RU184445U9 - Broadband power addition device for RF oscillators - Google Patents

Abstract

The utility model relates to radio engineering and can be used in radio communications, in particular in powerful broadband transistor radio transmitting devices.

The technical result is the expansion of the operating range of the adder in the high frequency region.

To do this, in the broadband device for adding the power of RF generators of electrical oscillations, the beginning of the braid (1.2) of the first segment of the coaxial cable is connected to the end of the braid (2.2) of the second segment of the coaxial cable, the beginning of which is connected to the end of the braid (1.2) of the first segment of the coaxial cable, while the ballast resistor (3) is connected between the connection points of the beginning and end of the braids of the first (1.2) and second (2.2) segments of the coaxial cable, respectively, in addition, the ends of the inner conductors of the first (1.1) and second (2.1) segments coaxial cable combined and are the output of the device. 3 ill.

Description

The utility model relates to radio engineering and can be used in radio communications, in particular in powerful broadband transistor radio transmitting devices.

In modern high-power radio transmitting devices, the method of adding the power of individual transistor generators using bridge devices has become widespread. Subject to the balance conditions of the bridge circuit, the currents of one of the generators are mutually compensated at the terminals of another generator, thereby not creating voltage at these terminals, as a result of which the generators operate independently of each other.

The most important characteristics of bridge adders are the SWR of inputs σ and the degree of their isolation ξ. For practical use, it is considered sufficient to provide σ ≤ 1.2 and ξ ≥ 20 dB in the operating frequency range [Design and technical operation of radio transmitting devices / M.A. Sivers, G.A. Zeitlenok, Yu.B. Nesvizh, et al .: Textbook. manual for universities. - M .: Radio and communications, 1989., Broadband radio transmitting devices (RF paths on semiconductor devices) / Alekseev O.V., Golovkov A.A., Polevoy V.V., Soloviev A.A .; Ed. O.A. Alekseeva. - M.: Communication, 1978.]

Structurally, the adders are made of segments of transmission lines, which can be, for example, segments of a two-wire line, strip or coaxial cable, wound, if necessary, on ferrite cores, i.e. transmission lines are used in the form of long-line type transformers.

Known are the addition devices of two RF generators made using two long-line type transformers based on coaxial cable segments [Broadband radio transmitting devices (Radio frequency paths on semiconductor devices) Alekseev OV, Golovkov AA, Polevoy VV, Soloviev A.A .; Ed. O.A. Alekseeva. - M .: Communication, 1978., Andrei Grebennikov, "RF AND MICROWAVE TRANSMITTER DESIGN". A JOHN WILEY and SONS. 2011 .; Devices for adding and distributing high-frequency oscillation capacities Zentsev, V.M. Katushkina, S.E. London, Z.I. Model; Ed. Z.I. Model. - M .: Owls. radio, 1980., Design of radio transmitting devices: Textbook. manual for universities / V.V. Shahgildyan, V.A. Vlasov, V.B. Kozyrev et al .; Ed. V.V. Shahgildyan. - 3rd ed., Revised. and add. M .: Radio and communications, 1993 - 512 p., H. Granberg. BROADBAND TRANSFORMERS AND POWER COMBINING TECHNIQUES FOR RF. APPLICATION NOTE AN749, Motorola. 1993].

The closest analogue in technical essence to the proposed one is the bridge adder of the power of two generators, presented in [Degtyar G.A. Transformers in the coordination circuit and the addition of the power of radio-frequency generators: Textbook. allowance. - Novosibirsk: Publishing House of NSTU, 2003 .-- 504 p. - (Series "Textbooks of NSTU"), Fig. P.5.8.], Adopted as a prototype.

The circuit of the prototype device is shown in FIG. 1, where indicated:

1, 2 - the first and second segments of the coaxial cable;

1.1, 1.2 - the inner conductor and the braid of the first segment of the coaxial cable;

2.1, 2.2 - the inner conductor and the braid of the second segment of the coaxial cable;

3 - ballast resistor;

n, k - the beginning and ends of the inner conductors and braids of the segments of the coaxial cable.

The prototype device (adder) contains two identical along the length of the length of the coaxial cable 1 and 2, which are located on separate ferrite cores, and a ballast resistor 3 (Fig. 1). Moreover, the beginning of the inner conductor 1.1 of the segment of the coaxial cable 1 is connected to the first generator input of the adder, the end of the inner conductor 1.1 of the segment of the coaxial cable 1 is connected to the end of the inner conductor 2.1 of the segment of the coaxial cable 2 and the first terminal of the ballast resistor 3. The second terminal of the ballast resistor 3 is connected to the end of the braid 1.2 of the length of coaxial cable 1 and the end of the inner conductor 2.1 of the length of coaxial cable 2.

The beginning of the inner conductor 2.1 of the segment of coaxial cable 2 is connected to the second generator input, and the beginning of the braid 1.2 of the segment of coaxial cable 1 is connected to the output of the adder and the beginning of the braid 2.2 of the segment of coaxial cable 2.

