KR100882102B1 - Gsm front-end module - Google Patents

Abstract

A GSM(Global Systems for Mobile communication) front-end module is provided to implement a band pass filter and a switching device on a substrate in a multi-chip module structure. A GSM front-end module(20) comprises the followings: the first multichip module(21) which switches transmission signals and receipt signals according to the time to separate the signals by having a plurality of diodes which are arranged in a multi-chip module structure; the second multichip module(22) which prevents a transmission signal transmitted from a transmission circuit from being detoured/inputted to a receiving circuit as removing the harmonic component of a received signal. In a passive element part(23), passive elements such as a resistor, inductor and capacitor forming the GSM front-end module are arranged on a substrate(24) in a multichip module type.

Description

GSM Front-End Module

The present invention relates to a GSM front end module, and more particularly, in a switching device used to separate a transmission call and a hand signal during RF communication, a band pass filter and a switching device are mounted on a substrate in a multi-chip module structure to arrange elements. The present invention relates to a GSM front end module that can improve efficiency and simplify the production process.

Recently, with the development of mobile communication systems, mobile communication devices such as mobile communication terminals and PDAs are rapidly spreading.

Among these mobile communication devices, in particular, the GSM (Global Systems for Mobile communication) terminal system is a system for transmitting and receiving signals of different frequency bands in a variety of directions from 800 MHz to 1 GHz or 1.5 GHz to 2.0 GHz. Is being provided.

In general, in such a GSM terminal system, a transmitting system and a receiving system share one antenna. In this case, a switch circuit is inserted between the antenna, the transmission system, and the reception system, and the switch circuit serves to separate and switch over time the transmission signal to the antenna and the reception signal from the antenna.

That is, in the terminal system configured as described above, the amplified transmission signal generated by the transmission circuit is transmitted to the antenna via the switch circuit when transmitting, is radiated to the air by the antenna as a radio wave signal, and is received by the antenna upon reception. The RF signal is supplied to the receiving circuit of the receiving system via the switch circuit.

1 is a block diagram schematically showing the components of a conventional GSM terminal system.

Referring to FIG. 1, a conventional GSM terminal system 10 includes an antenna 11, a duplexer 12, first and second RF switches 13a and 13b, and first and second surface acoustic wave (SAW) filters ( 14a, 14b) and first and second low pass filters 15a, 15b. This example deals with the dual band case.

First, the signal received at the antenna 11 is divided into a DCS / PCS signal of a high frequency band and a GSM signal of a low frequency band by the diplexer 12, each of which is divided into a first RF switch and a second RF switch. Signals out of a predetermined range are removed by the 13a and 13b and the first and second SAW filters 14a and 14b and transmitted to the receiving end Rx. In this case, the first and second RF switches 13a and 13b perform a function of separating and connecting a transmission path and a reception path in each band.

On the other hand, the signals of each band transmitted from the transmitter Tx are first and second RF switches 13a opposite to the paths through which harmonic components are removed by the first and second low pass filters 15a and 15b to receive the signals. 13b) and through the diplexer 12 are radiated to the outside by the antenna.

The RF switches 13a and 13b included in the conventional GSM terminal system 10 are manufactured by arranging each individual element necessary for realizing the characteristics at appropriate intervals on the substrate, and miniaturizing and internally arranging the module. In order to simplify the structure, a method of reducing the number or size of devices disposed or reducing device spacing is used.

However, this method has a limitation in miniaturizing the module and simplifying the manufacturing process of the module, and thus requires a technology for more efficient device placement.

The present invention is to solve the above problems, an object of the present invention is a switching device used for separation of a transmission call and a hand signal during RF communication, the band pass filter and the switching device to the substrate in a multi-chip module structure The solution is to provide a GSM front-end module that can be mounted to improve device placement efficiency and simplify the production process.

In order to achieve the above object, a preferred embodiment of the present invention,

A first multi-chip module disposed in a first region on the substrate, the first multi-chip module having a plurality of diodes for switching and separating transmission and reception signals over time, and a second region on the substrate; A second multi-chip module having a plurality of bandpass filters to selectively pass signals of a desired frequency band among the received signals separated by one multi-chip module, and the first and second multi-chips in a third region on the substrate; It is arranged to be electrically connected to the module, and provides a GSM front-end module including a passive element unit provided in the form of a multi-chip module having one or more resistors, inductors and capacitors, respectively.

