CN205790335U - Radio-frequency antenna and well lid detecting system based on this radio-frequency antenna - Google Patents

Abstract

This utility model relates to a kind of radio-frequency antenna and well lid detecting system based on this radio-frequency antenna, and this antenna includes: metal well lid；Feed line, its one end is connected to and the position of described metal well lid centre distance L, and described L-value is the distance value of antenna pattern making described metal well lid reach requirement in the operating frequency needed；External terminal, is connected with the other end of described feed line.This utility model using metal well lid as antenna without perforate on well lid, fluting, it is only necessary to little tapped blind hole connects feed line, and mechanical strength and barrier propterty on well lid do not produce impact.Additionally it is possible to be optimized distributing point, reaching the antenna pattern being actually needed in given well lid size, given operating frequency, emittance is maximum in a desired direction, has less emittance at an undesired direction.

Description

Radio-frequency antenna and well lid detecting system based on this radio-frequency antenna

Technical field

This utility model relates to radio-frequency antenna and well lid detecting system based on this radio-frequency antenna, belongs to technology for radio frequency Field.

Background technology

Well lid is the closure at the top, gateway towards underground installation, every installation urban underground water drainage pipe road and underground The place of pipeline is required for installing well lid, and it is an indispensable part for the important infrastructure in city.Well lid is into and out Safeguard, the door of maintenance underground utilities, the Inspection and maintenance of well lid needs the biggest workload, and well lid damage or be stolen after meeting Pedestrian on road, vehicle are caused the biggest security risk.The Intelligent well cover of information and state can be detected to safeguarding city Properly functioning, ensure the city people normal produce, life and social developments the most significant.

Owing to, in detection equipment well to be positioned at, great majority all use the mode of radio communication that relevant information is transferred to ground On reception equipment, and greatly well lid is all that metal material is made, if wireless aerial to be installed to below well lid, Radio signal can be caused shielding by well lid, causes not receiving electronic information, has some technology to ask for solving this at present Topic, such as patent " 201310260883.5 inspection well cover wireless theft-proof alarm ", " 201320178269.X screwed radio frequency Antenna " and " 201520494800.3 1 kinds of multi-functional anti-metal solar energy well lid antennas " be all utilized in perforate on well lid, open Gap and the mode of reserved opening is set to solve the problem that radio signal is shielded by well lid.These solutions are required at well Cover perforate, groove etc., the problem that radio signal is shielded by well lid can be solved to a certain extent, but had a meeting after hole, groove Having influence on the overall structure of well lid, the little transmission characteristic to radio signal in hole opened is improved little, and the hole conference opened is to well lid Mechanical strength and barrier propterty produce impact, an equilibrium point can only be selected between both factors.

Summary of the invention

This utility model aims to overcome that above-mentioned a kind of radio-frequency antenna of existing offer and well lid based on this radio-frequency antenna Detecting system, this utility model by using metal well lid as the part of wireless aerial, well lid entirety knot need not destroyed On the basis of structure, improve the efficiency of signal transmission, and increase the transmission range of twoway radio under metal well lid.

Realizing this utility model purpose and employed technical scheme comprise that a kind of radio-frequency antenna, this antenna includes:

Metal well lid；

Feed line, its one end is connected to and the position of described metal well lid centre distance L, and described L-value is for making described metal Well lid reaches the distance value of the antenna pattern of requirement in the operating frequency needed；

External terminal, is connected with the other end of described feed line.

Further, described radio-frequency antenna also includes:

Match circuit, is connected between described external terminal and the other end of feed line.

In above-mentioned skill scheme, the operating frequency range of described metal well lid is 200～1000MHz.

This utility model also provides for a kind of well lid detecting system, including well lid detection device and above-mentioned radio-frequency antenna, and should System also includes:

Wireless signal transmission equipment, is connected with described external terminal；And

Reception of wireless signals equipment, receives the signal that described metal well lid gives off.

Accompanying drawing explanation

Fig. 1 is the structural representation of this utility model radio-frequency antenna.

Fig. 2 is the antenna pattern of metal well lid in this utility model radio-frequency antenna.

Fig. 3 is the structural representation of metal well lid embodiment one in this utility model radio-frequency antenna.

Fig. 4 is the antenna pattern of metal well lid in metal well lid embodiment one in this utility model radio-frequency antenna.

Fig. 5 is the input return loss figure of metal well lid embodiment one in this utility model radio-frequency antenna.

Detailed description of the invention

The utility model is described in further detail with specific embodiment below in conjunction with the accompanying drawings.

As it is shown in figure 1, this utility model radio-frequency antenna includes metal well lid 1, feed line 2, match circuit 3, external terminal 4 With wireless transmitting device 5.

Metal well lid 1 be radius be R round manhole cover, well lid thickness is H, and the material of well lid is conductive metallic material, then lead to Crossing suitably excitation and just can encourage concussion electromagnetic wave on well lid, this electromagnetic wave can be to spatial emission, above well lid The electromagnetic wave of spatial emission just can be received by outside reception of wireless signals equipment.

In this utility model the energisation mode of electromagnetic wave use feed line 2 be directly coupled on metal well lid 1 to be positioned at away from From the place of well lid center L, the spoke selecting to require to be to make described metal well lid reach requirement in the operating frequency needed of L-value Penetrate directional diagram.The electromagnetic radiation analysis of this structure can be analyzed with excellent with business electromagnetic software (such as HFSS) Change, just can obtain a kind of proper antenna pattern in the frequency needed by the value optimizing L.

