CN214672973U

CN214672973U - Structure for realizing high isolation of FMCW single antenna receiving and transmitting end broadband

Info

Publication number: CN214672973U
Application number: CN202121195608.6U
Authority: CN
Inventors: 隋磊; 卢煜旻; 朱欣恩
Original assignee: Zhejiang Xinli Microelectronics Co ltd
Current assignee: Zhejiang Xinli Microelectronics Co ltd
Priority date: 2021-05-31
Filing date: 2021-05-31
Publication date: 2021-11-09
Anticipated expiration: 2031-05-31

Abstract

The utility model discloses a realize structure of high isolation of FMCW single antenna receiving and dispatching end broadband, including antenna structure and isolation structure, isolation structure includes that microstrip annular coupler, first Wilkinson merit divide ware and second Wilkinson merit to divide the ware, annular coupler divides ware and antenna end electric connection through first Wilkinson merit, annular coupler passes through second Wilkinson merit and divides ware and load end electric connection. The utility model discloses a realize structure of FMCW single antenna receiving and dispatching end broadband high isolation, antenna structure of its receiving terminal and transmitting terminal sharing can reduce half area to two way signals equal and opposite phase according to the route, thereby offset each other when will revealing receiving terminal or transmitting terminal, and then high isolation in the broadband of realization transmitting terminal and receiving terminal.

Description

Structure for realizing high isolation of FMCW single antenna receiving and transmitting end broadband

Technical Field

The utility model belongs to the technical field of single antenna, concretely relates to realize structure of FMCW single antenna receiving and dispatching end broadband high isolation.

Background

Short-range radars using microwave technology have been widely used in the fields of speed meters, automotive sensors, medical sensors, and collision avoidance. These applications require radars with high performance, small size, simple structure and low cost. Frequency Modulated Continuous Wave (FMCW) or doppler radar is widely used in industrial, scientific and medical bands due to its relatively simple circuit structure, volume and cost advantages.

Among the various short-range radar technologies, the 24Ghz band has been widely studied due to its advantages in terms of the reduction in the size of passive and active devices. A single antenna system is chosen because the system using both transmit and receive antennas is twice as large as a single antenna system. However, if the transmission and reception signals are at the same frequency, a duplexer cannot be used, and thus leakage from the transmitting end to the receiving end is very important. But currently commercially available circulators, directional couplers and hybrid couplers can provide up to 25dB of isolation (port matching case) within a narrow band.

Therefore, the above problems are further improved.

SUMMERY OF THE UTILITY MODEL

The utility model discloses a main aim at provides a realize structure of FMCW single antenna receiving and dispatching end broadband high isolation, antenna structure of its receiving terminal and transmitting terminal sharing can reduce half area to two way signals equal and opposite phase according to the route, thereby offset each other when will revealing receiving terminal or transmitting terminal, and then high isolation in the broadband of realization transmitting terminal and receiving terminal.

In order to achieve the above object, the utility model provides a realize structure of high isolation of FMCW single antenna receiving and dispatching end broadband for realize the high isolation of single antenna transmitting terminal and receiving terminal, including antenna structure and isolation structure, isolation structure install in antenna structure, wherein:

the isolation structure comprises a microstrip annular coupler, a first Wilkinson power divider and a second Wilkinson power divider, wherein the annular coupler is electrically connected with an antenna end through the first Wilkinson power divider, and is electrically connected with a load end through the second Wilkinson power divider;

the antenna structure comprises a metal layer and a dielectric layer, wherein the metal layer is connected with the dielectric layer.

As a further preferable technical solution of the above technical solution, the microstrip ring coupler includes a first signal connection end and a second signal connection end, the first signal connection end is electrically connected to the first connection end of the first wilkinson power divider through a first connection piece, and the second signal connection end is electrically connected to the first connection end of the second wilkinson power divider through a second connection piece.

As a further preferable technical solution of the above technical solution, the length of the first connection element is the same as the length of the second connection element, and the first signal connection terminal (generated signal) and the second signal connection terminal (generated signal) have equal amplitudes and differ in amplitude by 180 °.

As a further preferred technical solution of the above technical solution, the microstrip ring coupler further includes a third signal connection end, the third signal connection end is electrically connected to the transmitting end, the antenna end is electrically connected to the antenna structure, and the load end is electrically connected to a 50 ohm load.

As a further preferable technical solution of the above technical solution, a second connection end of the first wilkinson power divider is electrically connected to a first connection end of a third wilkinson power divider, a second connection end of the second wilkinson power divider is electrically connected to a second connection end of the third wilkinson power divider, and the third wilkinson power divider is connected to a receiving end (two paths of signals reach the first and second wilkinson power dividers respectively through equal distances, most of the signals reaching the first wilkinson power divider are radiated through an antenna structure and partially leaked to the receiving end, most of the signals reaching the second wilkinson power divider are absorbed by a 50 ohm load and partially leaked to the receiving end, when the two paths of the signals reach the receiving end, due to equal paths and opposite phases, the signals cancel each other at the receiving end, thereby realizing high isolation between the transmitting end and the receiving end, when the receiving end works, the working principle is consistent with that of the transmitting end, and only the paths are opposite).

