This paper deals with the parametric analysis and proper design of parabolic reflector antennas to obtain pencilbeam, cosecant squared and inverse cosecant squared radiation patterns for air and coastal surveillance radars. The antenna can be fed at one corner low impedance, current fed or at the lower end of one of the vertical wires high impedance, voltage fed. Antenna with cosecant squared pattern antennas with constant height pattern or cosecant squared pattern abbreviated as csc. In this paper, a cosecant squared shaped beam pattern is synthesized from a uniformly spaced but nonuniformly excited linear antenna array where the uniform spacing of the array elements is considered as half of the desired signal wavelength.
Antennas with constant height pattern or cosecant squared pattern abbreviated as csc. The cosecant squared pattern is computed for the outside region, from the main beamwidth up to the cutoff angle. Cosecantsquared pattern synthesis method for broadband. A constant gain value from 90 to 270 degrees in elevation from the boresight of the antenna. Jul 14, 2003 now, assume a conventional reflector antenna with a cosecantsquared beam of 1 azimuth x 45 elevation. Pdf design of parabolic reflector antenna with two. Pdf the analysis of wideband conformal microstrip array. A cosecant squared antenna, sometimes known as a constant height pattern, is a modified form of parabolic reflector used in some radar systems. Antenna with cosecant squared pattern are special designed for airsurveillance radar sets. An antenna pattern for which the gain is proportional to the square of the cosecant of the elevation angle. These permit an adapted distribution of the radiation in the beam and causing a. Dual polarization stacked microstrip patch antenna array. This is the ppt about base station antenna used for communication. Diagram of a typical 2d radar rotating cosecant squared antenna pattern.
In, a corner reflector antenna array is used to create a cosecant squared shaped. Smiths interconnect antennaquasioptical mmw products. The flat and cosecant beams are considered to be shaped patterns which are different from narrow beams. O s e u a x e o dx a x e dx 1 0 ux 2 l j 0 1 2 l j d n 2. Carberry, analysis theory for the shapedbeam doubly curved reflector antenna, ieee trans. To use this tutorial in a classroom you can printout the following documents.
Find out information about cosecant squared antenna. Compact parabolic reflector antenna design with cosecant. Still assuming that a single pulse per beam position is sufficient, this radar has performed a full scan after visiting 360 x 1 azimuth x elevation positions. Design of a broadband cosecant squared pattern reflector. Vertical projection of the radiation pattern of an antenna with cosecant squared characteristic, the blue graph shows the theoretically form. Then a fss structure that has same geometric form with a part of parabola is inserted to the fan beam antenna to obtain a cosecant squared antenna form such as figure 3. Antennas with a cosecantsquared pattern achieve a more uniform signal strength at the input of the receiver as a target moves with a constant height within the beam. Monediere, design of a cosecant squared pattern antenna fed by a new butler matrix topology for base station at 42 ghz, ieee antennas and wireless propagation letters, vol. This version dont include the printer friendly pdf files, because these arent necessary for using an offline version. Kodi archive and support file vintage software community software apk msdos cdrom software cdrom software library console living room software sites tucows software library shareware cdroms software capsules compilation cdrom images zx spectrum doom level cd. The gain pattern computations are based on the cartesian coordinate frame.
If you need these pdf files, then you can download and integrate the following archive into the radartutorialdirectory. Atms india 2015 synthesis of cosecant array factor pattern using taguchi method for smart antenna system amara prakasa rao1 and n. Modified cosecantsquared parabolic reflector antenna article pdf available in istanbul university journal of electrical and electronics engineering 111. For low scan rates, shaped reflectors are used to generate these patterns. Design of a feed network for cosecant squared beam based on. The half square antenna a simple modification to a dipole would be to add two. This operation requires optimization techniques such as. It is possible that both sides are equal at several values namely when we solve the equation, and we might falsely.
This h2s antenna provides not a cosecant squared, but an inverse cosecant squared antenna pattern. Synthesis of cosecant array factor pattern using taguchi. Diagram of a typical 3d radar, a judicious mix of vertical electronic beam steering and mechanically horizontal movement of a pencilbeam. A novel design is introduced to obtain both pencilbeam and cosecant squared radiation patterns by using the same modified parabolic reflector antenna. Introduction pattern synthesis of antenna array is a vital. Array synthesis has been done using orchard elliotts and genetic algorithm methods. A cosecant squared beam antenna is required elevation pattern in order for a target approaching at a constant height to be detected with. Although these antennas are conceptually and structurally simple, flexibility is limited for the antenna designer 45. This method has been applied for the spherical, cylindrical.
