Once these currents are determined the electromagneticfields can be computed both in the far field region and in the aperture zone. However, many of these conclusions are based on guesses and a conclu. The dual reflector design is simulated on the induced current analysis of reflector antenna software. Cassegrain reflector antenna design consists of various effects caused by blockage and its effect on overall performance. Parabolic antenna calculator parabolic dish antenna. It features an innovative cassegrain feed and subreflector design which results in high gain, low noise. Antenna designers notebook companion site to ieee antenna and propagation magazine column. Current analysis of reflector antenna software by the antenna group at the university of virgo using physical optics po and sometimes also physical theory of diffraction ptd. With the proliferation of personal computers and affordable even free software, antenna modeling has become a. A cassegrain telescope consists of primary and secondary reflecting.
In this paper, a small aperture cassegrain antenna of 8mm band detector is optimally designed, whose main reflector diameter is limited at 96mm diameter less than 30. Pdf the cassegrainian reflector and feed system design. Cassegrain reflector antenna consists of two parts. The first cassegrain antenna was invented and patented by cochrane and whitehead at elliot bros in borehamwood, england, in 1952. Qwed company specialising in quickwave fdtd software for electromagnetic design and simulations including microwave heating.
When the antenna acts as a transmitting antenna, the energy from the feed radiates through a horn antenna onto the hyperboloid concave reflector, which again reflects back on to the parabolic reflector. Ems antools software engineering metrology services home page. This site contains a set of practical techniques for designers. There is software provided by silicon radar that runs the dev board. They use the same principle as cassegrain telescope. Operates as a design aid for antenna optics layout of prime focus, cassegrain and gregorian antenna types, as well as their component reflectors. It can be designed for very high gains up to 50 dbi and the horn can be fed from behind the main reflector. Ticra is the worlds leading supplier of reflector antenna and em modeling software for antenna industries, including spacecraft manufacturers and space. Cavitybacked logarithmic slot spiral with absorber.
Cassegrain reflector antenna, reflector antenna, antenna. Ticra is the worlds leading supplier of reflector antenna and em modeling software for antenna industries, including spacecraft manufacturers and space agencies, earthstation antenna suppliers, defence industries and research institutions. Today, cassegrain antennas are used in communication. The primary radiator is a machined corrugated conical horn providing exceptional polarization discrimination performance, sidelobe suppression, and beam symmetry. Dedicated software for reflector systems, enabling fast and accurate analysis and design of the most advanced reflector antenna systems. This page describes function and basics of cassegrain feed used in antenna system. In more complex designs, such as the cassegrain antenna, a sub reflector is used to direct the energy into the parabolic reflector from a feed antenna located. The design for minimum blockage condition results in geometry that offers. Parabolic dish is widely used as satellite tv channel receiver across the world. Design of primary feeds for 32m kddi antenna system iba4.
After design and processing, this antenna measured results show its gain is 26db, the sidelobe level is close to12db and3db beamwidth is 4. This antenna offers a reflector design that incorporates precisionformed panels, contoured radials and a machined hub assembly. The goal for microwave update 2018 was to verify a 3d printed cassegrain antenna design for 122ghz amateur use. Home ticra reflector antenna and em modeling software. Ansoft hfss is used to obtain the radiation characteristics. The design for minimum blockage condition results in geometry that offers lower amount of blockage and increased spillover past the subreflector.
The first cassegrain antenna was invented and patented by cochrane and whitehead at elliot bros in borehmahwood, england, in 1952. This design was adapted from the customizable cassegrain dish by drxenocide on thingiverse. Dish focal length dish illumination halfangle feedhorn illumination halfangle. It looks to me like it would be much easiercheaper to get a gregorian secondary compared to a classical cass. I tom milligan have started this website in the spirit of the column.
It contains theoretical consideration and foundation, as well as procedure for design in the wipld software suite. Optimization design of a small aperture cassegrain antenna. Its success there has caused a considerable quantity of publications, whose main conclusion is that the cassegrain is superior to the prime focus antenna. Reflector antennas examples of design, simulation and analysis. Cassegrain antenna article about cassegrain antenna by.
The small lens system is a small galileotype optical antenna. Granet, designing axially symmetric cassegrain or gregorian dual reflector antennas from combinations of prescribed. Obviously, the optical antenna is the most important component of the optical system. Antenna modeling used to be the domain of scientists and engineers with very expensive antenna ranges covering acres and acres of land strewn with expensive equipment. The hornfed cassegrain reflector needs no introduction. New type optical cassegrain antenna with lenses telescope. Very large cassegrain antennas are usually simulated using specialized asymptotic methods. Wave wizard antenna mician software solutions for fast.
This is a powerful but complex, high cost antenna and not something that one would typically attempt to. Optimized design of axially symmetric cassegrain reflector. Antenna information the leading antenna design software. Grasp for reflector antenna analysis and design ticra. A dish antenna with multiple reflectors, like the cassegrain antenna at oh2aue1 in figure 1, looks like an obvious solution to one of the major problems with dishes, getting rf to the feed. This design was adapted from the customizable cassegrain dish by. Jpole antenna is pretty easy to build and usually designed by amateur radio operators. This paper presents the procedure for the design of cassegrain reflector antenna. There are many different configurations with the placement of horn antenna. Thus, the design procedure is approximately divided into two steps corresponding to the design of single part. The cassegrain type has mainly been used for relatively sm 1 antennas for very high frequencies above 10 ghz. Antenna designing software instructions to build a beam for 40 m band, uhfshf antenna design, antenna design article collection, yagi design for 50 mhz and up, yagi design program for 144 mhz and up. In more complex designs, such as the cassegrain antenna, a sub reflector is used to direct the energy into the parabolic reflector from a feed antenna located away from the primary focal point.
