Showing papers on "Parabolic reflector published in 1993"
Patent•
27 Sep 1993
TL;DR: In this paper, an ultraviolet (UV) sterilization system for food cartons is described, where a parabolic cylinder reflector is mounted in a housing with the focus of the reflector coinciding with the axis of the arc in the UV lamp.
Abstract: An ultraviolet (UV) sterilization system for food cartons is disclosed. An elongated UV lamp is mounted in a housing. A parabolic cylinder reflector is mounted in the housing with the focus of the reflector coinciding with the axis of the arc in the UV lamp. The shape of the parabolic reflector directs radiation from the lamp into cartons positioned on a conveyor below the lamp. The axis of the arc is parallel to the direction of movement of the cartons on the conveyor. The front surface of the reflector also absorbs heat from the lamp and heat is removed from the reflector by circulating air over the back surface of the reflector.
42 citations
TL;DR: In this article, a two-stage optical design for parabolic dish concentrators is presented, which can attain close to 90% of the thermodynamic limit to concentration with practical, compact designs (e.g., at parabola rim half-angles of around 45°).
37 citations
Patent•
18 Oct 1993
TL;DR: In this article, a first and second light transmitting system consisting of a light emitting element and a second light receiving element is proposed. But the system is not suitable for the transmission of Manchester coded signals.
Abstract: An optical radio communication system comprising a first light transmitting system and a second light transmitting system. Each of said first and second light transmitting system comprising a transmitting means and a receiving means. Said transmitting means comprising a light emitting element positioned in a region including and surrounding a focal point of a first parabolic reflector for emitting light beams, said first parabolic reflector having an inner reflective surface for reflecting said light beams emitted from said light emitting element, and a means for driving said light emitting element with a signal to be transmitted. Said receiving means comprising a second parabolic reflector having an inner reflective surface for reflecting incident light beams, a light receiving element positioned in a region including and surrounding a focal point of said second parabolic reflector for receiving light beams reflected by said second parabolic reflector to output signals, and means for taking out information from said signals outputted from said light receiving element. In this optical radio communication system, broadband signals such as Manchester coded signals are directly transmitted on optical radio.
26 citations
Patent•
06 Apr 1993
TL;DR: In this article, a modified parabolic reflector was used to produce a more uniform spot beam and a greatly improved broad beam without unilluminated areas, and the range of distance in which these effects were provided was increased.
Abstract: A flashlight which selectively provides an enhanced spot beam and fully illuminated broad beam. The modified parabolic reflector produces with either a point source of light or an extended filament source of light a spot beam which is substantially more uniform across its disc as is produced by a conventional parabolic reflector, and a greatly improved broad beam without unilluminated areas. Further, the range of distance in which these effects are provided is importantly increased.
26 citations
Patent•
03 Jun 1993
TL;DR: In this article, a metal halide ramp is used to restrain illumination non-uniformity of a light source and restrain generation of irregular color of a display, where an anode ray and a cathode ray are facing each other within a luminescent space.
Abstract: PURPOSE:To restrain illumination non-uniformity of a light source and restrain generation of irregular color of a display. CONSTITUTION:A metal halide ramp 42 in which an anode ray 55 and a cathode ray 54 are facing each other within a luminescent space 51 is guided to penetrate the bottom part of a bowl shaped parabolic mirror 43 in its projecting state from the bottom part, and the anode ray 55 is led outside through the inside of the parabolic mirror 43. The anode ray 55 and an extended part 52(a) of a quartz tube body 53 near the tip of the cathode ray 54 are connected to each other by a trigger wire 58 in the vicinity of the hole 43(a) of the parabolic mirror 43.
25 citations
TL;DR: In this article, a rigorous three-dimensional ray tracing program was developed to evaluate the reflection losses and their effect on the concentration of a two-stage compound parabolic concentrator with two configurations: a parabolic dish as a first stage and a Cassegrainian as a second stage.
17 citations
TL;DR: An aspherical mirror is made by a thin-film coating technique where a special mask is placed between the evaporation source and the substrate that is to be coated as an aspheric.
Abstract: An aspherical mirror is made by a thin-film coating technique. A special mask is placed between the evaporation source and the substrate that is to be coated as an aspheric. The design principle of the mask is fully described. An ion-assisted deposition technique is used to relieve aluminum film stress and to increase surface reflectance. The final wave front is tested by conventional interferometric methods for aspherics. Less than one-fifth of a wave (632.8 nm) of spherical aberration is achieved without much trial and error.
