FIELD INTENSITY AND SIGNAL LEVEL
|
|
- Crystal Fox
- 6 years ago
- Views:
Transcription
1 FIELD INTENSITY AND SIGNAL LEVEL It is important to understand the relationship between field intensity and the signal level at the input to a receiver or other monitoring device. For example, pager sensitivity is usually expressed in terms of microvolts per meter (μv/m) or decibels referenced to 1μV/m (dbu). Field strength contours are often expressed in dbu or μv/m. But what does it mean in terms of actual signal level at the receiver input, that is, in terms of microvolts or dbm in 50Ω? Figure 1: This antenna can be used as a calibrated antenna for use in making field strength measurements. The balun known as a Pawsey stub is used to convert the balanced antenna to an unbalanced coax line while maintaining a 1:1 impedance ratio. Although calibrated field strength meters (not relative field strength indicators) are not commonly found around the typical radio shop, spectrum analyzers are. By using a calibrated antenna the spectrum analyzer reading in dbm can be converted into field intensity units in dbu or μv/m. Commercial antennas are available for such measurements but are fairly expensive. Antennas for this purpose can be constructed as shown in Figure 1 or Figure Page 1
2 2. The antenna in Figure 1 is better for VHF high band while the antenna in Figure 2 is most easily constructed for use at MHz or 800MHz use. Figure 2: This antenna is easily constructed for use at MHz or 800MHz. One-quarter wavelength of braid is folded back over the coax cable with one-quarter wavelength of center conductor exposed. Since the antenna is unbalanced, no balun is needed. When using such an antenna to determine field intensity from signal level in dbm (from the spectrum analyzer display) it is necessary to know the antenna correction factor (k) in decibels per meter (db/m). The graph in Figure 3 can be used to determine the antenna factor (db/m) for a 50Ω or 75Ω antenna system. This graph is for unity-gain antennas or 0dB referenced to a half-wave dipole (0dBd). The antenna factor must be adjusted for gain antennas. Antenna gain (dbd) will decrease the antenna factor while antenna loss in dbd (negative gain) will increase the antenna factor by an amount equal to the loss in dbd. To adjust the antenna factor for antennas with gain simply subtract the gain figure (dbd) from the antenna factor taken from the graph in Figure 3. Page 2
3 Figure 3: This graph provides the antenna correction factor in decibels per meter (db/m) for either 75Ω or 50Ω antenna systems over a frequency range of 10MHz to 1000MHz. For example, if the antenna factor taken from the graph in Figure 3 is 0dB/m and the antenna has a gain of 6dBd them the adjusted antenna factor is -6dB/m. The antenna factor for the antennas shown in Figures 1 and 2 can be determined from the graph in Figure 3. These are 75Ω antennas so the correction factor must be taken from the 75Ω graph. Suppose an antenna like the one in Figure 2 is to be used at 450MHz. From the graph in Figure 3 locate 450MHz and move over to the 75Ω line and down to the db/m scale. The antenna correction factor (k) is +19dBm. Watch the sign antenna factors can be negative or positive. Suppose this antenna is used in the setup shown in Figure 4. Notice that an impedance-matching pad is used to match the 75Ω antenna system to the 50Ω input of the spectrum analyzer. This is a minimum-loss resistive pad with an insertion loss of 5.7dB. If desired, a 75Ω/50Ω F impedance Page 3
4 Figure 4: This setup can be used to measure field strength. The resistive matching pad can be replaced with an L-C matching network or F impedance matching transformer for less insertion loss. Alternately, a transmission line tuning stub could be used to match the 75Ω antenna to the 50Ω impedance of the spectrum analyzer. transformer could be used to provide the impedance with less than a 1dB insertion loss. The loss of this matching pad must also be taken into account. The procedure is explained by the following example. Suppose the signal level on the spectrum analyzer is -70dBm at 450MHz. We already know that the antenna factor is +19dB/m. On the graph in Figure 5 locate -70dBm on the horizontal scale and move vertically to the graph line and to the right scale to approximately +37dBu. Since this graph is for an antenna factor of 0dB/m we must adjust the reading by adding the antenna correction factor to get ( ) +56dBu. The loss of the impedance matching transformer must also be taken into account. Add this figure to 56dBu to get ( ) 61.7dBu. This goes off scale on the inner scale so move to the outer scale (with matching figures in parentheses) near the bottom to 61.7dBu. This corresponds to a field intensity of approximately 10μV/m on the left side (outer scale). Page 4
