KR100986499B1 - Duplexer circuit - Google Patents

Abstract

The present invention discloses a duplexer circuit that can improve the characteristics of a module by allowing tuning of phase shift among modules manufactured by the LTCC process. The disclosed invention includes a diplexer for filtering to transmit and receive two frequency band signals through an antenna; A first transmitter for transmitting a high frequency signal of the two frequency band signals, and a second transmitter for transmitting a low frequency signal; A first receiving end receiving a high frequency band signal among the signals received separately from the diplexer and a second receiving end receiving a low frequency band signal; A first filter connected in series with the first transmitting end, and a second filter connected in series with the second transmitting end; A first phase shift in series with the first receiver and a second phase shift in series with the second receiver; And a first tuning unit and a second tuning unit respectively connected to and tuned to both sides of the phase shifts.

Tuning, LTCC, Module, Impedance, Phase Shift

Description

Duplexer circuit {DUPLEXER CIRCUIT}

1 is a block diagram illustrating a dual band duplexer module made of LTCC according to the prior art.

2 is a block diagram designed to tune phase shift in a dual band duplexer module in accordance with the present invention.

3 is an equivalent circuit for explaining a method of tuning phase shift in accordance with the present invention.

* Description of the symbols for the main parts of the drawings *

200: duplexer 201a: first filter

201b: second filter 203a: first phase shift

203b: second phase shift 205a: first tuning section

205b: second tuning section

The present invention relates to a duplexer circuit, and more particularly, a module generated in a manufacturing step by externally tuning elements of a duplexer module manufactured by stacking a plurality of ceramic substrates according to a low temperature co-fired ceramic (LTCC) process. The present invention relates to a duplexer circuit that can improve the yield reduction of the.

Background Art In recent years, with the development of mobile communication systems, mobile communication devices such as mobile phones and portable information terminals are rapidly spreading, and the demand for miniaturization and high performance of these devices has been required to reduce the size and performance of components used therein.

In addition, two types of wireless communication systems, analog and digital, are used in mobile telephones, and the frequencies used for wireless communication are in the 800 MHz to 1 GHz band and the 1.5 GHz to 2.0 GHz band.

In particular, SAW filters are widely used as band pass filters in communication devices and other electronic devices. SAW filters include a lateral SAW filter having two interdigital transducers (IDTs) arranged at a predetermined distance on a piezoelectric substrate, and a SAW resonator filter constituting a resonator on a piezoelectric substrate.

Recently, a duplexer is manufactured and used as a chip to filter and transmit only a predetermined band frequency of a signal when transmitting and receiving a signal in a communication device, or to receive a signal of a predetermined frequency band when receiving a signal.

In the above description, the saw-duplexer is used for an intermediate frequency filter of an image, a time delay of a signal, etc. in a television, and its configuration is modified or mechanical vibration of an electrical input signal on a piezoelectric body such as LiTaO3, LiNbO3, etc. An input converter for converting and an opposing shape are formed, and an output converter for converting a mechanical vibration into an electrical signal and outputting the load to the load is formed. have.

In addition, a duplexer incorporating the above-described saw filter has recently been integrated with circuit elements formed on a ceramic laminate substrate by a technology called low temperature co-fired ceramic (LTCC). It is manufactured.

The LTCC is generally manufactured by forming a substrate into a substrate and coating a metal on the circuit, but this method has difficulty in integration and miniaturization.

Therefore, when the LTCC is used, since it is a co-fire process technology in which a metal and its ceramic substrate are simultaneously made at low temperature, integration and miniaturization can be achieved.

Glass-based or mixed ceramic-based substrates can be pressed and fired to metal-clad substrates at around 800 ~ 1000 ℃ and are well suited for high-frequency passive device fabrication.

1 is a block diagram illustrating a dual band duplexer according to the prior art.

As shown in FIG. 1, a duplexer for transmitting / receiving a dual band frequency signal includes a DCS which transmits and receives a data signal using a frequency band of 1800 MHz or more and a frequency band of 900 MHz or less. It is a structure in which GSM to be transmitted and received is formed and arranged in the same front end module (FEM).