16 citations
Patent•
12 Feb 1993
TL;DR: In this article, a cylindrical mirror in a shape of a frustum of a circular cone on the downstream side of a metal halide lamp was used to make reflected light from a light collecting reflector into a parallel light beam by a mirror.
Abstract: PURPOSE:To make reflected light from a light collecting reflector into a parallel light beam by a mirror and to improve the utilization efficiency the emitted light of a light source arranged at the focus of the light collecting reflector by arranging a cylindrical mirror in a shape of a frustum of a circular cone on the downstream side of the light source CONSTITUTION:A cylindrical mirror 10 in the shape of the frustum of the circular cone is provided on the optically downstream side of a metal halide lamp 1 and the light converging reflector 7 consisting of a parabolic mirror and an optical element such as a polarization beam splitter 6 is arranged on the downstream side of them The mirror 10 is arranged so that its comic surface having the vertex positioned on an optical axis passing the focus of the reflector 7, namely, so that the center axis is aligned with the optical axis In this case, the mirror 10 is reduced in diameter in the light emission direction Consequently, the reflected light from the light collecting reflector 7 is further reflected by the mirror 10 to become an effective light beam Further, even light which is angled too much to the optical axis in the primary reflection of the reflector 7 becomes close to parallel light in the secondary reflection based upon the angle of an external mirror surface 10b
11 citations
Patent•
22 Dec 1993TL;DR: In this article, the surface shapes for subreflectors in a suboptic assembly of a tri-reflector spherical antenna system are calculated from a generalization of Galindo-Israel's method of solving partial differential equations to correct for spherical aberration and provide uniform feed to aperture mapping.
Abstract: A novel method for calculating the surface shapes for subreflectors in a suboptic assembly of a tri-reflector spherical antenna system is introduced, modeled from a generalization of Galindo-Israel's method of solving partial differential equations to correct for spherical aberration and provide uniform feed to aperture mapping. In a first embodiment, the suboptic assembly moves as a single unit to achieve scan while the main reflector remains stationary. A feed horn is tilted during scan to maintain the illuminated area on the main spherical reflector fixed throughout the scan thereby eliminating the need to oversize the main spherical reflector. In an alternate embodiment, both the main spherical reflector and the suboptic assembly are fixed. A flat mirror is used to create a virtual image of the suboptic assembly. Scan is achieved by rotating the mirror about the spherical center of the main reflector. The feed horn is tilted during scan to maintain the illuminated area on the main spherical reflector fixed throughout the scan.
10 citations
Patent•
30 Sep 1993TL;DR: In this paper, a parabolic or approximately parabolic reflector is provided that is connected to a support strip supporting the semiconductor chip such that the latter is as close as possible to the focal point of the parabolic surface of the reflector.
Abstract: The invention relates to an opto-electronic component having a narrow aperture angle. The conventional design of components transmitting radiation or reacting to radiation and concentrating that radiation with the aid of lenses results, on account of the increasing distance between the lens and the semiconductor chip, in increasing component dimensions in the radiating or detecting direction with an increasingly narrow aperture angle. In accordance with the invention, a parabolic or approximately parabolic reflector is provided that is connected to a support strip supporting the semiconductor chip such that the latter is as close as possible to the focal point of the parabolic or approximately parabolic surface of the reflector. The reflector is preferably connected to the support strip by engaging elements and surrounded by a housing.
8 citations
28 Jun 1993
TL;DR: A design for the DirecTv DBS (direct broadcast satellite) coverage of the United States using a single shaped reflector is presented, which is interesting and challenging because of the high ratio of the area of the coverage to the Area of the pencil beam obtained using an unshaped reflector.
Abstract: A design for the DirecTv DBS (direct broadcast satellite) coverage of the United States using a single shaped reflector is presented This design is interesting and challenging because of the high ratio of the area of the coverage to the area of the pencil beam obtained using an unshaped reflector (>40) For the initial multifeed study, a parabolic reflector with a diameter of 96" was considered After a detailed trade-off study, a design with a 56-element feed array was chosen For the shaped reflector approach, a diameter of 85" was chosen after an initial trade-off study A sensitivity study using a 'potato-chip' distortion model was conducted >
Patent•
16 Apr 1993
TL;DR: In this paper, a light emitted by a light source inside a parabolic mirror is made to be a light H of which the cross-sectional shape of the light flux is circular, by a round cover plate 12 covering the central part of the paraboloid mirror 8.
