JP2006033618A - Transformer for broadcast wave distributor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transformer for a broadcast wave distributor capable of rapidly improving the gain of signal transmission. <P>SOLUTION: One distribution transformer and two impedance transformers are arranged so that all four cylinder holes in total, i.e. two cylinder holes of each of two impedance transforming transformers and the center axis of a signal line insertion hole may be arranged in the same straight line. In this state, in plan view opposing the mounting surface of an object to be mounted of this transformer for broadcast wave distributor, the lengths L<SB>-</SB>L1 and L<SB>-</SB>L3 of signal lines from exposition from signal line insertion holes to disappearance closed by an impedance transformation transformer are made to be approximately the same as the lengths L<SB>-</SB>L1 and L<SB>-</SB>L3 from the end 1a1 of the signal line insertion hole of the distribution transformer to an external surface 1b forming the approximately cylindrical shape of the distribution transformer. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a transformer for a broadcast wave distributor.

  A conventional transformer for a broadcast wave distributor will be described with reference to FIGS. 4A and 4B are explanatory views of a conventional broadcast wave distributor transformer. FIG. 4A is a plan view, FIG. 4B is a side view, and FIG. 4C is a bottom view. FIG. 5 is a perspective view showing a state in which the broadcast wave distributor transformer is mounted on a circuit board such as a printed board.

  Generally, a distributor that distributes a reception signal obtained by receiving a television broadcast wave is required to be able to transmit a wide band from a low frequency to a high frequency. For this reason, a ferrite-wired transformer is generally used as a transformer device mounted on the distributor.

  Such a broadcast wave distributor transformer is shown in FIG. One distribution transformer 1 is a substantially cylindrical (so-called bead-shaped) ferrite core provided with one signal line insertion hole 1a for inserting a signal line L for transmitting a broadcast signal, and two cylindrical holes 2a and 2b. Two impedance transformation transformers 2 which are ferrite cores (so-called balloon type) formed in parallel are used. Such a transformer for broadcast wave distributor becomes an integrated part through the signal line L by winding the signal line L inserted through the signal line insertion hole 1a around each of the two cylindrical holes 2a and 2b. .

  The signal line L includes four lines L1, L2, L3, and L4, and the distribution transformer 1 has the signal line L1 inserted from one end to the other end. The signal line L1 is twisted with another signal line L2 inserted into the transformer 2 by winding inside the impedance transformation transformer 2 on the other end side of the distribution transformer 1. In addition, the signal line L3 is inserted from the other end to the one end of the distribution transformer 1. The signal line L3 is twisted with another signal line L4 inserted into the transformer 2 around the inside of the impedance transformation transformer 2 on one end side of the distribution transformer 1.

In such a broadcast wave distributor transformer, since the signal lines L1 and L3 are not interrupted between the three transformers, for example, they are soldered via lands or patterns on the printed circuit board P to be mounted shown in FIG. As a result, compared to the configuration in which the signal lines L1 and L3 are integrated, the number of assembling steps is reduced because connection work such as soldering is not necessary. Compared to the configuration in which the signal lines are soldered and the signal lines L1 are unified or the signal lines L3 are unified, there is no need for connection work such as soldering to the signal lines L1 and L3. Has the advantage of requiring less.
JP 2001-345216 A

  Recently, the market demands that signal gain in the high-frequency band be further improved as soon as possible, but in order to improve performance, the size and material of the ferrite core used for each transformer, and the signal line It is necessary to repeat the design and experiment using the wire diameter as a parameter. In addition, there are various improvement factors such as considering the mounting position on the printed circuit board, preferably on the ground pattern area, and there are cases where these parameter groups are correlated. As a result, it was difficult to quickly improve the signal transmission gain.

  The present invention has been made to solve such problems, and an object of the present invention is to provide a transformer for a broadcast wave distributor that can quickly improve the gain of signal transmission.