5 Figure 5: This graph can be used to convert beween dbm and microvolts per meter or dbu. For direct conversions an antenna factor of 0dB/m is assumed. Antenna factors other than 0 must be factored in for the conversion to be valid. See text for full details on use. Figure 6 shows a setup using a 50Ω antenna system with a gain of 6dBd. Let s assume that the spectrum analyzer is being used to measure the level of a signal at 150MHz. The antenna factor from the graph in Figure 3 for a 50Ω system at 150MHz is +11.5dB/m. Since the antenna has a gain of 6dBd we must adjust the antenna correction factor by subtracting the antenna gain in db from the 0dB antenna factor. The adjusted antenna factor becomes: = +5.5dB/m. Suppose the spectrum analyzer reading is -80dBm. Using the graph in Figure 5 locate -80dBm on the horizontal scale. Move up to the graph line and over to the right scale to 27dBu. Now we must adjust for the antenna factor and line loss. Add the antenna factor and line loss to +27dBu to get: = 34.5dBu or approximately 53μV/m. Page 5
6 Figure 6: A 50Ω antenna with a gain of 6dB is connected to the 50Ω input of a spectrum analyzer in order to make signal strength measurements. The graph in Figure 5 can be used to convert from signal level at the receiver input to field intensity at the antenna or the reverse field intensity at the antenna to signal level at the receiver input. In fact, the graph in Figure 5 has multiple uses. Some examples will illustrate the many uses. The specification states that the db quieting sensitivity of a pager is 25μV/m in terms of field intensity or 0.5μV at the receiver F input jack. The frequency is 150MHz. Since pager antennas are located inside the small unit they are necessarily very lossy. Compared to a half-wave dipole a pager antenna might have a gain of -25dBd or so. (Any way you look at it, a negative gain is a loss!) We don t know the gain of the pager antenna compared to a half-wave dipole but we can determine this from the graph in Figure 5. The ratio of the required field intensity (μv/m) to the required signal level at the receiver input for db quieting is 25μV/m to 0.5μV or 50:1. On the graph (Figure 5) locate 50 on the left side and move over to the dbu scale to approximately +34dBu. From Figure 3 the antenna factor for a 0dBd gain antenna at 150MHz (50Ω) is +11.5dB/m. Now, subtract the +34dBu reading from the antenna factor to yield: = -22dB. This is the gain of the pager antenna in dbd. Page 6
7 emember, a negative gain is a loss and so the pager antenna has a loss of 22.5dB compared to a half-wave dipole. We might say that the pager antenna has a handicap of 22.5dB. Here is another example. Suppose that a receiver operating at 450MHz is connected to an antenna with a gain of 6dBd. The field intensity at the antenna is 10μV/m. The line loss is 2dB and the system impedance is 50Ω throughout. What is the signal level at the receiver input in dbm? First, find the antenna factor from Figure 3. At 450MHz the antenna factor is +21dB/m. The gain of the antenna (6dBd) must be subtracted to give an adjusted antenna factor of 21-6 = 15dB/m. Next, on the graph of Figure 5 locate 10μV/m on the left vertical scale and move over to +dbu on the right vertical scale. Now, subtract the antenna factor and line loss to yield: = 3dBu or approximately 1.42μV. To obtain the signal level in dbm move over to the graph line and down to the horizontal scale at approximately -104dBm. Thus, the scales can be used to convert between dbm and microvolts very easily. For example, 10μV = -87dBm. The scales can also be used to convert voltage ratios to decibels or vice versa. Suppose you want to convert a voltage ratio of 7:1 to decibels. Simply locate 7 on the μv/m scale and move over to the dbu scale to approximately 17. You can also convert decibels to voltage ratios by doing the reverse. Find the decibel figure on the dbu scale and move over to the μv/m scale to find the equivalent voltage ratio. For example, db corresponds to a voltage ratio of 10:1. It is also very easy to find levels such as 15dB above 3μV. Locate 3 on the μv/m scale and move over to 9.5 on the dbu scale. Then move up 15dB to 24.5dBu and back over to approximately 17μV. emember, when converting from field intensity units (dbu) to signal level units (dbm) subtract the antenna factor. Also, subtract any loss (line loss, etc.) between the antenna and receiver input. When converting from signal level units (dbm) to field intensity units (dbu) add the antenna factor and add any loss in db between the antenna and receiver input. Be sure to do the adding and subtracting algebraically (observe Page 7
8 signs). The accompanying formulas should cover about any conversion you will ever need to make concerning signal level and field intensity. The most frequently used of these formulas are included in the software package. SIGNAL & FIELD STENGTH CONVESIONS μv log( μv / m) + G log F + 32 L = anti log [1] log( μv) G + log F 32 + L μv / m = anti log [2] μv dbu + G log F + 32 L = anti log [3] dbu = log( μ V ) G + log F 32 + L [4] dbμv = log( μv / m) + G log F + 32 L [5] dbμv G + log F 32 + L μv / m = anti log [6] dbμ V = dbu + G log F + 32 L [7] dbu = dbμv G + log F 32 + L [8] dbm = log( μ V / m) + G log F 75 L [9] dbm G + log F L μv / m = anti log [10] Page 8
9 μv μv = 40( μv / m) F μv( F) / m= 40 for unity-gain antenna (0dBd) [11] for unity-gain antenna (0dBd) [12] dbm = log( μ V ) 107 [13] μv dbm + = anti log 107 [14] dbw = log( μ V / m) + G log F L [15] dbw G + log F L μv / m = anti log [16] dbm = dbμv 107 [17] dbμ V = dbm +107 [18] dbμv = log( μv ) [19] μv dbμv = anti log [] dbu = log( μ V / m) [21] dbu μv / m = anti log [22] Page 9
