KR960011159B1 - High frequency flat transformer - Google Patents

Abstract

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Description

High frequency average transformer formed by wiring extending on an insulated substrate

1 is a block diagram of a conventional tuner circuit.

FIG. 2 is a block diagram of the mixer circuit shown in FIG.

3 is an equivalent circuit diagram of the mixer circuit shown in FIG.

4A and 4B are perspective views of the balun transformer shown in FIG. 2 viewed from different directions.

4c is a connection diagram of the balun transformer shown in FIG.

5 is a circuit diagram showing another example of a conventional mixer circuit.

6A is a plan view of a high frequency planar transformer, showing an embodiment of the present invention.

7 is a plan view of a mixer circuit showing another embodiment of the present invention.

The present invention relates to a high frequency plane transformer, and more particularly, to a high frequency plane transformer formed by wiring extending on an insulating substrate.

The present invention has particular applicability to diode mixers that operate at high frequencies above the microwave band.

INDUSTRIAL APPLICABILITY The present invention is widely applicable to a transformer operable at a high frequency of more than a microwave band. In the following description, a phase broadcast receiver will be briefly described as an application example.

The receiver for a satellite broadcasting service includes a tuner circuit for selecting a signal of a desired channel among the high frequency signals received by the antenna.

1 is a block diagram of a conventional tuner circuit.

Referring to FIG. 1, the tuner circuit 60 includes a high frequency amplifier AMP 61 for amplifying a high frequency signal Si received by an antenna not shown in the figure, and a low pass for removing an image signal. A low-pass filter (LPF) 62, a mixing amplifier 63, a mixer circuit (MIX) 64, a local oscillator 65, a band-pass filter (BDF) 66, and an output amplifier 67 are included. In operation, the high frequency amplifier 61 amplifies the high frequency signal Si received by the antenna and supplies the amplified signal to the low-pass filter 62.

The low pass filter 62 removes an image signal included in the provided high frequency signal and provides the output signal to the amplifier 63.

The amplifier 63 amplifies the supplied signal again and supplies the amplified high frequency signal S _RF to the mixer circuit 64.

Local oscillator 65 generates a signal S _LO having a predetermined local oscillation frequency f _LO depending on the channel.

The mixer circuit 64 multiplies the signals S _RF and S _LO to output the frequency signal S _IF .

Outputs the frequency signal S _IF .

The intermediate frequency signal S _IF is supplied to the output amplifier 67 through the band pass filter 66.

Amplifier 67 amplifies the supplied signal S _IF and outputs an output signal So.

For example, a satellite broadcasting receiver generally used in Japan receives high frequency signals in a band of 1035 to 1335 MHz (1049.48 to 1318.00 MHz in the center frequency).

Therefore, the received signal is supplied to the tuner circuit 60 shown in FIG. 1 as signal Si.

Local oscillator 65 generates a signal S _LO having a frequency f _LO of 1452.26 to 1720.78 MHz, depending on the channel.

Therefore, the intermediate frequency signal S _IF supplied as the output by mixing in the mixer circuit 64 has a frequency of 402.78 MHz.

2 is a circuit block diagram of the mixer circuit 64 shown in FIG.

The mixer circuit 64 shown in FIG. 2 is of a single balance type including a balun transformer BU70.

The mixer circuit 64 includes a balun transformer 70 having an input winding 71, an output winding 72 and 73, a mixing diode 74 and 75, a high pass filter (HPF) 76 and a low pass filter (LPF) 77. The balun transformer 70 is connected such that the input winding receives the signal S _LO generated by the local oscillator.

The output winding 72 is connected to the anode of the diode 74 and the output winding 73 is connected to the cathode of the diode 75.

The high frequency signal S _RF is supplied through the filter 76 to the common connection node NC of the diodes 74 and 75.

The signal at the node NC is supplied as an intermediate wave signal S _IF to the outside through the filter 77.

Since the two output windings 72 and 73 of the balun transformer 70 are wound in opposite directions, output signals S1 and S2 inverted from each other are generated in the output windings 71 and 73.