As a further preferred technical solution of the above technical solution, the metal layer includes a first metal layer, a second metal layer, a third metal layer, and a fourth metal layer, and the dielectric layer includes a first dielectric layer, a second dielectric layer, and a third dielectric layer, wherein:

the antenna structure comprises a first metal layer, a first dielectric layer, a second metal layer, a second dielectric layer, a third metal layer, a third dielectric layer and a fourth metal layer (all the layers are fixedly connected) from top to bottom (the isolation structure is arranged at the bottom end of the antenna structure).

As a further preferable technical solution of the above technical solution, the first metal layer is provided with a radiation patch, and the radiation patch is used for radiating electromagnetic waves.

As a more preferable configuration of the above configuration, each of the first wilkinson power divider, the second wilkinson power divider, and the third wilkinson power divider is provided with a resistance of 100 ohms.

Drawings

Fig. 1 is a schematic overall structure diagram of a structure for realizing high isolation of the FMCW single-antenna transceiver end broadband according to the present invention.

Fig. 2 is a schematic structural diagram of a microstrip ring coupler of the present invention, which realizes a structure of high isolation of the FMCW single antenna transceiver end broadband.

Fig. 3 is an isolation structure diagram of the present invention, which realizes a structure of high isolation of the FMCW single antenna transceiver end broadband.

Fig. 4 is a schematic diagram of the isolation between the transmitting end and the receiving end of the structure of the present invention for realizing high isolation of the FMCW single-antenna transceiving end broadband.

The reference numerals include: 100. an isolation structure; 110. a microstrip ring coupler; 111. a first signal connection terminal; 112. a second signal connection terminal; 113. a third signal connection terminal; 114. a first connecting member; 115. a second connecting member; 120. a first Wilkinson power divider; 130. a second Wilkinson power divider; 140. a third Wilkinson power divider; 200. an antenna structure.

Detailed Description

The following description is presented to disclose the invention so as to enable any person skilled in the art to practice the invention. The preferred embodiments in the following description are given by way of example only, and other obvious variations will occur to those skilled in the art. The basic principles of the invention, as defined in the following description, may be applied to other embodiments, variations, modifications, equivalents and other technical solutions without departing from the spirit and scope of the invention.

The utility model discloses a realize structure of FMCW single antenna receiving and transmitting end broadband high isolation, combine preferred embodiment below, make further description to utility model's concrete embodiment.

In the embodiments of the present invention, those skilled in the art will note that the load, the connecting member, the radiation patch, and the like according to the present invention can be regarded as the prior art.

Preferred embodiments.

The utility model discloses a realize structure of FMCW single antenna receiving and dispatching end broadband high isolation for realize the high isolation of single antenna transmitting terminal and receiving terminal, including antenna structure 200 and isolation structure 100, isolation structure 100 install in antenna structure 200, wherein:

the isolation structure 100 includes a microstrip ring coupler 110, a first wilkinson power divider 120, and a second wilkinson power divider 130, where the ring coupler 110 is electrically connected to an antenna end through the first wilkinson power divider 120, and the ring coupler 110 is electrically connected to a load end through the second wilkinson power divider 130;

the antenna structure 200 includes a metal layer and a dielectric layer, which are connected together.

Specifically, the microstrip ring coupler 110 includes a first signal connection end 111 and a second signal connection end 112, the first signal connection end 111 is electrically connected to the first connection end of the first wilkinson power divider 120 through a first connection element 114, and the second signal connection end 112 is electrically connected to the first connection end of the second wilkinson power divider 130 through a second connection element 115.

More specifically, the length of the first connection element 114 is the same as the length of the second connection element 115, and the first signal connection 111 (generated signal) and the second signal connection 112 (generated signal) are equal in amplitude and differ in amplitude by 180 °.

Further, the microstrip ring coupler 110 further includes a third signal connection terminal 113, the third signal connection terminal 113 is electrically connected to the transmitting terminal, the antenna terminal is electrically connected to the antenna structure 200, and the load terminal is electrically connected to a 50 ohm load.

Further, the second connection end of the first wilkinson power divider 120 is electrically connected to the first connection end of the third wilkinson power divider 140, the second connection end of the second wilkinson power divider 130 is electrically connected to the second connection end of the third wilkinson power divider 140, the third wilkinson power divider 140 is connected to the receiving end (two signals respectively reach the first and second wilkinson power dividers through equal distances, most of the signal reaching the first wilkinson power divider is radiated through the antenna structure, and a small part of the signal leaks to the receiving end, most of the signal reaching the second wilkinson power divider is absorbed by 50 ohm load, and a small part of the signal leaks to the receiving end, when the two paths of the signal leak to the receiving end, due to equal paths and opposite phases, the two paths of the signal cancel each other at the receiving end, thereby realizing high isolation between the transmitting end and the receiving end, when the receiving end works, the working principle is consistent with that of the transmitting end, and only the paths are opposite).

