Abstracta printed logperiodic dipole array lpda is presented. All innovantennas lpdas are design using the very latest computer optimisation techniques and are largely designed and built to order although examples such as this band optimised log periodic dipole array bolpa which has had its performance highly. The logperiodic loop antenna with ground reflector lplagr is investigated as a new type of antenna, which provides wide bandwidth, broad beamwidth, and high gain. The free space directivity of a logperiodic dipole array lpda is a function of its taper. Band optimised log periodic dipole array 14mhz to 30mhz by. A logperiodic antenna lp, also known as a logperiodic array or logperiodic aerial, is a multielement, directional, antenna designed to operate over a wide band of frequencies. Introduction a multi element, directional, antenna designed to operate over a wide band of frequencies a broadband, multielement, unidirectional, narrowbeam ant. Pdf design and performance analysis of a log periodic dipole. A printed log periodic dipole array lpda is presented, operating over the c, x and ku bands. The work on the lpda in free space environment has been extended to treat the. Due t o space and resource cons traints, amateur r adio logperiodic antennas. This kind antenna could cover ultrawideband with a ratio of above 5. Introduction in telecommunication, a logperiodic antenna is a broadband, multi element, directional, narrowbeam antenna that has impedance and radiation characteristics that are regularly repetitive as a logarithmic function of the excitation frequency.
That is, there is a bit of intuition we can give regarding this antenna as in the preceeding paragraphs. Log periodic ldpa log periodic dipole array very broadband, an octave or more bigger and heavier than a yagi multiple band with a single feedpoint alternating elements are phased 180 apart uses stubs for impedance matching example. A step by step procedure is presented which enables one to design a log periodic dipole antenna over a wide range of input impedance, bandwidth, directivity, and. A more formal name is logarithmic periodic dipole array lpda. A log periodic antenna is an antenna that can operate on a wide frequency band and has the ability to provide directivity and gain. The main goal of this paper is to apply one of fractal structures, i. Pdf the introduction of broadband systems to communication and. Introduction this small log periodic antenna, which we call the logi, is ideal for getting the maximum performance out of any uhf to low frequency microwave wireless system.
In figure 1, we show the basic 5 element logperiodic dipole antenna array. A log periodic antenna lp, also known as a log periodic array or log periodic aerial, is a multielement, directional antenna designed to operate over a wide band of frequencies. The spr230 antenna is designed using log periodic principles to achieve broadband performance while mounting over earth. Several geometries with different parameters are analyzed numerically using esp. As a standard, the antenna is designed for horizontally polarized base station use but by means of an adapter, vertical polarization is also possible. The excellent characteristics flat gain over a large bandwidth, low swr of the ordinary log. It has radiation and impedance characteristics that are repeated as a logarithmic function of excitation frequency. The type favored by amateurs is the log periodic dipole arra y, often abbreviated lpda. Stlp 9128 c stacked log periodic antenna schwarzbeck. Pdf design of a printed logperiodic dipole array for ultra. Due t o space and resource cons traints, amateur r adio. Tupavco tp514 yagi directional antenna 3g4glte 9dbi 806mhz960mhz and 1. Nothing contained herein shall constitute emc test systems, l.
Dipole, bowtie, spiral and log periodic ir antenna coupled detectors were measured at 10. The design of the log periodic dipole array antenna as shown in figure 1 is somewhat of an empirically successful design. Modeling and measuring the creative design clp52n log. Unfortunately, their theory was only applicable to dipole elements with half. Analysis and design of the logperiodic dipole antenna by carrel, robert louis. Method fabrication was done on 200nm of sio 2 e s 4. The feed coax is routed through the inside of the right boom. The results from the mathematical model are shown to be in good agreement with measurements. The yagiuda antenna is mostly used for domestic purpose.
Decreasing \\tau\ will decrease both the boom length \l\ and the number of elements \n\. Comparison of dipole, bowtie, spiral and logperiodic ir antennas. If the antenna has a reasonably large number of elements, namely 5 or more, the plot of impedance versus logarithm of frequency gives an almost periodic function, with its period being log tau, because within every period we have one dipole. Lpda8003 log periodic dipole antenna product overview the tdk lpda8003 log periodic dipole antenna is a new generation compact antenna used for transmitting and receiving broadband radio signals. The model 3148 log periodic antenna is constructed of. The stacked logarithmic periodic dipole antenna consists of two ordinary log. Software development and construction of log periodic dipole. The freespace properties of several of these arrays have been measured and the results. Free space directivity the free space directivity of a logperiodic dipole array lpda is a function of its taper \\tau\ and its chosen spacing \\sigma\. The limiting values 01 the various parameters that describe the antenna are explored.
It was invented by dwight isbell and raymond duhamel at the university of illinois in 1958 the most common form of logperiodic antenna is the logperiodic dipole array or lpda, the lpda consists of a number of. The log periodic term is derived because of the uniform spacing between the resonant frequencies of antennas in a log periodic scale. Modeling and measuring the creative design clp52n log periodic antenna whitham d. Due to space and resource constraints, amateur radio logperiodic antennas are. Log periodic antennas antennas are designed for the specific purpose of having a very wide bandwidth. A printed logperiodic dipole array lpda is presented, operating over the c, x and ku bands. Comparison of dipole, bowtie, spiral and logperiodic ir. There are three importa the bandwidth of such an antenna depends on the. Freespace directivity the freespace directivity of a logperiodic dipole array lpda is a function of its taper \\tau\ and its chosen spacing \\sigma\.