In this case, the bandpass filter is preferably a surface acoustic wave (SAW) filter.

In addition, the first multi-chip module is preferably disposed in the center of the substrate in terms of process efficiency.

Preferably, the method may further include one or more resistors, inductors, and capacitors embedded in the substrate.

In this case, the substrate is preferably a printed circuit board (PCB) or low temperature cofired (LTCC) substrate.

The apparatus may further include a low pass filter (LPF) for removing harmonic components of the transmission signal transmitted to the first multi-chip module.

As described above, according to the present invention, in a switching device used for separation of a transmission call and a hand signal during RF communication, a band pass filter and a switching device are mounted on a substrate in a multi-chip module structure to improve device arrangement efficiency and production. It is possible to provide a GSM front end module that can simplify the process.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

However, embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. In addition, embodiments of the present invention is provided to those skilled in the art to more fully describe the present invention. Accordingly, the shape and size of elements in the drawings may be exaggerated for clarity, and the elements denoted by the same reference numerals in the drawings are the same elements.

2 is a top view illustrating a GSM front end module according to an embodiment of the present invention.

In this embodiment, the GSM front end module 20 includes a substrate 24, first and second multichip modules 21 and 22 disposed on the substrate 24, and a passive element unit 23. do.

In the present specification, a front end module (FEM) is a transmitting / receiving device that controls radio signals used on a mobile communication terminal, and various electronic components are serially implemented on a single board so that an integrated space thereof is defined. Means a minimized composite part.

The substrate 24 on which the respective modules are disposed is a substrate suitable for high frequency communication, and a printed circuit board (PCB) or a low temperature co-fired (LTCC) substrate, which may be generally employed, may be used.

In the present exemplary embodiment, the first and second multi-chip modules 21 and 22 may be disposed on the substrate 24, and although not illustrated, a resistor having an appropriate size may be provided inside the substrate 24. Passive devices such as inductors, capacitors, and the like may be embedded, and the embedded devices may form a low pass filter or a matching circuit.

The first multi-chip module 21 performs a switching function, that is, a function of switching and separating a transmission signal and a reception signal according to time, and has a structure in which a plurality of diodes are provided in the form of a multi-chip module.

A single switching device included in the first multi chip module 21 will be described in more detail with reference to FIG. 3.

3 is an equivalent circuit diagram schematically illustrating components of a single switching device included in the first multi-chip module 21.

Referring to FIG. 3, the switching device constituting the first multi-chip module 21 is a transmission signal transmitted from the transmitting end Tx to the antenna 11 and the antenna 11 coming in to the receiving end Rx as described above. The received signal to be transmitted is separated by an appropriate control signal.

Specifically, in the transmission mode, the first and second diodes D1 and D2 are turned on by applying a positive voltage using the control power supply Vs, and thus, in the transmission terminal Tx. The transmitted signal passes through a low pass filter (not shown) to the antenna 11.

In this case, since the first diode D1 is turned on to cause the grounding effect, it is possible to block transmission of the transmission signal to the receiving end Rx.

In addition, the quarter wave line L1 acts like an impedance transformer so that when one end is grounded, the other end appears to be open, thereby transmitting a signal from the transmitting end Tx to the receiving end Rx. It is a function to block the operation.

It will be apparent to those skilled in the art that other well-known switching circuits capable of separating transmission / reception signals may be employed in addition to the switching device such as the equivalent circuit diagram of FIG. 3 described in the present embodiment.

The first multi-chip module 21 is a structure in which a plurality of chips are provided in one module form, and includes a switching device as shown in FIG. 3 as many as the number of bands used for RF communication. That is, it may be understood that two switching devices are included in the multi-chip module in the case of the dual band, and four switching devices in the quad band.

On the other hand, as shown in Figure 2, the first multi-chip module 21 is disposed in the central region of the substrate 24 can provide a high efficiency during the surface mount process (SMT), more details about this Will be described later.

As not shown in FIG. 3, a low pass filter for removing harmonics of a signal transmitted from the transmitter Tx may be employed in the form of a circuit shown in FIG. 4.

