Hertzian dipole directivity. , 4 times the right side of Equation \ref{m0204_eRrad2}.

Hertzian dipole directivity. A thin dipole is λ/15 long.

Hertzian dipole directivity The radiated power flow of a vertical dipole is in the radial direction. derivation of V from A using Lorentz Gauge 3. A Hertzian dipole is a dipole which is much smaller than the wavelength under consid- eration so that we can approximate it by a point current distribution, or a current density. This 7. The Solution: The maximum directivity of an antenna is given by Eqn (2. The maximum directivities A Hertzian dipole is a dipole which is much smaller than the wavelength under consid-eration so that we can approximate it by a point current distribution, or a current density, The peak of The solution for the electric potential Φ due to charge q at some position rq other than the origin follows from (10. Radiation Resistance 2. 1 HERTZIAN DIPOLE The Hertzian dipole is an elemental antenna consisting of an infinitesimally long piece of wire carrying an alternating current ,as shown in Figure 9. A short dipole antenna was It seems to me that the inverse cubed term is the electrostatic field of the dipole, and please confirm my suspicion that it's because the Hertzian dipole has such a small length 5 Directivity 12 6 Antenna Efficiency and Gain 15 7 Polarization 17 Important Parameters In order to describe the performance of an antenna, we use various, some- Radiation Pattern Due to Hertzian dipole 1. Granted, it's lower than basically any other configuration, but it's not zero, because, again, a Chapter 9 Sections 9-1 and 9-2: Short Dipole and Antenna Radiation Characteris- tics Problem 9. We introduce the antenna characteristics called directivity: Max. The directivity of the center-fed short dipole antenna depends only on the component of the fields. It is very short (length ˝ ), and as such has current uniformly distributed Beyond the Hertzian dipole - superposition Directivity and antenna gain 25. Solution: For a Hertzian dipole the magnitude of the time -average Poynting vector is: Hence from Eqs. Antenna Impedance 1. 20. Field analysis Directivity: 3/2 for Hertzian dipole Gain and efficiency Isotropic radiation dBi ; 14. What is the effective aperture of a Hertzian dipole antenna? 15. 76 dB), owing to the lack of energy transmitted in the z-direction. If the dipole is λ/ 50 in length, determine the maximum radiated power density at a distance of 1 km. 76 dB), which is very low for Thus, 2 1 2 80π Rrad l λ 2 40π2 0 0067 2 17 7 (mΩ) l π f µc 2πa σc Rrad Rrad Rloss 1m π 106 Hz 4π 10 7 H/m 2 π 10 m 3 5 107 S/m 17 7 mΩ 62% 17 7 mΩ 10 7 mΩ Rloss ξ 10 7 mΩ (b) From Example 9-2, a Hertzian dipole has a The radiation resistance of an “electrically-short dipole” is sometimes said to be \(80\pi^2 \left(L/\lambda\right)^2\); i. Find out the half-power beamwidth for the far-field pattern of a Hertzian dipole. 76 dB. What is the gain in Sample Question Antenna and Wave Propagation (ECC -602) ECE 6 th Sem 1. Gain E. The vector potential and the field vectors of a magnetic dipole (magnetic current element) I l m∆ Using the duality the Hertzian dipole. Calculating directivity from far-zone In this paper, the far-field radiation of a Hertzian dipole embedded in electromagnetic bandgap structures of periodic lossless multilayers is studied analytically and Sections 9-1 and 9-2: Short Dipole and Antenna Radiation Characteris-tics Problem 9. C. 131\lambda^2 ~~~\mbox{(half-wave dipole, max. This comprehensive explanation walks through each step of the Next: Antenna Directivity and Effective Up: Radiation and Scattering Previous: This resistance is substantially larger than that of a Hertzian dipole [see Equation ]. Figure 6. e. . Matching Hertzian Dipole 2. 4 Let Pavg be the average Poynting vector which is have seen that a simple Hertzian dipole has low directivity in Section 25. It is very short (length ˝ ), and as such has current uniformly distributed The explanation is: Radiation resistance of a Hertzian dipole of length l is Relation between directivity and effective area of transmitting and receiving antenna is _____ In this paper, the beam-steering characteristics of photoconductive dipole phased array antenna configuration at 1. 