10 dbw = log( μ V ) 137 [23] μv dbw + = anti log 137 [24] dbμ V = dbw +137 [25] dbw = dbμv 137 [26] dbm = dbw +30 [27] dbw = dbm 30 [28] E = db antilog [29] P = db antilog 10 [30] dbm K + L μv / m = anti log [31] dbm = log( μ V / m) 107 K L [32] dbu = dbm G + log F L [33] dbm = dbu + G log F 75 L [34] K = log F G 32 (for 50Ω antenna system) [35] Page 10
11 K = log F G 338. (for 75Ω antenna system) [36] dbu = dbm K + L [37] dbm = dbu 107 K L [38] dbu = dbw G + log F L [39] dbw = dbu + G log F 105 L [40] dbu = dbw K + L [41] dbw = dbu 137 K L [42] The following abbreviations are used in formulae μv = signal level in microvolts dbμv = signal level in decibels referenced to 1μV dbm = signal level in decibels referenced to 1 milliwatt in 50Ω dbw = signal level referenced to 1 watt in 50Ω μv/m = field intensity in microvolts per meter dbu = field intensity in decibels referenced to 1 microvolt per meter (μv/m) F = frequency in MHz G = receiver antenna gain in decibels referenced to half-wave dipole (dbd) K = antenna factor in decibels per meter (db/m) L = any losses between the antenna and receiver (spectrum analyzer) input including line loss, filter insertion loss, matching network or transformer Page 11
12 loss, etc. This is a positive value. FOM TO K- FOMULA FACTO μv/m μv NO #1 µv/m dbµv NO #5 µv/m dbm NO #9 µv/m dbw NO #15 µv/m dbu N/A #21 µv/m dbm YES #32 µv µv/m NO #2 µv dbu NO #4 µv dbm N/A #13 µv dbµv N/A #19 µv dbw N/A #23 dbµv dbu NO #8 dbµv µv N/A # dbµv dbw N/A #26 dbu µv NO #3 dbu dbµv NO #7 dbu µv/m N/A #22 dbu dbm NO #34 dbu dbm YES #38 This table is used to determine which formula to choose in making conversions between measurements. For example, to convert from dbu to dbm using the antenna factor or K-factor use formula #38. To make the same conversion without using the K-factor use formula #34. Page 12
Intermediate Course (5) Antennas and Feeders
Intermediate Course (5) Antennas and Feeders 1 System Transmitter 50 Ohms Output Standing Wave Ratio Meter Antenna Matching Unit Feeder Antenna Receiver 2 Feeders Feeder types: Coaxial, Twin Conductors
More informationTechnician License Course Chapter 4. Lesson Plan Module 9 Antenna Fundamentals, Feed Lines & SWR
Technician License Course Chapter 4 Lesson Plan Module 9 Antenna Fundamentals, Feed Lines & SWR The Antenna System Antenna: Transforms current into radio waves (transmit) and vice versa (receive). Feed
More informationTechnician License. Course
Technician License Course Technician License Course Chapter 4 Lesson Plan Module - 9 Antenna Fundamentals Feed Lines & SWR The Antenna System The Antenna System Antenna: Transforms current into radio waves
More informationField Intensity Units
Page 1 of 5 Field Intensity Units Q: What is the difference between dbu, dbm, dbuv, and other units? A: There is a great deal of confusion when engineers, technicians, and equipment salespersons talk about
More informationCray Valley Radio Society. Real Life Wire Antennas
Cray Valley Radio Society Real Life Wire Antennas 1 The basic dipole The size of an antenna is determined by the wavelength of operation In free space: ~3x10 8 m/s Frequency x Wavelength = Speed of Light,
More informationAntenna Design for FM-02
Antenna Design for FM-02 I recently received my FM-02 FM transmitter which I purchased from WLC. I researched the forum on what antennas where being used by the DIY community and found a nice write-up
More informationFundamentals of Antennas. Prof. Ely Levine
Fundamentals of Antennas Prof. Ely Levine levineel@zahav.net.il 1 Chapter 3 Wire Antennas 2 Types of Antennas 3 Isotropic Antenna Isotropic radiator is the simplest antenna mathematically Radiates all
More informationTHE ELECTRIC WAVE BALUNS AND COAXIAL AERIALS
THE ELECTRIC WAVE BALUNS AND COAXIAL AERIALS If you are dealing with radiofrequency aerials you might like to experiment with the configurations proposed. In fig. 1 there is a balun which transforms an
More informationMilton Keynes Amateur Radio Society (MKARS)
Milton Keynes Amateur Radio Society (MKARS) Intermediate Licence Course Feeders Antennas Matching (Worksheets 31, 32 & 33) MKARS Intermediate Licence Course - Worksheet 31 32 33 Antennas Feeders Matching
More informationECC Recommendation (16)04
ECC Recommendation (16)04 Determination of the radiated power from FM sound broadcasting stations through field strength measurements in the frequency band 87.5 to 108 MHz Approved 17 October 2016 Edition
More information02680SX Series UHF Mount Dipole Array Series
02680SX Series UHF Mount Dipole Array Series Page 1 of 11 Description The 02680SX series antennas are 0dB, 3dB and 6dB Gain, Stainless Steel Side Mount Dipole Array antennas, for use in the Commercial
More informationMFJ-219/219N 440 MHz UHF SWR Analyzer TABLE OF CONTENTS
MFJ-219/219N 440 MHz UHF SWR Analyzer TABLE OF CONTENTS Introduction...2 Powering The MFJ-219/219N...3 Battery Installation...3 Operation Of The MFJ-219/219N...4 SWR and the MFJ-219/219N...4 Measuring
More informationThis Antenna Basics reference guide includes basic information about antenna types, how antennas work, gain, and some installation examples.