Preferably, the metal layers include a first metal layer, a second metal layer, a third metal layer and a fourth metal layer, and the dielectric layers include a first dielectric layer, a second dielectric layer and a third dielectric layer, wherein:

Preferably, the first metal layer is provided with a radiation patch for radiating electromagnetic waves.

Preferably, the first wilkinson power divider 120, the second wilkinson power divider 130 and the third wilkinson power divider 140 are all provided with 100 ohm resistors.

Preferably, the specific antenna structure is:

four layers of metal made of copper; three layers of media, wherein the first layer of dielectric material is Rogers 4350, the dielectric constant is 3.66, and the loss tangent is 0.004; the second and third layers of dielectric material are FR4, the dielectric constant is 4.4, and the loss tangent is 0.02; wherein the names are from top to bottom: TOP Layer (first metal Layer, thickness 0.035mm) - - -D1 (first dielectric Layer Rogers 4350, thickness 0.254mm) - - -Layer1 (second metal Layer, thickness 0.035mm) - -D2 (second dielectric Layer FR4, thickness 0.5mm) - -Layer 2 (third metal Layer, thickness 0.035mm) - -D3 (third dielectric Layer FR4, thickness 0.254mm) - -Bottom Layer (fourth metal Layer, thickness 0.035 mm);

preferably, the signal via connects the Top Layer and the Bottom Layer, and simultaneously, a part of the Layer1 and the Layer2 is hollowed out to prevent the signal via from being shorted, and four ground vias are arranged around the signal via and used for realizing impedance matching and reducing energy leakage.

It is worth mentioning that the technical features such as the load, the connecting piece and the radiation patch related to the patent application of the present invention should be regarded as the prior art, and the specific structure, the working principle of these technical features and the control mode and the space arrangement mode that may be related to adopt the conventional selection in the field, and should not be regarded as the invention point of the present invention, and the present invention does not further specifically expand the detailed description.

It will be apparent to those skilled in the art that modifications and variations can be made in the above-described embodiments, or some features of the invention may be substituted or omitted, and any modification, substitution, or improvement made within the spirit and principle of the present invention shall fall within the protection scope of the present invention.

Claims

1. A structure for realizing FMCW single antenna receiving and transmitting end broadband high isolation, which is used for realizing high isolation between a single antenna transmitting end and a single antenna receiving end, and is characterized by comprising an antenna structure and an isolation structure, wherein the isolation structure is installed on the antenna structure, and the FMCW single antenna receiving and transmitting end broadband high isolation structure is used for realizing high isolation between the single antenna transmitting end and the single antenna receiving end, and is characterized in that the FMCW single antenna receiving and transmitting end broadband high isolation structure comprises an antenna structure and an isolation structure, wherein:

2. The structure for realizing high isolation of FMCW single antenna transceiver port broadband as claimed in claim 1, wherein said microstrip ring coupler includes a first signal connection terminal and a second signal connection terminal, said first signal connection terminal is electrically connected to the first connection terminal of said first Wilkinson power divider through a first connection element, and said second signal connection terminal is electrically connected to the first connection terminal of said second Wilkinson power divider through a second connection element.

3. The structure for realizing FMCW single antenna transceiver high isolation wideband as set forth in claim 2, wherein said first connection member has a length equal to that of said second connection member, and wherein said first signal connection terminal and said second signal connection terminal have amplitudes equal to each other and different by 180 °.

4. The structure of claim 3, wherein the microstrip ring coupler further comprises a third signal connection terminal, the third signal connection terminal is electrically connected to the transmitter, the antenna terminal is electrically connected to the antenna structure, and the load terminal is electrically connected to a 50 ohm load.

5. The structure for realizing high isolation of FMCW single antenna transceiving end broadband as claimed in claim 4, wherein said first Wilkinson power divider second connection end is electrically connected to the first connection end of the third Wilkinson power divider, said second Wilkinson power divider second connection end is electrically connected to the second connection end of the third Wilkinson power divider, and said third Wilkinson power divider is connected to the receiving end.

6. The structure for realizing FMCW single antenna transceiving end broadband high isolation according to any of claims 1-5, wherein said metal layers comprise a first metal layer, a second metal layer, a third metal layer and a fourth metal layer, and said dielectric layers comprise a first dielectric layer, a second dielectric layer and a third dielectric layer, wherein:

the antenna structure sequentially comprises a first metal layer, a first dielectric layer, a second metal layer, a second dielectric layer, a third metal layer, a third dielectric layer and a fourth metal layer from top to bottom.

7. The structure of claim 6, wherein the first metal layer is provided with a radiation patch for radiating electromagnetic waves.

8. The structure for realizing FMCW single antenna transceiver end broadband high isolation as set forth in claim 5, wherein said first Wilkinson power divider, said second Wilkinson power divider and said third Wilkinson power divider each have 100 ohm resistors.