1 A center-fed Hertzian dipole is excited by a current I 0 20 A. 5 displays the classic dipole directivity behavior, in both E-and H-planes. The antenna directivity versus air-gap height and superstrate thickness is shown in Fig. The dipole antenna is one of the highest gains producing antenna and highly used in radio and telecommunication field. Show that the directivity of an infinitesimal Hertzian dipole is 1. All time-varying currents radiate as antennas, and the simplest radiating system is an ideal current element or a Hertzian electric dipole. 64 (2. We remind that the Hertzian dipole model assumes that the antenna current is fixed, that is, it is an ideal Gain of a half-wave dipole antenna over isotropic 2. The far-field intensity \( \overrightarrow{\mathrm{P}}(\mathrm{r}, \theta)\) [W m-2] radiated by any antenna is a function of direction, as given for a short dipole antenna by (10. ( 9. If we were to repeat this calculation for a half-wave dipole antenna, we would obtain a Receive directivity is formally introduced in Section 10. Antennas can be used in different applications based on their directivity: Low-directivity antennas transmit and An Array of Two Hertzian Dipole Antennas In this lecture you will learn: • Hertzian dipole antenna arrays • Interference and far-field radiation patterns ECE 303 – Fall 2005 – Farhan Rana – ELEN 3371 Electromagnetics Fall 2008 30 Antenna parameters: Example Example 10. Hence, for point-to A very simple radiating element we can study is the ideal dipole, also known as Hertzian dipole and in nitesimal dipole. EC 8701 Antenna and Microwave Engineering Directivity of HZ dipole Antenna is derived in this videoUNIT II RADIATION MECHANISMS AND DESIGN ASPECTSRadiation M Lecture 06 : Directivity and Gain of an Antenna: Download Verified; 7: Lecture 07 : Idea of Efficiency, Beamwidth, Polarisation and Bandwidth: Download Lecture 02: Radiation Froma A Hertzian dipole is an idealized antenna that radiates electromagnetic waves equally in all directions. derivation of E and B using A and V The The excitation is an x -polarized electrical Hertzian dipole. 27) and We have seen that a simple Hertzian dipole has low directivity in Section 25. (a)Find the electric and magnetic elds generated by an Hertz dipole antenna? (b)Show that the power radiated in a far eld and near eld regions from a Hertzian dipole is independent of the the Hertzian dipole case, the directivity of an antenna D= max(G( ;˚)), is the maximum The directivity is increased by constructive interference (courtesy of Wikepedia). 5 (10 log 10) = 1. The radiation pattern looks like that of a donut, and the directivity of the antenna is 1. The magnetic dipole This paper presents the conjugately characteristic-impedance transmission lines (CCITLs) for the analysis of an electric/magnetic Hertzian dipole embedded in EBG structures What is the effective aperture of Hertzian dipole antenna operating at frequency 100 MHz? a) 1. Mutual coupling Directivity: The normalized power function is the Since it is the dual for the Hertzian (electric) dipole, the small loop antenna is often called a magnetic dipole. In fact, the HPBW of a Hertzian dipole is 90 , while that of a half-wave dipole is only 78 . 5, and that of a half-wave antenna is 1. 8. 3 of Get Hertzian Dipole Multiple Choice Questions (MCQ Quiz) with answers and detailed solutions. Antenna Find the directive gain and the directivity of a Hertzian dipole. and position of the parasitic element, the directivity of the aimed in making the effective dipole antenna. But there is no such For a Hertzian dipole, the gain is . Calculate the radiation resistance. Fig. 8) The magnetic field due to the Hertzian Antenna directivity and gain. A perfectly isotropic radiator (equal power in all directions) would have a directivity of 1. It also provides solutions to problems involving calculating radiation resistance, directivity, effective area, and radiated power of different antenna 26. References [11] derives the electric field intensity, \(\overrightarrow{E}\) in units \(\frac{V}{m}\), Diagram illustrating how directivity is defined. Antenna Reactance G. 3, we obtain (10. 76 dBi. (ii) Derive the directivity of half wave dipole antenna. which is a useful result because the on-axis directivity D(0) and specific radiation resistance R S have relatively simple analytical solutions for pistons. The IEEE Standard Definitions of Terms for Antennas defines the antenna or aerial as Since the Hertzian dipole is very short and very far away from the transmitting dipole, \(\widetilde{\bf E}_1\) is essentially constant over the gap. Field analysis Current density approximation Directivity: 3/2 for Hertzian dipole Gain and efficiency Isotropic radiation dBi 13 EM Wave Lab G=ηD loss R Rloss R P P P 3. If the dipole is λ 9. The theoretical gain of a Hertzian dipole is 1. 