Antenna Basics This Antenna Basics reference guide includes basic information about antenna types, how antennas work, gain, and some installation examples. What Do Antennas Do? Antennas transmit radio
More informationAmateur Extra Manual Chapter 9.4 Transmission Lines
9.4 TRANSMISSION LINES (page 9-31) WAVELENGTH IN A FEED LINE (page 9-31) VELOCITY OF PROPAGATION (page 9-32) Speed of Wave in a Transmission Line VF = Velocity Factor = Speed of Light in a Vacuum Question
More informationBill Ham Martin Ogbuokiri. This clause specifies the electrical performance requirements for shielded and unshielded cables.
098-219r2 Prepared by: Ed Armstrong Zane Daggett Bill Ham Martin Ogbuokiri Date: 07-24-98 Revised: 09-29-98 Revised again: 10-14-98 Revised again: 12-2-98 Revised again: 01-18-99 1. REQUIREMENTS FOR SPI-3
More informationTechnician Licensing Class. Antennas
Technician Licensing Class Antennas Antennas A simple dipole mounted so the conductor is parallel to the Earth's surface is a horizontally polarized antenna. T9A3 Polarization is referenced to the Earth
More informationHalf-Wave Dipole. Radiation Resistance. Antenna Efficiency
Antennas Simple Antennas Isotropic radiator is the simplest antenna mathematically Radiates all the power supplied to it, equally in all directions Theoretical only, can t be built Useful as a reference:
More informationArchived 3/18/10 USER MANUAL EMCO MODEL 3141 BICONILOG TM LOG-PERIODIC / T BOW-TIE ANTENNA Rev A 01/97
USER MANUAL EMCO MODEL 3141 BICONILOG TM LOG-PERIODIC / T BOW-TIE ANTENNA 399236 Rev A 01/97 GENERAL DESCRIPTION The EMCO Model 3141 is the latest evolution in the popular bow-tie/log periodic combination
More informationAdjust Antenna Tuners Antenna Measurements Capacitor Measurement Measure Feed Point Impedance Measure Ground Loss Inductor Measurement
The Micro908 antenna analyzer is an extremely useful instrument to have around the ham shack or homebrewer s workbench. This section describes the basic uses, as well as some advanced techniques for which
More informationThe J-Pole Antenna. Gary Wescom
The J-Pole Antenna Gary Wescom - 2018 Much has been written about the J-Pole antenna. A simple Google search will net days worth of reading material on the subject. That would tend to indicate this paper
More informationRF Emissions Test Report To Determine Compliance With: FCC, Part 15 Rules and Regulations
RF Emissions Test Report To Determine Compliance With: FCC, Part 15 Rules and Regulations Model numbers: HT130022 Rev. B. December 17, 2002 Manufacturer: HQ, Inc. 210 9th Steet Drive Palmetto, FL 34221
More informationTrees, vegetation, buildings etc.
EMC Measurements Test Site Locations Open Area (Field) Test Site Obstruction Free Trees, vegetation, buildings etc. Chamber or Screened Room Smaller Equipments Attenuate external fields (about 100dB) External
More informationTechnician Licensing Class T9
Technician Licensing Class T9 Amateur Radio Course Monroe EMS Building Monroe, Utah January 11/18, 2014 January 22, 2014 Testing Session Valid dates: July 1, 2010 June 30, 2014 Amateur Radio Technician
More informationThe G4EGQ RAE Course Lesson 13 Pt1 Transmitter Power Measurements
Transmitter Power Output Measurements. Introduction The Radio Amateur is limited to the transmitter power output as laid down in the BR68 schedule. Column 4 it gives the Maximum power level (in db relative
More informationDECIBELS. This reading begins with the human senses of sight, touch and hearing.
Reading 22 Ron Bertrand VK2DQ http://www.radioelectronicschool.com DECIBELS For some reason decibels are disliked by many, and misunderstood by many amateur radio operators, engineers, technicians and
More informationEE334 Gain and Decibels Worksheet
EE334 Gain and Decibels Worksheet In electrical engineering one often finds situations where one is interested in either amplifying (making larger) or attenuating (making smaller) values such as voltage,
More informationMFJ-249B HF/VHF SWR ANALYZER
TABLE OF CONTENTS MFJ-249B... 2 Introduction... 2 Powering The MFJ-249B... 3 Battery Installation... 3 Alkaline Batteries... 3 NiCd Batteries... 4 Power Saving Mode... 4 Operation Of The MFJ-249B...5 SWR
More informationSWR myths and mysteries.
SWR myths and mysteries. By Andrew Barron ZL3DW September 2012 This article will explain some of the often misunderstood facts about antenna SWR at HF and uncover some popular misconceptions. The questions
More informationINTERNATIONAL STANDARD
INTERNATIONAL STANDARD IEC 60489-1 1983 AMENDMENT 2 1999-05 Amendment 2 Methods of measurement for radio equipment used in the mobile services Part 1: General definitions and standard conditions of measurement
More informationThe db Concept. Chapter six
Chapter six The db Concept CHAPTER OUTLINE dbdpower Ratio... 40 dbdamplitude Ratio... 40 From db to Power or Amplitude Ratio... 41 Conversion Table... 41 Reference Values... 41 Other Relative Units...43
More informationFeed Line Currents for Neophytes.