Abstract: PURPOSE:To obtain a device for inspecting a defect such as a flaw or nonuniformity in plating in the surface of a cylinder for a photogravure press or the like. CONSTITUTION:A light emitted by a light source 10 disposed inside a parabolic mirror 8 is made to be a light H of which the cross-sectional shape of the light flux is circular, by a round cover plate 12 covering the central part of the parabolic mirror 8. This light H advances in the direction Y along the surface 2a of a cylinder and it is transmitted through a half mirror 16 and falls on a region T to be inspected of the surface 2a of the cylinder from the direction of a normal line. A reflected light H' thereof follows the forward path reversely and falls on an incident surface of the half mirror 16. The reflected light H' transmitted in the direction Z through the half mirror 16 is reflected in the direction Y by a mirror 18 and projected on a screen 6. An image 22 projected on the screen 6 is an image of the outer peripheral surface of the cylinder 2 in the region T to be inspected and, therefore, a defect in the region T can be detected from the projected image 22.
TL;DR: In this paper, a two-mirror system has been proposed, where one mirror is spherical and the other is an aspherical surface that is equidistant to the virtual parabolic mirror, the focal length of the latter being equal to the air separation between the mirrors.
Abstract: With mirrors of any aperture, the afocal two-mirror system has no spherical aberration. One mirror is spherical, and the other mirror is always an aspherical surface that is equidistant to the virtual parabolic mirror, the focal length of the latter being equal to the air separation between the mirrors. Therefore, a possibility exists of inspecting the aspherical surface shape by means of the known testing methods of the parabolic mirror. The system under consideration has some important technological advantages in comparison with the well-known Mersen system.
TL;DR: In this paper, a dual-band feed system for very long-baseline interferometry (VLBI) was proposed. But the system was designed to give as high efficiency as possible in both bands, consisting of two offset primary-fed parabolic reflectors.
Abstract: The authors describe a dual-band feed system, operating at S- and X-band, that can be temporarily mounted and used in a classical Cassegrainian-type radio telescope without removing the existing feed systems. The feed system, designed to give as high efficiency as possible in both bands, consists of two offset primary-fed parabolic reflectors, one for each frequency band. The X-band reflector, located behind the S-band reflector, radiates through a plane dichroic surface that replaces the central part of the S-band reflector. The feed system is to be used for space geodesy utilizing the very-long-baseline interferometry (VLBI) technique and has been tested and used at a radio telescope in Chile. Results of both a theoretical design study and measurements are given. >
Patent•
22 Jan 1993
TL;DR: In this article, a reflection mirror for a discharge lamp which effectively guides the light of the discharge lamp to the irradiation surface of an object to be irradiated is provided, where the main reflection mirror is composed of a parabolic mirror and the auxiliary mirror is a spherical surface mirror.
Abstract: PURPOSE:To provide a reflection mirror for a discharge lamp which effectively guides the light of the discharge lamp to the irradiation surface of an object to be irradiated. CONSTITUTION:This reflection mirror has a main reflection mirror 3 for irradiating the irradiation surface of the object to be irradiated with the light of the mounted discharge lamp 2 and an auxiliary reflection mirror 4 provided to face the main reflection mirror 3 on the open end 8 side of the main reflection mirror 3. The main reflection mirror 3 is constituted of a parabolic mirror and the auxiliary reflection mirror 4 is constituted of a spherical surface mirror, the approximate center of the spherical surface of which exists at the focus F of the main reflection mirror 3 and an aperture 7 which guides the light from the discharge lamp 2 to the object to be irradiated.
Patent•
02 Feb 1993
TL;DR: In this paper, the authors proposed a parabolic reflector (PA) consisting of diffraction rings (21o to 21N) together exhibiting a radial saw tooth-shaped profile.
Abstract: The antenna particularly for domestic, collective or communal installations receives several telecommunications beams. The reflector (11) comprises diffraction rings (21o to 21N) together exhibiting a radial saw tooth-shaped profile, and obtained preferably by cutouts in a parabolic reflector (PA). The heights of the "saw teeth" between rings are substantially equal to multiples of the average half-wavelength of the beams. Such a reflector thus compensates for the phase differences between beams substantially in the same direction but of different frequencies, so as to focus them at a focus (FD1, FD2). In practice, the reflector exhibits a focal line (LF) along which a UHF head is moved, or along which several UHF heads (31 to 37) allocated to different beams are positioned.