The prototype device works as follows.

In the coordinated mode, equal amplitude and common-mode signals of the generators are fed to the first and second generator inputs of the adder and propagated, respectively, along the segments of coaxial cable 1 and 2 to the output of the adder, where they are summed in the load of the adder without reflections if its resistance is equal to the wave impedance of each of the segments of the coaxial cable 1 and 2, while the potentials at the terminals of the ballast resistor 3 are the same, and power is not transmitted to the ballast resistor.

Changing the amplitudes and phases of the signals supplied to the generator inputs of the adder leads to a redistribution of signals between the adder load connected to its output and the ballast 3. In the worst case, for example, when one of the generators is turned off, half of the power of the second working generator is transferred to the adder load , and the other half of this power is transmitted to the ballast resistor 3 and dissipated in it.

The disadvantage of the prototype device is the low upper operating frequency, determined by the permissible isolation value between the inputs of the adder ξ ≥ 20 dB

The objective of the proposed technical solution is to expand the operating range of the adder in the region of high frequencies.

To solve this problem, in a broadband device for adding the power of HF generators of electrical oscillations, containing two identical lengths of coaxial cable located on separate ferrite cores, as well as a ballast resistor, with the beginning of the inner conductors of the first and second segments of the coaxial cable connected to the first and second inputs accordingly, according to a utility model, the beginning of the braid of the first segment of the coaxial cable is connected to the end of the braid of the second segment of the coaxial about the cable, the beginning of which is connected to the end of the braid of the first segment of the coaxial cable, while the ballast resistor is connected between the connection points of the beginning and end of the braids of the first and second segments of the coaxial cable, respectively, in addition, the ends of the inner conductors of the first and second segments of the coaxial cable are combined and are the output devices.

A diagram of the proposed device is shown in FIG. 2, where indicated:

1, 2 - the first and second segments of the coaxial cable;

1.1, 1.2 - the inner conductor and the braid of the first segment of the coaxial cable;

2.1, 2.2 - the inner conductor and the braid of the second segment of the coaxial cable;

3 - ballast resistor;

n, k - the beginning and ends of the inner conductors and braids of the segments of the coaxial cable.

The proposed device (adder) contains two identical along the length of the length of the coaxial cable 1 and 2, which are located on separate ferrite cores, and a ballast resistor 3, and the beginning of the inner conductor 1.1 of the first segment of the coaxial cable 1 is connected to the first generator input of the adder, the beginning of the inner conductor 2.1 the second segment of coaxial cable 2 is connected to the second generator input, the beginning of the braid 1.2 of the first segment of coaxial cable 1 is connected to the end of the braid 2.2 of the second segment of coaxial th cable 2, the beginning of which is connected to the end of the first section 1.2 braid of the coaxial cable. In addition, the ballast resistor 3 is connected between the beginnings of the braids of the first 1.2 and second 2.2 segments of coaxial cables 1 and 2. Moreover, the ends of the inner conductors of the first 1.1 and second 2.1 segments of coaxial cable 1 and 2 are connected to the output of the device.

The proposed device operates as follows.

In the coordinated mode, equal amplitude and common-mode signals of the generators are fed to the first and second generator inputs of the adder and propagated, respectively, along the lengths of coaxial cable 1 and 2 to the output of the adder, where they are summed in the adder load without reflections if its resistance is equal to the wave resistance of each of the segments of the transmission line 1 and 2, while the potentials at the terminals of the ballast resistor 3 are the same, and power is not transmitted to the ballast resistor.

The change in the amplitudes and phases of the signals supplied to both generator inputs of the adder leads to a redistribution of signals between the adder load connected to its output and the ballast 3. In the worst case, for example, when one of the generators is turned off, half the power of the second working generator is transferred to the adder load , and the other half of this power is transmitted to the ballast resistor 3 and dissipated in it. Moreover, the presence of a ballast resistor provides electrical isolation of the inputs of the adder.

In FIG. 3. presents the dependence of the isolation ξ between the inputs of the adder on the frequency (prototype device is curve 1, the proposed device is curve 2).

As can be seen from FIG. 3 data in the proposed device, the frequency at which the isolation between the inputs of the adder ξ ≥ 20 dB is much higher than in the prototype device.

Claims (1)

A broadband device for adding the power of HF generators of electrical oscillations, containing two identical lengths of coaxial cable segments located on separate ferrite cores, as well as a ballast resistor, and the beginning of the inner conductors of the first and second segments of the coaxial cable are connected to the first and second inputs, respectively, characterized in that the beginning of the braid of the first segment of the coaxial cable is connected to the end of the braid of the second segment of the coaxial cable, the beginning of which is connected to the end of the braid of the first segment of the coaxial cable, while the ballast resistor is connected between the connection points of the beginning and end of the braids of the first and second segments of the coaxial cable, respectively, in addition, the ends of the inner conductors of the first and second segments of the coaxial cable are combined and are the output of the device.

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