Feed Line Currents for Neophytes. This paper discusses the sources of feed line currents and the methods used to control them. During the course of this paper two sources of feed line currents are discussed:
More information4/25/2012. Supplement T9. 2 Exam Questions, 2 Groups. Amateur Radio Technician Class T9A: T9A: T9A: T9A:
Amateur Radio Technician Class Element 2 Course Presentation ti ELEMENT 2 SUB-ELEMENTS Technician Licensing Class Supplement T9 Antennas, Feedlines 2 Exam Questions, 2 Groups T1 - FCC Rules, descriptions
More informationAmateur Radio License. Propagation and Antennas
Amateur Radio License Propagation and Antennas Todays Topics Propagation Antennas Propagation Modes Ground wave Low HF and below, ground acts as waveguide Line-of-Sight (LOS) VHF and above, radio waves
More informationCOAXIAL TRANSMISSION LINE COMMON-MODE CURRENT
COAXIAL TRANSMISSION LINE COMMON-MODE CURRENT Introduction Coaxial transmission lines are popular for their wide frequency bandwidth and high resistance to electromagnetic interference (EMI). Coax cables
More informationChapter 6 Antenna Basics. Dipoles, Ground-planes, and Wires Directional Antennas Feed Lines
Chapter 6 Antenna Basics Dipoles, Ground-planes, and Wires Directional Antennas Feed Lines Some General Rules Bigger is better. (Most of the time) Higher is better. (Most of the time) Lower SWR is better.
More informationLeast understood topics by most HAMs RF Safety Ground Antennas Matching & Feed Lines
Least understood topics by most HAMs RF Safety Ground Antennas Matching & Feed Lines Remember this question from the General License Exam? G0A03 (D) How can you determine that your station complies with
More informationMeasurement Procedure & Test Equipment Used
Measurement Procedure & Test Equipment Used Except where otherwise stated, all measurements are made following the Electronic Industries Association (EIA) Minimum Standard for Portable/Personal Land Mobile
More information6 Radio and RF. 6.1 Introduction. Wavelength (m) Frequency (Hz) Unit 6: RF and Antennas 1. Radio waves. X-rays. Microwaves. Light
6 Radio and RF Ref: http://www.asecuritysite.com/wireless/wireless06 6.1 Introduction The electromagnetic (EM) spectrum contains a wide range of electromagnetic waves, from radio waves up to X-rays (as
More informationEVLA Memo 172 The Modified J-Pole Antenna
EVLA Memo 172 The Modified J-Pole Antenna Steve Ellingson, Sterling Coffey, Dan Mertley September 20, 2013 This memo describes the modified J-pole (MJP), a broadband end-fed dipole-like antenna that was
More informationAntenna. Wave length Km/s
Antenna 5% Wave length 300 000 Km/s 066 velocity factor RG-58 = C = = F : 120 Impedance 50 50 50 VSWR and Reflected Power SWR VSWR VSWR 2:1 Voltage Standing Wave Ratio VSWR 15:1 15:1 VSWR 100 Watt 1:1
More informationScreening Attenuation When enough is enough
Screening Attenuation When enough is enough Anders Møller-Larsen, Ph.D. M.Sc. E.E. Product Manager, Coax Network Introduction This white paper describes the requirements to screening attenuation of cables
More informationELEC 425 Interference Control in Electronics Lecture 7(a) Introduction to Antennas: Terminology
Dr. Gregory J. Mazzaro Fall 017 ELEC 45 Interference Control in Electronics Lecture 7(a) Introduction to Antennas: Terminology Chapter 9 THE CITADEL, THE MILITARY COLLEGE OF SOUTH CAROLINA 171 Moultrie
More informationEFFECT OF SHIELDING ON CABLE RF INGRESS MEASUREMENTS LARRY COHEN
EFFECT OF SHIELDING ON CABLE RF INGRESS MEASUREMENTS LARRY COHEN OVERVIEW Purpose: Examine the common-mode and differential RF ingress levels of 4-pair UTP, F/UTP, and F/FTP cables at an (RJ45) MDI port
More informationAppendix A Decibels. Definition of db
Appendix A Decibels Communication systems often consist of many different blocks, connected together in a chain so that a signal must travel through one after another. Fig. A-1 shows the block diagram
More informationRadio Frequency Lighting Devices (RFLDs)
Issue 2 February 2007 Spectrum Management and Telecommunications Interference-Causing Equipment Standard Radio Frequency Lighting Devices (RFLDs) Aussi disponible en français NMB-005 Contents 1. General...