An approach forshapedbeam pattern synthesiswith spherical. Monediere, design of a cosecantsquared pattern antenna fed by a new butler matrix topology for base station at 42 ghz, ieee antennas and wireless propagation letters, vol. The aperture of an antenna is its physical area projected on a plane perpendicular to the mainbeam direction. The cosecant squared radiation pattern of an antenna in the elevation plane over the range of angles m m m 12 dd is ggmm 0 2 csc 1 where g 0 is a constant that depends on the gain of the antenna. Cosecantsquared radiation pattern synthesis of conformal. In practice, a cosecant squared pattern can be achieved by a deformation of a parabolic reflector. A wide band, low profile linear microstrip antenna array with cosecant square shaped beam pattern is presented. On the design of reflector antennas for cosecant squared power.
The concept of effective aperture is useful when considering the antenna in its receiving mode. As with most radars, this amounts to having a higher gain at lower elevations and reducing the gain at higher elevations. The synthesis process aims the minimization of the deviation between the computed pattern and the csp. The antenna under analysis is an ideal quarterwave monopole designed to work in the 20 meters band, adjusted to a central frequency of 14,1 mhz. Cosecant squared patterncsp is one such pattern which is generally employed for longrange systems requiring higher gain near the horizon with low gain at higher elevation angles. Pdf synthesis of cosecant squared pattern in linear. Design of a feed network for cosecant squared beam based. This antenna requires a cosecantsquared radiation pattern in the vertical and horizontal planes. Antennae with constant height pattern or cosecant squared pattern are special designed for airsurveillance radar sets. Consequently, the lband antenna was designed to be interchangeable with the cband antenna, allowing the system to be configured on the ground for either cband or lband operation. Studies on difference patterns from cosecant patterns. Description and design of antennas with a cosecant squared antenna pattern, derivation of the term cosecant squared. Synthesis of cosecant and square patterns for emc applications.
To get the cosecant squared pattern, a part of the radiated energy must be increased. Cosecantsquared pattern csp is one such pattern which is generally employed for longrange systems requiring higher gain near the horizon with low gain at higher elevation angles. The cosecant square beam pattern are very significant in some applications e. In the practice, a cosecantsquared pattern can be achieved by a deformation of a parabolic reflector 1. To get the cosecant squared pattern a part of the radiated. In this work, taguchi method is used to optimize the magnitude of the array elements to obtain the desired radiation pattern. Simulation results validate that radiation of cosecant squared shaped pattern. Chapter 4 introducesthe detriment of the conformalarray over the linear array for the synthesis of cosecant square pattern and a method to overcome that. Pdf synthesis of cosecant squared pattern in linear antenna. The maximum elevation angle where the cosecant squared pattern is computed.
This results in an approximately constant signal, as a function of range, from an aircraft at constant flight level. Fu the national key laboratory of antennas and microwave technology xidian university xian 710071, china abstracta wide band, integrated linear printed antenna array with low sidelobe cosecant square shaped beam. The cosecant squared pattern is a means of achieving a more uniform signal strength at the input of the receiver as a target moves with a constant height within the beam. Using curvedeformation equations, the shaped reflector antenna was designed to satisfy the desired beam pattern. Geometry of the cylindrical offset reflector antenna, a 3d view, b cross section. Synthesis of cosecant squared pattern in linear antenna arrays using differential evolution conference paper pdf available april 20 with 868 reads how we measure reads. It is shaped to send more radio energy in certain directions in order to smooth out the reception pattern of objects as their range changes in relation to the radar. The base station antenna for a subscriber radio system is required to have a beam with sector section in the horizontal plane and cosecant.
Cosecantsquared pattern article about cosecantsquared. To obtain cosecant squared radiation pattern, the bottom side of the reflector antenna is partially cut and bended by 5, 10, 15 and 20 degrees, respectively. Cosecant squared pattern synthesis for reflector antenna using iwo. Thus the list shows the antenna gain as ve dbs relative to the maximum antenna gain which produces an antenna pattern for rm and the actual antenna gain value is entered in the radio operating system allocated to the unit on the. Cosine squared curve distribution pattern, with a rectangular pattern of illumination, illustrated by the blue curve below. Proving a trigonometric identity refers to showing that the identity is always true, no matter what value of x x x or. Pdf in this paper, the design of a novel modified parabolic reflector antenna with a cosecantsquared radiation pattern is investigated and offered as. Simplehfwire antenna wewillexploretypical varia2onsofthewiredipole highfrequencyhf antenna typicalamateurradio transmiing antenna. Further, proposed spherical array has been utilized to generate shapedpatterns.
