by omitting unnecessary wiring to T.
The method of connecting directly is adopted. Therefore, as shown in the principle diagram of FIG. 1 showing the basic configuration of the present invention, a hexahedron dielectric block (10) having a height h of about λg / 4 of the effective wavelength λg of the transmitted / received signal.
A plurality of holes in the height h direction of each hole (11, 12)
A filter (1) for a transmission / reception duplexer in which a transmission filter (11) and a reception filter (12) are integrated by metallizing the inner surface of the block and the five surfaces except the outer surface of the block, and the transmission filter The inner surface is metalized and the one end is opened by the hole that connects the (11) and the antenna (20), and the inner surface is metalized and the one end is opened by the hole that connects the receiving filter (12) and the antenna (20). It has a hollow hole (2) for antenna coupling that shares the same hole with the
This is achieved by the structure of the present invention in which the vicinity of the open end of the hole (2) contacts the conductor wire of the antenna (20) when the antenna (20) is inserted and the antenna is extended and used.

[0005]

In the present invention, the filter 1 of the transmission / reception demultiplexer has a plurality of hexahedral blocks in which the height h of the dielectric block 10 is about λg / 4 of the effective wavelength λg of the transmission / reception signal in the height h direction. It is made by metallizing the inner surface of each hole 11 and 12 and the five surfaces except one surface of the outer surface of the block. The hole 2 for antenna coupling is a hollow hole in the height h direction of the dielectric block 10 like the holes 11 and 12 for the filter, and is a coupling circuit between the transmitting filter 11 and the antenna 20 (metallized inner surface). (Hole with one end opened), receiving filter 12 and antenna 20
It is commonly used in the same coupling circuit with and when the antenna 20 is inserted into the antenna coupling hole 2 and the antenna is extended and used, the vicinity of the open end of the coupling hole 2 is the conductor of the antenna 20. The antenna 20 and the filter 1 of the transmission / reception demultiplexer are electrically coupled and connected in contact with the line.

[0006]

2 (a) is a diagram showing mounting of a dielectric filter of a first embodiment corresponding to claim 1 of the present invention on a printed board, and FIG. 2 (b) is It is a figure which shows mounting of the dielectric filter of 2nd Example corresponding to Claim 2 and Claim 3 on the printed board. 3A is a structural diagram of a dielectric filter of a second embodiment corresponding to claim 2 of the present invention, and FIG. 3B is a third embodiment corresponding to claim 3. FIG. 3 is a structural diagram of the dielectric filter of FIG. The Tx Fil in the transmission filter hole 11 and the Rx Fil in the reception filter hole 12 of the transmission / reception demultiplexer of FIGS. 2 and 3 have a conventional height h of about λg of the effective wavelength λg of the transmission / reception signal. / 4 hexahedral dielectric block
10 holes, 3 holes each in the height h direction, and each hole 11,
A so-called TEM resonator is constructed by metallizing the inner surface of 12 and the five surfaces except one surface of the outer surface of the block. In this figure, the transmission filter Tx Fil and the reception filter Rx Fil each have a three-stage configuration, but basically no change is made in any number of stages. In FIG. 1 (b), the antenna 20 is inserted into the hole 2 for the coupling circuit.

In the second embodiment of FIG. 2B, the hole 2 for coupling the antenna 20 is arranged not at the center of the printed board but at the lateral end in consideration of mounting the entire circuit. In this embodiment, the hole 11 of the transmitting filter and the hole 12 of the receiving filter are bent around the hole 2 for the antenna insertion coupling circuit as shown in FIGS. 3 (a) and 3 (b). Thus, a space slit 3 or a dielectric-only region 4 is provided. In Fig. 3 (a), a slit 3 is provided to prevent mutual interference between the hole 11 of the transmission filter Tx Fil and the hole 12 of the reception filter Rx Fil, and this slit is used.
Mount the printed circuit board of the required circuit in 3. Of FIG.
In (b), not the slit 3 but the area 4 of only the dielectric is provided, and the area 4 of only the dielectric is provided with a plurality of holes 41 whose inner surface is metallized to short-circuit the transmission / reception filters 11 and 12. Mutual interference between the transmission filter 11 and the reception filter 12 can be prevented by providing the end faces in the direction of the open end with respect to the surface 13 and connecting the end faces of the plurality of holes 41 in the direction of the open end to each other.

[0008]

As described above, according to the present invention, the filter can be directly connected to the antenna without forming unnecessary wiring on the printed board from the filter of the transmission / reception duplexer to the antenna. The output power of the equipment and the NF of the receiver can be expected to improve. Also, since unnecessary wiring on the printed board is eliminated, the mounting efficiency of the printed board is improved, and the effect of making the portable radio telephone compact can be obtained.

[Brief description of drawings]

FIG. 1 is a principle diagram showing a basic configuration of a dielectric filter according to claim 1 of the present invention.

FIG. 2 is a diagram showing mounting of a dielectric filter of a first embodiment corresponding to claim 1 and a second embodiment corresponding to claims 2 and 3 of the present invention on a printed board.

FIG. 3 is a structural diagram of a dielectric filter of a second embodiment corresponding to claim 2 and a third embodiment corresponding to claim 3 of the present invention.

FIG. 4 is a connection diagram of a filter of a transmission / reception duplexer of a conventional portable radio telephone and its antenna coupling circuit.

FIG. 5 is an internal structure diagram of a filter of a conventional transmission / reception duplexer.

[Explanation of symbols]

1 is a filter of a transmission / reception demultiplexer, 2 is a hole for an antenna coupling circuit, 3 is a slit, 4 is an area of only a dielectric, 10 is a dielectric block, 11 is a hole of a transmitting filter, 12 is a receiving filter. A hole, 13 is a short-circuit surface of the transmission / reception filter, and 20 is an antenna.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masago Fukuda 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited (72) Inventor, Yasuyuki Kondo 1015, Kamedotachu, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited

Claims (3)

[Claims] 1. The height (h) is the effective wavelength (λg
) Of a hexagonal dielectric block (10) with a height of about 1/4
A transmission filter (11) and a reception filter (12) in which a plurality of holes are opened in the (h) direction and the inner surface of each hole (11, 12) and five surfaces except one surface of the outer surface of the block are metalized. A filter (1) for a transmission / reception demultiplexer in which the two are integrated with each other, a hole for connecting the transmission filter (11) and the antenna (20) with its inner surface metallized and one end open, and the reception filter (12 ) And antenna (2
(0) is provided with a hollow hole (2) for antenna coupling, which is common to the hole whose inner surface is metallized and whose one end is open, and the antenna (20) is provided in the coupling hole (2). A dielectric filter, characterized in that the vicinity of the open end of the hole comes into contact with the conductor wire of the antenna when the antenna is extended and used. 2. The transmitting filter (11) and the receiving filter (12) are bent around the antenna coupling hole (2) to provide a space slit (3), and the inner surface of the slit is formed. The dielectric filter according to claim 1, wherein the dielectric filter is metallized. 3. The transmission filter (11) and the reception filter (12) are bent around the antenna coupling hole (2) to provide an area (4) of only dielectric material, and the dielectric material (11) is provided. A plurality of holes (41) whose inner surface is metallized in the only area are provided in the direction of the open end from the short-circuit surface (13) of the transmitting / receiving filter (11, 12), and the plurality of holes (41) are 2. The dielectric filter according to claim 1, wherein the end faces in the direction of the open ends are connected to each other.