RU2486640C1 - Waveguide-microstrip junction with below-cutoff load - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: waveguide-microstrip junction with a below-cutoff load, wherein a microstrip board is buried in an input waveguide channel with a rectangular cross-section perpendicular to its longitudinal axis, and a microstrip probe is deposited thereon, the probe being buried in the wide wall of the waveguide channel. Energy is output from the waveguide channel through an output microstrip line connected to the probe, which passes through an opening in the wide wall of the waveguide channel; furthermore, the waveguide-microstrip junction has a blade-type dielectric insert which forms a junction from the air waveguide channel to the dielectric-filled waveguide channel of a smaller cross-section, wherein the dielectric-filled waveguide is loaded by a below-cutoff waveguide load.

EFFECT: wider operating frequency band of the junction while maintaining the transfer constant.

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Description

The invention relates to the field of microwave (microwave) radio engineering, and more particularly to energy transfer devices on waveguide and microstrip lines, and can be used in measuring equipment, microwave transmitting and receiving devices, antenna technology.

Known waveguide-microstrip transition (VMP), in which a microstrip substrate with a microstrip line (MPL) is immersed in the transcendental waveguide path connected to the input dielectric waveguide channel of a similar cross section along the longitudinal axis of the waveguide path [Bharj Sarjit S. Evanscent mode waveguide to microstrip transition // Microwave Journal. - 1983, February]. This design has the following disadvantages: the irrational position of the microstrip line in the waveguide path makes it difficult to match, this transition has a narrow working frequency band (~ 15%), high intrinsic loss of the transition (up to 1 dB at the central frequency of 10 GHz).

The known design of the VMP from a rectangular waveguide channel on the MPL [B.N. Budanov, A.Ya. Ilyin, E.I. Chernenko. Measuring transition devices for microwave integrated circuits // Electronic Engineering. Ser 1. Electronics microwave. - 1975. - Issue 2. p. 76-80], taken as a prototype. In this design, a segment of a rectangular waveguide loaded on a reactive load (short-circuited quarter-wave loop) is used for energy transfer. The waveguide is connected with the MPL using a probe, which is a continuation of the MPL microstrip conductor, placed on a dielectric substrate and immersed through a gap in a wide wall. The energy transfer efficiency is determined by the orientation of the probe on the microstrip board relative to the waveguide walls, its dimensions, and also the length of the short-circuit load. To improve matching, the short-circuit load length is selected equal to about a quarter of the wavelength in the waveguide path at a frequency where the best matching is required. This design has the following disadvantage: the resonant nature of the short-circuit load greatly limits the width of the working frequency band of the device (about 25-30% at 40 GHz).

The aim of the invention is to increase the working frequency band of the transition while maintaining the magnitude of the transmission coefficient.

To achieve this goal, a micro-strip waveguide transition with an overload load is proposed, in which a microstrip board is immersed in a rectangular input waveguide channel perpendicular to its longitudinal axis and a microstrip probe is immersed in it, immersed in a wide waveguide channel wall, while the energy from the waveguide channel is output through microstrip output line connected to the probe passing through an opening in a wide wall of the waveguide channel.

According to the invention, it contains a knife-type dielectric insert forming a transition from an air waveguide channel to a waveguide channel with a dielectric filling of a smaller cross section, while the waveguide with dielectric filling is loaded on the transcendent waveguide load.

The combination of distinctive features and properties of the proposed waveguide-microstrip junction with a transcendental load are not known from the literature, therefore it meets the criteria of novelty and inventive step.

Figure 1 shows the structural diagram of the device.

Figure 2 shows the topology of the upper layer of the microstrip board.

Figure 1 shows the input waveguide channel of rectangular cross section (1), a smooth transition with a knife-type dielectric insert (2), a microstrip board (3), a microstrip probe (4) deposited on a microstrip board (3), and an output microstrip line (5 ) connected to the microstrip probe (4) and the transcendental waveguide load (ZVN) (6).

Figure 2 shows a microstrip board (3) immersed perpendicular to the waveguide channel with a probe (4) deposited on it and a microstrip line (5) connected to the probe (4).

The principle of operation of such a HFM is based on the phenomenon of total in-phase reflection at the interface in the waveguide channel of two media with different dielectric constants, while the cross section of the waveguide channel remains unchanged. A TE wave enters the device through an input waveguide channel of rectangular cross section (1), is converted into a TE wave for a dielectric waveguide channel of a smaller cross section on a knife-type dielectric insert (2), and then it enters a microstrip board (3) immersed perpendicular to the waveguide channel where it is directed to the microstrip probe (4) and converted into a quasi TE wave, which is output through the microstrip output line (5) connected to the microstrip probe (4). The remnants of the TE wave that are not transformed by the microstrip probe (4) pass into the ZVN (6), where in the antinode regions of the magnetic field they are in-phase reflected in the volume of the ZVN and are again guided to the microstrip probe (4). In the area of ZVN in this invention, according to the Maxwell equations, for a rectangular waveguide, the entire component of H _x becomes imaginary, which gives rise to a wave that is opposite in direction but identical in phase. Thus, the wave that has entered the ZVN returns in an identical phase, in the entire frequency range, where the ZVN is still transcendental. To fulfill the reflection condition, it is necessary that the wave is reflected precisely in the volume of the waveguide channel, therefore, the length of the explosive wave should be at least half the wavelength in the path, which corresponds to the antinode region of the magnetic field in the entire working frequency band.

The estimated transition loss is not more than 0.5 dB in the frequency band 28-48 GHz (~ 52%).

Thus, the invention allows to increase the working frequency band while maintaining the transmission coefficient compared with the prototype.

Claims (1)

A waveguide-microstrip junction with an overwhelming load, in which a microstrip board is immersed in a rectangular input waveguide channel perpendicular to its longitudinal axis, and a microstrip probe immersed in a wide wall of the waveguide channel is applied to it, while the energy from the waveguide channel is output through the microstrip output line, connected to the probe passing through an opening in a wide wall of the waveguide channel, characterized in that it contains a knife-type dielectric insert forming Navigate to Air waveguide channel waveguide channel filling with the dielectric smaller cross-section, wherein the waveguide is filled with a dielectric loaded waveguide at exorbitant load.

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