JPH04145707A - Voltage controlled oscillator - Google Patents

Abstract

PURPOSE:To attain adjustment without soldering a metallic line by providing several thin slits in a varactor line in a comb-shape in the travelling direction of an electromagnetic wave and cutting off its slit pattern so as to fine-adjust the modulation sensitivity. CONSTITUTION:One or two slit patterns are cut off at cut-off parts 12A, 12B, 13A, 13B shown with dotted lines among several thin slit patterns formed by making a thin hole to a comb-shape slit 1 provided on a varactor line 9A to adjust the modulation sensitivity. The modulation sensitivity is changed proportionally to the number of cut slit patterns by cutting off the cut-off parts shown with dotted lines in the slit 1. Thus, the modulation sensitivity is changed stepwise depending on the number of cut-off slit patterns. Thus, the desired modulation sensitivity is obtained without soldering a metallic line.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a voltage controlled oscillator, and particularly to a voltage controlled oscillator in the microwave band.
The present invention relates to a voltage controlled oscillator that can finely adjust the modulation sensitivity of a feedback oscillator having a /4 to λ/2 resonator.

[Conventional technology]

As shown in FIG. 4, a conventional voltage controlled oscillator includes a transistor 2, a strip line 3A, 3B coupling the base and collector of the transistor 2 to a λ/4 to λ/2 strip line resonator 4, and a coupling capacitor 5. , 6, a capacitor 7 connected to the emitter, a resistor 8, and a varactor line 9 connected to a modulation varactor diode 11 via a coupling capacitor 10 coupled to the stripline resonator 4. In such a configuration, the resonant frequency of this oscillator is mostly set by the stripline resonator 4. On the other hand, by applying a voltage to the varactor diode and changing the isometric capacitance, the above-mentioned resonant frequency is changed.
Fine adjustments were made by changing the length of the soldering line for different lines, etc.

[Problem to be solved by the invention]

The above-mentioned conventional voltage controlled oscillator has an enclosure configuration in which the length of the varactor line is changed, and therefore has the disadvantage that the metal line must be soldered in order to finely adjust the modulation sensitivity.

(Means for Solving the Problems) The voltage controlled oscillator of the present invention connects one ends of two strip lines formed on a dielectric substrate to the collector and base of a transistor, respectively, and A strip line resonator with an electrical length of λ/4 to λ/2 with both ends open is connected to the other end by electric field coupling or magnetic field coupling, and a varactor line equipped with a varactor diode is connected to the strip line resonator by electric field coupling. In the connected voltage controlled oscillator, several thin slits are provided in the varactor line in a comb shape in the direction of propagation of electromagnetic waves, and the required number of slit patterns are cut to finely adjust the modulation sensitivity of the varactor diode. There is.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a circuit diagram of an embodiment of the present invention, FIG. 2 is an enlarged explanatory diagram of the main part of this embodiment, and FIG. 3 is a diagram illustrating characteristics of this embodiment.

The embodiment shown in FIG. 1 includes an oscillation transistor 2, strip lines 3A and 3B formed on a dielectric substrate, a strip line resonator 4, coupling capacitors 5 and 6, a capacitor 7, a resistor 8, a varactor line 9A, It is composed of a varactor line coupling capacitor 10, a varactor diode 11, and a comb-shaped slit 1 for fine adjustment of modulation sensitivity according to the present invention.

As shown in FIG. 2, the modulation sensitivity is determined by cutting several thin slit patterns formed by drilling long comb-shaped slits 1 provided in the varactor line 9A into the dotted line cut section 12A.
Cut one or two pieces at 12B, 13A, and 13B. By cutting the comb-shaped slits 1 along the dotted lines, the modulation sensitivity can be changed in proportion to the number of cutting slit patterns, as shown in FIG. In this way, the modulation sensitivity can be changed finely in steps by changing the number of patterns to be cut. The characteristic diagram in Figure 3 is for 2.4GH
In a voltage controlled oscillator in the Z band, the modulation sensitivity changes in steps of 2 MHz/■ in proportion to the number of cut comb-shaped slit patterns provided in the varactor line.

〔Effect of the invention〕

As explained above, according to the present invention, a comb-shaped slit pattern is provided in the varactor line parallel to the direction of propagation of electromagnetic waves, and the modulation sensitivity can be finely adjusted by simply cutting several thin slit patterns. Therefore, it is possible to obtain the desired modulation sensitivity without soldering metal lines as in the conventional example.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram of an embodiment of the present invention, Fig. 2 is an enlarged explanatory diagram of the main parts of this embodiment, Fig. 3 is a characteristic diagram of this embodiment, and Fig. 4 is a diagram showing the characteristics of this embodiment.
The figure is a circuit diagram of a conventional voltage controlled oscillator. 1... Comb-shaped slit, 2... Transistor, 3A
, 3B... Strip line, 4 river strip line resonator, 5, 6.10... Coupling capacitor, 7...
Capacitor, 8...Resistor, 9,9A...Varactor line, 11...Varactor diode, 12A, B, 1
3A, B...Dotted line cutting section.

Claims (1)

[Claims] One ends of two strip lines formed on a dielectric substrate are connected to the collector and base of the transistor, respectively, and the other ends of the two strip lines are connected to the collector and base of the transistor.
A voltage controlled oscillator in which a strip line resonator with an electrical length of /4 to λ/2 with both ends open is connected by electric field coupling or magnetic field coupling, and a varactor line equipped with a varactor diode is connected to the strip line resonator by electric field coupling. A voltage characterized in that several thin slits are provided in the varactor line in a comb shape in the direction of propagation of electromagnetic waves, and the modulation sensitivity of the varactor diode is finely adjusted by cutting the required number of slit patterns. Controlled oscillator.