RU8186U1 - BROADBAND DOUBLE BALANCE MIXER - Google Patents

Abstract

A broadband double balanced mixer containing two converting modules, the heterodyne inputs of which are connected respectively to the common-mode and quadrature outputs of the first quadrature bridge, the bridge input is connected to the heterodyne input of the mixer, and the ballast output is connected to the first ballast load, and the second quadrature bridge, whose ballast output is connected with a second ballast load, characterized in that a phase inverter is inserted into it, connected between the output of the second converting module and the output of the first transform present module connected to the load, and the signal inputs of the first and second converting units connected respectively to in-phase and quadrature outputs of the second quadrature bridge whose input is connected to the signal input of the mixer.

Description

BROADBAND DOUBLE BALANCE MIXER

The utility model relates to radio engineering, in particular to radio reception technology, and can be used in panoramic survey receivers and in other broadband devices of telecommunication equipment.

A balanced conversion module is known that contains two diodes connected in series, the common connection point of which is connected to the load, the anode of the first diode is connected to the first terminal, and the cathode of the second diode is connected to the second terminal of the transformer secondary winding, the primary transformer winding is connected to the signal input and to the common wire , the middle point of the secondary winding of the transformer is connected to the input of the local oscillator 1, p. 102, Fig. 5.26, c. However, the known device does not provide selectivity for the mirror channel of the reception.

The closest in technical essence and the achieved result to the proposed solution is a broadband double balanced mixer containing two converting modules, the heterodyne inputs of the first and second converting modules are connected respectively to the common-mode and quadrature outputs of the heterodyne quadrature bridge, the input of which is connected to the heterodyne input of the mixer, and the ballast output is connected to the first ballast load, the signal inputs of the first and second converting modules are connected to the outputs of the oinnika (in-phase directional power divider), the input of the tee is connected to the signal input of the mixer, and the outputs of the converting modules are connected to the hub via a second quadrature bridge containing the second ballast load 2, p. 119, Fig. 4.21. However, the known mixer due to the characteristics of the tee has a small frequency range of operation, insufficient attenuation of the local oscillator signal at the signal input and insufficient attenuation of the signal at the local oscillator input.

H 03 D 7/04

two conversion modules, the heterodyne inputs of which are connected respectively to the common-mode and quadrature outputs of the first quadrature bridge, the input of the bridge is connected to the heterodyne input of the mixer, and the ballast output is connected to the first ballast load; and a second quadrature bridge, the ballast output of which is connected to the second ballast load, a phase inverter is inserted, connected between the outputs of the second and first converting modules, the output of the first converting module is connected directly to the load, the signal inputs of the first and second converting modules are connected respectively to common-mode and quadrature outputs the second quadrature bridge, and the input of the second quadrature bridge is connected to the signal input of the mixer.

The introduced phase inverter can be made, for example, on the basis of a segment of a two-wire transmission line covered by a magnetic circuit 3, p. 17, Fig. 1.14.

By eliminating the tee and the described circuit changes, the frequency range of the mixer increases, the attenuation of the local oscillator signal at the signal input increases, and the attenuation of the signal at the heterodyne input increases.

Figure 1 presents the structural diagram of the proposed broadband double balanced mixer, figure 2 - the transmission characteristics of the quadrature bridge and tee, and Fig.Z - standing wave coefficients (SWR) of the quadrature bridge and tee in offsets normalized center frequency.

The mixer contains a first converting module 1 and a second converting module 2, the heterodyne inputs of which are connected respectively to the common-mode and quadrature outputs of the first quadrature bridge 3, and

the signal inputs are connected respectively to the common-mode and quadrature outputs of the second quadrature bridge 5, the input of the first quadrature bridge 3

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connected to a source of oscillations 9, and its ballast output is connected to the second ballast hub 6, a phase inverter 8 connected between the output of the second conversion module 2 and the output of the first conversion module 1 connected to the load 7.

