RU1798839C - Waveguide polarizer - Google Patents

Abstract

The invention relates to radio engineering and can be used for an electromagnetic field in transmission paths. The goal is to increase electrical strength. The polarizer comprises a segment of a square waveguide connected to segments of a rectangular waveguide having a common narrow wall by a transition. The transition is made in the form of a waveguide of a T-shaped cross section. The limits of the size of the transition in the direction of the segment of the square waveguide and the formula for determining its length are given. 3 ill.

Description

The invention relates to radio engineering and can be used in antenna-waveguide paths as a device for converting polarization of an electric field.

. The purpose of the invention is to increase electric strength.

In FIG. 1 shows a device; in FIG. 2 - device, isometrics; in FIG. Figure 3 shows the structure of the electric field in various sections of the waveguide polarizer for even and odd types of waves.

The waveguide polarizer comprises a segment of a square waveguide 1 connected by a transition 2 to two rectangular waveguides 3.4 connected by a common narrow wall. Transition 2 is made in the form of a T-shaped waveguide of variable cross section, in which the size of the wide wall c increases from a value equal to the width of a square waveguide 1 to a doubled width 2ap of a rectangular waveguide 3.4, the height h decreases from a value equal to the height of 3c square waveguide 1, to a height p of a rectangular waveguide 3.4, the height hi of the narrow part of the T-shaped waveguide increases from 0.01 mm to a value equal to the height b of the rectangular waveguide 3.4, and the width d of the central part of the T-shaped waveguide decreases from different quantities the width a of the square waveguide 1, to a value ranging from 0.01 mm to the width a of the square waveguide. The size of 0.01 mm is set due to the presence of tolerances in the manufacture of the transition.

The waveguide polarizer (Figs. 1 and 2) works as follows.

An HIQ type wave enters one of the rectangular waveguides, for example, waveguide 3. This wave can be decomposed into two waves of the Hto type of the same amplitude, which are in phase in one rectangular waveguide (in waveguide 3) and antiphase in the other (in waveguide 4). The superposition of these two waves is equivalent to the fact that a wave of double amplitude enters the waveguide 3, and there is no incident wolf in the waveguide 4.

s

Thus, when 3.4 antiphase waves arrive from the waveguides, a field appears whose structure corresponds to a wave of type H Nao (odd type), and when common-mode waves arrive, a field appears whose structure corresponds to a wave of Ho (even type) (Fig. 3). A further transformation of each type of wave is shown in: FIG. 3 ,. -H; l-: -; -. :

The length (of transition 2 is chosen so that at the output of the transition these waves acquire a phase shift, equal to l: / 2. This condition is satisfied if the difference between the electric transition lengths for waves of an even and odd type is equal to: --y -lch; -g-,

/ y ..

..... 4 F.JQ A. f t -. AND . {-. Y: I 2 -

(.z) (P

n 2

where LD-Z) I, A (Z), respectively, the wavelengths of even and odd type in the T-shaped waveguide at the center frequency of the operating range; C I - transition length; , Z is the coordinate along the longitudinal axis of the transition. ;;;; i; -; - ;;; ;; -;. ;; ; v4v - ;; V -., - .-:: l ,; To determine the length I, consider transition 2 of unit length. It gives: the difference in electric lengths for an even and odd type of waves equal to; ...; :

g

L „(z)

dz

In order to difference the electric ..; -, the lengths for the even and odd types of waves of transition 2 was equal to / 2, its length must be chosen from the condition: 4

"L

II-TRIJ

-) dz

Then, as a result of a superposition of mutually perpendicular linearly polarized waves with equal amplitudes and a phase shift of / 2 in a square waveguide 1, a circularly polarized wave is obtained. In the event that the incoming Nu enters the waveguide 4. then, similarly to reasoning, we will also obtain in the square waveguide 1 a wave of circular polarization, but of the opposite direction of rotation of the electric field vector. In the case when the device requires simple design and manufacturing technology, then re

10

fifteen

twenty

0 -. R

35

.; - , 4

45

50 55, travel 2 from rectangular waveguides 3.4 to square waveguide 1 can be linear. When it is required to achieve high agreement in a wide frequency range, then transition 2 should be performed smoothly complex or stepwise.

Claims (1)

It should be noted that the length of transition 2 can also be chosen such that waves of even and odd type at the output of transition 2 will be in phase if the difference in the electrical lengths of transition 2 for even and odd types of waves is a multiple of ft. In this case, a linearly polarized wave forms in the square waveguide 1, the electric field strength vector is oriented along the diagonal of the square waveguide. This means that the proposed device can also be used as a polarized selector. SUMMARY OF THE INVENTION: A waveguide polarizer containing a cut of a square waveguide connected by a junction with two segments of a rectangular waveguide having a common wall, and so that, in order to increase the electric strength, the junction made in the form of a waveguide of a T-shaped cross section, the dimensions of which vary with the direction to a segment of a square waveguide within 2a c ak. Bh 8k,. b hi 0.01 n (0.01 ... ak) d ak. where a. b - respectively, the width and height of the cross section of a segment of a rectangular waveguide; ak is the side size of a segment of a square waveguide; c, d — cb, respectively, the width of the wide and narrow parts of the waveguide of the T-shaped cross section; h, hi - respectively, the full height and height of the wide part of the waveguide of the T-shaped cross section, when this, the segments of the rectangular waveguide have a common narrow wall, and the length of the I transition is 1 4 / ( ) dz where Ax (z), A ,, (z) are the wavelengths of even and odd type in the T-shaped waveguide at the center frequency of the operating range, respectively; Z coordinate along the longitudinal axis of the transition. nf P 71 HE G) ssg l