KR900002656Y1 - Rf modulator - Google Patents

Abstract

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Description

RF modulator

1 is a circuit diagram of an RF modulator of the present invention.

FIG. 2 is a structural diagram of main parts of one embodiment of FIG.

3 is a main structural diagram of another embodiment of the RF modulator of the present invention.

4 is a main structural diagram of still another embodiment of the RF modulator of the present invention.

5 is a circuit diagram of a conventional RF modulator.

6 is a structural diagram of the main part of FIG.

* Explanation of symbols for main parts of the drawings

1: pickup coil 2: bypass capacitor

14: circuit board 15: conductor pattern

21,22: Diode 23: Twin diode

24-29: Inductance element

The present invention relates to an RF modulator using a twin diode housed in a pair of two diodes as a modulation diode.

5 shows a circuit diagram of a conventional RF modulator.

As described in detail in Japanese Patent Laid-Open No. 59-47815, the RF modulator of Fig. 5 functions the pick-up coil as a balanced transformer, eliminating the parallel trans as a component.

The configuration is briefly described below. The center of the pickup coil 1 is grounded at high frequency to the housing 3 of the oscillator via the bypass capacitor 2, and both ends of the pickup coil 1 are connected to the modulation diodes 4 and 5, respectively. .

Thus, the UHF carrier wave oscillated to the oscillator composed of the coaxial line 6, the termination capacitor 7, the variable capacitor 8 and the oscillation transfer 9 is picked up by the pickup coil.

Thus, the carrier wave flows into the modulation diodes 4 and 5, receives AM modulation by the modulation signal input from the modulation signal input terminal 10, and modulates the output wave terminal 12 through the carrier pass capacitor 11. )

The center of the pickup coil 1 is supplied with a bias voltage supplied to the bias control terminal B. As shown in FIG.

In this configuration, the pickup coil 1 functions substantially as a balanced transformer. Therefore, compared with using a balanced transformer as an expensive component, it is cheaper and the space of the balanced transformer is reduced on it.

By the way, in the circuit shown in FIG. 5, as shown in FIG. 6, its main structure is used, the individual component which has a lead angle in the modulation diodes 4 and 5 is used.

In Fig. 6, reference numeral 14 denotes a circuit board on which the pickup coil 1 and the modulation diodes 4 and 5 are arranged, and 15, 15 and 15 are conductor patterns.

As shown in FIG. 6, conventionally, since two elements having a lead angle are used for the modulation diodes 4 and 5, the modulation diodes 4 and 5 have the same shape as that of the pickup coil 1 or the like. There is a problem in that it must be disposed on the surface (surface which is not to be soldered) of 14), it requires an installation space, and the miniaturization of the RF modulator cannot be achieved.

In addition, since the two modulation diodes 4 and 5 need to be elements having the same characteristics, a pair of elements must be arranged in advance.

Therefore, there is a problem that the device becomes expensive and the management of its manufactured parts is complicated.

The object of the present invention is to solve the above problems of the conventional RF modulator, and it is possible to miniaturize and reduce the value by using a popped diode housed in one chip as a modulating diode. An inexpensive RF modulator is provided.

In order to achieve the above object, the RF modulator of the present invention is grounded at high frequency at the center of the pick-up coil and connected at both ends to a modulation diode, so that the pair of RF modulators function as a balanced transformer. The two diodes are configured to be installed via an electric interposed diode, which is housed in one chip. It is comprised so that it may interpose between this popped diode and an electric pick-up coil via an inductance element.

Since two pairs of diodes use a popped diode housed in one chip as a modulating diode and an inductance element is installed between the popped diode and the pick-up coil, the inductance component lacking in the leaded diode without lead angle is eliminated. The inductance element provided therebetween can be supplemented and matched, and the carrier wave can flow into the popped diode as a modulation diode at a sufficient level. In addition, since the use of chip components can be arranged on the back of the circuit board, the RF modulator can be easily miniaturized, and since one chip is formed from two pairs of diodes, management as a manufacturing component is easy.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a circuit diagram of an RF modulator of the present invention, and FIG. 2 is a structural diagram of a main part of one embodiment of FIG.

In FIG. 1 and FIG. 2, the circuit element and the same member which are the same as FIG. 5 and 6 are attached | subjected with the same code | symbol, and overlapping description is abbreviate | omitted.

In FIG. 1 and FIG. 2, two paired diodes 21 and 22 are housed in one chip, and a diode 23 is popped up.

In addition, a pair of diodes 21 and 22 is a diode selected from the same fabrication process, so that it is easy and inexpensive, and the price is cheap compared to the diodes selected one by one to form a pair.

The popped diode 23 is disposed on the back surface of the circuit board 14. Further, inductance elements 24 and 25 are formed by meandering conducting wire patterns 15 and 15 connecting the popped diode 23 and the pick-up coil 1.

In this configuration, since the popped diode 23 has no lead angle, the inductance component is insufficient as compared with the elements 4 and 5 having the lead angle shown in FIG.

For this reason, when the pick-up coil 1 is directly connected to the popped-up diode 23, an inconsistency arises that no matching is obtained. However, matching is obtained by providing the inductance elements 24 and 25 to provide sufficient carrier waves. It may flow into the popped diode 23.

In addition, by arranging the chip component of the popped diode 23 on the back surface of the circuit board 14, it is easy to downsize the RF modulator.

Since two pairs of diodes are housed on one chip, it takes no time to manage the manufactured parts.

3 is a main structural diagram of another embodiment of the RF modulator of the present invention.

In FIG. 3, the same reference numerals are given to the second member and the same member, and the duplicate explanation is omitted.

In FIG. 3, the difference from the second point is that the lead wires are replaced by inductance elements 24 and 25 in a meandering conductor pattern between the popped diode 23 and the pick-up coil 1, respectively. The inductance elements 26 and 27 to be provided are interposed.

4 is a structural diagram of another embodiment of an RF modulator of the present invention. In FIG. 4, the second figure and the same member are attached | subjected with the same code | symbol, and overlapping description is abbreviate | omitted.

In FIG. 4, the difference from the second is that the arms are extended substantially parallel to the circuit board 14 at both ends of the pickup coil 1 to form an arm portion, and the inductance elements 28 and 29 serving as the arm portions. It connects to the diode 23 which protruded through ().

Thus, by forming the arm part in the pick-up coil to form the inductance elements 28 and 29, the posture of the pick-up coil 1 is stabilized by the arm part, and it is easy to keep the coupling degree with the coaxial line 6 constant. .

In addition, although the structure of the inductance 24-29 was shown in various types by the said Example, it is a matter of course that it is not limited to this.

As described above, according to the RF modulator of the present invention, it is possible to reduce the size and facilitate the part management by using the diode which is popped up as the modulation diode.

In addition, by correcting the inductance component lacking as a popped diode with an inductance element provided through a popped diode and a pickup coil, there is an excellent effect that a matching can be obtained and the carrier wave can flow into the popped diode at a sufficient level.

Claims (4)

In the RF modulator which grounds the center of the pick-up coil at high frequency and connects both ends to a modulation diode to function as a parallel transformer of electric pick-up coil, two pairs of diodes are stored in one chip. An RF modulator comprising a diode and an inductance element disposed between both ends of an electric pickup coil. An RF modulator as set forth in claim 1 of claim 1, wherein the inductance element is constituted by a conductor pattern provided on a circuit board on which an electric pick-up coil and a twist diode are disposed. The RF modulator according to claim 1, wherein the inductance element is constituted by a lead wire. The RF modulator according to claim 1, wherein the electric inductance element is configured as an arm portion extending from both ends of the electric pickup coil.