01 Jan 1993
TL;DR: In this paper, the authors examined the properties of 45 degree-off-axis parabolic mirrors using a Prometec laser scope, with comparison to those of 90, 60 and 30 degree-of-axis (DOA) parabolic mirror.
Abstract: The focussing properties of 45 degree-off-axis parabolic mirrors were examined using a Prometec Laser Scope, with comparison to those of 90, 60 and 30 degree-off-axis parabolic mirrors. These mirrors are all SPDT (Single Point Diamond Turning)-treated, Mo-coated surface and their focal lengths are 254mm. We examined (1) The focussing properties (focal spot size, spot elliptical shape and ellipticity) differ depending on misalignment and mode (Power). (2) With attention to the fact that ZnSe window is frequently used with parabolic mirrors, and the affect on focussing properties of parabolic mirror by the thermally induced optical distortion of this window. And (3) The condition of the parabolic mirrors under irradiation of 5kw laser was simulated.The focussing properties of 45 degree-off-axis parabolic mirrors were examined using a Prometec Laser Scope, with comparison to those of 90, 60 and 30 degree-off-axis parabolic mirrors. These mirrors are all SPDT (Single Point Diamond Turning)-treated, Mo-coated surface and their focal lengths are 254mm. We examined (1) The focussing properties (focal spot size, spot elliptical shape and ellipticity) differ depending on misalignment and mode (Power). (2) With attention to the fact that ZnSe window is frequently used with parabolic mirrors, and the affect on focussing properties of parabolic mirror by the thermally induced optical distortion of this window. And (3) The condition of the parabolic mirrors under irradiation of 5kw laser was simulated.
Patent•
02 Sep 1993TL;DR: In this article, a parabolic or approximately parabolic reflector is provided which is joined to a carrier strip supporting the semiconductor chip in such a way that the chip is as far as possible at the focus of the parabolic surface of the reflector.
Abstract: In the conventional construction of radiation-emitting components or components responding to radiation which focus the radiation with the aid of lenses, increasingly large component dimensions in the radiation or detection direction, accompanied by increasing constriction of the beam angle, result from the increasing distance between lens and semiconductor chip. According to the invention, a parabolic or approximately parabolic reflector is provided which is joined to a carrier strip supporting the semiconductor chip in such a way that the semiconductor chip is as far as possible at the focus of the parabolic or approximately parabolic surface of the reflector. The reflector is preferably joined by latching elements to the carrier strip and to a housing.
Patent•
01 Oct 1993
TL;DR: An ultraviolet sterilization system for food cartons is described in this paper, where an elongated UV lamp is mounted in a housing and a parabolic cylinder reflector is used to direct radiation from the lamp into cartons positioned on a conveyor below the lamp.
Abstract: of EP0591001An ultraviolet (UV) sterilization system for food cartons is disclosed. An elongated UV lamp (6) is mounted in a housing (12). A parabolic cylinder reflector (52) is mounted in the housing with the focus of the reflector coinciding with the axis of the arc (68) in the UV lamp. The shape of the parabolic reflector directs radiation from the lamp into cartons positioned on a conveyor below the lamp. The axis of the arc is parallel to the direction of movement of the cartons on the conveyor. The front surface of the reflector also absorbs heat from the lamp and heat is removed from the reflector (52) by circulating air (Fig. 4) over the back surface of the reflector.
Patent•
02 Mar 1993
TL;DR: In this article, a polygon mirror 3 is placed near a focusing position of an optical system for deflection which consists of a parabolic reflector M. It is not necessary to use expensive optical parts such as an ftheta lens for enabling a light beam to be scanned in parallel, thus enabling cost to be reduced.
Abstract: PURPOSE:To enable a light beam which is scanned at a equal-angle speed to be converted to that to be scanned in parallel without using an expensive ftheta lens in an optical dimension measuring apparatus using a polygon mirror. CONSTITUTION:A polygon mirror 3 is placed near a focusing position of an optical system for deflection which consists of a parabolic reflector M. It Is not necessary to use expensive optical parts such as an ftheta lens for enabling a light beam to be scanned in parallel, thus enabling cost to be reduced. Also, since the parabolic reflector M is a reflection optical system, it can be manufactured by using a plastic which cannot be used easily in a transmission optical system, thus enabling cost to be reduced.
