JPS6033004B2 - transistor oscillator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a transistor oscillator that is small and lightweight and has good frequency stability.

A conventional device of this kind is shown in FIG. 1, and is provided with a coaxial waveguide converter 3 having a structure capable of supplying a bias voltage to a waveguide 2 whose one end is terminated with a shorting plate 1. Insert the FET transistor 5 into the coax 4 of the tube converter 3, connect the drain terminal 6 and gate terminal 7 to the inner conductor of the coax 4, connect the source terminal 8 to the outer conductor of the coax 4, and connect the seven gate terminals. It has a structure in which a predetermined length of coax is short-circuited in the high frequency band and a bias voltage can be supplied to the gate terminal.The oscillation frequency is adjusted by the coaxial line length on the gate side, and the coaxial waveguide converter 3 is short-circuited. The oscillation output is adjusted based on the plate 1 position. However, since the resonant system of this oscillator is coaxial, the Q of the oscillator is low and the frequency stability is poor. In order to increase the Q, it is necessary to take measures such as loading an empty arm with a high Q. In addition, FE via the coaxial waveguide converter 3
In order to mount the T transistor, this part protrudes from the waveguide and becomes dimensionally large. In order to solve these problems, the present invention mounts an FET transistor in a waveguide cavity, and will be described in detail below. Second
The figure shows an embodiment of a transistor oscillator according to the present invention, in which the waveguide 2 is terminated with a coupling window 9 and a shorting plate 11 to form a cavity 10, and from the coupling window 9 at the required operating frequency, the tube is folded approximately 1/2 times. A coax 4 capable of supplying a bias voltage over the wavelength range is inserted to the required length, and a coaxial package type FET transistor 5 is inserted that can connect the drain terminal 6 to the outer conductor at the tip of the coax 4 and the gate terminal 7 to the inner conductor. At the same time, a metal post 11 capable of supplying a bias voltage is inserted from the surface opposite to the waveguide surface into which the coaxial cable is inserted, and the source terminal 8 is connected to the metal post 11.

The oscillation frequency is mainly determined by the distance between the coupling window 9 and the coax 4,
The oscillation output can be adjusted by adjusting the coaxial length connected to the gate terminal 7, the coaxial length inserted into the waveguide 2, the size of the coupling window, the deviation of the coaxial insertion point in the tube axis direction, etc. The oscillation frequency is tuned by inserting a metal or dielectric rod 12 whose insertion length can be changed by a screw mechanism at an intermediate distance between the coupling window 9 and the coax 4. FIG. 3 shows an example of values for a transistor oscillator according to the invention.

Instead of inserting a metal post 11, a bias voltage is applied between the coax 4 and the waveguide 2. Note that although the case where FET transistors are used has been described above, the present invention is not limited to this, and transistors such as bipolar transistors may also be used.

Furthermore, although the coaxial package style has been described, a stripline package style as shown in FIG. 1 may also be used. Furthermore, the terminals of the FET transistor connected to the coaxial inner conductor, outer conductor, and metal post may be changed from those described above. As described above, in the transistor oscillator according to the present invention, the oscillator can be made smaller by inserting a coaxial tube into the waveguide cavity, and since the waveguide cavity 8 is used as a resonant system, the coaxial resonator This has the advantage that the Q of the oscillator can be made higher than when using the oscillator, and the oscillation frequency can be easily adjusted by inserting a conduit birch or the like in the space 8.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the structure of a conventional transistor oscillator, FIG. 2 is a diagram showing an example of the structure of the transistor oscillator according to the present invention, and FIG. 3 is a diagram showing another example of the structure of the transistor oscillator according to the present invention. be. In the figure, 1 is a short circuit plate, 2 is a waveguide, 3 is a coaxial waveguide converter,
4 is coaxial, 5 is FET transistor, 6 is drain terminal, 7 is gate terminal, 8 is source terminal, 9 is coupling window, 10
11 is a metal post, and 12 is a metal or dielectric rod. Note that the same or corresponding parts in the figures are indicated by the same reference numerals. Multi 1 diagram ゑZ diagram so key

Claims (1)

[Claims] 1 A coaxial line of a predetermined length is inserted almost perpendicularly to the H-plane wall of the waveguide at a predetermined position in a cavity formed by terminating one end of a rectangular waveguide with a shorting plate and the other end with a coupling window, and this coaxial line A FET transistor is attached to one end, the first terminal of the FET transistor is connected to the end face of the coaxial outer conductor, the second terminal is connected to the coaxial inner conductor, and further an H-plane wall facing the surface into which the coaxial line is inserted is connected. A metal post structured to be able to apply a bias voltage is inserted and connected to the third terminal, and a point at a predetermined length from the second terminal of the coaxial conductor becomes high impedance or low impedance in the microwave band and the bias voltage is applied. A transistor oscillator characterized in that it is configured so that a voltage can be applied.