JPS60224312A - Frequency converter - Google Patents

Abstract

PURPOSE:To take out easily only a desired signal wave with a simple circuit by suppressing unnecessary waves due to one cross modulation dropped into a signal band. CONSTITUTION:The input signal from a terminal 9 is divided into two by a hybrid 1, and one is given to a diode 4a for mixer through a band stop filter 3a, and the other is given to a diode 4b for mixer through a phase shifter 2 and a band stop filter 3b. Meanwhile, the local oscillated signal from a terminal 10 is divided into two by a hybrid 7, and one is given to the diode 4a through a low-pass filter 5a, and the other is given to the diode 4b through a phase shifter 6 and a low-pass filter 5b. Only the wave having a desired frequency out of waves which are subjected to frequency conversion by diodes 4a and 4b is applied to the hybrid 1 and is synthesized and is outputted to an output terminal 11. In this case, unnecessary waves are suppressed and do not appear in the terminal 11. Thus, only the desired signal wave is taken out easily with a simple circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a frequency converter that is used in the field of wireless communication and is capable of separating and extracting desired output signal waves and unnecessary waves.

[Prior art]

In addition to the desired output signal wave generated by mixing the input signal wave and the local signal wave, the frequency converter used in microwave communication converts the harmonics of the five input signal waves to the local signal wave. , and their mixture generates a lot of unnecessary waves. For this purpose, an f-wave generator is generally used to attenuate the unnecessary waves to a required level and extract only the desired waves. However, depending on the setting conditions of one frequency.

These unnecessary waves may fall within or near the signal band, and in that case, even if a wave filter is used, it becomes impossible to distinguish between the signal waves and the unnecessary waves. Such disadvantages often occur especially when using wideband frequency converters.

In order to eliminate the above-mentioned disadvantages, a conventional method has been to handle only the sum and difference frequencies of the input signal wave and the local signal wave, and to separate and extract only the desired wave by applying a non-reciprocal circuit to this. It was widely adopted. However, this method has the disadvantage that circuit design is difficult, complicated, and uneconomical.

[Object of the Invention] An object of the present invention is to suppress unnecessary waves caused by any one cross-modulation falling within a signal band, without using a non-reciprocal circuit.

It is an object of the present invention to provide a frequency converter that can effectively extract only desired signal waves.

[Structure of the invention]

The frequency converter according to the invention includes a first hybrid means for applying an input signal to a first terminal and dividing and outputting power to a second and a sixth terminal.

a first phasing means connected to a fifth terminal of said first hybrid means; a second terminal of said first hybrid means and an output side of said first phasing means respectively connected to said first and second phasing means; a frequency conversion means connected to the second input terminal; a second hybrid means for applying a local oscillation signal to the first terminal and dividing and outputting power to the second and third output terminals; and a second phase means connected to a third terminal of the hybrid means, wherein the second terminal of the second hybrid means and the output side of the second phase means are respectively connected to the frequency conversion means. The input signal applied to the first input terminal of the frequency conversion means is converted to a desired frequency by the local oscillation signal applied to the third input terminal. and applied to the second terminal of the first hybrid means, while the input signal applied to the second input terminal of the frequency conversion means is caused by the local oscillation signal applied to the fourth input terminal. is converted into a desired frequency and passed through the first phase means to the first
to a sixth terminal of the hybrid means;
and the desired frequency signal wave is output from the fourth terminal of the first hybrid means and the unnecessary signal wave is output from the first terminal by phase adjustment by a second phase means. .

[Embodiments of the invention]

The flow side will be explained with reference to one drawing.

FIG. 1 is a block diagram showing the configuration of an embodiment according to the present invention. In the figure, the input signal applied to terminal 9 is divided into two equal parts by hybrid 1, and one is divided into two equal parts by output terminal 12.
from the band-stop f-wave filter 3a to the mixer diode 4.
added to a. The other side of the hybrid 1 is applied from the output end 13 to the phase shifter 2, and after having its phase changed by 9, is applied to the mixer diode 4b via the band rejection f-wave device 3b. On the other hand, the power of the local oscillation signal applied from the terminal 10 is divided into two by the hybrid 7, and one of these is applied to the diode 4a via the low-frequency f-wave generator 5a. Also.

The other half of the halves has its phase changed by a phase shifter 6, and then passes through a low-frequency wave generator 5b to a diode "4".
added to b. Do as above.

Among the waves frequency-converted by the diodes 4a and 4b, only the waves of the desired frequency are applied to the high print 1 via the f-wave generator 3a, and the other is applied to the yr5 wave generator 3b.
It is added to ' + do 1. These two inputs are combined in hybrid 1.