In order to solve the above problems, the broadcast wave distributor transformer according to claim 1 is a substantially cylindrical ferrite core provided with one signal line insertion hole through which a signal line for transmitting a broadcast signal is inserted. One distribution transformer and two impedance transformation transformers, which are ferrite cores formed in parallel with two cylindrical holes, are wound around the two cylindrical holes by the signal lines inserted into the signal line insertion holes. In a broadcast wave distributor transformer as an integrated part via a signal line,
One distribution transformer and two impedance transformation transformers are arranged so that all four cylindrical holes of each of the two impedance transformation transformers and the central axis of the signal line insertion hole are aligned in a straight line. In this state, when viewed in a plan view directly facing the mounting surface of the broadcast wave distributor transformer,
The length of the signal line that is exposed from the signal line insertion hole and hidden behind the impedance transformation transformer is from the end of the signal line insertion hole of the distribution transformer to the outer surface that forms the substantially cylindrical shape of the distribution transformer. It is characterized by being approximately equal to the length.

  One distribution transformer and two impedance transformation transformers are arranged so that all four cylindrical holes of each of the two impedance transformation transformers and the central axis of the signal line insertion hole are aligned in a straight line. In this state, the length of the signal line that is exposed from the signal line insertion hole and hidden behind the impedance transformation transformer when it is seen in a plan view directly facing the mounting surface of the broadcast wave distributor transformer to be mounted. The length from the end of the signal line insertion hole of the distribution transformer to the outer surface forming the substantially cylindrical shape of the distribution transformer was made substantially equal.

  In other words, with the distribution transformer at the center, the impedance transformation transformer is extended from the signal line insertion hole of the signal line with the distribution transformer and the two impedance transformation transformers arranged in a single horizontal shape on both sides. The part leading up to the impedance transformation transformer was made to be straight and straight without being bent while being approximately equal to the length from the end of the signal line insertion hole of the distribution transformer to the outer surface forming the substantially cylindrical shape of the distribution transformer. .

  If such a transformer for broadcast wave distributor is used, the gain of signal transmission can be greatly improved as the frequency becomes high by simply devising the length of the signal line without the need for complicated design changes. it can. In addition, since the arrangement positions of the two impedance transformation transformers with respect to the distribution transformer can be movably arranged up to a maximum relative angle of 180 degrees, the degree of freedom in designing the arrangement of the impedance transformation transformer can be minimized.

  An embodiment of a transformer for a broadcast wave distributor according to the present invention will be described below with reference to FIGS. 1A and 1B are explanatory views of a transformer for a broadcast wave distributor according to the present invention, where FIG. 1A is a plan view when arranged in a U-shape, FIG. 1B is a side view of FIG. 1A, and FIG. It is a top view at the time of arrange | positioning in a shape. 2 is a plan view showing a state in which the broadcast wave distributor transformer of FIG. 1 is mounted on the mounting surface of the printed circuit board to be mounted. FIG. 2A is a cross-sectional view, and FIG. Each case is shown in a U shape. FIG. 3 is a characteristic diagram showing that the gain characteristic of signal transmission is improved by using the transformer for broadcast wave distributor of the present invention.

  The broadcast wave distributor transformer includes one distribution transformer 1, which is a substantially cylindrical (so-called bead-shaped) ferrite core provided with one signal line insertion hole 1 a for inserting a signal line L for transmitting a broadcast signal. Two impedance transformation transformers 2 are used which are ferrite cores (so-called balloon type) in which two cylindrical holes 2a and 2b are formed in parallel. Such a transformer for broadcast wave distributor becomes an integrated part through the signal line L by winding the signal line L inserted through the signal line insertion hole 1a around each of the two cylindrical holes 2a and 2b. .

  The signal line L includes four lines L1, L2, L3, and L4, and the distribution transformer 1 has the signal line L1 inserted from one end to the other end. The signal line L1 is twisted with another signal line L2 inserted into the transformer 2 by winding inside the impedance transformation transformer 2 on the other end side of the distribution transformer 1. In addition, the signal line L3 is inserted from the other end to the one end of the distribution transformer 1. The signal line L3 is twisted with another signal line L4 inserted into the transformer 2 around the inside of the impedance transformation transformer 2 on one end side of the distribution transformer 1.

  In addition, as shown in FIG. 1, the signal line L is a pair in which the signal lines L1 and L2 out of the four lines L1, L2, L3, and L4 are combined by one impedance transformation transformer 2. The signal lines L3 and L4 are a pair of twists in the other impedance transformation transformer 2.