The mixer operates as follows. Direction 5 "the Kenyan local oscillator with a frequency fg enters the input of the first bridge 3 and from its common mode output without

phase shift arrives at the heterodyne input of the first converting module

1.From the quadrature output of the first bridge 3, the local oscillator voltage with a phase shift of -71/2 is applied to the heterodyne input of the second converting module

2. The voltage of the signal with a frequency fg is fed to the input of the second bridge

a common-mode output without a phase shift is fed to the signal input of the first converting module 1. From the quadrature output of the second bridge 5, the voltage of the signal with a phase shift - tf / 2 is fed to the signal input of the second converting module 2. Under the action of the local oscillator and the signal, the output of the balanced converting modules Raman voltage

± nifs ± (2n + l) fg |, (t 0,1,2 ...; n 0,1,2, ...). (1)

moreover, the phase delay of the voltages of the combination frequencies of the form (1) at the output of the first module (hereinafter it is assumed that the phase delays due to the inertia of module 1 and module 2 are the same and are not taken into account when considering the operation of the mixer):

Ф, ± mq) s ± (2n + l) 9g; (2)

at the output of the second module 2:

92- ± m (9s-7t / 2) ± (2n + l) (9g-7i / 2), (3)

where fd, 9g are the initial phases of the signal and local oscillator on the signal and

heterodyne mixer inputs

double frequency conversion 3 is used, p. 123, the first frequency converter being step-up and its intermediate frequency

In this case, the useful signal forms at the output of the first module 1, in accordance with (1), an intermediate frequency voltage with a phase delay

9l (fg + fg) 9s + 9g, (6)

and at the output of the second module 2, in accordance with (2), the voltage of the intermediate frequency with a phase delay

92 (fs + fg) 9s + 9g- - (7)

As follows from (6) and (7), the intermediate frequency voltages generated by the signal conversion at the outputs of module 1 and module 2 are out of phase. The phase inverter 8 changes the phase of the output voltage of the intermediate frequency of module 2 by the angle tg, which leads to the summation of the voltage of the intermediate frequency from module 1 and from module 2 in the load of the mixer 7.

The interference with the frequency of the mirror channel (4) generates an intermediate frequency voltage with a phase delay at the output of the first module 1

9lz (fz-fg) 9z-9g. (8)

and at the output of the second module 2 with a phase delay

Ф2z (fz-fg) Фz-фg- / 2 + 7T / 2-ф2-фg. (9)

From (8) and (9) it follows that at the outputs of module 1 and module 2, the intermediate-frequency voltages from interference through the mirror channel are in phase. The phase inverter 8 changes the phase of the output voltage of module 2 by an angle tf, which leads to mutual suppression of intermediate frequency voltages from module 1 and from module 2 in the load of mixer 7. Thus, the proposed device retains the prototype property by phase suppression of reception through the mirror channel.

4 - fg + h ()

fh-fs + fg. (5)

module 2 due to its final attenuation in the modules, it enters the signal input of the mixer in two circuits with different phase delays. The phase delay along the first circuit (input is the common mode output of the first bridge 3, first module 1, common mode output is the input of the second bridge 5) is determined only by the initial phase of the local oscillator:

Phase delay along the second circuit (input - quadrature output of the first bridge 3, second module 2, quadrature output - input of the second bridge 5):

Ф2gs Фg 2 2 фg-7I. (11)

From (10) and (11) it follows that the local oscillator voltage, not completely suppressed by module 1 and module 2, have opposite phases at the input of the proposed mixer and are mutually compensated. Thus, in contrast to the prototype (in the prototype, the voltage of the local oscillator from module 1 and from module 2 are summed up at the signal input in quadrature), the proposed device has a positive property of suppressing the voltage of the local oscillator at the signal input.