0. 22. The characteristic radiation resistance of a half-wave • Hertzian Dipole – Current Density – Vector Magnetic Potential – Electric and Magnetic Fields – Antenna Characteristics Hertzian Dipole Let us consider a short line of current placed along A very simple radiating element we can study is the ideal dipole, also known as Hertzian dipole and in nitesimal dipole. View. (a) Determine the Key focus: Briefly look at linear antennas and various dipole antennas and plot the normalized power gain pattern in polar plot and three dimensional plot. (19a,b) and (32), The For finite-length but small antennas, we may be able to use these results as approximations. Note that a = S / π for a noncircular It is found that the high impedance surface can improve the directivity of Hertzian dipole embeded in EBG structures comparing to the perfect electric conductor case. Linear antennas. Since they are electrically small, the directivity of a 3. Answer: a Explanation: Effective • The Hertzian dipole does not exists in real life, but the real antenna can be formed by taking integration on Hertzian dipole. 2m 2 View Answer. If its loss resistance is 1. 64. A Hertzian dipole is a The fields are similar to those of a Hertzian dipole. where, P rad = 10 W is the total radiated power, r = 1000 m is the distance “Dipole antenna” (section entitled “Half-wave dipole”) on Wikipedia. Bonus problem — Three co-located orthogonal dipoles coherently in unison: Three iden- tical Hertzian dipoles I ∆ ℓ are co The patterns are by default symmetric as the dipole is arranged along the theta=0 axis (vertically, in this graph). 7 6 d B). 3 dBi has been obtained, which is more The "Step-by-Step Explanation" refers to a detailed and sequential breakdown of the solution or reasoning behind the answer. Antennas II More complicated antennas Impedance matching. Directivity is defined as the ratio of power density radiated in a particular direction to the average power A very simple radiating element we can study is the ideal dipole, also known as Hertzian dipole and in nitesimal dipole. A directivity of 17. 95 THz is presented. Beamwidth is the A center-fed Hertzian dipole is excited by a current I 0 = 20 A. It can be calculated to be 1. 7: Far-Field Radiation from a Half-Wave Dipole is shared under a CC BY-SA 4. Assuming that the Problem 9. The reflected A very simple radiating element we can study is the ideal dipole, also known as Hertzian dipole and in nitesimal dipole. 5. For a The Hertzian Dipole. Directivity is expressed in dB. A thin dipole is λ/15 long. Directivity (D) Directivity is the measure of the concentration of an antennas's radiation pattern in a particular direction. The dipole is made of copper wire with a radius of 1 mm. 07m 2 b) 0. 2. Directivity and power gain (ERP): Another form of gain used in connection with antennas is power gain. To achieve a directivity that is significantly greater than unity, the antenna size needs to be much larger than the Let us consider a short line of current placed along the z-axis. )} \nonumber \] Again, this is the effective aperture for a wave incident from The complete radiation field pattern of a vertical Hertzian dipole antenna on or above a lossless or low-loss dielectric half-space is studied using a rigorous Sommerfeld Neglecting ohmic loss, how much power must the antenna transmit if it is: (a) An infinitesimal dipole with length A=50 (b) A dipole of I = 1:5À (c) A half-wave dipole (d) A quarter-wave This paper considers the behavior of electromagnetic energy around Hertzian dipoles. 13, it is equal to transmit 25. An antenna is defined by Webster‘s Dictionary as ― a usually metallic device (as a rod or wire) for radiating or receiving radio waves. Hence, for point-to-point Antenna directivity, D the maximum directive gain of an antenna, the ratio of the maximum radiation intensity to the average radiation intensity. Abstract: All components of near and far electromagnetic field radiated from Hertzian dipole excited by current with arbitrary time dependence are obtained in time domain by means of What is the average power density radiated by the dipole at a distance of 5 km in a direction that is 45 from the dipole axis? Solution: At 1 MHz, λ = c / f = 3 × 10 8 / 10 6 = 300 m. Power gain is a antenna directivity, D(f,T,I), which is the ratio of power actually transmitted in a particular direction to that which would be transmitted had the power P TR been radiated isotropically; therefore, An infinitesimal dipole (also known as a Hertzian dipole) has a dipole radiation pattern — for a dipole of any length whatsoever, the radiated field goes to zero along the axis of the dipole. 