  Here, as depicted in the plan view of FIG. 1 (c) when arranged in a horizontal straight line, a plan view (that is, directly facing the mounting surface of the printed circuit board P to which the broadcast wave distributor transformer is mounted) The signal line insertion hole 1a for the two signal lines L1 and L3 connecting the distribution transformer 1 and the impedance transformation transformer 2 among the signal lines L when viewed from the top mounted on the printed circuit board P) The lengths L_L1 and L_L3 that are exposed from the terminal and hidden behind the impedance transformation transformer 2 from the end 1a1 of the signal line insertion hole 1a of the distribution transformer 1 to the outer surface 1b that forms a substantially cylindrical shape of the distribution transformer 1 Is approximately equal to the length of The lengths L_L1 and L_L3 of the signal line L extending from the signal line insertion hole 1a to the impedance transformation transformers 2 and 2 are strained linearly without bending.

  The lengths L_L1 and L_L3 may be left as they are, and may be arranged in a U shape as shown in FIG. When designing the mounting arrangement on the printed circuit board, in addition to Fig. 1 (a) U-shaped arrangement and Fig. 1 (c) horizontal alignment, Fig. 2 (a) C-shaped arrangement It can be the case. Of course, the present invention is not limited to these three arrangement forms, and the arrangement positions of the two impedance transformation transformers with respect to the distribution transformer can be movably arranged up to a maximum relative angle of 180 degrees. There is an advantage that the degree is not limited as much as possible. For this reason, the degree of freedom in layout design is high when considering the mounting position on the printed circuit board, preferably on the ground pattern area.

  According to the broadcast wave distributor transformer formed as described above, actual measurement characteristics as shown in FIG. 3 are obtained. In FIG. 3, the vertical axis represents signal transmission gain (unit: dB (decibel)), and the horizontal axis represents broadcast wave transmission frequency band (unit: MHZ (megahertz)). Compared with the characteristic A, the characteristic B of the transformer for broadcast wave distributor according to the present invention is improved in gain from the low frequency band to the high frequency broadcasting band of 3000 MHz (megahertz), and the effect of gain improvement is obvious at a glance. is there.

It is explanatory drawing of the transformer for broadcast wave dividers concerning the present invention, (a) is a plan view when arranged in a U-shape, (b) is a side view of (a), (c) is a horizontal straight line It is a top view at the time of arrange | positioning. FIG. 2 is a plan view showing a state where the broadcast wave distributor transformer of FIG. 1 is mounted on a mounting surface of a printed circuit board to be mounted, where (a) is arranged in a C shape, and (b) is a U shape. When arranged in a shape, it represents each. It is a characteristic view which shows that the gain characteristic of signal transmission was improved using the transformer for broadcast wave dividers concerning the present invention. It is explanatory drawing of the transformer for the conventional broadcast wave divider | distributor, (a) is a top view, (b) is a side view, (c) is a bottom view. It is a perspective view showing the state which mounted the same broadcast wave divider | distributor transformer on circuit boards, such as a printed circuit board.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Distribution transformer 1a Signal line insertion hole 1a1 End 1b of signal line insertion hole of distribution transformer Outer surface 2 which forms the substantially cylindrical shape of distribution transformer 2, 2 Impedance transformation transformers 2a, 2b Cylindrical hole
L (L1, L2, L3, L4) Signal line L_L1, L_L3 Length of the part extending from the signal line insertion hole to the impedance transformation transformer

Claims (1)

One distribution transformer, which is a substantially cylindrical ferrite core provided with one signal line insertion hole for inserting a signal line for transmitting a broadcast signal, and an impedance transformation transformer, which is a ferrite core having two cylindrical holes formed in parallel In the transformer for a broadcast wave distributor, in which the signal line inserted through the signal line insertion hole is wound around each of the two cylindrical holes, and the two are integrated parts via the signal line,
One distribution transformer and two impedance transformation transformers are arranged so that all four cylindrical holes of each of the two impedance transformation transformers and the central axis of the signal line insertion hole are aligned in a straight line. In this state, when viewed in a plan view directly facing the mounting surface of the broadcast wave distributor transformer,
The length of the signal line that is exposed from the signal line insertion hole and hidden behind the impedance transformation transformer is from the end of the signal line insertion hole of the distribution transformer to the outer surface that forms the substantially cylindrical shape of the distribution transformer. A transformer for a broadcast wave distributor, characterized by being approximately equal in length.

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