28 Jun 1993
TL;DR: In this article, a finite-size parabolic reflector in two and three dimensions is illuminated by a two or three-dimensional Gaussian beam (GB), respectively, and the aim is to evaluate analytically the reflected and the edge diffracted field.
Abstract: In the geometry considered, a finite-size parabolic reflector in two- and three- dimensions is illuminated by a two or three-dimensional Gaussian beam (GB), respectively. The aim of the study is to evaluate analytically the reflected and the edge diffracted field. In particular, the relatively general 3-D problem of the reflection of an incident electromagnetic GB by a perfectly conducting parabolic surface whose principal directions may not coincide with the plane of incidence is considered. >
Patent•
26 Feb 1993
TL;DR: In this article, the authors proposed a method to improve the illuminous efficacy of a light source in a projection illuminating device using a parabolic mirror and reduce the cost and weight of the device.
Abstract: PURPOSE:To improve the illuminous efficacy of a light source in a projection illuminating device using a parabolic mirror and reduce the cost and weight of the device. CONSTITUTION:In a projection illuminating device having a parabolic mirror 1 and a light source 2 disposed on the focus of the parabolic mirror 1 in which the light from the light source 2 is reflected by the parabolic mirror 1 and collected parallelly, and the collected parallel light and the direct light from the light source 2 are emitted to a body 3 to be illuminated, a spherical mirror 5 with the focus as the center having an opening part 4 in the center is disposed opposite to the parabolic mirror 1 in the front of the light source 2. Thus, of the light from the light source 2 never contributing to the illumination to the body 3 to be illuminated (the diffused light corresponding to ranges A and B), the diffused light corresponding to ranges C and D is reflected by the spherical mirror 5, and the resulting reflected light is passed through the focus and formed into the parallel light by the parabolic mirror 1, so that the illuminating light quantity of the body 3 to be illuminated is increased, or the luminous efficacy of the light source 2 can be improved. Further, since the use of an optical system such as a lens as in the case of a spherical type or elliptic type is not required, the cost and weight of the device can be reduced.
Patent•
23 Feb 1993
TL;DR: In this paper, a reflecting mirror device consisting of a 1st parabolic mirror 21 having large focal length and a 2nd parabolic reflector 25 having less focal length was proposed to emit parallel light conforming with the shape of an object of photodetection.
Abstract: PURPOSE:To provide the light emission device which has high light utilization efficiency and excellent heat radiation characteristics and emits parallel light conforming with the shape of an object of photodetection. CONSTITUTION:The light emission device consists of the reflecting mirror device 2 constituted by combining a 1st parabolic mirror 21 having large focal length and a 2nd parabolic mirror 25 having less focal length and a metal halide lamp 1 which has a light source 1c arranged at the position of the focal length of the parabolic mirror 21. The parabolic mirror 25 is made asymmetrically longitudinally and laterally so as to emit the parallel light conforming with the shape of the object of photodetection. The parabolic mirror 21 is provided with an opening 21c and the length part of the lamp 1 is projected to radiate the heat from the lamp 1. The light from the light source 1c is reflected by the parabolic mirror 25 and emitted as parallel light, and also reflected by both the parabolic mirrors 21 and 25 and emitted as parallel light. The light source 1c is arranged on the side of the parabolic mirror 21 having the large focal length, the diameter of the opening 21c is held small, and light leaking from the opening 21c to the rear is reduced.
01 Nov 1993
TL;DR: In this paper, a light source is not treated as a single entity, but rather is divided into two or more separate adjoining sources, and an asymmetric Compound Parabolic Luminaire is then designed around each half-source.
Abstract: Luminaire designs based on multiple asymmetric nonimaging compound parabolic reflectors are proposed for 2-D illumination applications that require highly uniform far-field illuminance, while insuring maximal lighting efficiency and sharp angular cutoffs. The new designs derive from recent advances in nonimaging secondary concentrators for line-focus solar collectors. The light source is not treated as a single entity, but rather is divided into two or more separate adjoining sources. An asymmetric Compound Parabolic Luminaire is then designed around each half-source. Attaining sharp cutoffs requires relatively large reflectors. However, severe truncation of the reflectors renders these devices as compact as many conventional luminaires, at the penalty of a small fraction of the radiation being emitted outside the nominal cutoff. The configurations that maximize the uniformity of far-field illumination offer significant improvements in flux homogeneity relative to alternative designs to date.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Journal Article•
TL;DR: In this article, the scalar approximation of the reference wave was used to compute holographic correctors for a 4-m diameter f/4 parabolic primary mirror for monochromatic light at the recording wavelength.