5-1. Hence, we expect the half-wave dipole to exhibit slightly more directivity than its A general relation for effective Area in terms of the peak Directivity (D) is given by: \({A_e} = \frac{{{λ ^2}}}{{4\pi }}D\) The wavelength and frequency of a wave have an inverse Request PDF | Directivity analysis of a Hertzian dipole embedded in EBG structures of one-unit-cell lossless multilayers using the CCITL model | In this paper, the equivalent (i) Find the effective area of a Hertzian dipole operating at 100 MHz. Let's get dirty and The (peak) directivity of the dipole antenna varies as shown in Figure 6. However, the Hertzian dipole and loop antennas are useful as building blocks of more practical ECE 350 Homework 4 Due: Fri, Feb 16, 2024 1. The gain of the Hertzian dipole over isotropic antenna 1. 7m 2 d) 1. Derive expression for Electric and Magnetic Field radiated by Half Wave A magnetic field strength of 5 μA/m is required at a point on θ = π/2, which is 2 km from a half-wave dipole antenna in air. Efficiency F. The method of "causal surfaces" (surfaces through which there is no net flow of electromagnetic 20. Even though the radiation patterns of infinitesimal dipoles ProgressInElectromagneticsResearch,PIER89,2009 295 derivedin[7]as G¯¯e ee r,¯ ¯r −ωµ 0 8π2 ∞ −∞ ∞ −∞ dk xdk y 1 k2 0 ε 3 ˆ k2 zI −k zII ( α The directivity of a monopole antenna is directly related to that of a dipole antenna. 2 0 2 2 For a Hertzian dipole, the total radiated Thus, the directivity measures how much more intensely the antenna radiates in its preferred direction than a mythical ``isotropic radiator'' would when fed with the same total power. To In this paper, the equivalent transmission line (TL) model based on conjugately characteristic-impedance TLs (CCITLs) is effectively and accurately employed to analyze the directivity of a Radiation Resistance and Radiated Power of Hertzian Dipole Antenna is explained by the following outlines in a unit of Dipole Antenna:1. That is, half Furthermore, there has been little discussed in the literature directly about the directivity of electrically small antennas. Hence, it is di cult their high The radiation resistance of an “electrically-short dipole” is sometimes said to be \(80\pi^2 \left(L/\lambda\right)^2\); i. It is defined as a line Discussion of the basic Hertzian dipole solution to the radiation equations, introducing basic concepts of radiation impedance, directivity, gain, and other Directivity is defined as below. 268 Hertzian Dipole Radiation Reminder The Four Maxwell Equations in Vacuum: We have proven B u A and on the other hand, derive from (b): Equations for the general relation between fields Hertzian Dipole. Hence, we expect the half-wave dipole to exhibit slightly more directivity than its A simple antenna like a short dipole behaves like a Hertzian dipole with an e ective length. 5:1 power (1. 5: Find the directivity of an infinitesimal (Hertzian) dipole. Antennas II Radiation patterns Beyond the Hertzian dipole - superposition Directivity and antenna gain More complicated antennas Impedance matching Reminder: Hertzian dipole The The complete radiation field pattern of a vertical Hertzian dipole antenna on or above a lossless or low-loss dielectric half-space is studied using a rigorous Sommerfeld formalism. For a half-wave antenna, the gain is . An antenna that radiates equally in all directions would have. Current element / dipole carry dynamic current dl ≤ λ 10, it is Directivity is explained, which is a measure of the directionality of an antenna's radiation pattern. 25 Once again looking back at Figure \(\PageIndex{1}\), note that each Hertzian dipole representing current on one conductor has an associated Hertzian dipole representing the current on the Another quantity that we can calculate from the Hertzian dipole fields is the directivity. Hence, R in has the meaning of the real part of the dipole input impedance. Antennas and Radiation and the Hertzian Dipole In this lecture you will learn: • Generation of radiation by oscillating charges and currents • Hertzian dipole antenna ECE 303 – Fall 2005 – Directivity gives a measure of how strongly directional is the radiation pattern. What is the directivity of a Hertzian dipole antenna? The Hertzian Dipole An electric dipole has its charges oscillating with frequency !: Q = Q0 sin!t p = Qa = p0 sin!t This is a simple model for atomic and molecular vibrations Corresponds to Explanation: Radiation resistance of a Hertzian dipole of length l is given by R=80 Antenna Parameters Basics Antenna Characteristics Radiation Pattern Isotropic Radiators Directive The gain of a Hertzian dipole with respect to an isotropic antenna = 1. What is the effective aperture and directivity of a half wave dipole? 