CN201449421U - Field strength meter - Google Patents
Field strength meter Download PDFInfo
- Publication number
- CN201449421U CN201449421U CN2009200420426U CN200920042042U CN201449421U CN 201449421 U CN201449421 U CN 201449421U CN 2009200420426 U CN2009200420426 U CN 2009200420426U CN 200920042042 U CN200920042042 U CN 200920042042U CN 201449421 U CN201449421 U CN 201449421U
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- varactor
- parallel
- field intensity
- radio frequency
- meter
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Abstract
The utility model relates to a field strength meter, which is a communication detection instrument and is used for the radio frequency research and development and the antenna design. The field strength meter is manufactured by a variable capacitance diode and comprises a receiving unit and a displaying unit, the displaying unit is a 0-100 microamp direct current meter, a current-limiting resistance is serially connected on the direct current meter; the receiving unit is a parallel-resonance circuit which is composed of a variable capacitance diode (D1) and an inductance coil (L1), the parallel-resonance circuit is connected with half-wave rectifying circuits (D2, L2, C2) and then is connected with the displaying unit, the receiving unit and the displaying unit are connected by an insulating wire; the receiving unit is provided with an antenna; the variable capacitance diode (D1) is serially connected with a direct current blocking capacitor (C1) and is connected with the inductance coil (L1) in parallel, a current-limiting resistance (R1) is serially connected between the variable capacitance diode (D1) and the direct current blocking capacitor and is serially connected with a radio frequency choke (L2) and is connected with a power supply through a potentiometer, a radio frequency choke is connected with a high frequency filter capacitor in parallel.
Description
One, technical field:
The utility model relates to a kind of communication check instrument, the field intensity meter that especially utilizes varactor to make.
Two, background technology:
Field intensity meter is the equipment and the instrument of wireless communication engineering indispensability, though its function and simple structure often can play big effect.After for example certain new wireless communications products is succeeded in developing, except doing every routine test (as high temperature, high humidity, low temperature, vibrations, impact etc.) outside, a wherein very important ring is exactly open-air communication experiment, new equipment is gone out test first if communication efficiency is undesirable, differ greatly from expected effect even, be need find problem, that Party A's emissive power is big inadequately? still is Party B's receiving sensitivity not high enough? be frequency of operation select improper or antenna-feedback system what is wrong? generally need to use field intensity meter that wireless power is transmitted or the number of collection of letters is located field intensity and measured.
Also can adopt field intensity meter with observational measurement index, though use it can not provide a model answer at once, but can help you to analyze the not good reason of communication efficiency at least, for example we can carry out field strength measurement to each communication facilities at scene, emission field intensity as both sides (promptly satisfying the practical communication requirement) all up to standard, we just have adequate reasons and suspect to have at least to receive existing problems in two communication facilitiess so, perhaps two have, this just need further search reason, is properly settled up to problem.The tradition field intensity meter comes out and has last 100 years history so far, and import field intensity meter price is expensive at present, and homemade field intensity meter is done manual work meticulous inadequately.
Three, utility model content:
The utility model purpose is to propose a kind of and field intensity meter that utilize varactor to make is comparatively economical and practical, can satisfy general scientific research, production unit uses.For improving the precision that detects metering, receiving unit and display part are added on shielding with anti-ripple cover, and as preventing the ripple cover at hand, the available radio-frequency cable of isolating skin that has replaces effect the same.
The technical solution of the utility model is: a kind of field intensity meter, the field intensity meter that utilizes varactor to make comprises receiving element and display unit formation, display unit is the DC ammeter of 0-100 microampere, and on DC ammeter series limiting resistor; Receiving element constitutes antiresonant circuit by varactor and telefault, and antiresonant circuit connects display unit after connecting half-wave rectifying circuit again, and receiving element is connected by code wire with display unit two parts; Receiving element is provided with antenna; Varactor is with in parallel with telefault again after capacitance is connected, be connected in parallel between varactor and capacitance current-limiting resistance, described current-limiting resistance connected radio frequency choke more again by being connected power supply behind the potentiometer, radio frequency choke high-frequency filter capacitor in parallel.
Telefault L1 is a plug-in type inductance coil, when the transmission frequency of communication facilities is 50MHz, the L1 inductance value should be near the 4.7uH, when communication facilities is sending, slow regulator potentiometer VR2, till the output maximum of DC ammeter, the total indicator reading that is to say reometer is to the maximum suitable, D2 is the high-frequency rectification diode, capacitor C 1 is a capacitance, to avoid DC control circuit to be formed direct-current short circuit by the L1 telefault, wherein the appearance value of C1 will be far longer than the equivalent capacitance value of varactor, here L1 constitutes a resonant circuit in parallel with the equivalent capacity of varactor, when near the field intensity of transmitter being used to receive, field intensity around antiresonant circuit is sensed, telefault L1 both end voltage is maximum, the DC voltage of half-wave rectification diode D2 negative terminal also is to present maximal value, and the DC voltage after the rectification is sent to the DC ammeter of display part through one section shielding wire, and same DC ammeter is output as maximum.
DC control supply is the anode that will be applied to varactor through potentiometer VR2, the value that changes VR2 is exactly the amount of capacity that changes varactor, be exactly at the height that changes tuned frequency, change the value of inductance L 1 thus or change adjustable resistance VR2 and all can change moving continuously of resonance frequency, in other words, in frequency 40-60MHz scope all can by regulate VR2 (or value of change L1) be tuned to.Varactor is a kind ofly to utilize its voltage and change the size of varactor internal capacitance value,
The beneficial effect of utility model: this is one and has the field intensity meter that practical value utilizes varactor to make, and can be satisfied with the needs of general design effort, no matter is engaged in the radio frequency R﹠D work and still does Antenna Design, all will become useful testing tool.Entire circuit is also uncomplicated, all is some devices commonly used, is fit to designing and producing of numerous radio amateurs equally.