More informationThe DBJ-1: A VHF-UHF Dual-Band J-Pole
By Edison Fong, WB6IQN The DBJ-1: A VHF-UHF Dual-Band J-Pole Searching for an inexpensive, high-performance dual-band base antenna for VHF and UHF? Build a simple antenna that uses a single feed line for
More informationDefinitions of Technical Terms
Definitions of Technical Terms Terms Ammeter Amperes, Amps Band Capacitor Carrier Squelch Diode Dipole Definitions How is an ammeter usually connected = In series with the circuit What instrument is used
More informationField Calibration of Un-calibrated Antenna
Field Calibration of Un-calibrated Antenna Z Technology Application Note No: 42 Background In a DriveTest situation of measuring several frequencies in a single drive a challenging issue can be what antenna
More informationAntennas and Propagation Chapters T4, G7, G8 Antenna Fundamentals, More Antenna Types, Feed lines and Measurements, Propagation
Antennas and Propagation Chapters T4, G7, G8 Antenna Fundamentals, More Antenna Types, Feed lines and Measurements, Propagation =============================================================== Antenna Fundamentals
More informationJacques Audet VE2AZX. Nov VE2AZX 1
Jacques Audet VE2AZX VE2AZX@amsat.org Nov. 2006 VE2AZX 1 - REASONS FOR USING A BALUN - TYPES OF BALUNS - CHECK YOUR BALUN WITH AN SWR ANALYZER - MEASURING THE IMPEDANCE OF A NUMBER OF FERRITES - IMPEDANCE
More informationAntenna Circular Polarization
Antenna Circular Polarization Space communication has forced the use of Circular polarization. The fundamental advantage of circular polarization is that all reflections change the direction of polarization,
More informationA Low-Loss VHF/UHF Diplexer
A Low-Loss / Diplexer Why use two lengths of expensive feed line when one will do? This hy box lets you use one feed line for both energy, simultaneously! By Pavel Zanek, OK1DNZ Do you need to operate
More informationTechnician Licensing Class. Lesson 4. presented by the Arlington Radio Public Service Club Arlington County, Virginia
Technician Licensing Class Lesson 4 presented by the Arlington Radio Public Service Club Arlington County, Virginia 1 Quiz Sub elements T6 & T7 2 Good Engineering Practice Sub element T8 3 A Basic Station
More informationAntenna? What s That? Chet Thayer WA3I
Antenna? What s That? Chet Thayer WA3I Space: The Final Frontier Empty Space (-Time) Four dimensional region that holds everything Is Permeable : It requires energy to set up a magnetic field within it.
More informationTDS-535 Tuned Dipole Set Operation Manual
TDS-535 Tuned Dipole Set Operation Manual 1 TABLE OF CONTENTS INTRODUCTION Antenna Set Contents...3 Intended Purposes...4 Range of Environmental Conditions...5 GENERAL INSTRUCTIONS General Description...5
More informationCorrelation Between Measured and Simulated Parameters of a Proposed Transfer Standard
Correlation Between Measured and Simulated Parameters of a Proposed Transfer Standard Jim Nadolny AMP Incorporated ABSTRACT Total radiated power of a device can be measured using a mode stirred chamber
More informationAntenna Basics. Antennas. A guide to effective antenna use
A guide to effective antenna use Antennas Antennas transmit radio signals by converting radio frequency electrical currents into electromagnetic waves. Antennas receive the signals by converting the electromagnetic
More informationL.S. Compliance, Inc. W66 N220 Commerce Court Cedarburg, WI
L.S. Compliance, Inc. W66 N220 Commerce Court Cedarburg, WI 53012 262-375-4400 COMPLIANCE TESTING OF: Quartex Synchronization Transmitter Model FM-72 PREPARED FOR: Quartex, Division of Primex, Inc. 965
More informationTechnician License. Course
Technician License Course Technician License Course Chapter 4 Lesson Plan Module - 10 Practical Antennas The Dipole Most basic antenna The Dipole Most basic antenna The Dipole Total length is ½ wavelength
More informationMEASUREMENT PROCEDURE AND TEST EQUIPMENT USED
MEASUREMENT PROCEDURE AND TEST EQUIPMENT USED Except where otherwise stated, all measurements are made following the Electronic Industries Association (EIA) Minimum Standard for Portable/Personal Land
More informationARNSW Balun Day. Balun construction
ARNSW Balun Day Balun construction Typical Baluns All built from locally available components. Balun uses Most baluns are used to match the 50Ω output of a transceiver to an antenna. A centre fed dipole
More informationRX Directional Antennas. Detuning of TX Antennas.