3 is an equivalent circuit diagram of the mixer circuit 64 shown in FIG. Referring to FIG. 3, the operation of the mixer circuit 64 will be briefly described below. The switching circuit 78 is constituted by the balun transformer 70 and diodes 74 and 75 shown in FIG.

Thus, the switching circuit 78 is turned on and off in response to the signal S _LO .

That is, the node NC is periodically grounded in response to the signal S _LO . In the period when the node NC is not grounded, the high frequency signal S _RF supplied through the bypass filter 76 is output through the low pass filter 77.

On the other hand, the signal S _RF and the ground level signal are alternately output to obtain the intermediate frequency signal S _IF .

In particular, the intermediate frequency signal S _IF is generated by the multiplication of the signal S _RF and S _LO .

4A and 4B are perspective views of the balun transformer 70 shown in FIG. 2 viewed from different directions.

As shown in Figures 4a and 4b, the balun transformer 70 is a ferrite core 83 having two parallel holes, one to several turns, each of which are insulated coated wires 71, 72 and 73, respectively. Is formed.

Wires 71, 72 and 73 are connected to the mixing diodes 74 and 75 and the like through holes in the printed circuit board not shown in the figure.

4C is a connection diagram of the balun transporter 70 shown in FIG. 2.

Referring to FIG. 4C, one end of each of wires 71, 72, and 73 is grounded.

The other ends of the wires 71, 72 and 73 are connected to the input terminals 80 and the output terminals 81 and 82, respectively.

In order for the mixer circuit 64 shown in FIG. 2 to operate like the equivalent circuit 64 of FIG. 3, the two output signals S1 and S2 of the balun transformer 70 must be inverted from each other and have the same amplitude.

That is, the phases of the output signals S1 and S2 are 180 degrees out of each other and need to have the same voltage value.

Accordingly, it is pointed out that a balun transformer 70 having output windings 72 and 73 capable of satisfying such a condition needs to be used for the mixer circuit 64.

If the above conditions of the two output signals S1 and S2, i.e., the phase and amplitude are not balanced, the signal S _LO generated at the local oscillator 65 is transmitted in the reverse direction through the high-pass filter 76, so that jammers are generated. do.

Generated jammers are generally undesirable because they leak at the antenna terminals of the receiver, disturbing other receivers.

Thus, in order to prevent the occurrence of jammers, it is necessary to balance the two output signals S1 and S2 of the balun transporter 70.

In order to achieve this balance, in the past, in the factory, an operator had inserted the ends of wires 71, 72, and 73, which had been modified in advance, directly into the holes in the printed wiring pipe, and connected them to the diodes 74, 75, and the like.

That is, in order to obtain parallel output characteristics of the balun transformer 70, factory workers installed the parallel transformer on the printed wiring board by manual operation.

Therefore, this is one of the reasons for obstructing automation in the manufacturing process because of the tuner circuit 60 shown in FIG.

In addition, the output characteristics of the balun transformer 70 installed by manual operation are not constant, thus increasing the time required for adjusting the tuner circuit 60.

5 is a circuit diagram showing another example of the conventional mixer circuit.

Referring to FIG. 5, the mixer circuit 40 includes strip lines 41 to form a phase generator.

By installing the strip line 41, it is not necessary to use the balun transformer 70, but the area of this circuit 40 on the insulating board is increased.

That is, in order to construct a phase inverter, it is necessary to select the electric field of strip line 41 to 1/2 of the wavelength (lambda) of intermediate frequency _fLO .

For example, when the intermediate frequency f _LO is 1 GHz, it is necessary to set the length of the strip line 41 to about 15 cm (= lambda / 2).

As a result, the area on the insulating substrate is occupied to form the strip line 41, which hinders the integration of the mixer circuit 40 shown in FIG.

It is an object of the present invention to provide a high frequency transformer that does not require the manual work of an operator for installation.

Another object of the present invention is to provide a high frequency transformer having stable characteristics.

Another object of the present invention is to form a high frequency transformer with a small footprint.

Still another object of the present invention is to achieve automation in the manufacture of a tuner circuit including a mixer circuit using a high frequency transformer.

