CN105305041B - Broadband antenna with integrated parasitic unit and slotted DR structure - Google Patents

Abstract

Developing high-performance antennas is key to RF energy harvesting. The invention proposes a broadband antenna integrating a parasitic unit and a slotted dielectric resonator (DR), which is used for WSN radio frequency energy collection. This structure can significantly improve the antenna gain and increase the bandwidth. The present invention adopts 50 ohm coaxial feeding in the cavity of the resonator, and three notch grooves are symmetrically opened along the center on the upper plane of the rectangular DR; Rectangular patches of grooves, reflow grooves form "n" type. Through slotting on the plane of the rectangular DR cavity, the coupling strength is increased and the impedance characteristics of the DR are changed; two "n"-shaped slots are symmetrically opened on the left and right sides of the parasitic unit to adjust the resonant frequency and bandwidth of the antenna; the opening in the middle of the patch of the parasitic unit The slot structure improves the antenna gain. The frequency range of the invented antenna is 1.70GHz‑2.69GHz, covering GSM1800, 3G, and WLAN frequency bands, and the gain can reach up to 6.8dB.

Description

Broadband antenna with integrated parasitic unit and slotted DR structure

technical field

The invention relates to a broadband antenna integrating a rectangular slotted dielectric resonator (DR) and a parasitic coupling unit structure. The antenna is mainly used for radio frequency energy collection of a wireless sensor network and belongs to the technical field of wireless communication.

Background technique

As an indispensable key component in modern communication equipment, antenna is a device for transmitting and receiving electromagnetic waves. The function of the antenna is to convert the guided electromagnetic wave on the transmission line into a radio wave (in the transmitting system) in the unbounded medium (usually free space), or to do the opposite conversion (in the receiving system), so that between any two points Realize the transmission of radio signals between. It plays a pivotal role in signal reception and transmission, and its performance directly affects the performance of the entire wireless system.

As one of the most important technologies in the 21st century, Wireless Sensor Network (WSN) technology has the advantages of self-organizing nodes, wide monitoring range, low system cost and little impact on the ecological environment. However, WSN nodes are usually powered by batteries with limited energy, and it is difficult to replenish energy after deployment. Therefore, in order to solve the problem of limited energy in wireless sensor networks, we can collect radio frequency (RF) energy from the surrounding environment; RF signals have the characteristics of all-weather and all-time, but natural RF energy is very weak, so high-gain, broadband antennas are required to collect. There are multiple frequency bands of radio frequency energy radiation in nature. In order to make full use of the existing multiple frequency spectrum radiation energy, it is one of the effective ways to design multiple communication frequency band antennas that can work simultaneously in the energy harvesting system. Therefore, the research and development of microwave antennas with high performance, high gain and wide frequency band is the key to RF energy harvesting.

In the existing literature, Michal Mrnka and Jasmin Grosinger published "Wide-band Dielectric Resonator Antennas for RF Energy Harvesting" on the research of dielectric resonant antennas. This document proposes a bowtie-shaped dielectric resonant antenna (DRA) and improves on the basis of the bowtie-shaped DRA, and proposes a bowtie-shaped DRA with a single slot. The working frequency band and antenna gain of the dielectric resonant antenna are also analyzed in the literature.

However, in the existing literature, there has never been a structure with double slots in the cavity of a rectangular dielectric resonator; the dielectric resonator loads the parasitic unit and the rectangular parasitic patch opens "n" slots, and based on this basis, the parasitic unit opens three The structure of the rectangular radiation patch of the section meander trough has not been reported in the literature either. The invention integrates a rectangular slotted dielectric resonator and a slotted rectangular coupling unit structure broadband antenna, which has the characteristics of miniaturization, wide frequency band and high gain. Loading the slotted parasitic patch on the basis of the original dielectric resonator can effectively increase the bandwidth and gain, while changing the slot width can flexibly adjust the resonant frequency of the antenna and the coverage of the antenna frequency band.

Contents of the invention

The invention proposes a new dielectric resonator antenna structure, and designs a broadband antenna based on the structure to be applied to an RF energy collection system of a wireless sensor network node. In order to design a wide-band, high-gain antenna, a rectangular double-slotted dielectric resonator is used to load a parasitic radiation patch with "n"-shaped slots and three-segment meander slots on the basis of DRA to increase antenna bandwidth and gain, and optimize the antenna performance.

The technical solution of the present invention is to adopt the coaxial line feeding mode in the cavity of the 50-ohm dielectric resonator, and open the rectangular slot structure 1, 2, 3 on the plane of the rectangular dielectric resonator. The radiation patch of the parasitic unit opens two "n" type slots 4,5. Parasitic element radiating patch meander trough6,7,8.

The rectangular slotted resonator in the present invention is shown in Figure 1, and its structural feature is that symmetrical slots are respectively opened along the central symmetrical axis to change the impedance of the rectangular resonator, and at the same time, the coupling effect with the radiation patch is stronger.

In the present invention, the "n" type groove of the radiation patch of the parasitic unit is shown in Figure 2. Its structural characteristics are that the n type grooves on both sides of the patch are symmetrical along the central axis, and the radiation of the antenna is uniform. The width of the "n" type groove has an influence on the resonant frequency of the antenna. Larger, changing the width can change the frequency range covered by the antenna.

In the present invention, the structure of the meander groove of the rectangular patch of the parasitic unit is shown in Fig. 3. Its structural features are that each meander groove has 5 turns, and the three meander grooves form an "n" shape. The function of the meander groove increases the gain of the antenna and optimizes the performance of the antenna.

The invention optimizes and improves the existing DRA structure for RF energy collection; compared with the traditional DRA structure, the slotted dielectric resonator is easier to couple with the parasitic unit.