1. Models Impact of Resonant TX antennas on the Radiation Pattern of RX Directional Antennas. Detuning of TX Antennas. Chavdar Levkov, lz1aq@abv.bg, www.lz1aq.signacor.com 2-element small loops and 2-element
More informationBeams and Directional Antennas
Beams and Directional Antennas The Horizontal Dipole Our discussion in this chapter is about the more conventional horizontal dipole and the simplified theory behind dipole based designs. For clarity,
More informationSUBELEMENT T5 Electrical principles: math for electronics; electronic principles; Ohm s Law 4 Exam Questions - 4 Groups
SUBELEMENT T5 Electrical principles: math for electronics; electronic principles; Ohm s Law 4 Exam Questions - 4 Groups 1 T5A Electrical principles, units, and terms: current and voltage; conductors and
More informationRange Considerations for RF Networks
TI Technology Days 2010 Range Considerations for RF Networks Richard Wallace Abstract The antenna can be one of the most daunting components of wireless designs. Most information available relates to large
More informationAntennas 101 Don t Be a 0.97 db Weakling! Ward Silver NØAX
Antennas 101 Don t Be a 0.97 db Weakling! Ward Silver NØAX Overview Antennas 101 2 Overview Basic Antennas: Ground Plane / Dipole How Gain and Nulls are Formed How Phased Arrays Work How Yagis Work (simplified)
More informationYagi beam antennas CHAPTER 10 COMPOSITION OF A BEAM ANTENNA _
CHAPTER 10 Yagi beam antennas The Yagi beam antenna (more correctly, the Yagi Uda antenna, after both of the designers of Tohoku University in Japan 1926) is unidirectional. It can be vertically polarized
More informationMFJ-208 VHF SWR Analyzer
MFJ-208 VHF SWR Analyzer Thank you for purchasing the MFJ-208 VHF SWR Analyzer. The MFJ-208 gives you a direct readout of your antenna's SWR without the need for formulas or indirect readings. The MFJ-
More informationc 2014 Christie M. Bermudez-Rivera
c 2014 Christie M. Bermudez-Rivera AN INVESTIGATION OF SERIES LC RESONANT CIRCUITS WITHIN A SLEEVE BALUN TO ACHIEVE WIDEBAND OPERATION BY CHRISTIE M. BERMUDEZ-RIVERA THESIS Submitted in partial fulfillment
More informationBulk Current Injection Probe Test Procedure
Bulk Current Injection Probe Test Procedure 1 TABLE OF CONTENTS INTRODUCTION 3 GENERAL INFORMATION 4 TEST METHODS 6 SAFETY 8 FIGURES 9 FORMULAS 12 MAINTENANCE 13 WARRANTY 14 2 INTRODUCTION CURRENT PROBE
More informationP a g e 1 ST985. TDR Cable Analyzer Instruction Manual. Analog Arts Inc.
P a g e 1 ST985 TDR Cable Analyzer Instruction Manual Analog Arts Inc. www.analogarts.com P a g e 2 Contents Software Installation... 4 Specifications... 4 Handling Precautions... 4 Operation Instruction...
More informationUNIVERSITI MALAYSIA PERLIS
UNIVERSITI MALAYSIA PERLIS SCHOOL OF COMPUTER & COMMUNICATIONS ENGINEERING EKT 341 LABORATORY MODULE LAB 2 Antenna Characteristic 1 Measurement of Radiation Pattern, Gain, VSWR, input impedance and reflection
More informationAdvanced Test Equipment Rentals ATEC (2832)
Established 1981 Advanced Test Equipment Rentals www.atecorp.com 800-404-ATEC (2832) A.H. Systems Model TDS-536 Tuned Dipole Set TDS-536 TV Dipole Set Operation Manual 1 TABLE OF CONTENTS WARRANTY 2 INTRODUCTION
More informationAntenna Trainer EAN. Technical Teaching Equipment INTRODUCTION
Antenna Trainer EAN Technical Teaching Equipment Products Products range Units 3.-Communications INTRODUCTION Antennas are the main element of aerial communications. They are the transition between a transmission
More informationTransmission lines carry RF
Transmission Line asics Technical techniques: primer for transmission lines Part I n understanding of transmission lines and tips on using them as transformers and filters can help techs properly configure
More informationThe Amazing MFJ 269 Author Jack Tiley AD7FO
The Amazing MFJ 269 Author Jack Tiley AD7FO ARRL Certified Emcomm and license class Instructor, Volunteer Examiner, EWA Technical Coordinator and President of the Inland Empire VHF Club What Can be Measured?
More informationAntenna Fundamentals
HTEL 104 Antenna Fundamentals The antenna is the essential link between free space and the transmitter or receiver. As such, it plays an essential part in determining the characteristics of the complete
More information14 What You Should Know About Decibels
14 What You Should Know About Decibels Every year dozens of students who should know much better lose a lot of exam marks because they haven t grasped the concept of the decibel. This is a great pity:
More information1) Transmission Line Transformer a. First appeared on the scene in 1944 in a paper by George Guanella as a transmission line transformer, the 1:1
1) Transmission Line Transformer a. First appeared on the scene in 1944 in a paper by George Guanella as a transmission line transformer, the 1:1 Guanella Balun is the basic building Balun building block.
More information4/29/2012. General Class Element 3 Course Presentation. Ant Antennas as. Subelement G9. 4 Exam Questions, 4 Groups
General Class Element 3 Course Presentation ti ELEMENT 3 SUB ELEMENTS General Licensing Class Subelement G9 Antennas and Feedlines 4 Exam Questions, 4 Groups G1 Commission s Rules G2 Operating Procedures
More informationGalcon Galil Control
Cert. No. 1152.01 Electrical (EMC) DATE: 16 April 2006 I.T.L. (PRODUCT TESTING) LTD. AS/NZS EMC Test Report for Galcon Galil Control Equipment under test: Fertilizer System FERTIMIX*, FERTIGAL**, FERTIJET**
More informationAntenna Glossary. BEAMWIDTH The angle of signal coverage provided by an antenna. Beamwidth usually decreases as antenna gain increases.
