JP3155449B2 - Multi-band antenna duplexer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-band antenna duplexer, and more particularly to a multi-band antenna duplexer suitable for use in a relay device of a portable telephone system.

[0002]

2. Description of the Related Art In an analog cellular phone system,
The 870-885 MHz band is used for downlink from the base station to the slave station, and the 925-940 MHz band is used for uplink from the slave station to the base station. In a relay amplifier or the like for improving communication in a blind spot where radio wave propagation between a base station, a slave station, and a base station is large, the antennas for the downlink and uplink are shared by one antenna. Therefore, an antenna duplexer is used for this purpose.

FIG. 3 shows an example of the configuration of an antenna duplexer in an equivalent circuit diagram. In this example, the resonators 310 to 310
314, a five-stage bandpass filter composed of coupling capacitors 321 to 324 and matching capacitors 331 and 332, and resonators 315 to 319, coupling capacitors 325 to 328 and matching capacitors 333 and 3
34 is composed of five pole bandpass filter constituted by, respective band-pass filter includes a uplink signal passing through the upstream terminal T _U and the antenna terminal T _A, passes through the downstream terminal T _D and the antenna terminal T _A This is to separate the signal from the downlink signal.

On the other hand, in a digital cellular phone system, a band of 810 to 818 MHz is used for downlink and a band of 940 to 948 MHz is used for uplink. Even in the case of this digital system, a base station or the like uses an antenna duplexer similar to that shown in FIG.
The antenna is shared.

[0005] By the way, there are areas where the analog system and the digital system coexist, and in such an area, when a relay amplifier for the above-mentioned blind spot is installed, if the main body of the relay amplifier is shared, miniaturization and economical operation are possible. Can be achieved. For this purpose, a multi-band antenna duplexer having a function of combining one or both of the two types of downlinks and uplinks into one terminal and having a function of separating the downlink and uplink of each type is required.

FIG. 4 shows a conventional configuration example of the above-described multi-band antenna duplexer.
And 42 are the common antenna duplexers shown in FIG. The antenna terminals T _A1 and T _A2 of each antenna duplexer are connected to analog and digital antennas, respectively, and the uplink terminals T _U1 and T _U2 are connected to uplink relays of each type. . On the other hand, the downlink terminals T _D1 and T _D2 of the two antenna duplexers are connected to one downlink common terminal via λ / 4 transmission lines 43 and 44 having lengths determined according to the respective frequency bands used in the two systems. Connected to T _DC .
This insertion of the λ / 4 transmission line is for compensating for a change in the matching condition that occurs when two antenna duplexers are connected, and for separating the two antenna duplexers. In this way, a relay amplifier for two systems can be connected to the downstream common terminal T _DC .

Although the above-mentioned multi-band antenna duplexer has a common down terminal, the same applies to a common up terminal or both down and up.

[0008]

In the above-mentioned prior art, a λ / 4 transmission line is used at the connection between the antenna duplexers. As this transmission line, a semi-rigid cable having a length of several centimeters or the like is used to reduce the loss as much as possible. However, this is difficult to bend and requires a space for routing. In addition, such a cable connection causes an increase in the number of parts and assembling time, such as the need to attach a connector to the cable terminal and a junction box for receiving the connector. It was difficult to make a compact structure that was integrated.

It is an object of the present invention to provide a multi-band antenna duplexer which requires a small number of parts and assembling time, and is compact and inexpensive.

[0010]

According to the present invention, a first downlink signal of a first frequency band transmitted / received via a first antenna is connected to a downlink terminal thereof and transmitted / received via the first antenna. A first antenna duplexer for connecting a first uplink signal of the second frequency band to the uplink terminal thereof;
A second downlink signal of a third frequency band transmitted and received via the second antenna is connected to its downlink terminal, and a second uplink signal of the fourth frequency band transmitted and received via the second antenna is transmitted. A multi-band antenna duplexer configured by using the second antenna duplexer for connecting to the upstream terminal, providing one common terminal, and connecting the downlink terminal of the first antenna duplexer to the common terminal. And a terminal connected through a first capacitor, and a downstream terminal of the second antenna duplexer connected via the common terminal and a second capacitor. Disclose.

[0011]

In place of the conventional λ / 4 transmission path, the value of the matching capacitor of the duplexer originally used, and
When the resonance frequency of the resonator attached to the matching capacitor side is viewed from the common terminal connected to it, the value of the matching state is changed so that the impedances of the bands of the other party become ∞. is there. This eliminates the need for a λ / 4 wavelength transmission line, and enables downsizing, integration, reduction in the number of components, and cost reduction.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to embodiments. FIG. 1 shows an embodiment of a multi-band antenna duplexer according to the present invention. As in the conventional example of FIG. 4, only the downstream common terminal T _DC is common, and the upstream terminals are different terminals T _U1 and T _U2 , respectively. The difference from the conventional FIG. 4 is that the values of the capacitors 13, 14 and the resonators 15, 16 are changed in place of the λ / 4 transmission lines 43, 44 in FIG. ,
The point is that the antenna duplexers 11 and 12 are connected. Therefore, the configurations of the antenna duplexers 11 and 12 themselves are not different from those of the related art.

