JPH0613203U - Lumped constant type isolator and circulator - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] Used in the 200 to 500 MHz band to obtain small lumped constant type isolator and circulator. [Structure] Two ceramic substrates 1 and 2 having a dielectric constant εr of 90 or more are used, and the electrostatic capacitances formed on the ceramic substrates 1 and 2 are connected in parallel to the respective central conductors 9 and the The diameter is 3 mm or more and 6 mm or less.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a lumped constant type isolator and a circulator used in cordless phones, mobile phones, etc., which are used at 200 to 500 MHz.

[0002]

[Prior art]

 An example of a conventional lumped constant isolator is shown in FIG. In this conventional example, three core conductors 53 are folded into one ferrite core 51 in an insulated state, and the core conductors 53 are arranged in the holes of one ceramic substrate 54. It is connected to the capacitance forming electrode 55 formed on the above, and another ceramic substrate 56 and another ferrite core 52 are stacked thereon. A shield plate 57 is attached to the upper part of the ferrite core 52. These are arranged on the lower case 58 and covered with an upper case on which a magnet 59 and an iron plate 60 are mounted. Further, one of the capacitance forming electrodes 55 on the ceramic substrate is connected to the ground via the dummy resistor 62. FIG. 4 shows an exploded perspective view of another conventional lumped constant isolator. In this conventional example, one ceramic substrate 63 and one ferrite core 64 are configured. The ceramic substrate 63 is arranged on the lower case 65 and the holes formed in the ceramic substrate 63. , A ferrite core 64 provided with a central conductor 66 folded in an insulating state is arranged on the upper side of the ferrite core 64, and an upper case 68 having a magnet 67 mounted thereon is covered therewith.

[0003]

[Problems to be solved by the device]

 Conventional lumped-constant type isolators and circulators are generally used in the 800 MHz to several GHz band. However, there has been a new demand for lumped-constant isolators and circulators used in the 200 to 500 MHz band for cordless phones or mobile phones. When constructing a small lumped constant isolator and circulator for the 200 to 500 MHz band, the structure shown in FIG. 3 has a large number of parts, and there are problems in terms of man-hours and cost. It was difficult to make the structure compatible with low frequencies such as 200 to 500 MHz. An object of the present invention is to provide a lumped constant type isolator and a circulator used in the 200 to 500 MHz band, which are small in size.

[0004]

[Means for Solving the Problems]

 According to the present invention, a central conductor and a ferrite core, which are arranged in an insulated state from each other, are arranged in holes of two ceramic substrates, and a capacitance formed on the ceramic substrates is arranged in parallel with each of the central conductors. A lumped-constant isolator and a circulator to be connected to the ceramic substrate, wherein the ceramic substrate has a dielectric constant εr of 90 or more, an outer diameter of the ferrite core is 3 mm or more and 6 mm or less, and is used at 200 to 500 MHz. A constant type isolator and a circulator.

[0005]

[Action]

 In the present invention, by using a ceramic substrate having a dielectric constant εr of 90 or more, and by using two ceramic substrates and connecting the capacitances formed in parallel to each other, a large area can be obtained in a small area. Capacitance was made possible, and it was made possible to cope with the large capacitance required at a relatively low frequency of 200 to 500 MHz. Further, in the present invention, the outer diameter of the ferrite core is set to 3 mm to 6 mm, but if it is smaller than 3 mm, the characteristics of the lumped constant circuit become insufficient, and if it is larger than 6 mm, it is difficult to downsize the lumped constant isolator and circulator. . Therefore, the outer diameter of the ferrite core is set to 3 mm to 6 mm. At this time, the thickness of the ferrite core is 0. 6 mm to 1.0 mm was suitable. With this ferrite core and the above-mentioned ceramic substrate, a compact lumped-constant type isolator and circulator that can be used at 200 to 500 MHz could be constructed.

[0006]

【Example】

 An exploded perspective view of an embodiment according to the present invention is shown in FIG. In this embodiment, two ceramic substrates 1 and 2 having a dielectric constant εr of 110 are used. Electrodes 3 for forming capacitance are formed on the ceramic substrates 1 and 2, respectively. The electrode 3 is connected to the ground electrode 5 via the dummy resistor 4. A hole 7 into which the ferrite core 6 is inserted is formed in each of the ceramic substrates 1 and 2. This one ceramic substrate 1 is placed on the lower case 8, a ferrite core 6 having three central conductors 9 arranged in an insulated state is inserted into the hole 7, and another ceramic substrate 2 is overlaid. . The ferrite core 6 has an outer diameter of 5.1 mm and a thickness of 0.9 mm. Further, each center conductor 9 is connected to the electrodes 3 for forming electrostatic capacitance of the ceramic substrates 1 and 2. Then, the upper case 11 having the magnet 10 mounted thereon is covered. In this embodiment, the capacitance formed on each of the ceramic substrates 1 and 2 is connected in parallel to each central conductor. According to this example, insertion loss of 0.60 dB and isolation of 30 dB were obtained at 380 MHz. The characteristics of this embodiment are shown in FIG. In this embodiment, the outer size was 10 mm × 10 mm, which was extremely small.

[0007]

[Effect of device]

 According to the present invention, it is possible to configure a lumped-constant type isolator and a circulator used at a lower frequency of 200 to 500 MHz than before, and also to make it compact, which is effective for cordless phones or mobile phones.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an embodiment according to the present invention.

FIG. 2 is a characteristic diagram of an embodiment according to the present invention.

FIG. 3 is an exploded perspective view of a conventional example.

FIG. 4 is an exploded perspective view of another conventional example.

[Explanation of symbols]

 1, 2 Ceramic substrate 3 Electrode for capacitance formation 4 Dummy resistor 5 Ground electrode 6 Ferrite core 7 Hole 8 Lower case 9 Center conductor 10 Magnet 11 Upper case

Claims (1)

[Scope of utility model registration request] 1. A central conductor and a ferrite core, which are arranged in an insulated state from each other, are arranged in holes of two ceramic substrates, and the capacitance formed on the ceramic substrates is applied to each of the central conductors. A lumped-constant type isolator and a circulator connected in parallel, wherein the ceramic substrate has a dielectric constant εr of 90 or more, and the ferrite core has an outer diameter of 3 mm or more and 6 mm or less.
Lumped element type isolator and circulator characterized by being used at 500 MHz.