Another object of the present invention is to prevent interference from occurring in a mixer circuit using a high frequency transformer.

Another object of this invention is to reduce the footprint on the substrate of a mixer circuit using a transformer.

In short, the high frequency planar transformer according to the present invention includes an insulated substrate having a main surface, and an input winding line and an output winding line extending on the main surface of the insulated substrate and formed in parallel with each other.

The input winding wiring and the output winding wiring are placed on the main surface of the substrate so as to be coupled to each other by electromagnetic coupling.

This planar transformer is constituted by input winding wirings and output winding wirings which are formed on the main surface of the substrate and run in parallel with each other, and thus can be formed together with other circuits in the manufacturing process.

Thus, no manual work is required for the installation of this planar transformer.

As a result, automation is achieved in manufacturing.

According to another aspect of the present invention, a high frequency plane transformer includes an insulated substrate having a main surface, an input winding line extending on the main surface of the insulated substrate and formed in parallel with each other, and first and second output winding lines. .

It is placed on the first major surface of the substrate so as to be coupled to each other by the input winding wiring and the first and second output winding wiring corresponding electron couplings.

The first and second output winding wirings respectively output output signals inverted from each other.

The above objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the invention in the accompanying drawings.

6A and 6B, the high frequency planar transformer includes an input winding line 12 and two output winding lines 14 and 16 which extend on the main surface of the insulating substrate 11 and are formed in parallel with each other.

The wirings 12, 14, and 16 are each formed in a U shape.

The wirings 12, 14, and 16 are formed in close proximity to each other so as to be coupled by electron coupling.

One end of the wirings 12, 14 and 16 are connected to the input terminal 22 and the output terminals 26 and 24, respectively.

FIG. 6B is a sectional view of the high frequency planar transformer shown in FIG. 6A along line 6B-6B.

It is connected to the grounded conductor plate 20 on the back surface 13 opposite to the main surface 11 of the insulating substrate 10.

The other end of the output winding wiring 14 is connected to the conductor plate 20 through the through hole 36.

Similarly, the input winding wiring 12 and the output winding wiring 16 are also connected to the conductor plate 20 through the through holes 32 and 34, respectively.

In operation, a high frequency input signal is supplied to the input winding line 12 through the input terminal 22.

Therefore, a high frequency alternating magnetic field in the vertical direction is generated on the insulating substrate 10 around the wiring 12.

Since the input winding wiring 12 and the output winding wirings 14 and 16 are coupled by electromagnetic coupling, a high frequency output signal is induced to the output winding wirings 14 and 16.

The induced output signal is output through terminals 24 and 26, respectively.

The output windings 14 and 16 are subjected to electromagnetic coupling in the opposite direction from the input winding wiring 12.

Therefore, two output signals inverted from each other are supplied through the output terminals 24 and 26.

That is, two output signals having a phase difference of 180 degrees are obtained. In addition, since the wirings 12, 14, and 16 have the same length, two output signals having the same amplitude are obtained.

The high frequency planar transformer shown in FIG. 6A indicates that it can operate in the same manner as the conventional balun transformer 70 shown in FIG.

That is, the high frequency plane transformer shown in FIG. 6A also has its circuit like FIG. 4C.

Therefore, this high frequency planar transformer can be applied to a mixer circuit in a tuner circuit as one application example.

Referring to FIG. 7, a mixer circuit 50 using a high frequency planar transformer is shown.

The anode of the mixing diode 74 is connected to the output terminal 24.

The cathode of diode 75 is connected to output terminal 26.

The common connection node NC of the high pass filter 76 and the low pass filter 77 is connected to the cathode of the diode 74 and the anode of the diode 75.

The high frequency signal S _RF is supplied through the high pass filter 76 and the intermediate frequency signal S _IF obtained by the mix phase is output through the low pass filter 77.

The signal S _LO generated by the local oscillator is supplied via input terminal 22.

In addition, when the broadband property of the high frequency transformer shown in FIG. 6A or FIG. 7 is requested | required, it can improve by forming a ferrite around the input winding wiring 12 and the output winding wiring 14 and 16. FIG.

