RU2494501C1 - Out-of-limit waveguide load - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: out-of-limit waveguide load consists of a section of a rectangular waveguide with length of at least 2/5 of the wavelength at the highest frequency of the operating frequency band and a short-circuiting wall and is used in dielectric-filled waveguide channels. The out-of-limit waveguide load is used to reflect TE modes while maintaining phase and amplitude owing to the effect of coherent reflection of waves inside the section of the out-of-limit rectangular waveguide.

EFFECT: providing complete coherent wave reflection by a load in a wide band in dielectric-filled rectangular waveguide channels.

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Description

The invention relates to the field of microwave (microwave) radio engineering and can be used in waveguide measuring, antenna technology, receiving and transmitting microwave devices.

A known design of a short-circuit waveguide load on a waveguide of rectangular cross section [I.V. Lebedev. Microwave engineering and instruments, 1970], taken as a prototype. This load is a segment of a rectangular waveguide ending with a short-circuit wall on one side. The distance from the open part of the waveguide channel to the wall is often chosen to be equal to a quarter of the wavelength in the waveguide path, which is necessary in matching various microwave devices. This type of load is used to obtain waves in the path that are identical to the original in amplitude and phase, but opposite in direction. This prototype has the following drawback: the phase of the reflected wave is identical to the initial one only at one point in the frequency band of the waveguide path, which leads to the limitation of the working frequency band to 10-20%.

The aim of the invention is the implementation of full in-phase reflection of a wave by a load in a wide frequency band (up to 66%) in rectangular waveguide paths with dielectric filling.

To achieve this goal, a transverse waveguide load (ZVN) is proposed, consisting of a segment of a rectangular waveguide and a short-circuit wall.

According to the invention, the load is used in waveguide paths with dielectric filling, the length of the waveguide is extraordinary and has a length of at least 2/5 of the wavelength at the highest frequency of the working frequency band.

The combination of distinctive features and properties of the proposed transcendental waveguide load from the literature are unknown, therefore, it meets the criteria of novelty and inventive step.

Figure 1 shows the structural diagram of the device.

Figure 2 shows possible schemes for connecting the load to the waveguide path with dielectric filling.

Figure 1 shows: a segment of a transverse rectangular waveguide (1) of length a and a short-circuiting wall (2).

The goal is achieved due to the total in-phase reflection of the wave entering the ZVN in the volume of the segment of the transcendent waveguide (1) with a length of at least 2/5 of the wavelength at the highest frequency of the working frequency band. Minor energy residues not reflected by the transverse waveguide (1) are reflected by a short-circuiting wall (2) in order to avoid energy leakage from the path.

The principle of operation of the device is to reflect the input TE wave in the volume of the segment of the transcendental waveguide (1). For the operation of this load, the wave H10 is used, propagating in a rectangular waveguide with a dielectric constant of a medium larger than that in the ZVN, with a cross section identical to the section of the ZVN. The load length is due to the principle of reflection of the wave in the volume of the transcendental waveguide.

A wide frequency band of the device is ensured by the fact that the reflection in the volume of the transcendental waveguide is almost independent of frequency. According to Maxwell's equations [I.V. Lebedev. Microwave equipment and devices. 1970], a wave in a rectangular waveguide, omitting the factor e ^{-j (ωt-βz)} , can be decomposed into components:

$$\{\begin{array}{l}{E}_y=-D\frac{\omega \pi }{a}\sin \left(\frac{\pi }{a}x\right)\\ H_x=D\frac{\beta \pi }{\mu {\mu }_{0}a}\sin \left(\frac{\pi }{a}x\right),\left(\mathrm{one}\right)\\ H_z=-jD\frac{{\pi }^2}{\mu {\mu }_0{a}^2}\cos \left(\frac{\pi }{a}x\right)\\ E_x=H_y=E_z=0\end{array}$$

where E _x , E _y , E _z are the components of the electric field in the waveguide channel,

H _x , H _y , H _z are the components of the magnetic field in the waveguide channel,

ω = 2πf is the circular frequency,

β is the longitudinal wave number,

µ is the magnetic constant of the medium,

µ ₀ is the magnetic constant of the vacuum,

a is the width of the larger wall section of a rectangular waveguide channel,

D is a quantity, generally depending on power.

$${\beta }^2=k^2-{\pi }^2\left(\frac{m^2}{a^2}+\frac{n^2}{b^2}\right),k^2={\omega }^2\epsilon {\epsilon }_0\mu {\mu }_0,\left(2\right)$$

where k is the wave propagation constant,

ε is the dielectric constant of the medium,

ε ₀ is the dielectric constant of the vacuum,

a is the width of the wide wall section of a rectangular waveguide channel,

b is the width of the narrow wall of the waveguide channel,

m and n are integers H _mn , for the wave H ₁₀ -m = 1, and n = 0.

When a wave passes from the input path to the volume of a segment of a transcendent rectangular waveguide, according to equation (2), the value of β becomes imaginary. In this case, the amplitude H _x becomes imaginary. This gives rise to a wave that is identical in phase and opposite in direction.

The phase of the wave reflected from the ZVN extremely weakly depends on the frequency within the working frequency band of a rectangular waveguide path with dielectric filling. This allows us to consider the ZVN weakly dependent on the frequency within this task.

Thus, the invention provides an increase in the working frequency band compared to the prototype.

Figure 2 shows the possible load connection schemes: A - coaxial to the input waveguide path, B - perpendicular to the input waveguide path from the side of the wide wall, B - perpendicular to the input waveguide path from the side of the narrow wall, where VT is the input waveguide path with dielectric filling, ZVN - transcendental waveguide load.

Claims (1)

The transcendental waveguide load, consisting of a segment of a rectangular waveguide and a short-circuiting wall, characterized in that the load is used in waveguide paths with dielectric filling, the transducer segment is transcendental and has a length of at least 2/5 of the wavelength at the highest frequency of the working frequency band.

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