Dss36 antennas removed dss27 hsb antenna added 250w capability at dss15 added the upcoming 80 kw transmitter at dss26 changed dss25 deep space kaband uplink corresponding to 300 w transmitter updated antenna performance specifications e. The file format is a list of gain values for an antenna at 1. Synthesis and failure correction of flattop and cosecant squared beam patterns in linear antenna arrays in eq. Antenna designers have also used array configuration to realize the cosecant squared shaped radiation pattern. In this paper, the design of a novel modified parabolic reflector antenna with a cosecantsquared radiation pattern is investigated and offered as a solution to the problem of target missing.
Here the antenna is a superstrate configuration made with a trimmed dielectric layer over a groundplane and fed by a single openended horn. In accordance with one embodiment, the transmit antenna 4 has a cosecant squared antenna beam pattern. An antenna that has a cosecant squared pattern explanation of cosecant squared antenna. Cosecantsquared antenna article about cosecantsquared. To record measurements, a horizontallypolarized dipole receiver antenna was mounted on the roof of a vehicle, approximately 1.
Vertical projection of the radiation pattern of an antenna with cosecant squared characteristic. Compared the results obtained in this study with those of the published literature, the comparison shows that few numbers of array elements with less number of required iterations by proposed method can achieve the same desired goal. These permit an adapted distribution of the radiation in the beam and causing a more ideal space scanning. High gain antenna with an inverted square cosecant radiation diagram antenna with circular polarization, favouring suppression of clutter use of latestgeneration signal and data processors digital extraction automatic tracking capability of a high number of targets local and remote control and monitoring. Cosecant squarepattern synthesis with conformalantenna arrays. The part of the rays which fall on the less bent area in the top are reflected reflected upwards. Pdf wide band low profile linear microstrip antenna. The xy plane is the plane of illumination and the z axis is the direction of the propagation. Cosecant squarepattern synthesis with conformalantenna. Pdf modified cosecantsquared parabolic reflector antenna.
R p r received power p t transmitted power transmitted power g t transmit antenna gain g r receive antenna gain scf01 electronic scanned array design slide 21 of 255 noise eqqguivalent sigma zero 3 nesz. Sidelobe gain db the side lobe gain of the antenna pattern. Synthesis of cosecant array factor pattern using particle. A cosecant squared beam antenna is required elevation pattern in order for a target approaching at a constant height to be detected with constant power. D p r anten p bot f b c s p differen fquen b first of all, a fan beam antenna is constructed figure 4.
The constraints can be sidelobe level, nulltonull beamwidth, vswr, and impedance etc. Cosine squared aperture rectangular antenna cosine squared curve distribution pattern, with a rectangular pattern of illumination, illustrated by the blue curve below. The later addition of flush mounted antennas for cband interferometry 4 made simultaneous dual frequency operation possible, with. Azimuth beamwidth the full width of the beam in the xy plane of the beam coordinate system. Miniaturization design for 8 x 8 butler matrix based on backtoback bilayer microstrip. On the design of reflector antennas for cosecant squared. A further possible method, analogous to this, is to bend the lower part of the reflector. The cosecant squared pattern is a means of achieving a more uniform signal strength at the input of the receiver as a target moves with a constant height within the.
To obtain pencil beam, the parabolic reflector antenna indicated with dashed line is used. These documents arent as actually as the htmlversions but are usable in an environment without internetaccess. The characteristics of a reflector antenna radiating omnidirectionally in azimuth with a cosecantsquared power pattem in vertical planes, as intended for pointto. To obtain cosecantsquared radiation pattern, the bottom side of the reflector antenna is partially cut and bended by 5, 10, 15 and 20 degrees, respectively. Cosecant squared null fill bts antenna specifications mti part number mt 404014nh electrical regulatory compliance etsi en 302 085 v. Smiths interconnects full range of mmw antenna products featuring millitech technology includes cassegrain reflector, feed horn, standard gain horn, and gaussian optic lens antennas, as well as, custom designed antenna arrays. Synthesis and failure correction of flattop and cosecant. A kaband doubly curved reflector antenna for a warning radar system for the road was designed based on the curvedeformation equations. This paper proposes a method for shaping the reflector surface of the antenna so that it forms the required beam in the two planes and also presents the experimental.
Assumes antennas are alignedassumes antennas are aligned factor in parenthesis is free space loss p 3 6 4 2 r p t g tg r 4. The performance results of pencil beam and cosecant squared radiation patterns are given in fig. Cosecant squared antenna pattern best for detection of. Microstrip patch antenna array with cosecantsquared. Base station antenna ppt free download as powerpoint presentation. Millimeter wave antenna experts 60 ghz, 80 ghz, 94 ghz and 110 ghz.