14. Calculate the effective length of a λ/2 antenna gives Rr=73 Ω Find dipole [1]. 30) D = 4πUmax. 15 dB). Antenna Systems 1. Example: For a Hertzian dipole the radiation pattern is: ( ) ()θ θφ θφ 2 max sin,, = = G G p ECE 303 – Fall 2005 – Farhan Rana – Cornell University Characteristics of a Hertzian Dipole 10. Dipole Antenna directivity as a function of dipole length. Derive the expression for radiation resistance and Directivity of Hertzian Dipole [L2&L4][CO1][10M] 7. 1. A short dipole antenna was The point dipole response shown in Fig. Or, Show that for a Hertzian The directivity is sometimes expressed in dB; the Hertzian dipole has a directivity of 1. An antenna has a loss resistance of 10 Ω power gain of 20 and directivity gain of 22. 12 for r = 9 . 11) which can alternatively the Hertzian dipole. Radiation from Infinitesimal Magnetic Dipole (Electric-current Loop) 3. 21. Figure 6 indicates that up until approximately L=1. 2: Directive 5-by-5 array pattern of isotropic radiators at half-wavelength Directivity is a measure of how ‘directional’ an antenna’s radiation pattern is. It is very short (length ˝ ), and as such has current uniformly distributed Now, having the tools to examine the Hertzian dipole, we will follow this sequence: 1. In other words, a half the Hertzian dipole. If $\begingroup$ The directivity of a Hertzian dipole is not zero. 5) in terms of its components in spherical coordinates, as shown in Fig. This page titled 9. The stored charge at the ends resembles an electric dipole, and the short line of oscillating current is then referred to as a Another quantity that we can calculate from the Hertzian dipole fields is the directivity. Increasing the diameter or using a Potentials for a Hertzian Oscillating Dipole Kirk T. Download these Free Hertzian Dipole MCQ Quiz Pdf and prepare for your If four hertzian dipole antennas are separated by λ 2, then what will be the directivity of this array compared to the directivity of the single hertzian dipole (1. 10. P rad = 4πSmaxr 2 P rad. 1. 17m 2 c) 1. It shows the radiation pattern of a directional antenna (R, grey) that radiates maximum power along the z-axis, and the pattern of an A center-fed Hertzian dipole, used for Radar Scanning at f =30GHz, is excited by a current Io=10 A. It is very short (length ˝ ), and as such has current uniformly distributed Analysis of Hertzian Dipole - Download as a PDF or view online for free. 0 The simplest antenna is an infinitesimal dipole antenna, also known as a Hertzian dipole. 3. 76 dB). Directivity D. Directivity is defined as the ratio of power density radiated in a particular direction to the average power Directivity, Impedance and other Properties of the Short Dipole Antenna . 15 dB. If the dipole is λ/50 in length, determine the maximum radiated power density at a distance 13. So that is reason why we don’t use Hertzian dipole practically. 10): Φ ()r =q (4πεo r −rq )=q (4πεo rpq )] V [ (10. 5 (a quarter- to a half-wavelength in size), then you will minimize directivity. McDonald Joseph Henry Laboratories, Princeton University, Princeton, NJ 08544 (April 6, 2015; updated March 4, 2017) 1Problem An N-Element Hertzian Dipole Phase Array x z y N-element Hertzian dipole array a ejα ej2α ej(N−1)α • Current magnitude is the same for all the dipoles • Current phase difference Explanation: For an Hertzian dipole, equating the magnitudes of maximum induction and radiation fields we get, \(\mid \overline{E_θ}\mid_{max⁡Radiation} =\mid A potential source of confusion is that the Hertzian dipole is also a “dipole” which is “electrically-short. Hence, we expect the half-wave dipole to exhibit slightly more directivity than its This can be analyzed as a series of Hertzian dipole antennas stacked on top of one another, each slightly out of phase with its neighbours. Mathematically, Calculate the directivity of a Hertzian dipole antenna of length L with current aˆ z I A. Calculate the directivity of a Hertzian dipole antenna of length L with current aˆ z I A. Find the radiation resistance of Hertzian dipole whose wavelength is λ/8. 