Conventionally, the use of a λ / 4 transmission line is to adjust the impedance at the terminals so that the impedance of the other band becomes ∞ in order to eliminate mutual interference between the filters. is there. In the present invention, the values of the capacitors 13 and 14 and the resonators 15 and 16 are set such that the impedance of the partner band becomes ∞ in the frequency band of each other from the value of the single resonator. This is achieved by setting a value.

According to this embodiment, the capacitor is small and inexpensive, and can be mounted very easily by soldering. In each antenna duplexer, only the value originally configured is changed. Thereby, the whole can be easily formed into an integrated structure. Furthermore, in this integrated structure, the number of parts does not increase at all, and the assembling work can be greatly reduced.

FIG. 2 is a block diagram showing another embodiment of the multi-band antenna duplexer according to the present invention, in which terminals are shared for both downlink and uplink. That is, antenna duplexer 2
Reference numerals 1 and 22 denote ordinary antenna duplexers similar to those shown in FIG. 3, and their downstream terminals T _D1 and T _D2 are combined into one downstream common terminal T _DC via capacitors 23 and 24 and further upstream. Terminals T _U1 and T _U2 are also integrated as one upstream common terminal T _UC via capacitors 25 and 26. Here, the capacitors 23 to 26 are capacitors that are used for both matching and connection.

According to the present embodiment, as in the case of FIG.
This has the effect of reducing the number of parts, shortening the assembly time, reducing the cost, and facilitating integration. Then, a common repeater of an analog and digital system can be connected and used in both the up direction and the down direction. Note that it is easy to share only the upstream terminal by the configuration similar to that of FIG.

[0017]

According to the present invention, it is possible to realize a multi-band antenna duplexer which requires a small number of parts and requires a short assembling time, is low in cost, and can be easily integrated.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of a multi-band antenna duplexer according to the present invention.

FIG. 2 is a configuration diagram showing another embodiment of the multi-band antenna duplexer according to the present invention.

FIG. 3 is an equivalent circuit diagram illustrating a configuration example of a normal antenna duplexer.

FIG. 4 is a diagram illustrating a configuration example of a conventional multi-band antenna duplexer.

[Explanation of symbols]

 11, 12, 21, 22 Antenna duplexer 13, 14 Capacitor 15, 16 Resonator 23-26 Capacitor 310-314 Resonator 315-319 Resonator 321-324 Coupling capacitor 325-328 Coupling capacitor 331-334 Matching Capacitor

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-63-206016 (JP, A) JP-A-6-188622 (JP, A) JP-A-64-71222 (JP, A) JP-A-6-206 237101 (JP, A) JP-A-1-298804 (JP, A) JP-A-54-170749 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H03H 7/46 H04B 1 / 48 H04B 7/26

Claims (3)

(57) [Claims] 1. A first downlink signal of a first frequency band transmitted / received via a first antenna is connected to its downlink terminal, and a first downlink signal of a second frequency band transmitted / received via the first antenna is connected to the first terminal. A first antenna duplexer for connecting one uplink signal to its uplink terminal, and a second downlink signal of a third frequency band transmitted and received via a second antenna connected to its downlink terminal; A second antenna duplexer for connecting a second uplink signal of a fourth frequency band transmitted and received via the second antenna to its uplink terminal; and a multi-band antenna duplexer configured using: One common terminal is provided, and the downstream terminal of the first antenna duplexer is connected to the common terminal via a first capacitor, and the downstream terminal of the second antenna duplexer is connected to the common terminal and the second terminal. Conde Antenna duplexer for multi-band, characterized in that formed by connecting via the service. 2. A first downlink signal of a first frequency band transmitted / received via a first antenna is connected to its downlink terminal, and a first downlink signal of a second frequency band transmitted / received via the first antenna is connected. A first antenna duplexer for connecting one uplink signal to its uplink terminal, and a second downlink signal of a third frequency band transmitted and received via a second antenna connected to its downlink terminal; A second antenna duplexer for connecting a second uplink signal of a fourth frequency band transmitted and received via the second antenna to its uplink terminal; and a multi-band antenna duplexer configured using: One common terminal is provided, the upstream terminal of the first antenna duplexer is connected to the common terminal via a first capacitor, and the upstream terminal of the second antenna duplexer is connected to the common terminal and the second terminal. Conde Antenna duplexer for multi-band, characterized in that formed by connecting via the service. 3. A first downlink signal of a first frequency band transmitted / received via a first antenna is connected to a downlink terminal thereof, and a second downlink signal of a second frequency band transmitted / received via the first antenna is connected. A first antenna duplexer for connecting a first uplink signal to its uplink terminal; connecting a second downlink signal of a third frequency band transmitted and received via a second antenna to its downlink terminal; A second antenna duplexer for connecting a second uplink signal of a fourth frequency band transmitted / received via the second antenna to an uplink terminal thereof; , A first and a second common terminal are provided, and a downstream terminal of the first antenna duplexer is connected to the first common terminal via a first capacitor; Connect the downstream terminal to the first A common terminal is connected via a second capacitor, an upstream terminal of the first antenna duplexer is connected via the second common terminal via a third capacitor, and an upstream terminal of the second antenna duplexer is connected. A multi-band antenna duplexer comprising terminals connected to the second common terminal via a fourth capacitor.