Abstract: Fixed telescopes are considerably less expensive than tiltable ones but can only access a limited region of the sky. To extend their field of view, we have investigated the use of holographic elements. We have used the scalar approximation to compute holographic correctors for a 4-m diameter f/4 parabolic primary mirror. We identify a few critical areas of research. The computation of the reference wave needed for our holographic correctors is presently limited by computing power, because of the large parameters of the mirror at optical wavelengths. Our computations show that it is possible to achieve an excellent correction with a single CGH for monochromatic light at the recording wavelength
Patent•
13 Oct 1993
TL;DR: In this paper, the authors characterized the utility model of an electric heating infrared radiator with a long manubrium, the facade of the mushroom head is of dished conical surface, the reverse of the male cone is of male cone, a large parabolic reflector is corresponding to the female cone, and the heated resistance wire is arranged in a plurality of circular grooves in a male cone.
Abstract: The utility model discloses an electric heating infrared radiator. The utility model is characterized in that the core of a heating element is a mushroom head with a long manubrium, the facade of the mushroom head is of dished conical surface, the reverse of the mushroom head is of male cone, a large parabolic reflector is corresponding to the male cone; the heated resistance wire is arranged in a plurality of circular grooves in the male cone, the radial grid bars on the groove position the resistance wire by blocking the resistance wire in the groove, the heat energy first irradiates on the parabolic reflector, then the parabolic reflector reflects the heat energy to the right front; the inner conical surface of the mushroom head headed by the resistance wire and radiates infrared heat energy to right front for composing the double radiation surfaces infrared electric heater.
Patent•
07 May 1993
TL;DR: In this paper, the authors proposed a laser beam synthesizer which can transmit and synthesize the plural laser beams obtd. from plural laser oscillators at the smallest possible diameter, which can be used to provide the laser beam generator.
Abstract: PURPOSE:To provide the laser beam synthesizer which can transmit and synthesize the plural laser beams obtd. from plural laser oscillators at the smallest possible diameter. CONSTITUTION:The 1st laser beam 1a is made incident on a laser beam shaping condenser 12, is returned at a right angle by a reflection mirror 13 and is made incident through the hole in the central part of a ring plane mirror 19 on a parabolic mirror 14 by which mirror the laser beam is reflected and condensed. The 2nd laser beam 2a is shaped to the annular laser beam by a circular conical mirror 17 and an inside surface circular conical mirror 18. This annular laser beam is reflected by the ring plane mirror 19 and is condensed coaxially with the 1st laser beam by the parabolic mirror 14.
TL;DR: A system of three spherical mirrors can be used as a replacement for an off-axis parabolic mirror collimator and has ∼2.5X larger diffractionlimited field of view.
Abstract: A system of three spherical mirrors can be used as a replacement for an off-axis parabolic mirror collimator. The system is more compact and has ~2.5× larger diffraction-limited field of view.
01 Jan 1993
TL;DR: In this paper, a phase reversing zone plate reflector of the same dimension was used as a reference to reduce the aperture blockage, and the phase correcting mechanism made the main beam narrower and sidelobes lower.
Abstract: The Fresnel zone plate reflector antenna takes the form of a flat plate, yet offers similar focusing properties to the conventional parabolic dish. To improve the antenna performance, phase correcting techniques must be used. One successful approach is to employ the multi-layered structure. A novel zone plate reflector with a single phase correcting metallic layer is presented. By covering different sub-zones with uniformly distributed resonators of different dimensions, the phase correction required by an ideal zone plate is approximately provided, thus yielding a high efficiency zone plate reflector. As an experimental prototype, a microwave quarter-wave zone plate reflector was fabricated. A phase reversing zone plate reflector of the same dimension served as a reference. In order to reduce the aperture blockage, a helical antenna was employed as the feed. Experiments showed that both reflectors have about 12% 3 dB bandwidth. In the operating band, the new reflector has an average of 2 dB gain increase. The phase correcting mechanism makes the main beam narrower and sidelobes lower, and a 11 dB improvement in interference rejection is obtained at +or-8 degrees .