They send out a wide chirped radar signal and measure the return. The above figure shows the working model of cassegrain feed. Antenna designer home page, antenna design, reflector. Jpole is a free and portable antenna design software for windows. Productsservices for cassegrain antenna design software antenna design software companies antenna design software is used for the design and electromagnetic analysis of all types of antenna systems, including. Page 1 of 2 classical cassegrain vs gregorian posted in atm, optics and diy forum. Thus th antenna becomes an ordinary singledish design, having the same main dish but a di. Learn about advanced features and options in antenna magus and cst studio suite. The cassegrain object creates a cassegrain antenna. The cassegrain antenna design was adapted from the cassegrain telescope, a type of reflecting telescope developed around 1672 and attributed to french priest laurent cassegrain. Aditionally, ticra offers software designed for satellite coverage planning.
Heres a demonstration of a 3d printed cassegrain antenna system for 122ghz. Mechanical requirements mechanical design and construction was to conform. Multiple antennas may be defined within the same project, and the general command structure enables the user to define which of. The signal gets reflected into the space from there. A reconfigurable antenna is an antenna capable of modifying its frequency and radiation properties dynamically, in a controlled and reversible manner. It is based on the physical optics approximation of the induced currents on the reflector surfaces. Various examples of reflector antenna design, simulation and analysis using wipld electromagnetic simulation software. The following demonstration shows how the field from this geometry is analyzed with icara.
These are consistent with simulation optimization results. Design of primary feeds for 32 m kddi antenna system iba4 in. Other than being physically longer for a given focal length, are there any disadvantages to a gregorian style scope compared to a classical cassegrain. Cassegrain provides an option to increase focal length, reducing side lobes. This orientation reduces side lobes and the use of dual reflectors helps in tailoring radiation pattern for maximum antenna performance. In order to provide a dynamic response, reconfigurable antennas integrate an inner mechanism such as rf switches, varactors, mechanical actuators or tunable materials that enable the intentional redistribution of the rf currents over the. Cassegrain reflector antenna design guide this paper presents the procedure for the design of assegrain reflector antenna. The antenna edition features a graphical reflector design tool for synthesizing standard single and dual reflector systems prime focus, gregorian and cassegrain. In this paper, a double pyramidal system in cassegrain system has been designed, meanwhile an optical system software has been set up to analyze the performances of the traditional cassegrain antenna and the performances of this optical antenna. Antenna designing software instructions to build a beam for 40 m band, uhfshf antenna design, antenna design article collection, yagi design for 50 mhz and up, yagi design program for 144 mhz and up, antenna maker v6. Hi i have to design a cassegrain antenna, with a circular horn feed.
In this antenna, the primary mirror is just full of laser beam 3. The goal for microwave update 2018 was to verify a 3dprinted cassegrain antenna design for 122 ghz amateur use. This video shows how to design a complete parabolic reflector dish antenna in cst from the scratch including simulation results s11, radiation pattern, efield and hfield. A cassegrain antenna is a parabolic antenna using a dual reflector system. It is used to design jpole antennas for the desired frequency. Cassegrain feedfunction and basics of cassegrain feed. For more information see, architecture of cassegrain antenna. It features an innovative cassegrain feed and subreflector design which results in high gain, low noise temperature, high antenna efficiency and excellent rejection of noise and microwave interference. This antenna offers a reflector design that incorporates precisionformed panels, truss radials and hub assembly. The initial material is a collection from short courses i taught with hal schrank and material related to various. Cassegrain antennacassegrain antenna is a system composed of double reflecting mirrors. The executable granetds linux version can be downloaded for the geometry parameters.
I just have the diameter of the main reflector and the fd. It uses cassegrain type of design where in horn antenna is placed at the focal point of the dish. Using the cassegrain design increases antenna performance as the feed antenna is directed forward rather than towards a dish in front fed antenna. Classical cassegrain vs gregorian atm, optics and diy. Frequency ghz mm inches wavelengths dish diameter dish fd feedhorn equivalent fd feedhorn diameter w1ghz 2004 suggested illumination taper db decision point. Math model sometimes called a polarization twist mirrorscan antenna 1, an inverse cassegrain antenna comprises a feed 1 illuminating a polarizationselective wire grid subreflector 2, which collimates the rf field to illuminate a polarization twisting mirror 3 this antenna type is a possible choice for a missile antenna 2 because it confers several advantages. The radius of the big lens of the lenses system is designed to 0. Cassegrain symmetrical reflector the reflector can be analyzed using the student version of grasp available from ticra using a gaussian beam feed antenna.
Sieur guillaume cassegrain was a french sculptor who invented a form of reflecting telescope. Reflector antennas examples of design, simulation and. Antarray the program antarray allows to study the effects of the number, distance and phase shift of several coupled antennas on the radiation pattern. As we know parabolic dish antenna is made of parabolic dish and horn at the focal point.