Size reduction of printed logperiodic dipole array antenna. However, for commercial purpose and to tune over a range of frequencies, we need to have another antenna known as the log periodic antenna. Etslindgrens model 3147 log periodic dipole array is primarily designed for use with the fcc part 15. Pdf on jul 29, 2019, jalil a hamadamin and others published analysis. Model spr230hf log periodic spiral antenna 230 mhz 5 dbi. A traditional lpda antenna with wire dipole elements can achieve wide bandwidth of 10. These simple formulas give an insight into the log periodic antenna theory. This antenna has smaller transverse dimensions by a factor of 2. Logperiodic dipole antenna, printed antennas, miniaturization. The etslindgren model 3148b log periodic dipole array is a linearlypolarized broadband antenna designed to operate over the frequency range of 200 mhz to 2 ghz. Like the yagi antenna it exhibits forward gain and has a high front to back ratio, but the lpda is able to operate over a much wider bandwidth and will have a lower gain for an equivalent number of elements. Several varieties of log periodic antenna systems exist, such as the zigzag, planar, trapezoidal, slot, v, and the dipole.
These antennas are fractal antenna selfsimilar antenna arrays. At frequencies below 20 mhz, the antenna provides a broad, horizontally polarized beam directed at the zenith to accommodate short range skywave circuits. The logperiodic dipole array is first considered as a parallel connection of two. Microstrip antennas have some attractive advantages such as small volume, very lowpro. Design of microstrip log periodic antenna for wireless. It can be used as either a receiving antenna or as a transmitting antenna.
A log periodic antenna is that whose impedance is a logarithamically periodic function of frequency. Its directional properties compresses the signal into a powerful beam that is 4 times more powerful in the desired direction. It was invented by dwight isbell and raymond duhamel at the university of illinois in 1958. A computational method of analysis of the logperiodic dipole. Also looking at these log periodic antenna equations or formulas it is possible to see why the antenna gain its name. Pdf analysis, design, and simulation of a log periodic antenna for. The freespace directivity of a logperiodic dipole array lpda is a function of its taper. In this paper, we make an effort in designing a portable lpda that suitable. University of illinois electrical engineering research laboratory, engineering experiment station. Apr 16, 2020 bolpa10 a super wide band, high performance log periodic dipole array lpda 14mhz to 30mhz optimised for all ham bands just 7.
The model 3147 has excellent vswr characteristics throughout the entire operating frequency range and has a relatively constant linear gain measured in the far field. The choice of scaling factors, the various diameters of each element, and the centertocenter spacing of the booms yield excellent. In this thesis, a high gainaround 9dbi log periodic dipole. It is possible to explain the theory behind the log periodic antenna in a qualitative basic form. The most common form of log periodic antenna is the log periodic dipole array or lpda, the lpda consists of a number of. A log periodic dipole antenna lpda for solar burst monitor in the range of 45 870 mhz applications is presented. Al is the freespace wavelength at the lowest operating frequency. Introduction a log periodic antenna is an array of dipoles with mathematically related lengths and spacings. This means that each dipole is 25% longer than the one to the left of it, and the separation d between each dipole also increases by 25%. The log periodic dipole array, lpda is generally able to operate over a frequency range of around 2. Logperiodic dipole array lpda with a coaxial feed this is typically 50. It is possible to explain the theory behind the log periodic antenna in. A log periodic antenna lp, also known as a log periodic array or log periodic aerial, is a multielement, directional, antenna designed to operate over a wide band of frequencies. Pdf design of a printed logperiodic dipole array for.
The achievable bandwidth is theoretically infinite. Only the center conductor of the coaxial cable is connected to the left boom by means of a rivet. Analysis and design of the logperiodic dipole antenna. For the array in figure 1, we use an expansion factor k1. The al100 is a broadband, linearly polarized log periodic antenna dipole array lpda antenna, operating over the frequency range of 200 mhz to 1 ghz.
And because the antenna designs discussed earlier are based upon resonant elements, offresonance operation introduces reactance which causes the swr in the feeder system to increase. Pdf in this paper we were study a wide band antenna working in the ism band. Winradio ax31b planar log periodic antenna the ax31b antenna is a compact vhfuhf directional antenna with an inbuilt amplifier, which provides a lowcost alternative to conventional vhfuhf antennas for example discones, especially for indoor professional and amateur applications. Publication date 1961 topics antennas electronics publisher.
The antenna feeding structure consists of two coaxial cables, in order to realize an infinite balun. A special type of directional antenna is the logperiodic dipole antenna. Log periodic antennas wide band, high gain, low vswr small size, light weight, easy assembly cd model clp5x series is a high gain, wide band vhf and uhf log periodic type beam antenna. It is especially suited for dual band communication testing where the antenna must not interfere with the measurement environment. The antennas described provide unidirectional radiation patterns of constant. In essence, log periodic arrays are a group of dipole antennas of varying sizes strung together and fed alternately through a common transmission line.