JPS59186402A - Oscillation circuit device - Google Patents

Abstract

PURPOSE:To attain oscillations at frequencies over a wide range without any deterioration in characteristics by providing plural oscillation circuits, connecting their output sides to one buffer in parallel, and powering on only a specific oscillation circuit to be put in oscillating operation selectively. CONSTITUTION:Resonance elements 7 and 8 are connected in parallel through capacitors, and a varactor diode 9 is applied with a control voltage CT to vary in equivalent electrostatic capacity. The output side of each oscillation circuit is connected to the input side of a common amplifier (buffer) 10. A power source B is connected between the collectors and emitter of every oscillation circuit during operation. A bias power source, however, is connected to between the base and emitter of an oscillation circuit selectively by a switch 11. For this purpose, the switch 11 is only changed over to obtain two oscillation outputs of different frequencies selectively at the output side of the amplifier 10.

Description

[Detailed description of the invention] The present invention relates to an oscillation circuit device.

When you want to obtain multiple oscillation frequency outputs using an oscillation circuit device, the first thing you can think of is to provide a dedicated resonant element, feedback circuit, and buffer for each oscillation frequency, but this makes it difficult to downsize and reduce costs, so some kind of ingenuity is needed. Is required. Therefore, conventionally, a varactor diode was connected in parallel to the resonant element, or a capacitor was connected in parallel to the resonant element via a switching transistor to obtain oscillation outputs with a plurality of different frequencies.

However, in these methods, something that degrades the Q is connected in parallel to the resonant element, which leads to deterioration of the overall characteristics.
There was also a limit to the range of frequency variation.

SUMMARY OF THE INVENTION An object of the present invention is to provide an oscillation circuit device that can oscillate over a wide range of frequencies without deteriorating its characteristics, and is inexpensive and compact.

The gist of this invention is to have N number of oscillation circuits, and
This oscillation circuit device is characterized in that the output side of each oscillation circuit is connected in parallel to one buffer, and a power supply is selectively connected only to a specific oscillation circuit to be oscillated.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 conceptually shows the present invention. In one case 1, there are two oscillation circuits 2.
3 and one buffer 4 are included. Oscillation circuit 2
．． The output side of 3 is a buffer connected in parallel to the buffer 4. A power supply (not shown) is connected to the buffer 4 during operation, but the power supply to the oscillation circuit 2.3 is selective only to the oscillation circuit to be operated. connected.

In this way, it is possible to provide an oscillation circuit that can selectively oscillate over a wide range of frequencies without deteriorating its characteristics and is inexpensive and compact.

FIG. 2 shows a more specific example. In the figure, 5 is the feedback circuit portion of the first oscillation circuit, 6 is the feedback circuit portion of the second oscillation circuit, and 7 is the resonant element of the first feedback circuit portion. , 8 is the second
It is a resonant element in the feedback circuit section of . Each resonant element uses, for example, a dielectric coaxial resonator. Each resonant element 7.8 is connected in parallel via a capacitor, and further a varactor diode 9 for fine adjustment is connected in parallel as required.

A control voltage CT is applied to the varactor diode 9 to change its equivalent capacitance. The output side of each oscillation circuit is also connected in parallel and connected to the input side of a common amplifier (buffer) 10. Further, during operation, 8 power supplies (Vcc) are applied between the collectors and emitters of all oscillation circuits. However, a bias power supply (Vee) is selectively applied by a switch 11 between the base and emitter of the oscillation circuit.

Therefore, according to this embodiment, two oscillation outputs having different frequencies can be alternatively obtained on the output side of the amplifier 10 by simply switching the switch 11. When fine adjustment of each oscillation frequency tool is required, the control voltage applied to the varactor diode may also be switched using a switch (not shown) that is linked to the switch 11.

Figure 3 shows another more specific example. In the example in Figure 2, a specific oscillation circuit was operated by switching the bias power supply, but in this example, the same can be done by switching the collector side power supply. has achieved its purpose.

FIG. 4 shows yet another more specific example in which the same objective is achieved by selectively connecting the emitters of each feedback circuit 5.6 to ground in a direct current manner. Note that the fine adjustment circuit is not shown in FIG. 3.4.

Among the above examples, the example shown in FIG. 2 has the least number of parts and is stable.

Note that although the above embodiment has two oscillation circuits, the present invention can also be applied to an arrangement having any number of oscillation circuits greater than or equal to three. Furthermore, although bipolar transistors are used for the oscillation circuit, it goes without saying that FETs or ICs formed from these may also be used.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory block diagram of the present invention, FIG. 2 is a first specific example circuit diagram, FIG. 3 is a second specific example circuit diagram, and FIG. 4 is a third specific example circuit diagram. 2.3 is an oscillation circuit, 4 is a buffer, 5.6 is a feedback portion of the oscillation circuit, 7.8 is a resonant element, and 11 is a switch. Patent application person Murata Manufacturing Co., Ltd. Figure 7 To Sakai Figure 2 Figure 31!

Claims (1)

[Claims] An oscillation circuit device comprising a plurality of oscillation circuits, the output side of each oscillation circuit is connected in parallel to one buffer, and a power supply is selectively connected only to a specific oscillation circuit that should stop oscillating.