ADAPTIVE (SMART) ANTENNA An antenna system having circuit elements associated with its radiating elements such that one or more of the antenna properties are controlled by the received signal. ANTENNA
More informationHF Wire Antennas with Gain
Learning Unit 5 HF Wire Antennas with Gain Objectives and Overview: Take the student to the next step beyond the half-wave dipole and introduce wire antennas with enhanced directivity and gain. The concept
More informationFCC PART 15 B CLASS B TEST REPORT
849 NW State Road 45 Newberry, Fl 32669 USA Phone: 888.472.2424 or 352.472.5500 Fax: 352.472.2030 Email: info@timcoengr.com Website: www.timcoengr.com FCC PART 15 B CLASS B TEST REPORT Applicant Address
More informationElectromagnetic Compatibility ( EMC )
Electromagnetic Compatibility ( EMC ) Introduction EMC Testing 1-2 -1 Agenda System Radiated Interference Test System Conducted Interference Test 1-2 -2 System Radiated Interference Test Open-Area Test
More informationElectrical Fundamentals and Basic Components Chapters T2, T3, G4
Electrical Fundamentals and Basic Components Chapters T2, T3, G4 Some Basic Math, Electrical Fundamentals, AC Power, The Basics of Basic Components, A Little More Component Detail, Reactance and Impedance
More informationUnderstanding the Precision Antenna, Cable, and Power Measurements on the 3550 Radio Test System
Application Note Understanding the Precision Antenna, Cable, and Power Measurements on the 3550 Radio Test System The Aeroflex 3550 Radio Test System now includes new methods for more accurately measuring
More informationOther Arrays CHAPTER 12
CHAPTER 12 Other Arrays Chapter 11 on phased arrays only covered arrays made of vertical (omnidirectional) radiators. You can, of course, design phased arrays using elements that, by themselves, already
More informationECE 440L. Experiment 1: Signals and Noise (1 week)
ECE 440L Experiment 1: Signals and Noise (1 week) I. OBJECTIVES Upon completion of this experiment, you should be able to: 1. Use the signal generators and filters in the lab to generate and filter noise
More informationCommon EMC Measurement Terms
Common EMC Measurement Terms According to Krause 1, A radio antenna may be defined as the structure associated with the region of transition between a guided wave and free space, or vice versa. The EMC
More informationComing next: Wireless antennas for beginners
Coming next: Wireless antennas for beginners In other rooms: Logbook of the World (Sussex Suite) SO2R contest operation (Stable Suite) Wires for your wireless: Simple wire antennas for beginners dominic
More informationA TRANSMISSION LINE BALANCE TEST METER
by Lloyd Butler VK5BR with modifications by Phil Storr VK5SRP. Here is a simple meter to check the balance of currents running in the two legs of a transmission line. It can be used to check the balance
More informationMicroair Avionics Pty Ltd ABN VHF Aerial Installation FAQ
Pty Ltd ABN 92 091 040 032 P O Box 5532 Airport Drive Bundaberg West Queensland 4670 Australia Phone: Fax: Email: Web: 07 4155 3048 +61 7 4155 3048 07 4155 3049 +61 7 4155 3049 support@microair.com.au
More information4 Antennas as an essential part of any radio station
4 Antennas as an essential part of any radio station 4.1 Choosing an antenna Communicators quickly learn two antenna truths: Any antenna is better than no antenna. Time, effort and money invested in the
More informationAntenna fundamentals: With answers to questions and problems (See also Chapter 9 in the textbook.)
adio Technology Metopolia/A. Koivumäki Antenna fundamentals: With answes to questions and poblems (See also Chapte 9 in the textbook.) 1. a) Make up a definition fo the tem "antenna". Answe: One definition:
More informationAdvanced Test Equipment Rentals ATEC (2832)
Established 1981 Advanced Test Equipment Rentals www.atecorp.com 800-404-ATEC (2832) LOG PERIODIC DIPOLES 20 MHz - 18 GHz TRANSMIT - RECEIVE SPECIFICATIONS ELECTRICAL Impedance: 50 ohms INDIVIDUALLY CALIBRATED
More informationMWA REVB LNA Measurements
1 MWA REVB LNA Measurements Hamdi Mani, Judd Bowman Abstract The MWA LNA (REVB) was measured on the Low Frequency Radio astronomy Lab using state of the art test equipment. S-parameters of the amplifier
More informationModel 3140B BiConiLog Antenna User Manual
Model 3140B BiConiLog Antenna User Manual Model 3140B mounted onto a 7-TR tripod (not included) ETS-Lindgren L.P. reserves the right to make changes to any product described herein in order to improve
More informationElectromagnetic Compatibility Test Report FCC test results of an automatic dog brush, model EUT: Type 1 AC/DC adaptor: SYS W2E
Electromagnetic Compatibility Test Report FCC test results of an automatic dog brush, model EUT: Type 1 AC/DC adaptor: SYS1308-1809-W2E Customer Customer's representative In the capacity of Reference number
More informationRadio ETI031 Laboratory Experiments 2: VECTOR NETWORK ANALYSER, ANTENNA and RECEIVER MEASUREMENTS
Lund University Electrical and Information Technology GJ 2007-09-30 Radio ETI031 Laboratory Experiments 2: VECTOR NETWORK ANALYSER, ANTENNA and RECEIVER MEASUREMENTS Göran Jönsson 2007 Objectives: Part
More information