JPH0213846B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to an oscillation multiplier that uses transistors to generate ultra-high frequencies.

Prior Art and Problems Gunn diode oscillators are known for generating ultra-high frequencies, but they have the disadvantage of low efficiency. Also known is a configuration in which the harmonic components of an oscillator using a transistor are extracted using a filter.
Since the harmonic components included in the oscillation output are relatively small, there is a drawback that it is not easy to extract harmonics of sufficient magnitude.

Purpose of the Invention The present invention oscillates a fundamental wave using a transistor, and generates ultra-high frequency harmonics obtained by multiplying the fundamental wave.
The purpose is to enable efficient generation with a simple configuration. Examples will be described in detail below.

Embodiment of the invention FIG. 1 is an explanatory diagram of an embodiment of the present invention.
This is for the case where GaAsFET (field effect transistor) is used. This GaAs FET will be simply referred to as transistor Q hereinafter. The open stub 1 is connected to the gate G of the transistor Q, the open stub 2 is connected to the source S, and the drain D is grounded. When the wavelength of the fundamental wave is λ ₁ and the wavelength of the harmonic to be output is λn, the open stub 1 has a length of about λ ₁ /4, and the open stub 2 has a length of about λ ₁ /2. Also, L1 and L2 are inductances, C1 and C2 are capacitors, and R1 and R2 are resistors, and the power supply voltage -V is applied to the source S of the transistor Q via the resistor R1 and inductance L1, and the voltage drop due to the resistor R1 is , resistor R2, and inductance L2 as a bias voltage. Further, 3 is a coupling line of λn/4, which is connected to the output terminal OUT.

Open stubs 1 and 2 are connected to the gate G and source S of the transistor Q, forming a fundamental wave oscillation circuit with a common drain. The coupled line 3 is coupled to the connection side of the oven stub 2 to the source S,
Since the coupling line length is λn/4, only harmonics of wavelength λn are output to the output terminal OUT. That is, the fundamental wave of wavelength λ ₁ propagates through the open stub 2, is totally reflected at the open end of the open stub 2, is fed back to the transistor Q, is multiplied by the nonlinear characteristics of the transistor Q, and becomes the fundamental wave. Harmonics that are integral multiples of the wave are generated, and only the wavelength λn of the multiplied harmonics is extracted by the coupling line 3 having a coupling length of λn/4.
At this time, harmonics other than the wavelength λn are totally reflected by the open stub 2 and fed back to the transistor Q in the same manner as the fundamental wave, so that the multiplication efficiency can be improved. Therefore, for example, ultra-high frequencies of about 40 GHz can be efficiently generated.

Also, since it is joined at the base of the open stub 2,
Since the harmonic signal of wavelength λn to be extracted does not pass through the fundamental wave circuit that satisfies the oscillation conditions (open stub 2 has a large loss for harmonics), the resulting circuit loss is not included, and the fundamental wave is Oscillation and harmonic output adjustment can be done independently.

FIG. 2 shows another embodiment of the present invention, and the DC power supply system is not shown. In this example, λn/
This is for the case where a two-wavelength distributed coupling type bandpass filter 4 is used, and each wavelength is λn/2.
The length of the coupled line is λn/4, and the length of the coupled line is λn/4. Note that the same symbols as in FIG. 1 indicate the same parts.

FIG. 3 shows still another embodiment of the present invention, and the DC power supply system is not shown. This example is about the case where a dielectric resonator 5 is provided,
Open stub 1 as shown in Figures 1 and 2
When configured with strip lines, Q ₀ is approximately 100 ~
200, whereas the dielectric resonator 5 has a Q ₀ of about 400 to 5000, making it possible to stabilize the frequency. Furthermore, although the case is shown in which a coupled line 3 of λn/4 is provided at the root of the open stub 2 connected to the source S, it is also possible to use a distributed coupled bandpass filter as in the embodiment shown in FIG. can. Note that the same reference numerals as in FIG. 1 indicate the same parts.

Although each of the above-mentioned embodiments shows the case where the drain is grounded and the output port is on the source S side, it is of course possible to use other connection types and the output port is on the gate G side.

Effects of the Invention As explained above, the present invention provides a GaAs FET
In an oscillation multiplier using transistors such as
A fundamental wave oscillation circuit is constructed by connecting open stubs to the input and output terminals of each transistor, and a distributed coupling bandpass filter or the like is installed to extract harmonics from one of the roots of each open stub, that is, on the transistor side. Provide a joint,
It is configured to extract harmonics multiplied by a transistor, and can be made into a microwave integrated circuit (MIC) by forming open stubs and coupling parts with microstrip lines. In addition, harmonics several times higher than the oscillation frequency of the transistor can be extracted by multiplication, and the harmonics can be extracted by combining at the root of the open stub, so it is possible to efficiently generate ultra-high frequencies of several tens of GHz. There is an advantage in that the oscillation of the fundamental wave and the extraction of the harmonics can be independently adjusted. Further, since the direct current is cut off by the coupling portion, there is no need to provide special means for cutting off the direct current.

[Brief explanation of drawings]

FIGS. 1, 2, and 3 are explanatory diagrams of different embodiments of the present invention. 1 and 2 are open stubs, 3 is a coupled line, 4 is a distributed coupling bandpass filter, 5 is a dielectric resonator, Q is a transistor, and OUT is an output terminal.

Claims (1)

[Claims] 1 In an oscillation multiplier using transistors,
Open stubs are connected to the input and output terminals of the transistors to form a fundamental wave oscillation circuit, and a coupling portion for extracting harmonics is provided on the transistor side of the open stubs connected to the input and output terminals of the transistors. An oscillation multiplier characterized by having a configuration that extracts harmonics multiplied by nonlinear characteristics.