The beneficial effect of the present invention compared with the prior art is that the slotted DRA structure loaded with parasitic units not only has the characteristics of simple structure and miniaturization, but also has adjustable frequency coverage, wide frequency band and high gain compared with traditional energy harvesting antennas. features.

Due to the advantages of small size, relatively low processing complexity, easy integration and the like, the invention is suitable for collecting RF energy of wireless sensor network nodes.

Description of drawings

Figure 1 is a structural diagram of a rectangular slotted resonator;

Figure 2 is a structural diagram of a rectangular parasitic unit "n" type slot;

Fig. 3 is a structural diagram of a meander groove of a rectangular parasitic unit;

Fig. 4 is the overall structural design drawing of the present invention;

Fig. 5 is a simulation diagram of the return loss of the broadband antenna integrating the parasitic unit and the slotted DR structure of the present invention;

Fig. 6 is a simulation diagram of broadband antenna gain of the integrated parasitic unit and slotted DR structure of the present invention

As shown in the figure: 1 medium top rectangular groove; 2 medium top rectangular groove; 3 medium top rectangular groove; 4 patch "n" type groove; 5 patch "n" type groove; 6 patch meander groove; Sheet meandering groove; 8 patch meandering groove.

Detailed ways

Embodiments of the present invention are shown in Fig. 1 , Fig. 2 , Fig. 3 , Fig. 4 , Fig. 5 and Fig. 6 .

Fig. 1 is a structural diagram of a rectangular resonator in an embodiment of the present invention; Fig. 2 is a structural diagram of a rectangular parasitic unit "n" type groove in an embodiment of the present invention; Fig. 3 is a structural diagram of a meander groove of a rectangular parasitic unit; Fig. 4 is this Design diagram of the overall structure of the invention; Figure 5 is a simulation diagram of the return loss of a broadband antenna with an integrated parasitic unit and a slotted DR structure in this embodiment; Figure 6 is a broadband antenna with an integrated parasitic unit and a slotted DR structure in this embodiment Gain simulation graph.

This embodiment integrates the parasitic unit and the broadband antenna with slotted DR structure. The basic DR structure size is 80mm×80mm, the thickness is 20mm, and the dielectric resonator is 3.2.

In this embodiment, the dielectric resonator width W=80mm, the dielectric resonator width L=80mm; the dielectric resonator top slot width D=4mm, 1, 2 groove depth t=5mm, 3 groove depth t2=2mm, the dielectric resonator Height h=20mm. The height of the feeding needle (center position) h _f =22mm. Parasitic unit patch width W1=80mm, L1=80mm; "n" type slot length Lp=68mm, width d2=2mm, "n" type side length S=10mm. The meander groove width d3=1mm.

Due to the use of a rectangular DRA loaded parasitic unit structure, this structure can freely design the antenna of the frequency band we need according to our needs. The resonant frequency band of the antenna can be adjusted according to the width of the dielectric resonator and the "n" type slot. The resonant frequency of the designed antenna is 1.7GHz-2.68GHz (S11≤-10dB), and the bandwidth is 980M. The antenna covers GSM1800, 3G, and WLAN frequency bands, and the maximum gain of the designed antenna can reach 6.8dB.

From the simulation results of the circuit, it can be seen that the design exhibits good characteristics. Design a broadband antenna based on a new rectangular DRA loaded parasitic unit structure. Compared with the traditional DRA structure, it has wider bandwidth and higher gain, and is more suitable for RF energy harvesting in wireless sensor networks.

Claims (5)

1. A broadband antenna with an integrated parasitic unit and a slotted dielectric resonator (DR) structure, characterized in that the dielectric resonator structure is made up of a dielectric substrate with a first rectangular slot, a second rectangular slot and a third rectangular slot , where the third rectangular slot is located at the center of the dielectric substrate and is itself symmetrical along the x-axis, its length is equal to the length of the dielectric resonator, the first rectangular slot and the second rectangular slot are located on the y-axis, and are distributed on both sides of the third rectangular slot And it is symmetrically distributed, the first rectangular slot, the second rectangular slot and the third rectangular slot are in the shape of a cross; a parasitic unit patch is provided on the top of the dielectric substrate, and the parasitic unit patch on the top is provided with a first "n" type slot, the second "n" slot and the first meander slot, the second meander slot and the third meander slot, each of which has 5 turns, and the three meander slots are located in the parasitic unit patch In the middle position, it is arranged in an "n" shape and distributed symmetrically along the y-axis; the first "n"-shaped groove and the second "n"-shaped groove are symmetrically distributed on both sides of the three meandering grooves along the y-axis; the dielectric resonator cavity adopts 50 ohm coaxial feeding method for feeding. 2. the broadband antenna of a kind of integrated parasitic unit and slotted dielectric resonator (DR) structure according to claim 1, it is characterized in that slotting on the dielectric resonator cavity, has changed the impedance characteristic of the dielectric resonator, Radiation characteristics, increase the coupling effect with the parasitic unit. 3. A broadband antenna with integrated parasitic unit and slotted dielectric resonator (DR) structure according to claim 1, characterized in that the first "n" type groove and the second "n" type groove change the integrated The resonant frequency of the parasitic unit and the slotted dielectric resonator (DR) adjusts the frequency bandwidth. 4. The broadband antenna of a kind of integrated parasitic unit and slotted dielectric resonator (DR) structure according to claim 1, is characterized in that the first meander slot, the second meander slot and the third meander slot change Improve the antenna radiation characteristics and increase the antenna gain. 5. A broadband antenna integrating a parasitic unit and a slotted dielectric resonator (DR) structure according to claim 1, which is applied to radio frequency (RF) energy harvesting of wireless sensor network nodes.