The diameter of metal current well lid is typically 300～800mm, and thickness, at about 20mm, is simulated by electromagnetic field software Analyzing, the well lid of this size range can play the effect of irradiator in the frequency range of 200～1000MHz, thus this Utilizing metal well lid in utility model is 200～1000MHz as its operating frequency range of antenna of radiating element.

Use in above-mentioned antenna metal well lid as electromagenetic wave radiation structure, in general its input impedance and the electricity of connection Road is unmatched, it is therefore desirable to using match circuit 3, this match circuit 3 is made up of inductance and electric capacity, and inductance and electric capacity are storages Energy element, the loss that it produces is the least, it is possible to energy is farthest passed to radiating element.The output impedance of circuit part Generally 50 ohm, as long as measuring the input impedance of radiating element, it is possible to utilize circuit analysis software comprehensively to go out at given frequency Inductance in rate and capacitance.Owing to well lid size determines according to well, it is impossible to arbitrarily change its size, by scale Very little well lid, adjusts L-value and makes the antenna pattern of antenna reach requirement, but so this well lid might not be operated in our needs Frequency on, the effect of this match circuit be match it to we need frequency on.

This utility model radio-frequency antenna has two big advantages: one is without perforate on well lid, fluting, it is only necessary to one little Tapped blind hole connect feed line, mechanical strength and barrier propterty on well lid do not produce impact；Another is exactly this reality Well lid is utilized to do radiating element with novel, it is possible to distributing point is optimized, in given well lid size, given operating frequency On reach the antenna pattern that is actually needed, emittance is maximum in a desired direction, has at an undesired direction relatively Little emittance, Fig. 2 is the typical directions figure after an optimization.

Structure based on said radio-frequency antenna and advantage, this utility model also includes that the well lid detection using above-mentioned antenna is System, this well lid detecting system also includes well lid detection device, wireless transmitting device and radio receiver, wherein, wireless transmit Equipment 5 is connected with the external terminal 4 in radio-frequency antenna, and radio receiver receives the signal that described metal well lid gives off.

Well lid detecting system realizes including that the signals transmission of well lid detection information is as follows:

The signal including well lid detection information is transmitted to wireless transmitting device 5 by well lid detection device；

Well lid detection device transmits a signal to the feed line 2 in above-mentioned radio-frequency antenna, signal warp by external terminal 4 Feed line 2 transmits to metal well lid 1, and signal is given off by metal well lid 1 through electromagnetic wave outside；

Reception of wireless signals equipment receives the signal that metal well lid 1 gives off, thus obtains well lid detection information.

Embodiment one

The present embodiment provides concrete example so that structure and the use of this utility model radio-frequency antenna to be described.

As it is shown on figure 3, a diameter of 600mm of the metal well lid 1 of circle, thickness is 26mm, allows it be operated in 450MHz frequency Rate uses as antenna.The feeder line point of feed line 2 is made to be 90mm to the distance at well lid center by optimization, the length of feed line 2 For 10mm, use an inductance and an electric capacity to carry out coupling and obtain match circuit 3, mate inductance L=139nH, matching capacitance C The combining form of=91nH, inductance and electric capacity is not limited to the combination in Fig. 1, it is also possible to be other form.External terminal 4 and nothing Line is launched equipment 5 and is connected.

Circular metal well lid 1 can preferably be operated in 450MHz, its radiation side plus after match circuit 3 as antenna To figure as shown in Figure 4, its input return loss value after overmatching is as shown in Figure 5.From fig. 4, it can be seen that this well lid antenna 3dB beam angle be 60 degree, the center of wave beam is on the direction with a vertical 60 degree of angles.Typically set with well lid detection The device of standby communication installs the most several meters to tens meters high positions, and with well lid apart from hundreds of rice to one kilometer, this Wave beam just can cover these scopes.From fig. 5, it can be seen that this Antenna Operation is at the 450MHz ,-10dB of its return loss Bandwidth is 5MHz, can meet the launch requirements of well lid detection equipment completely.

Claims (6)

1. a radio-frequency antenna, it is characterised in that including:

Metal well lid；

Feed line, its one end is connected to and the position of described metal well lid centre distance L, and described L-value is for making described metal well lid The operating frequency needed reaches the distance value of requirement antenna pattern；

External terminal, is connected with the other end of described feed line.

Radio-frequency antenna the most according to claim 1, it is characterised in that including:

Match circuit, is connected between described external terminal and the other end of feed line, and this match circuit is needing with metal well lid Mate in the operating frequency wanted.

Radio-frequency antenna the most according to claim 2, it is characterised in that: the operating frequency range of described metal well lid is 200 ～1000MHz.

4. a well lid detecting system, including the radio-frequency antenna described in well lid detection device and claim 1, it is characterised in that Also include:

Wireless signal transmission equipment, is connected with described external terminal；And

Reception of wireless signals equipment, receives the signal that described metal well lid gives off.

Well lid detecting system the most according to claim 4, it is characterised in that including:

Match circuit, is connected between described external terminal and the other end of feed line, and this match circuit is needing with metal well lid Mate in the operating frequency wanted.

Well lid detecting system the most according to claim 5, it is characterised in that: the operating frequency range of described metal well lid is 200～1000MHz.