In this case, the phase relationship between the respective desired signal waves at the two terminals 12 and 13 of the hybrid l and the unwanted waves falling within the same band is determined by comparing the two input signal waves and the two local oscillation signal waves. By controlling the phase difference between the two, the desired signal output wave is taken out from the output terminal 11 of the hybrid 1 by utilizing the directivity of no hybrid.

At this time, unnecessary waves can be suppressed and not appear at the output terminal 11. Note that the diodes 4a, 4
A portion of b including the P-wave devices 3a, 3b and 5a, 5b is called a frequency conversion section.

The principle of the above operation will be explained in more detail.

Note that as the hybrids 1 and 7, either a 180 degree hybrid or a 90 degree hybrid can be used, but here, a case where a 90 degree hybrid is used will be taken as an example. Input terminals 12 and 1 of hybrid 1
When signals with equal amplitude and a phase difference of 90 degrees are added to terminal 3, if terminal 12 is 90 degrees ahead in phase, the combined output will be obtained at terminal 10, and terminal 13 will have a 90 degree phase difference. If the phase is leading, a composite output is obtained at terminal 11. Therefore, regarding unnecessary waves.

The phase difference between the two input signal waves described above is controlled so as to satisfy the latter condition.

Now, set the phase amount of 9 phase shifter 2 to 088. When the phase amount of the θb++ phase shifter 6 is set to 02, a quadratic relational expression is obtained. Here, θa1 is the input signal, and θb is the phase amount for the output signal. Hybrid terminal 12 for frequency-converted signals
The phase difference at
If so.

θB −(-90)+ msθa1±θb, +n8θ2
θd”±mdθ8.±ndθ2+θ.

be. In order to reflect unnecessary waves to the signal input end and guide the signal waves to the output end, it is necessary that θd-90° and θ8=-90°. Here, since the input signal and the output signal have different frequencies, θB and θb are not equal, and θ
It is expressed as a, = k, θb1.

Similarly, for unnecessary waves, θ5- becomes 2θb1.

Based on these conditions, the relationship between the 9 phase shifters 2 and 6 can be summarized.

-90= -90+ (k, m8±1)θb1±n8
θ290−(k2±”(+1)θb1±ndθ2.In this formula, m,, n,, md, nd
Since + kl + k2 is determined based on the frequency, θb1 and θ2 can be determined. As a specific example, input frequency is 14.25 GHz, output frequency is 11
．． For 95GHz and local frequency 2.3GHz.

m,= 1, ns= 1, ma:=Q, n, 1=
5 and soreha.

The unnecessary waves are 11.5 GHz. Therefore, 1=0
．． 8386. Since 2=0.9626 in ', θb--79.756. θ22 is 53.55.

In addition, in the description of the above embodiment, the case where a 9o0 hybrid was used was taken as an example.

It is clear that even when using a 180-degree hybrid, the present invention can be realized by operating on the same principle. Moreover, only the element used in the example of FIG.
It goes without saying that this does not limit the scope of application of the present invention. For example, it is of course possible to use other non-linear elements instead of diodes.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, unnecessary waves generated by any one cross-modulation falling within the signal band are suppressed.

It is possible to easily extract only the desired signal wave with a simple circuit, which has a great effect of improving productivity and economic efficiency.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment according to the present invention. In this figure, 1 and 7 are hybrid, 2,
6 is a phase shifter, 3a and 3b are f-wave filters for band rejection, 4a,
4b is a diode for a mixer, 5a and 5b are low-frequency f-wave devices, and 8 is a terminator.

Claims (1)

[Claims] 1. A first hybrid means that applies an input signal to a first terminal and divides and outputs power to a second and a fifth terminal, and a first hybrid means that is connected to a sixth terminal of the first hybrid means. 1 phase means and a second phase means of said first hybrid means.
and the output side of the first phase means are respectively connected to the first
and a frequency conversion means connected to the second input terminal;
a second hybrid means that applies a local oscillation signal to the first terminal and divides and outputs power to the second and sixth output terminals; 2 phase means, and a second terminal of the second hybrid means and an output side of the second phase means are connected to sixth and fourth input terminals of the frequency conversion means, respectively. wherein the input signal applied to the first input terminal of the frequency conversion means is converted to a desired frequency by the local oscillation signal applied to the fifth input terminal,
to the second terminal of the no-brid means;
The input signal applied to the second input terminal of the frequency converting means is converted to a desired frequency by the local oscillation signal applied to the fourth input terminal, and the input signal is converted to a desired frequency by the local oscillation signal applied to the fourth input terminal, and is then transmitted to the first hybrid via the first phase means. the desired frequency signal wave is outputted from the fourth terminal of the first hybrid means by phase adjustment by the first and second phase means, and the desired frequency signal wave is outputted from the fourth terminal of the hybrid means; A frequency converter characterized in that an unnecessary signal wave is output from a frequency converter.