As shown in FIG. 4, the low pass filter 41 is disposed between the transmitting end Tx and the switching device described in FIG. 3 to remove a harmonic signal from the amplified signals transmitted from the transmitting end Tx. do. The equivalent circuit diagram of FIG. 4 shows a lowpass filter 41 that can generally be employed, and other lowpass filters may be employed that can perform the same function.

Meanwhile, the low pass filter 41 may be implemented by the passive element unit 23 in the GSM front end module 20 illustrated in FIG. 2 and electrically connected to the first multi chip module 21. Alternatively, in the case of another embodiment, although the low pass filter 41 is not shown, it may be implemented by passive elements embedded in a PCB substrate or an LTCC substrate.

Referring to FIG. 2, the second multi-chip module 22 may include a surface elastic filter in which a part of the transmission signal from the transmission circuit does not bypass the reception circuit and includes a reception signal from the antenna. It removes harmonics. In this case, as in the case of the first multi-chip module 21 described above, the second multi-chip module 22 is mounted with the number of surface elastic filters in the form of a multi chip in the required number of bands.

The passive element unit 23 is a passive element such as resistors, inductors and capacitors constituting the GSM front end module is disposed on the substrate 24 in the form of a multi-chip module.

In this case, passive elements may be selected according to the number and arrangement of structures required for constituting the module, and as shown in FIG. 2, a plurality of multi-chip modules made of passive elements may be arranged on the substrate 24. have. In addition, although not shown, the entire passive element may be arranged in the form of one multi-chip module.

As described above, the passive element part 23 may include a low pass filter.

As such, in the case of the GSM front end module 20 according to the present embodiment, since each module disposed on the substrate 24 is provided in a multi-chip form, it is possible to reduce the inconvenience and inefficiency of mounting individual elements on the substrate one by one. have.

That is, in the present embodiment, the first multi-chip module 21 provided as the switching device, the second multi-chip module 22 and the passive element unit 23 performing the filter function perform a plurality of common functions. Since the device is provided in the form of one module, it is possible to provide the effect of mounting a plurality of individual devices at once.

As a result, in the case of the present embodiment, the number of steps for surface-mounting each element on the substrate can be greatly reduced as compared with the prior art.

Furthermore, the GSM front end module 20 may improve the efficiency of the device arrangement structure by disposing the first multi-chip module 21 having a plurality of diodes in a central region of the substrate 24.

Accordingly, in the surface mounting process in which the GSM front end module 20 is arranged to connect with other modules such as a power amplification module, the GSM front end module 20 may be absorbed while maintaining a balance on a pick up nozzle. The surface mount process can be performed without a case.

The present invention is not limited by the above-described embodiment and the accompanying drawings, but is intended to be limited by the appended claims. Accordingly, various forms of substitution, modification, and alteration may be made by those skilled in the art without departing from the technical spirit of the present invention described in the claims, which are also within the scope of the present invention. something to do.

1 is a block diagram schematically showing the components of a conventional GSM terminal system.

2 is a top view illustrating a GSM front end module according to an embodiment of the present invention.

3 is an equivalent circuit diagram schematically illustrating components of a single switching device included in a first multi-chip module.

4 is an equivalent circuit diagram of a lowpass filter included in the GSM front end module according to the present embodiment.

<Description of the symbols for the main parts of the drawings>

11: antenna 21: first multi-chip module

22: second multi-chip module 23: passive element

41: Lowpass Filter

Claims (6)

Board; A first multi-chip module disposed in the first region on the substrate and having a single module structure having a plurality of diodes for switching and separating transmission and reception signals over time; A second module disposed in a second region on the substrate and having a one-module structure including a plurality of band pass filters to selectively pass signals of a desired frequency band among the received signals separated by the first multi-chip module; Multi-chip module; And A passive element unit disposed in the third region on the substrate to be electrically connected to the first and second multi-chip modules, and having at least one resistor, an inductor, and a capacitor, each of which is provided in the form of a multi-chip module; GSM front end module comprising a. The method of claim 1, And said bandpass filter is a surface acoustic wave (SAW) filter. The method of claim 1, And the first multi-chip module is disposed at the center of the substrate. The method of claim 1, And at least one resistor, inductor, and capacitor embedded in the substrate. The method of claim 4, wherein And said substrate is a printed circuit board (PCB) or low temperature cofired (LTCC) substrate. The method of claim 1, The first multi-chip module further comprises a low pass filter (LPF) for removing harmonic components of the transmitted signal.

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