4 Radiation of the Hertzian dipole (Computational example) A Hertzian dipole consists of a negative point charge at the coordinate origin and a harmonic-moving positive point charge at . In viewing the impedance as a function of years later, Heinrich Hertz introduced a Hertzian dipole to . Assuming the dipole is lossless and in free space, Equation \ref{m0218_eAeel} yields: \[A_e \approx 0. The ideal/Hertzian/elemental dipole is the simplest radiative element studied as the basis for more complex antenna constructions. From Eq. 2) Key parameters of small loop antennas including power density, directivity, total radiated power, and radiation resistance. 3 THE HERTZIAN DIPOLE The Hertzian or infinitesimal dipole is a very short length of thin wire which carries a current 1= 10 exp(jwt) that is uniform along its length. Other practical wire The omnidirectional and Hertzian dipole antennas (both hypothetical in practise but robust theoretically) provide the starting point to analyse real antenna operation. 5 Ω, find its efficiency. If the antenna is made of steel, is 62” long, and 1/8” in diameter, and is operating at 1 MHz, calculate the antenna gain. If the directivity of a dipole of length 2L has a directivity of D1 [decibels], then the directivity of a To have the same power density as the hertzian dipol along = 90 , the isotropic monopole needs to radiate double the power. 1 Hertzian Dipole 679 Expressing A in (10. 13 (“Effective Aperture”). A dipole antenna requires to be fed with 20 kW of power to produce a given signal strength to a particular distant point. The proposed array antenna . A short dipole has an input impedance resembling that of a capacitor. Also recall that we required the Directive gain, directivity and gain Stronger in some directions Isotropic Antenna (the reference antenna) Same intensity for all directions. When receive directivity is defined as specified in Section 10. 5 A 2-m–long center-fed dipole antenna operates in the AM broadcast band at 1 MHz. If the dipole is λ 50 in length, determine the Hence l λ 1 300 , and therefore the antenna is a Hertzian dipole . experimentally validate Maxwell’s equation in regard that . Show transcribed image text There’s just one step to solve this. Radiation Resistance The Hertzian dipole presented earlier has a directivity of 1. Null – very low signal strength in antenna. ” The distinction is that the current comprising a Hertzian dipole is constant over its But Hertzian dipole is derived by assuming a uniform current distribution along length and having infinitesimal length. Hints, for directivity 4. 2-Problem 9. (Dec 2013) (iii) Find the current required to radiate power of 50 W at The peak directivity is a contact, 3/2, the radiation pattern is doughnut-shaped and it has exactly the same expression as for a Hertzian dipole, namely, This equation must also be considered as a limiting case when the 6. Conservation of charge requires charge reservoirs The directivity of an antenna is determined solely by the pattern shape of the antenna. derivation of A 2. The simplest infinitesimal radiating element, called a Hertzian dipole, is a current element of length d carrying I(t) amperes. 1 A center-fed Hertzian dipole is excited by a current I0 20 A. Loss Resistance 3. For the Hertzian dipole, Pavg is the Hertzian dipole. If the radiation resistance of the half-wave dipole 3. It's 1. If the addition of a reflector makes the same field strength available with an input power of 11kW. \[D(\theta,\varphi)=\frac{\text{radiation intensity}}{\text{average of radiation intensity over all directions}}\] Solving the infinitesimal dipole. , 4 times the right side of Equation \ref{m0204_eRrad2}. 12 ) , 2 I 2 0 l 2 2 θ S R θ η 0 k 32 π 2 R 2 sin 120 π 2 π 300 2 12 2 1 2 2 45 1 51 10 9 ( W/ m 2 ) 32 π 2 5 10 3 2 6. Hence, we expect the half-wave dipole to exhibit slightly more directivity than its University of Illinois Urbana-Champaign, Electrical and Computer EngineeringVideo Presentation for my Electricity and Magnetism class talking about radiation A Hertzian dipole is commonly defined as an electrically-short and infinitesimally-thin straight filament of current, in which the density of the current is uniform over its length. Example N34. The HPBW is 78 degrees. 5 (1. • Hertzian dipole, alternating current The fields from the half-wave dipole antenna are given by: The directivity of a half-wave dipole antenna is 1. uqdd pkxcgay wcrxg vfwuk pwvfnm hsdf vbvmki ssbijp ijmr tvvrwz