JPS6376603A - Multiplying circuit - Google Patents

Abstract

PURPOSE:To miniaturize and lighten a circuit and to improve an output power by constituting a band-pass filter of a ring resonator. CONSTITUTION:Since an open stub 11 of the 1/4 wavelength of a double wave to occur at a FET 7 is added to microstrip/slot line converters 9 and 10, an impedance in microstrip/slot line converters 9 and 10 comes to be short by the double wave and converted to a ring resonator 12 composed of a slot line. At this time, since the whole circumferential length of the ring resonator 12 is designed to the length of one wavelength of the double wave, resonance is generated to the double wave by the ring resonator 12 and the double wave is guided to an output terminal 2. Consequently, the ring resonator 12 is operated as the band-pass filter having a band-pass characteristic in the resonance frequency. Namely, since a band-pass filter 13a is constituted of the ring resonator, the circuit can be miniaturized and lightened and the output power can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a multiplier circuit, and particularly relates to improving its output power and making it smaller and lighter.

[Conventional technology]

Generally, when a field effect transistor (F B, T ) is biased under appropriate conditions, the distortion of the output wave becomes large because the FET has large signal nonlinear operating characteristics, and as a result, the distortion of the output wave becomes large, resulting in an integer multiple of the input wave and its frequency. It is known that high frequencies appear on the output side.

FIG. 2 is a schematic plan view of a conventional doubler circuit. In the figure, 1 is an input terminal, 2 is an output terminal, 3 is a dielectric substrate, and 4
is a capacitor for DC cut, 5 is a low-pass filter designed according to the input wave frequency, 7 is an FET, and 6 is an F
1 is an input matching circuit for matching the input side of ET1; 8 is an output matching circuit for matching the output side of FET7;
3 is FET'? This is a quarter-wavelength coupling bandpass filter designed to allow the second harmonic of the high frequency waves generated by the wave to pass through.

In such a circuit, input and output matching circuits 6 and 8 are provided on the input and output sides of the FET 7, respectively, and a bandpass filter 13 designed to allow only the second harmonic to pass is provided after the output matching circuit 8. Therefore, by applying an appropriate bias to FET7 and generating a high frequency,
You can get harmonics.

Note that the low-pass filter 5 provided in front of the input matching circuit 6 is for preventing the high frequency generated in the FET 7 from returning to the input terminal side.

[Problem that the invention seeks to solve]

In order to output only the second harmonic of the input wave from the output terminal 2, the conventional two-week doubler circuit as described above includes a bandpass filter 13 designed to allow only the second harmonic to pass after the output matching circuit 8. Since the bandpass filter 13 is made up of a cascade of quarter-wavelength coupling lines, the circuit size becomes large, and furthermore, the bandpass filter 13 causes a loss in the output wave. There was a 1%11 problem that the output power decreased.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a multiplier circuit that can prevent a decrease in output power and can reduce the size and weight of the circuit.

[Means for solving problems]

The multiplier circuit according to the present invention includes a ring resonator formed by electromagnetically coupling a bandpass filter to an output matching circuit and an output terminal through slot lines on the back surface of a dielectric substrate.

[Effect]

In the multiplier circuit of the present invention, since the band pass filter is constituted by a ring resonator, the circuit can be made smaller and lighter than the conventional circuit in which the band pass filter is composed of cascaded lines. Since there are fewer coupling points between lines in the bandpass filter, output power loss can be kept low.

〔Example〕

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

FIG. 1 shows a double multiplier circuit which is a multiplier circuit according to an embodiment of the present invention. In the figure, 1 to 8 are the same as the conventional example, and 12 is a multiplier circuit provided on the back surface of the dielectric substrate 3. A ring resonator consisting of a slot line with a length of one wavelength of the second harmonic, 9 and 10 are locations where the ring resonator 12 is electromagnetically coupled to the output matching circuit 8 and the output terminal 2, that is, microstrips/slots. Line converter, 11 is an open stub with a quarter wavelength of the double wave of the human power wave, 13a is a microstrip/slot line converter, 9.10.
Open stub 11. This is a bandpass filter consisting of a ring resonator 12.

In a circuit configured like this, the 2 generated in FET7
Since the open stub 11 with a quarter wavelength of the harmonic is added to the microstrip/slot line converter 9.
The impedance at 10 is short-circuited by the second harmonic and is converted into a ring resonator 12 consisting of a slot line. At this time, the entire circumference of the ring resonator 12 is 1 of the double wave.
Since the ring resonator 12 is designed to have a wavelength length, resonance occurs for the second harmonic wave, and the second harmonic wave is guided to the output terminal 2. Therefore, the ring resonator 12 operates as a bandpass filter having bandpass characteristics at the resonant frequency.

In this way, in this embodiment, the bandpass filter 13a is configured with a ring resonator, so that the circuit can be miniaturized and
It is possible to reduce the weight, and since the bandpass filter has fewer coupling points between lines, it is possible to reduce the loss that occurs when coupling between lines, and it is possible to improve the output power of the multiplier circuit.

In the above embodiment, a double-multiplying circuit has been described, but this may be any number of times as many circuits, and the same effect will be achieved.

Furthermore, the configuration of the bandpass filter of the present invention can be applied to any circuit having a bandpass filter, and produces the same effects as the above embodiments.

[Effects of the Invention] As described above, according to the multiplier circuit of the present invention, since the bandpass filter is constituted by a ring resonator, the circuit can be made smaller and lighter, and the output power can be improved. be.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view showing a multiplier circuit according to an embodiment of the present invention, and FIG. 2 is a schematic plan view showing a conventional multiplier circuit. In the figure, 1 is an input terminal, 2 is an output terminal, 3 is a dielectric substrate, 4 is a capacitor, 5 is a low-pass filter, 6 is an input matching circuit, 7 is a FET, 8 is an output matching circuit, 9, 10
11 is a microstrip/slot line converter, 11 is an oven stub, 12 is a ring resonator, and 13.13a is a bandpass filter. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] (1) In a multiplier circuit having an input matching circuit, a field effect transistor, an output matching circuit, and a bandpass filter on a dielectric substrate, the bandpass filter has the output matching circuit formed by a slot line on the back surface of the dielectric substrate. 1. A multiplier circuit comprising a ring resonator formed by electromagnetically coupling a circuit and an output terminal, each having a total circumference length of one wavelength of a desired frequency.