Antenna dual-band reflector

Abstract

FIELD: antenna technology.SUBSTANCE: invention is intended for receiving and transmitting electromagnetic waves as part of reflector antennas. A dual-band reflector antenna feed is proposed, consisting of a circular waveguide, a radiator with external corrugation, a counter-reflector located opposite the end of the circular waveguide, two dielectric inserts and a metal rod. The first dielectric insert is made in the form of a hollow cylinder, secured on one side in the groove of the counter-reflector, and on the other side in the groove of the emitter. The second dielectric insert is installed inside the emitter and secured on a metal rod, which is connected on the opposite side by a threaded connection to the counter-reflector.EFFECT: increase in the level of matching of the antenna system with the load.1 cl, 3 dwg

Description

[0001] The invention relates to antenna technology and is intended for receiving and transmitting electromagnetic waves as part of reflector antennas.

[0002] A known feed for an antenna system comprising a reflector and a counter-reflector [EU Patent No. 3972055, IPC H01Q19 / 19, published March 23, 2022], includes a circular waveguide terminating in a corrugated radiator. Opposite the radiator is a near-field counter-reflector, mechanically connected to the radiator via several dielectric inserts of complex shape.

[0003] The closest analogue in terms of the combination of essential features is the feed horn of a compact antenna with low side lobes [US patent No. 9246233, IPC H01Q13 / 00, published 01 / 26 / 2016 (prototype)]. The antenna includes a main reflector with a ring focus and a feed horn located on the reflector axis. The feed horn contains a circular waveguide, a radiator with external corrugation and a near-field counter-reflector located opposite the end of the radiator. The counter-reflector is attached to the radiator using two stepped dielectric inserts and a metal rod: the first hollow cylindrical insert of complex shape connects the counter-reflector with the end of the radiator along the periphery; The second dielectric insert is installed inside the emitter and has a hole in the center through which a metal rod passes, connected to the counter-reflector.

[0004] Common disadvantages of known designs, including the prototype design, are the low level of matching of the antenna system with the load.

[0005] The technical result of the claimed invention is to increase the level of matching of the antenna system with the load.

[0006] The claimed technical result is achieved due to the fact that in a dual-band reflector antenna feed consisting of a circular waveguide, an emitter with external corrugation, a counter-reflector located opposite the end of the circular waveguide, two dielectric inserts and a metal rod, what is new is that the first dielectric insert is made in the form of a hollow cylinder, fixed on one side in a groove of the counter-reflector, and on the other side - in a groove of the emitter, while the second dielectric insert is installed inside the emitter and fixed on a metal rod, which on the opposite side is connected by means of a threaded connection with the counter-reflector, wherein the metal rod has an external thread and is screwed into a through threaded hole located in the center of the counter-reflector, on the reverse side of which the threaded connection is fixed with a lock nut.

[0007] A comparative analysis with the prototype shows that the claimed device is distinguished by its inclusion of two dielectric inserts. The first insert is shaped like a hollow cylinder and is designed to mechanically couple the sub-reflector and the emitter. The second insert is located inside the emitter and secured to the end of a metal rod, the other end of which is connected to the sub-reflector. A significant difference is the threaded connection between the rod and the sub-reflector, allowing rotation of the rod and the second dielectric insert within the emitter along its axis, thereby improving the matching of the antenna system to the load.

[0008] This invention is illustrated by drawings. Fig. 1a shows a dual-band reflector antenna feed, Fig. 1b shows its cross-section, and Fig. 2 shows the dependences of the reflection coefficient of the prototype design and the claimed device.

[0009] The dual-band reflector antenna feed (Fig. 1a) comprises a circular waveguide (1) connected to a radiator with external corrugation (2); a near-field counter-reflector (3); a dielectric insert (4) installed in the grooves of the radiator (2) and the counter-reflector (3). Inside the radiator (2) there is a second dielectric insert (5) (Fig. 1b), into the inner central hole of which the end of a metal rod (6 and 7), consisting of two parts, is inserted. The metal rod (6 and 7) is divided into two parts to fix the second dielectric insert from displacement along the axis of the radiator (2). The second end of the metal rod (6 and 7) has a thread and is connected to the counter-reflector (3), a lock nut (8) is used to fix the connection.

[0010] The dual-band reflector antenna feed operates as follows. Let's consider the device's operation in signal emission mode (Fig. 1a). The electromagnetic wave from the transmitter propagates along the circular waveguide (1) in the fundamental mode H11 . At the end of the waveguide, a radiator with external corrugation (2) is installed, in the near zone of which a near-field counter-reflector (3) is located, therefore the electromagnetic wave generated by the radiator (2) is re-radiated by the near-field counter-reflector (3) towards the mirror reflector of the antenna system. Matching of the declared radiator of the reflector antenna with the load is carried out (Fig. 1b) by moving the second dielectric insert (5) due to rotation of the metal rod (6 and 7) on the side of the counter-reflector (3) in the process of measuring the reflection coefficient of the antenna system. For this, the metal rod (6 and 7) is rotated with a screwdriver, having previously loosened the lock nut (8), and changes in the reflection coefficient of the antenna system are observed on the screen of the S-parameter meter, achieving the best characteristics in the working frequency band. Upon completion of the adjustment, the lock nut (8) is tightened.

[0011] To demonstrate the achievement of the claimed technical result, calculations were performed using a numerical electromagnetic modeling program and prototypes were constructed. Figure 2 shows the reflection coefficient dependences for a design similar to the invention prototype (9) and for the claimed device (10) in two frequency ranges – receiving and transmitting. As can be seen from the graphs, it was possible to expand the operating frequency bands in both ranges and improve the level of matching with the load in them. Thus, the claimed technical result has been achieved.

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