That is, by using a ferrite core, the characteristics can be improved in the low frequency region of the high frequency planar transformer.

As described above, the mixer circuit 50 shown in FIG. 7 includes a high frequency plane transformer, and does not require a conventional balun transformer wound around a ferrite core.

The high frequency planar transformer is formed by the same manufacturing process as forming other circuits, and therefore does not require installation by a manual operation of an operator.

Thus, automation is achieved in the manufacturing process.

In addition, since the wiring lines 12, 14, and 16 having the correct length can be formed by patterning in the manufacturing process, stable transformer characteristics are obtained.

Therefore, the generation of jammers is prevented when the high frequency plane transformer is used in the mixer circuit.

Further, as in the conventional mixer circuit 40 shown in FIG. 5, since the strip line 41 having the length determined by the wavelength? Of the intermediate frequency signal is not required, the occupied area of the circuit is also reduced.

For example, the high frequency plane transformer shown in FIG. 6A can be formed in an area of about 1 cm x 1 cm.

In the above embodiment, an example has been described in which a high frequency plane transformer is used in a mixer circuit in a tuner circuit of a satellite broadcasting receiver, but this high frequency plane transformer is widely applicable to other high frequency circuits.

Although the present invention has been described and described in detail, it is to be understood that the methods of description and examples are not to be taken the same and in a limiting manner, and the spirit and scope of the invention are limited only by the terms of the appended claims.

Claims (6)

An insulating substrate having a first main surface and a second main surface opposite to the first main surface, an input winding wire and an output winding wire extending on the first main surface of the insulating substrate and formed in parallel with each other; One end of the input winding line through the first and second through holes and the first and second through holes penetrating the insulating substrate between the first main surface and the second main surface at one end of the input winding wire and the output winding wire; And a conductive layer formed on the second main surface of the insulating substrate such that one end of the output winding wiring is connected to each other. The high frequency planar transformer of claim 1, wherein the input winding line and the output winding line have a U shape and are electromagnetically coupled to each other. An insulating substrate having a first main surface and a second main surface opposite to the first main surface, an input winding wire and a first and second output winding wires which are serially arranged on and parallel to each other on the first main surface of the insulating board; First, second and third through holes formed through the first main surface and the second main surface of the insulating substrate at the other end of the input winding wire and the first and second output winding wires, and the input winding wires and the first and second outputs. A conductive layer formed on the second main surface of the insulating substrate to connect the other ends of the winding wires to each other, wherein the input winding wires are connected to receive a sliding input signal and the other end of the conductive wires through the first through hole. Connected to the layer, one end of the first output winding wire is connected to output the first output signal, and the other end is connected to the conductive layer through a second through hole, and one end of the second output winding wire is the second output. Connected to output a signal and the other end And an output signal connected to the conductive layer through a third through hole and inverted from each other by the first and second output winding wires. 4. The high frequency planar transformer of claim 3, wherein the input winding line and the first and second output winding lines have a U shape and are electromagnetically coupled to each other. An insulating substrate having a first major surface and a second major surface opposite the first major surface, the first major surface being formed parallel to each other so as to extend on the first main surface of the insulating substrate and be joined by electromagnetic coupling; First, second, and third through-holes formed on the first and second output winding wirings provided on the first and second output winding wirings and through the first and second main surfaces at the other ends of the first and second output winding wirings; And a conductive layer formed on the second main surface of the insulating substrate so that the other ends of the input winding line and the first, second, and output winding lines are connected to each other through the first, second, and third through holes. One end is connected to receive an input signal, the other end is connected to the conductive layer through the first through hole, and the first output winding wire is connected at one end to output the first output signal, and the other end is connected to the second through hole. A second output winding arrangement connected to the conductive layer Is a mixer comprising two diodes, one end of which is connected to output a second output signal and the other end of which is connected to the conductive layer through a third through hole, and wherein the first and second output winding wires are connected in a forward direction between output terminals. Circuit. 6. The mixer circuit according to claim 5, wherein the input winding wiring and the first and second output winding wiring have a U shape and are electromagnetically coupled to each other.