SU568164A1 - Shf mixer - Google Patents

Description

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The invention relates to radio engineering and can be used in the microwave paths of receiving devices of radio signals.

A super high frequency mixer is known to have a balanced ring, one arm of which is signal, the other heterodyne, and the other diodes flj are connected to the other two arms through high-pass filters.

However, this mixer does not provide optimal operation when converting according to the second harmonic of the local oscillator.

The purpose of the invention is to ensure optimal operation when transforming according to the second harmonic of the heterodyne.

To do this, an ultrahigh-frequency mixer that has a balanced ring, one arm of which is signal, is second-heterodyne, and two diodes, through the high-pass filters are connected to the mixing diodes, are added an additional arm with a multiplying diode connected to the balance ring for distances x, equal to a quarter of the wavelength of the input signal from shoulders with mixing

diodes, and diametrically prot: the opposite heterodyne shoulder.

The drawing shows a functional diagram of the microwave mixer.

The microwave mixer contains a balanced ring 1, the arm 2 of which is signal, the arm 3 is heterodyne, arm 6 and 7 are connected to arm 4 and 5, respectively, and the mixing diodes 8 to 9 are connected to arm 6, and the additional arm 10 is connected with multiplied diode 11 .to a balanced ring 1 at distances equal to a quarter of the wavelength of the input signal. From shoulders 4 to 5 with mixing diodes 8 to 9, diametrically opposed to heterodyne arm 3, at the input of the heterodyne arm 3 BKXIXV a low-pass filter 12 for blocking the heterodyne leg 3 from the frequency of the input signal.

The microwave mixer works as follows.

Claims (2)

The total circumference of the ring is 3 / i A. 1 where I-c is the wavelength of the input signal. Since the conversion is at the second harmonic of the local oscillator and the frequency of the input signal is not much different from the second harmonic of the local oscillator 2 f ,. , then it can be assumed that f- f c / 2, thus, with inaccurate geometrical dimensions, the total circumference of the ring is approximately equal to 3 / VAp, where is the heterodyne wavelength. The nearest shoulders 2 3, 2 5, 5 and 10 10-4 are located at a distance Ls / or Ar / s, which is the same. Shoulders 3 and .4 are located at a distance;, / 2 or Ar / H. When feeding into the shoulder 3 of a scoop heterodyne with a frequency of tp, shoulder 2 is compressed discharged from section 3. This is illustrated by calculating the phase difference between the signals coming from shoulder 3 to shoulder 2 at different distances around the circumference of the ring. The difference in the length of the path will have the form yg. Consequently, the signals are passed in opposite phase, mutually compensate, and the power with fp does not leak into arm 2, thereby providing one of the most important parameters of the mixer, the isolation between the local oscillator and signal. The remaining plzchi are not extended from shoulder 3; however, in front of the mixers 8, and 9, there are high-pass filters 6 and 7, which let only signals from frequencies {L two times higher than fp. . Consequently, the power of the local oscillator with f is supplied only to the placot 10 on the multiplying diode 11. Due to the n linear resistance of the multiplying diode 11, harmonics with a frequency nfj are formed (where P is 1,2,3, ...). In this case, the second harmonic is used. 2. From the shoulder 10, the power of this harmonic 16and spreads into the shoulders .4 S to the mixing diodes 8 and 9, where. and the conversion occurs, as these shoulders also receive input power. Thus, in the second harmonic 2 f, the circuit works as usual balanced, to fully imagine that arm 3 does not exist, which can be done, because arm 3 has a low-pass filter 12 that does not pass signals with frequencies twice as high as fji (t . e. 2 f, f c). Generic harmonics: the frequency of the local oscillator and the signal occur in different diodes, as a result of which the impedance matching frequency range of the diodes is divided; The diode generating the second harmonic needs to be matched only by the fundamental frequency, taking into account that it is not critical to the harmonic coordination. Thus, the smallest conversion losses and reduction of their non-uniformity in the operating range are ensured. Claims of the invention A microwave mixer with a balanced ring, one arm of which is signal, the other heterodyne, and the other two arms are connected through frequency filters mixing diodes, characterized in that, in order to ensure optimal operation when converting the second harmonic of the local oscillator, An additional arm with a multiplying diode, connected to the balance ring at distances equal to a quarter of the wavelength of the input signal from the shoulders with mixing diodes, and diametrically opposed to heterodyne shoulder. Sources of information taken into account in the examination; : 1. Golubev V.I. and others. Designing and calculating strip devices. Textbook for universities. Ed. prof. Kovaleva I.S., M. | Soviet Radio, 19/4, p. 134-142. // -m