JPH02112306A - Frequency converter - Google Patents

Abstract

PURPOSE:To easily switch images in the upper band of local frequencies and the lower band, and to convert them by providing a phase shifter between an RF band hybrid and one of mixers. CONSTITUTION:A phase shifter 8 to change a phase by 180 deg. is provided between an RF band hybrid 3 and either one of two unitary mixers 11 and 12 of the balanced mixers by an external control signal. Further, an input microwave changes and converts the upper band of the local carrier and the image frequencies to be the lower band by means of the control signal of a phase shifter 8. Thus, the necessity to alter a circuit pattern is eliminated, and switching is attained by a remote control in a place away from a frequency converter.

Description

[Detailed Description of the Invention] [Summary] Regarding a frequency converter, especially an image cancellation type frequency converter, which mixes a microwave input with a local carrier wave input and converts it into a differential intermediate frequency signal, the input microwave is a local carrier wave input. The purpose is to easily switch and convert between the image frequency of the upper band USB fto+f+r and the image frequency of the lower band LSB fLO-ftr. and two local carrier waves of the output of the RF band hybrid which orthogonally branches the input microwave, and orthogonally outputs an intermediate frequency signal of the difference between the frequency of the input microwave or its image frequency and the frequency of the local carrier wave. A balanced mixer consisting of one mixer and an imager that orthogonally combines the intermediate frequency signal output; and an IF band hybrid that cancels and outputs the intermediate frequency signal component of the frequency. A shifter 411 that changes the phase by 180'' is installed between one of the two single mixers of the I-type mixer of the Kaheira-Kata I type Miki by a control signal from the outside. Sukamai 7
It is configured to switch between a case where the 0 wave is in the L part band fco+r of the local unit transmission wave and a case where the image frequency is in the lower band fLo'llll.

Field of Industrial Application] The present invention relates to a frequency converter for a microphone I: two-wave band percussion device, and more particularly to an image-cancelling frequency converter.

[Conventional technology]

As shown in FIG. 3, the conventional frequency converter converts the microwave band frequency (fin□f LO+
A balanced mixer 1 which branches the input RFin of FTV (or its image frequency fLO-ftp) into two in an in-phase hybrid 2 and is composed of two mixers 11 and 12 using Schottky diodes, for example.
The local carrier waves 1 and Oin of the frequency fLO input from the LO input terminal 6 are orthogonally branched at the R-band hybrid 3, and the two local carrier waves of orthogonal phase are respectively inputted and mixed individually. 1, two signal outputs of orthogonal phase 6.) intermediate frequency f11' generated in each mixer 11 and 12 of the balanced mixer 1 whose phases differ by 90° are
P-band hybrid riff IP) orthogonally synthesized with IYB 4,
A composite output is output from the IP signal output terminal 7, and the image frequency fLO- of the microwave manual RFin frequency fin = f1° + f□ (upper band of local carrier wave f, .)
p signal output of f + r (lower band of local carrier fLO), or input frequency fin = f (-o-f IF (lower band) image frequency fL, +f, , (upper band) IF signal output is IF 1 (Yll 4), the signal is not output from the IF signal output terminal 7, and operates as an image cancel type reception mixer.

[Problems to be Solved by the Invention] Then, as the microwave manual Rin, the local carrier wave f1.
0 upper band IJsB fin = f , o + f I
F or take the local carrier [14o lower band LSB f
Since in = fLO - Lr is used depending on the case, it is desirable that the frequency converter can be easily switched. The switching means is an RF band hybrid 3 of orthogonal branch to the local 1 transmission wave input LO4n.
Or IP band hybrid 4 that orthogonally synthesizes intermediate frequency outputs.
The 0° boat and the 90° boat can be exchanged at , but this switching method requires changing the connection pattern of the circuit, so there is a problem in that it is not easy to switch. The present invention provides an image canceling frequency converter in which the microwave RFin is in the upper band LIS.
It is an object of the present invention to provide means for easily switching and converting between the case where B fin = f LO + f IF and the case where lower band LSB fin = f LO - f IF.

[Means to solve the problem]

This problem is solved in Fig. 1 when the local carrier is manually
The RF band hybrid 3 which orthogonally branches the RF band hybrid 3 and the IF band hybrid 4 which orthogonally combines the rain intermediate frequency outputs of the two mixers lL12 of the balanced mixer 1 are fixed, and the RF band hybrid 3 which orthogonally branches the local carrier manual power Loin. This problem is solved by the present invention, in which a phase shifter 8 is provided between the balanced mixer 1 and either one of the two mixers 11 and 12, the phase of which can be changed by 180 degrees in response to an external control signal C.