DCS using a diplexer 100 for filtering signals of different frequency bands transmitted and received from an antenna for transmitting and receiving high frequency signals of different frequency bands, and a 1800 MHz band frequency signal separated from the diplexer 100. A GSM transmit / receive terminal Tx, which is separated from the transmit / receive terminal Tx and the diplexer 100 and uses a 900 MHz band frequency signal, is disposed.

A first filter 201a is disposed at the DCS transmitting terminal Tx, and a type of filter is usually a saw filter or a FBAR filter, and a first phase shift 103a is disposed at the DCS receiving terminal Rx. There are two types of filters, similarly, a saw filter or a FBAR filter.

A second filter 101b is disposed at the GSM transmission terminal Tx, and a type of filter is usually a SAW filter or a FBAR filter, and a second phase shift 103b at the GSM reception terminal Rx. The filter is similarly using a saw filter or a FBAR filter.

 When the duplexer having the structure as described above is applied with a 900 MHz frequency signal generated inside the system through the GSM transmission terminal Tx, the diplexer is filtered around the band width through the second filter 101b. The signal is transmitted to the outside through the antenna while passing through the low pass filter region of 100.

A frequency signal of 900 MHz band is externally received from the antenna through the same path, and then applied to the GSM receiving terminal Rx through the diplexer 100 and the second phase shift 103b). The signal is received internally.

In addition, when a frequency signal of 1800 MHz band generated inside the system is applied through the DCS transmitting terminal Tx, the diplexer 100 is filtered around the band width through the first filter 101a. The signal is transmitted to the outside through the antenna while passing through the low pass filter region of the antenna.

After receiving the frequency signal of the 1800MHz band from the outside through the same path from the antenna, it is applied to the DCS receiving terminal (Rx) through the diplexer 100, the system through the first phase shift (103a) Receive a signal.

As described above, a duplexer for transmitting and receiving frequency signals of two bands is manufactured by stacking a plurality of ceramic substrates in one package according to the LTCC manufacturing process, and the module manufactured in the package form is treated as one electronic component. Used.

However, if the above duplexer circuit is manufactured according to the LTCC process, the value of each element on the duplexer circuit and the value of the elements formed by patterning the metal on the ceramic substrate are different, resulting in a change in module characteristics. There is.

In particular, when the ceramic substrate is laminated by the LTCC process, it is impossible to improve the defects of the device characteristics due to the dimensional defects, and there is a problem of remanufacturing when the change in the module characteristics is large.

Among the devices mounted on the duplexer module, the phase shift forms a long transmission line on the ceramic substrate, which causes a large difference from the value manufactured through the actual manufacturing process.

 The present invention provides a duplexer that can improve the characteristics of the LTCC module by mounting an inductor or a capacitor on the module surface to reduce the yield of devices generated during the manufacturing process among the modules manufactured by the LTCC process. The purpose is to provide a circuit.

In order to achieve the above object, a duplexer circuit according to the present invention,

A diplexer for filtering to transmit and receive two frequency band signals through an antenna;

A first transmitter for transmitting a high frequency signal of the two frequency band signals, and a second transmitter for transmitting a low frequency signal;

A first receiving end receiving a high frequency band signal among the signals received separately from the diplexer and a second receiving end receiving a low frequency band signal;

A first filter connected in series with the first transmitting end, and a second filter connected in series with the second transmitting end;

A first phase shift in series with the first receiver and a second phase shift in series with the second receiver; And

And a first tuning unit and a second tuning unit which are connected to and tuned to both sides of the phase shifts, respectively.

Here, the first tuning unit and the second tuning unit is composed of an inductor or a capacitor, the first tuning unit and the second tuning unit are connected in parallel to both sides of the phase shift, the first tuning unit and the second tuning unit It is characterized in that the impedance is adjusted by changing the value of either inductance or capacitance.

According to the present invention, a module manufactured by the LTCC process is difficult to accurately implement the device values presented in the design during the manufacturing process, thereby mounting an inductor or capacitor on the module surface and tuning the devices in the duplexer package formed in the LTCC to a constant value. Can be.

In particular, in the case of error-prone phase shifts, even after the duplexer package is completed, the LTCC module characteristics can be improved by externally connecting and adjusting inductors and capacitors in parallel.

