JPS6133699Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a demodulation phase shifter used in a quadruple layer detector, etc., in which an inductor and a double-tuned coil are connected in series. With the goal.

Conventionally, this type of double-tuned phase shifter 5 consists of an inductor _L3 and a primary coil of the double-tuned coil 3, as shown in FIG.
_L1 is generally connected in series, and connected to the semiconductor integrated circuit 1 to form a quad layer detector. In this demodulator, the inductor
L ₃ changes the phase of the demodulated signal by 90 degrees and transmits the signal to the primary coil L ₁ of the double-tuned coil, and the primary coil L ₁ and secondary coil L ₂ are tuned to the demodulated signal. It is a tuner. Note that 7 and 7' are tuning capacitors.

This demodulation phase shifter 5 includes a double-tuned coil 3
If the primary and secondary coils are placed close to each other, the degree of coupling between them becomes strong and the bandwidth becomes too wide, and an appropriate degree of coupling is required to obtain an appropriate demodulated output. Therefore, it is necessary to provide a certain distance between the primary and secondary coils, so winding both coils L ₁ and L ₂ on the same bobbin requires a certain height of the bobbin. On the contrary, in order to reduce the height, it is necessary to wind and connect them to separate bobbins, which has the disadvantage of increasing the number of parts such as bobbins and substrates.
Furthermore, a bobbin around which the inductor _L3 is wound is required, making it impossible to downsize the demodulating phase shifter 5 and reduce the number of components, making it impossible to supply inexpensive electronic components.

The present invention aims to improve the above-mentioned drawbacks and will be described in detail below. FIG. 2 shows an embodiment of the demodulating phase shifter of the present invention. In the figure, the present invention has a demodulating phase shifter 5 in which an inductor L ₃ is connected in series with the primary coil of a double-tuned coil 3, which has a terminal pin 11 and has tuning capacitors 7 and 7' housed in the lower surface. A hollow bobbin 15 is placed on the upper surface of the substrate 9 in which the recess 10 is formed, and the primary coil L ₁ and the secondary coil L ₂ of the double-tuned coil 3 are connected to the bobbin 1.
The inductor L ₃ is wound on a bobbin between the primary coil L ₁ and the secondary coil L ₂ , and the inductor L 3 is wound on the bobbin 15 between the primary coil L 1 and the secondary coil L _{2 .}
and shield case 13 covering inductor L ₃
shows a demodulating phase shifter fitted to the substrate 9. 17 is an inductance adjustment screw core screwed into the hollow part of the hollow bobbin 15.
In the present invention, the leads of the inductor L ₃ , the primary and secondary coils L ₁ and L ₂ of the double-tuned coil, and the capacitors 7 and 7' are connected via terminal pins 11, etc., and demodulated as shown in FIG. This constitutes a phase shifter 5. However, the feature of this invention is that one of the double-tuned coils
The secondary coils L ₁ and L ₂ and the inductor L ₃ are wound on the same bobbin 15, and the inductor L ₃ is wound between the double-tuned coils L ₁ and L ₂ .

This demodulation phase shifter 5 is a primary phase shifter of a double-tuned coil.
The secondary coils L ₁ and L ₂ are inductively coupled, but 1
Since the inductor _L3 is wound between the primary and secondary coils, the degree of coupling between the primary and secondary coils is reduced. Therefore, even if the distance between the primary and secondary coils is made closer than before and the distance between them is increased, the degree of coupling will not become significantly stronger, and the primary and secondary coils can be wound close together, making it possible to wind the bobbin 15. The height of the can be lowered. Moreover, even if not only the primary and secondary coils L ₁ and L ₂ but also the inductor L ₃ are wound on the same bobbin 15,
The conventional demodulating phase shifter 5 can be realized with a single bobbin without increasing the height of the bobbin 15, and the number of bobbins and boards can be greatly reduced, making it possible to provide inexpensive electronic components.

By the way, inductor L ₃ is one of the double tuned coils.
By winding the coil between the next and secondary coils, a coupled state is formed between them. But inductor L ₃
The method changes the phase of the demodulated signal by 90° at the tuning frequency of the double-tuned coil 3, but it is difficult to change the phase by 90° due to the influence of the internal resistance of the semiconductor integrated circuit 1. . In this respect, as in the present invention, inductor L ₃ and double-tuned coil 3, especially 1
By appropriately selecting the impedance ratio in connection with the secondary coil _L1 , a 90° phase change is possible, and a good demodulator with little distortion can be obtained.
This selection of the impedance ratio between the primary coil L ₁ and the inductor L ₃ is obtained by changing the coupling between L ₁ and L ₃ . FIG. 3 is an equivalent circuit diagram showing the coupling between L ₁ and L _3. In the figure, by changing the degree of coupling, the mutual inductance M changes, and the impedance ratio between the primary coil L ₁ and the inductor L ₃ . It is something that can change.

As explained above, the present invention provides a demodulation phase shifter consisting of an inductor and a double-tuned coil connected in series, in which the primary and secondary coils of the double-tuned coil are wound on the same bobbin, and the primary coil and 2
By winding the inductor between the secondary coils, there is an advantage that an inexpensive demodulation phase shifter that is small and has a small number of parts can be provided.

[Brief explanation of the drawing]

Figure 1: Circuit diagram showing demodulation phase shifter, Figure 2:
A sectional view showing an embodiment of the demodulating phase shifter of the present invention,
Figure 3: Equivalent circuit diagram showing the coupling between an inductor and a primary coil. 3: double tuning coil, L ₁ : primary coil, L ₂ : 2
Next coil, L ₃ : Inductor, 9: Board, 15:
bobbin.

Claims (1)

[Scope of utility model registration request] In a demodulation phase shifter which is formed by connecting an inductor and the primary coil of a double-tuned coil in series, the primary and secondary coils of the double-tuned coil are wound on the same bobbin, and the primary and secondary coils are connected between the primary and secondary coils. A demodulating phase shifter comprising the inductor wound around the inductor.