In the principle diagram of FIG. 1 showing the configuration of the frequency converter of the present invention, 1 is the microwave input to the RF input terminal 5 in the same phase.
A balanced system in which the local carrier wave that is split and input and input to another LO input terminal 6 is mixed with two local carrier waves that are split into two in quadrature phase and whose phases differ by 90' from each other, and outputs the difference intermediate frequency signal. type mixer, the input microwave frequency fLO+f+y (upper band of local carrier wave) or its image frequency fLO-f+r (lower band of local carrier wave)
and the local carrier frequency f1.0, the intermediate frequency "1.
The intermediate frequency signal of
1.12 and 12, respectively, are output in quadrature phase.

2 is an in-phase hybrid that branches the microwave Rtn input to the RF input terminal 5 into two in the same phase.

3 is a local carrier wave Loin input to the LO human horn terminal 6
is divided into two branches with orthogonal phases, and the phases of the two branches differ by 90° from each other.
This is an RF band hybrid that outputs two local carrier waves.

4 is an IF band hybrid that combines two intermediate frequency signals of orthogonal phase outputted from the single mixer 11 and 12 of the flat and side mixer 1 in orthogonal phase;
Image frequency f, of frequency fLO+4+r (upper band of local carrier) of n. −far (lower band of the local carrier wave) and the intermediate frequency signal (
-far) cancels out, and the frequency fcoff of input Rin
+r and the frequency f of the local carrier. Outputs only the intermediate frequency signal (+f IF) of the difference between the two.

5 is a frequency f, which is the upper band of the local 111 transmission wave input to the in-phase hybrid 2; ) f, or its image frequency f9., which is the lower band of the local carrier. .

This is an RF input terminal for inputting f□ microwaves.

6 is a frequency f input to the RF band hybrid 3;

This is an LO input terminal that inputs the local carrier wave of .

7 is! There is an IF output terminal that outputs an intermediate frequency converted signal of the input frequency orthogonally synthesized by the F-band hybrid 4 and erases the intermediate frequency converted output of the image frequency.

8 is a phase shifter between the RF band hybrid 3 and either one of the two single mixers 11 and 12 of the balanced mixer 1, and whose phase can be changed by 180'' in response to an external control signal C.

[Effect]

The in-phase hybrid 2 has a frequency f, which is input to the RF input terminal 5. 10fIF or its image frequency fLO
- The microwave of fIF is split into two in the same phase, and the branched microwaves are sent in the same phase to each mixer 11, 1 of the balanced mixer 1.
Send to 2.

I? The F-band hybrid 3 branches the local general transmission wave input to the LO input terminal 6 into two in orthogonal phase, and the phases are 90° to each other.
One of the local carriers is directly supplied to one of the mixers of the balanced mixer l, for example mixer 11, while the other local carrier is supplied to the phase shifter 8.
It is supplied to the other mixer 12 of the balanced mixer 1 via.

The phase shifter 8 changes the phase of the local carrier wave branched and inputted by the RF band hybrid 3 by 180 degrees using an external control signal C, and transfers the local carrier wave shifted by 180'' to the mixer of the balanced mixer 1. Supply to 12.

A balanced mixer 1 consisting of a mixer 11 and a mixer 12 receives the microwave from the in-phase hybrid 2 at the same time as the mixer 11 inputs the microwave to another LO input terminal 6 and receives the RF.
Frequency f split into two in quadrature phase in band hybrid 3
One of the two local carrier waves whose LO phases differ by 90 degrees from each other is input and mixed. Then, the mixer 12 inputs the microwave from the in-phase hybrid 2 and the frequency f which is input to the LO input terminal 6 and orthogonally branched by the RF band hybrid 3.
Two local carrier waves whose LO phases differ by 90" from each other and the output of the other phase shifter 8 are input and mixed, and the frequency of the input microwave is f, fIF or its image frequency fLO-, respectively. Two intermediate frequency signals of orthogonal phase having an intermediate frequency fIF that is the difference between fIF and the local carrier frequency fLO are generated and output to the 1F band hybrid 4.

When the phase shifter 8 is not driven by the control signal C, the IF band hybrid 4 combines two intermediate frequency signals output from the mixer 11112 of the balanced mixer 1 in orthogonal phase, and generates an image of the input microwave. Frequency fLO −far
(lower band signal) and the frequency of the local carrier, f,. The difference between the intermediate frequency signals (-f IF) and the input microwave frequency f, cancel each other out. The intermediate frequency signal (+f
IF), but when the phase shifter 8 is driven by the control signal C, the quadrature phase output from mixers 11 and 12 of the balanced mixer 1 at a point whose phase differs by 180° from the previous one is output. Combines two intermediate frequency signals in orthogonal phase and outputs only the intermediate frequency signal (-r IF) that is the difference between the input microwave image frequency fLO-fIF (lower band signal) and the local carrier frequency fLO. and the upper band frequency f LOof fIF of the input microwave and the frequency fl of the local carrier wave. intermediate frequency signal (+f IF)
cancel each other out and do not output.