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

2 is a block diagram designed to tune phase shift in a dual band duplexer module according to the present invention.

As shown in FIG. 2, a diplexer 200 for filtering signals of different frequency bands transmitted and received from an antenna for transmitting and receiving high frequency signals of different frequency bands, and 1800 MHz separated from the diplexer 200. A DC transmission / reception terminal Tx using a band frequency signal and a GSM transmission / reception terminal Tx using a 900 MHz band frequency signal are separated from the diplexer 200.

A first filter 201a is disposed at the DCS transmitting terminal Tx, and a type of filter is usually a saw filter or a FBAR filter, and a first phase shift 203a is disposed at the DCS receiving terminal Rx. The type of filter is similarly used as a saw filter or FBAR filter.

A second filter 201b is disposed at the GSM transmission terminal Tx, and a type of the filter is usually a SAW filter or a FBAR filter, and a second phase shift 203b at the GSM reception terminal Rx. And a first tuning unit 205a and a second tuning unit 205b each having a susceptance jB value in parallel for impedance control on both sides of the second phase shift 203b. The portions 205a and 205b are arranged using an inductor or a capacitor element.

Similarly, the type of the second phase shift 203b filter similarly uses a saw filter or an FBAR filter.

Hereinafter, since the signal processing process is the same as that of the duplexer described with reference to FIG. 1, only the tuning unit region to be distinguished will be described.

The ceramic substrate is stacked according to the LTCC process to complete the duplexer package, and then the tuning units are mounted on the exterior, and the tuning units 205a and 205b are disposed in the GSM receiving terminal among the stacked ceramic substrates as described above. Allow them to be connected in parallel to the left and right of the field.

Of course, although not shown in Figure 2, it can be connected in parallel to the left and right phase shifts arranged in the DCS receiving terminal.

The tuning units 205a and 205b disposed in the duplexer housing have a susceptance value of impedance at the front and rear ends of the phase shift by using an inductor or a capacitor, so that the transmission pattern on the ceramic substrate manufactured by the LTCC process is defective. Can be adjusted.

3 is an equivalent circuit for explaining a method for tuning phase shift in accordance with the present invention.

As shown in FIG. 3, the actual tuning unit is connected in parallel to the left and right ends of the phase shift, and equivalently represents an impedance value along a malleable line thereof.

When jB susceptance values arranged in parallel on the left and right sides of the phase shift are obtained from the load line, the ABCD parameter is as follows.

Then, ABCD parameters are obtained from the equivalent circuit.

therefore,

에 근접할 것이고 위의 결과는If b is small, θ e is

Will be close to the above result

Becomes

Therefore, by shifting the susceptance in parallel before and after the phase shift and adjusting the values of the inductor and the capacitor, impedance tuning of the main line can be performed.

Thus, the tuning of the difference between the device values presented in the actual design and the values produced by other LTCC processes can be improved by tuning to improve the characteristics of the duplexer module.

As described in detail above, the present invention is difficult to accurately implement a module manufactured by the LTCC process according to the design, the inductor or capacitor mounted on the module surface and connected in parallel with the phase shift formed in the LTCC control By doing so, the LTCC module characteristics can be improved.

The present invention is not limited to the above-described embodiments, and various changes can be made by those skilled in the art without departing from the gist of the present invention as claimed in the following claims.

Claims (4)

A diplexer for filtering to transmit and receive two frequency band signals through an antenna; A first transmitter for transmitting a high frequency signal of the two frequency band signals, and a second transmitter for transmitting a low frequency signal; A first receiving end receiving a high frequency band signal among the signals received separately from the diplexer and a second receiving end receiving a low frequency band signal; A first filter connected in series with the first transmitting end, and a second filter connected in series with the second transmitting end; A first phase shift in series with the first receiver and a second phase shift in series with the second receiver; And And a first tuning unit and a second tuning unit connected to and tuned to both sides of the phase shifts, respectively. The first tuning unit and the second tuning unit is composed of an inductor or a capacitor, And the first tuning unit and the second tuning unit adjust impedance by changing any one of inductance or capacitance. delete The duplexer circuit according to claim 1, wherein the first tuning unit and the second tuning unit are connected in parallel to both sides of the phase shift. delete

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