Omid Manoochehri

Ultra-Wideband Scanning Antenna Array With Rotman Lens

An ultra-wideband (6–18 GHz) phased-array antenna with a beam scanning angle of ±28° is proposed. A step-by-step design procedure consisting of beamforming network (BFN), end-launcher feed adapter, and the radiating element is presented. Microstrip Rotman lens has been designed to act as the BFN, and optimized to achieve minimum phase-error over the whole frequency range. In order to satisfy the condition needed for avoiding grating lobes, as well as achieving a wide radiation bandwidth and a high power handling capability, an

An Active 20-MHz to 2.5-GHz UWB Receiver Antenna System Using a TEM Horn

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A Compact Ultra-Wideband Multibeam Antenna System

-plane double-ridged horn antenna is used as the radiating element. A novel wideband end-launcher coaxial to double-ridged waveguide transition has also been developed for connecting the BFN to the antenna array. Extensive optimization procedures have been applied to the end-launched adapter together with the antenna to achieve the best return loss over the frequency band of operation. The whole system has been simulated using CST full-wave simulator. An excellent agreement between the measurements of the fabricated system and the simulated results is observed.

Wide band multi-beam cylindrical lens

An ultrawideband receiver antenna system is proposed. The radiating element is a transverse electromagnetic horn antenna, featuring a negative impedance converter at lower frequencies. The voltage standing-wave ratio (VSWR) is less than 2.0 in the bandwidth from 20 MHz to 2.5 GHz. A good agreement between the measurements of the fabricated system and the simulated results is observed. Sample applications include direction finding, broadband communication systems, radar systems, and electromagnetic compatibility measurement systems.

A new method for designing high efficiency multi feed multi beam reflector antennas

A compact UWB (6–18 GHz) multibeam antenna system is proposed. Design procedures comprising of ridged coaxial waveguide, radome with lens properties, and biconical antenna are presented. A novel UWB feed network consisting of a ridged coaxial waveguide with eight inputs has been designed and optimized to achieve minimum reflections as well as desired radiation pattern over the frequency range of operation. The radiating element is a biconical antenna, redesigned and optimized to meet the requirements for radiation characteristics. Another notable improvement made by our design is to employ a radome, which not only enhances the mechanical stability of the biconical antenna and protects the structure, but also it acts as a lens that improves the directivity of the radiating element. Extensive optimization procedures have been applied to all parts of the antenna system to achieve the desired performance. The whole system has been simulated using HFSS full-wave simulator. The measurement results of the fabricated system are in good agreement with simulations.

A short broadband monopole antenna

A novel ultra-wideband multi-beam cylindrical lens antenna for operation in the frequency range from 8 GHz to 18 GHz using parallel plate techniques is designed and fabricated. The cylindrical lens consists of four excitation ports, two parallel plates that are filled with teflon and a flare in order to produce four distinct fan-beams scanning in the azimuth plane with a minimum gain of 15 dB. CST Microwave Studio is used to analyze and optimize the antenna. The 3 dB E-plane and H-plane beamwidths are 10° and 30°, respectively, which can scan 40° in the azimuth plane with four distinct beams. The minimum gain of each beam is about 15 dBi at 8 GHz and 18 dBi at 18 GHz. There is a good agreement between the simulated and measured results.

Design of a high-gain omni directional microstrip dipole array with low side lobe level in the elevation plane

A novel method to design a high efficiency multi feed offset paraboloidal reflector antenna to be used in broadband multiband applications is presented. This method controls the arrangement of feed positions in order to increase the efficiency and gain of the whole structure. The structure has been designed, simulated and measured based on the proposed method in the frequency range from 6 GHz to 18 GHz and has the advantages of high efficiency and high gain. There is an excellent agreement between simulation and measurement results. The proposed antenna system is a good candidate for broadband access where wide coverage and high gain are simultaneously required. The maximum gain is 27 dBi at 18 GHz and the overall coverage is 30° in the elevation plane and 6° in the azimuth plane by producing 4 distinct beams and with an aperture efficiency of more than 51%. This method provides an alternative to other optimization methods because of its fast optimization time.