The signal voltage from the signal input of the mixer enters the heterodyne input of the mixer in two circuits. First circuit: input - common-mode output of the second bridge 5, module 1, common-mode output - input of the first bridge 3. Second circuit: input - quadrature output of the second bridge 5, module 2,

quadrature output - input of the first bridge 3. Phase delay along the first circuit

second circuit phase delay

92sg 9s / 2-7C / 2 9s-7C. (13)

From (12) and (13) it follows that the signal voltages at the heterodyne input of the proposed mixer are mutually compensated due to their antiphase, which is the second positive property when compared with the prototype (in the prototype, the signal voltages at the heterodyne input are summed in quadrature).

9lgs 9g. (10)

.(12)

Figure 3 shows the calculated dependences in offsets of the normalized central frequency of 1 f / f transmission coefficients (relative to the emf of the signal) of the quadrature bridge (K1kvm to common mode output, K2kvm to quadrature output) and tee (Kt) taking into account the values of their standing wave coefficients (KSVkvm - quadrature bridge, KSW - tee, Fig.Z). The calculation of the SWR and KW is carried out under the assumption that the SWR of the converting modules is 1.3 (the value achieved in practice). To reduce the non-identity of the transmission coefficients at the outputs of the quadrature bridge, the values of its resistances of the even and odd type of oscillations are selected: g ++ 133 Ohm; 8Ohm 4, p. 27-29. In this case, the intersection of the dependences K1kvm (Rn) and K2kvm (Rn) occurs at points Rn 1 ± 0.3 with the identical transmission coefficients to the common-mode and quadrature outputs 1 dB in the band (0.6 ... 1.4) Rn (cm Fig. 2)

From the dependencies of Figure 2 it follows that with limited unevenness of the transmission coefficient of 1 dB, the mixer with a signal quadrature bridge has

bandwidth normalized to f (Pkvm) approximately 1.26 times

more than a mixer with a tee (Fri). The increase in the operating frequency range of the proposed mixer is the third positive property when compared with the prototype.

Thus, the positive effect of the utility model is 1) to increase the frequency range of operation, 2) to increase the attenuation of the local oscillator signal at the signal input of the mixer, 3) to increase the attenuation of the signal at the local oscillator input of the mixer. A positive effect is achieved due to the inclusion of a signal quadrature bridge instead of a tee at the input, and a phase inverter instead of a quadrature bridge at the output.

Due to the combination of newly introduced features, the proposed wideband double balanced mixer on diodes AA112A compared with the known device with uneven frequency response of 1 dB and an intermediate frequency fj, 960 MHz based on experimental studies

It has:

the signal frequency range is 1.48 times greater (95 ... 235 MHz versus 120 ... 200 MHz);

the attenuation of the local oscillator signal at the signal input of the mixer is 8 dB more (30 dB versus 22 dB);

the attenuation of the signal at the heterodyne input is 11 dB more (38 dB versus 27 dB).

1. Radio receivers / Ed. A.P. Zhukovsky. - M.: Higher School, 1989. -343s.

2. Solid-state microwave devices in communication technology / L. G. Gassanov, A.A. Lipatov, V.V. Markov, N.A. Mogilchenko. - M .: Radio and communications, 1988 .-- 288 s.

3.Red E.T. Reference manual on high-frequency circuitry. - M .: Mir, 1990.-256s.

4. Microelectronic devices microwave / N.T. Bova, Yu.G. Efremov, V.V. Konin and others K.: Technique, 1984.-184 p.

f; /; e; zf /

LITERATURE

Applicant: Vice-Rector for

HS. Sharygin

Claims (1)

A broadband double balanced mixer containing two converting modules, the heterodyne inputs of which are connected respectively to the common-mode and quadrature outputs of the first quadrature bridge, the bridge input is connected to the heterodyne input of the mixer, and the ballast output is connected to the first ballast load, and the second quadrature bridge, whose ballast output is connected with a second ballast load, characterized in that a phase inverter is inserted into it, connected between the output of the second converting module and the output of the first transform present module connected to the load, and the signal inputs of the first and second converting units connected respectively to in-phase and quadrature outputs of the second quadrature bridge whose input is connected to the signal input of the mixer.