As described above, in the frequency converter of the present invention, depending on whether or not the phase shifter 8 is driven by the control signal C, the input RF multiplied signal frequency fin can be adjusted to f of the upper band USB of the local carrier wave.
LO+f IF and the lower band L of the local carrier
The problem is solved because the operation can be easily switched between the SB fLO4IF and the SB fLO4IF.

[Embodiment] FIG. 2 is a block diagram showing the configuration of a frequency converter according to an embodiment of the present invention.

In FIG. 2, circuits numbered 1 to 7 have the same configuration and function as the circuits with the same numbers in the conventional example shown in FIG. 3, and constitute an image cancellation type reception mixer.

The phase shifter 8 in FIG. 2 is composed of a reflection type phase shifter, specifically, a circulator 81. Transmission line 82, PI
N diode 83. Chalk 84. It consists of an input terminal 85 for control signals. Then, the circulator 81 orthogonally branches the local carrier wave LOin of frequency rto.
The output from the O° port of hybrid 3 is connected to the transmission line 82.
A PIN diode 83 is connected to the transmission line 82 at a length from its open end 821, and the length is equal to the frequency f of the local carrier power LOin. 1/4 wavelength λ
/4 selected. When there is no control signal C at the control signal input terminal 85, the PIN diode 83 exhibits high resistance, and the local carrier input Co1n is connected to the open end 82 of the transmission line 82.
1 is totally reflected and added to the single mixer 12 of the balanced mixer 1.

On the other hand, when the positive voltage signal of the control signal C is applied to the control signal input terminal 85, the PIN diode 83 has a low resistance, and the local carrier wave Loin is reflected here, and the control signal C
Balanced mixer 1 with a phase difference of 180° compared to the case without
is added to a single mixer 12.

Therefore, the frequency converter according to the embodiment of the present invention shown in FIG. The frequency fin of the F signal is the upper band signal USB f of the local carrier. ten f
There is no problem because the operation can be easily switched between the case of IF and the case of f LO-f IF of the lower band signal LSB of the local carrier wave, which is the image frequency.

Note that the explanation of the frequency converter of the embodiment shown in FIG. 2 has been made with respect to the frequency converter for reception, but the frequency converter for transmission which is the sum of the frequencies of the intermediate frequency signal and the local carrier wave and becomes the microwave transmission signal. As for the converter (so-called amplifier converter), the same structure and the same operation as in FIG. 2 can be obtained.

(Effects of the Invention) As described above, according to the present invention, a phase shifter with a simple configuration is provided, and the phase shifter is controlled by turning on/off a DC voltage of a control signal from outside, and can be easily input. When the frequency of the signal is the upper band signal USB of the local carrier wave, and its image frequency is the lower band signal LSH of the local carrier wave.
Since frequency conversion is performed by easily switching between the frequency converter and the frequency converter, there is no need to change the circuit pattern as in the conventional case, and it is also possible to perform the switching by remote control from a location away from the frequency converter.

[Brief explanation of drawings]

Figure 1 is a principle diagram showing the configuration of a frequency converter according to the present invention, Figure 2 is a block diagram showing the configuration of a frequency converter according to an embodiment of the present invention, and Figure 3 is a block diagram of a conventional frequency converter. be. In the figure, l is a balanced mixer, 2 is an in-phase hybrid, 3 is a quadrature-phase RF hybrid, 4 is a quadrature-phase IF hybrid, 5 is an RF input terminal, 6 is an LO input terminal, and 7 is an I
F output terminal 8 is a phase shifter.

Claims (1)

[Claims] Two microwave signals obtained by branching (2) an input microwave (RFin) in the same phase and a separately input local carrier wave (L
RF band hybrid (3
) are mixed with the two local carrier waves of the output of the input microwave (f_L_O+f_I_F or its image frequency f_L_O−f_I_F) and the intermediate frequency (f_I_F) of the difference between the frequency of the local carrier wave (f_L_O).
) and a balanced mixer (1) consisting of two single mixers (11, 12) that respectively output intermediate frequency signals of orthogonal phase.
In a frequency converter consisting of an IF band hybrid (4) that cancels and outputs an intermediate frequency signal of -f_I_F), two single mixers (11), the RF band hybrid (3) and the balanced mixer (1) , 12) is provided with a phase shifter (8) that changes the phase by 180° in response to an external control signal (C), and is inputted by the control signal (C) of the phase shifter (8). microwave is in the upper band of the local carrier (f_L_O+f_I_F)
A frequency converter is characterized in that it performs conversion by switching between the case of the image frequency and the case of the image frequency which is the lower band (f_L_O-f_I_F).