Four, description of drawings
Fig. 1 is the utility model circuit diagram
Five, embodiment
Circuit as shown in Figure 1.The field intensity meter that utilizes varactor to make is the high novel field intensity meter of a kind of degree of accuracy, error in the measurement that produces in order to prevent human body sensing, partly be added on shielding in the receiving element part with display unit with anti-ripple cover, the display part of test lead is furnished with the DC ammeter of a 0-100uA, the current-limiting resistance of VR1 DC ammeter wherein, to prevent that strong signal from causing crushing injury to DC ammeter, and its receiving unit reaches the antiresonant circuit of being made up of varactor D1 and telefault L1 by a half-wave rectifying circuit, and two parts are to connect with code wire.L1 among the figure is a plug-in type inductance coil, its numerical values recited is decided on the frequency of communication facilities, transmission frequency as communication facilities is 50MHz, the L1 inductance value should be near the 4.7uH, when communication facilities is sending, we are regulator potentiometer VR2 slowly, till the output maximum of DC ammeter, the total indicator reading that is to say reometer is to the maximum suitable, D2 is the high-frequency rectification diode among the figure, capacitor C 1 is a capacitance, to avoid DC control circuit to be formed direct-current short circuit by the L1 telefault, wherein the appearance value of C1 will be far longer than the equivalent capacitance value of varactor, here L1 constitutes a resonant circuit in parallel with the equivalent capacity of varactor, near the field intensity of transmitter being used to receive, when the field intensity of antiresonant circuit around sensing, telefault L1 both end voltage is maximum, the DC voltage of half-wave rectification diode D2 negative terminal also is to present maximal value, DC voltage after the rectification is sent to the DC ammeter of display part through one section shielding wire, same DC ammeter is output as maximum, R1 is a current-limiting resistance among the figure, L2, L3 is a radio frequency choke, controlling high-frequency current therefrom passes through, capacitor C2, C3, C4, C5 is a high-frequency filter capacitor, has had these electric capacity can make the circuit comparison peace and quiet that become.Antenna ANT can use the more piece telescopic antenna, and the total length when all pulling out should be about 1 meter 2.DC control supply is the anode that will be applied to varactor through potentiometer VR2, the value that changes VR2 is exactly the amount of capacity that changes varactor, be exactly at the height that changes tuned frequency, change the value of inductance L 1 thus or change adjustable resistance VR2 and all can change moving continuously of resonance frequency, in other words, in frequency 40-60MHz scope all can by regulate VR2 (or value of change L1) be tuned to.It is beyond any doubt that reometer indication maximum point is exactly the strongest value of radiation field intensity.Varactor is a kind ofly to utilize its voltage and change the size of varactor internal capacitance value, in some specific occasions, can substitute common capacitor, because its equivalent capacitance value is generally all little, less than 200PF, so can be used in the higher parts of frequency of operation, frequency tuner for example, pass filter, parameter amplifier, dynamic frequency control device etc.
Claims (1)
1. field intensity meter is characterized in that the field intensity meter that utilizes varactor to make comprising receiving element and display unit that display unit is the DC ammeter of 0-100 microampere, and on DC ammeter series limiting resistor; Receiving element constitutes antiresonant circuit by varactor (D1) and telefault (L1), and antiresonant circuit connects display unit after connecting half-wave rectifying circuit (D2, L2, C2) again, and receiving element is connected by code wire with display unit two parts; Receiving element is provided with antenna; Varactor (D1) with after capacitance (C1) is connected again with telefault (L1) formation in parallel antiresonant circuit, current-limiting resistance (R1), described current-limiting resistance (R1) radio frequency choke (L3) of connecting again that is connected in parallel between varactor (D1) and the capacitance is connected power supply by potentiometer (VR2) back, radio frequency choke parallel connection high-frequency filter capacitor again.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009200420426U CN201449421U (en) | 2009-04-02 | 2009-04-02 | Field strength meter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009200420426U CN201449421U (en) | 2009-04-02 | 2009-04-02 | Field strength meter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201449421U true CN201449421U (en) | 2010-05-05 |
Family
ID=42554142
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2009200420426U Expired - Fee Related CN201449421U (en) | 2009-04-02 | 2009-04-02 | Field strength meter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201449421U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20180118298A (en) * | 2017-04-21 | 2018-10-31 | 삼성전자주식회사 | Sensing device and measuring system for measuring electromagnetic waves |
| CN112147554A (en) * | 2020-09-05 | 2020-12-29 | 武汉联影生命科学仪器有限公司 | Frequency matching and tuning device for receiving coil, cryogenic probe and magnetic resonance device |
-
2009
- 2009-04-02 CN CN2009200420426U patent/CN201449421U/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20180118298A (en) * | 2017-04-21 | 2018-10-31 | 삼성전자주식회사 | Sensing device and measuring system for measuring electromagnetic waves |
| KR102404177B1 (en) * | 2017-04-21 | 2022-06-02 | 삼성전자주식회사 | Sensing device and measuring system for measuring electromagnetic waves |
| CN112147554A (en) * | 2020-09-05 | 2020-12-29 | 武汉联影生命科学仪器有限公司 | Frequency matching and tuning device for receiving coil, cryogenic probe and magnetic resonance device |
| CN112147554B (en) * | 2020-09-05 | 2023-08-15 | 武汉联影生命科学仪器有限公司 | Frequency and matching tuning device of receiving coil, low-temperature probe and magnetic resonance device |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20100505 Termination date: 20170402 |
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| CF01 | Termination of patent right due to non-payment of annual fee |