Abstract. Reflector antennas are characterized by very high gains (30 dB and higher) and narrow main beams. They are widely used in satellite and line-of-sight microwave communications as well as in radar. Reflector antennas operate on principles known long ago from the theory of geometrical optics. The first reflector system was made by Hertz back in 1888 (a cylindrical reflector fed by a dipo...

The microwave antenna holography imaging technique has progressed considerably in recent years. This technique has been successfully used for the diagnosis, analysis, and performance improvement of most of the National Aeronautics and Space Administration (NASA)/Jet Propulsion 1,aboratory (JPL) Deep Space Network (DSN) large reflector antennas, especially at the shorter wavelengths, The JPL Mic...

The Log-Periodic Loop Antenna with Ground Reflector (LPLA-GR) is investigated as a new type of antenna, which provides wide bandwidth, broad beamwidth, and high gain. This antenna has smaller transverse dimensions (by a factor of 2/π) than a log-periodic dipole antenna with comparable radiation characteristics. Several geometries with different parameters are analyzed numerically using ESP code...

A cavity-backed spiral antenna with ultra-wide band width is presented. By using a parabolic reflector, the radiation of the antenna becomes uni-directional, and the gain is promoted. The antenna is fed by a coaxial cut-away balun with fan-shaped patch which keeps a wideband impedance matching. The simulated bandwidth for VSWR < 2 covers 0.36 ~ 6.83GHz or bandwidth ratio of 19:1, and the gain a...

The wireless communication serves the efficient information among two or more points wirelessly. Antenna is the main component in the communication, which radiates and receives the radio waves or in broad way. The antenna also plays a role of impedance matching device, which performs the matching of impedances like free-space & transmitter and receiver impedances at receiver end. The antennas c...

This paper presents a new architecture for an AlGaN/GaN HEMT frequency doubler using the active integrated antenna design approach. A microstrip patch antenna designed at the second harmonic is integrated with the HEMT. The antenna operates as a fundamental frequency reflector in this circuit. Using AlGaN/GaN with 1mm gate periphery, a 4 8 GHz frequency doubler was designed by the suggested des...

In this paper, the radiation pattern of yagi-uda antenna is simulated in MATLAB using circuit theory approach. Our basic approach was to simulate the radiation pattern for a symmetrically shaped antenna and then maximizing the output parameters by using various techniques such as using reflector surfaces wherever the loss in antenna was due to side lobes. We have designed this antenna using cir...

In this paper, a novel wideband single-feed circularly polarized patch antenna is presented. The antenna consists of an L-shaped probe, four parasitic patches perpendicular to the probe, and a planar reflector. By modifying the structure of the patches, two orthogonal radiation modes are created to realize the circular polarization in the broadside direction. This antenna exhibits a wide impeda...

This paper proposes a compact microstrip Yagi-Uda antenna for 2.45 GHz radio frequency identification (RFID) handheld reader applications. The proposed antenna is etched on a piece of FR4 substrate with an overall size of 65 mm × 55 mm ×1.6 mm and consists of a microstrip balun, a dipole, and a director. The ground plane is designed to act as a reflector that contributes to enhancing the antenn...