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Articles 1 - 14 of 14

Full-Text Articles in Electromagnetics and Photonics

Planning Of Low-Cost 77-Ghz Radar Transceivers For Automotive Applications, Hossein Ameri Mahabadi, A. Attaran, M. Moghavvemi Apr 2012

Planning Of Low-Cost 77-Ghz Radar Transceivers For Automotive Applications, Hossein Ameri Mahabadi, A. Attaran, M. Moghavvemi

Hossein Ameri Mahabadi

The key to prevent driving accidents by automotive radar systems at high speed is to have optimum and accurate estimation of position representation and fast visualization of the environment.


Fabricate An 8.35-Ghz Frequency Synthesizer, A. Attaran, Hossein Ameri Mahabadi, M. Moghavvemi Sep 2011

Fabricate An 8.35-Ghz Frequency Synthesizer, A. Attaran, Hossein Ameri Mahabadi, M. Moghavvemi

Hossein Ameri Mahabadi

The article presents information on designing a low-noise frequency synthesizer for achieving low-phase-noise outputs past 8 GHz for digital microwave radios (DMRs). These synthesizers can be used with the DMRs, depending on advanced digital modulation such as quadrature-amplitude-modulation (QAM) and quadrature-phase-shift-keying (QPSK) formats.


A Compact Analytical Design Of Dual-Loop 18 Ghz Frequency Synthesizer To Enhance Signal Reliability In Digital Millimeter Radio Link System, M. Moghavvemi, Hossein Ameri Mahabadi, A. Attaran Jul 2011

A Compact Analytical Design Of Dual-Loop 18 Ghz Frequency Synthesizer To Enhance Signal Reliability In Digital Millimeter Radio Link System, M. Moghavvemi, Hossein Ameri Mahabadi, A. Attaran

Hossein Ameri Mahabadi

In this paper a high resolution dual-loop 17.7–19.7 GHz frequency synthesizer is presented which is compatible with ITU-R (F.595-6) standards. The investigations of phase noise and spur frequency contents are discussed in detail. The simulated and measured phase noise and spur frequency contents are similar to one another. Phase noise of –81 dBc/Hz in 17.7 GHz at 10 KHz offset frequency is measured by (HP8560) series Spectrum analyzer and it matches with predicted measurements.


Multifrequency Wilkinson Power Divider Using Microstrip Nonuniform Transmission Lines, M. Khalaj-Amirhossein, M. Moghavvemi, Hossein Ameri Mahabadi Apr 2011

Multifrequency Wilkinson Power Divider Using Microstrip Nonuniform Transmission Lines, M. Khalaj-Amirhossein, M. Moghavvemi, Hossein Ameri Mahabadi

Hossein Ameri Mahabadi

A new idea is proposed to modify the conventional Wilkinson power dividers to operate at two or several desired frequencies. The proposed structure contains two Microstrip Nonuniform Transmission Lines (MNTLs) instead of two uniform ones with nearly the same length at the minimum frequency. The strip width of MNTLs is considered variable and is written as a truncated Fourier series. Three nonuniform power dividers are designed and one of them operating at frequencies 1.0, 2.8, and 4.5 GHz is fabricated and measured. The measured results of the fabricated diplexer have a good agreement with the theoretical results.


Body-Biased Vco Tunes 12 To 16 Ghz, M. Moghavvemi, Hossein Ameri Mahabadi, A. Attaran Apr 2011

Body-Biased Vco Tunes 12 To 16 Ghz, M. Moghavvemi, Hossein Ameri Mahabadi, A. Attaran

Hossein Ameri Mahabadi

This body-biased voltage-controlled oscillator provides reasonably good phase-noise performance over a broad tuning range with relatively low power consumption and low jitter timing noise in the time domain.


Microstrip Diplexers With Double-Stub Bandpass Filters, M. Khalaj-Amirhosseini, M. Moghavvemi, Hossein Ameri Mahabadi, A. Attaran Feb 2011

Microstrip Diplexers With Double-Stub Bandpass Filters, M. Khalaj-Amirhosseini, M. Moghavvemi, Hossein Ameri Mahabadi, A. Attaran

Hossein Ameri Mahabadi

This paper presents a microstrip diplexer using two Double-Stub Band-Pass Filters (DS-BPFs), composed of several double-stubs connected to a main microstrip line. Each DS-BPF has a null at the center frequency of the other. Therefore, these types of filters are suitable for diplexers with two near frequencies. A diplexer at frequencies 5.875 and 6.225 GHz is designed, fabricated and measured. Measured results of the fabricated diplexer have a good agreement with the calculated results.


Design A Stable 14-To-20-Ghz Source, M. Moghavvemi, A. Attaran, Hossein Ameri Mahabadi Dec 2010

Design A Stable 14-To-20-Ghz Source, M. Moghavvemi, A. Attaran, Hossein Ameri Mahabadi

Hossein Ameri Mahabadi

Careful selection of key components and the use of straightforward multiplication schemes can be applied to the design of a low-noise frequency synthesizer for Ku-band signals to 20 GHz.


Design An X-Band Frequency Synthesizer, Hossein Ameri Mahabadi, A. Attaran, M. Moghavvemi Jun 2010

Design An X-Band Frequency Synthesizer, Hossein Ameri Mahabadi, A. Attaran, M. Moghavvemi

Hossein Ameri Mahabadi

This frequency synthesizer design aims at achieving low phase and high reliability for X-band digital microwave radio applications, using a commercial device and frequency tripling techniques.


Application Of Electromagnetic Waves As A Solution To Some Agricultural Problems, B. M. Ida Idayu, Maryam Ashayer Soltani, Amin Enayati, H. Aliakbarian, Hossein Ameri Mahabadi, M. Moghawemi Jan 2010

Application Of Electromagnetic Waves As A Solution To Some Agricultural Problems, B. M. Ida Idayu, Maryam Ashayer Soltani, Amin Enayati, H. Aliakbarian, Hossein Ameri Mahabadi, M. Moghawemi

Hossein Ameri Mahabadi

A review of some applications of electromagnetic waves in agriculture is presented. There are many applications in the literature which are categorized in two sections of post-harvest indoor and pre-harvest outdoor applications. Taking a look at the applications suggested, there are still works to be done to industrialize the method. However, the proposed method is promising in special cases when the cost and hazards of other methods are high.


Novel Biconical Antenna Configuration With Directive Radiation, M. Shahpari, F. H. Kashani, Hossein Ameri Mahabadi Jan 2009

Novel Biconical Antenna Configuration With Directive Radiation, M. Shahpari, F. H. Kashani, Hossein Ameri Mahabadi

Hossein Ameri Mahabadi

In this paper a novel biconical antenna geometry has been proposed that has directive radiation pattern, higher gain and enhanced front to back ratio. Wide band performance is another characteristic of this new antenna.


Assemble A Ku-Band Frequency Synthesizer, Hossein Ameri Mahabadi, M. Moghavvemi Jan 2009

Assemble A Ku-Band Frequency Synthesizer, Hossein Ameri Mahabadi, M. Moghavvemi

Hossein Ameri Mahabadi

This straightforward design shows how to assemble commercial components into a low-noise 14.4-to-15.5-GHz frequency synthesizer with 625-kHz tuning steps for digital microwave radio systems.


Dual Band Dual Polarized Antenna With High Efficiency For Base Transceiver Stations, F. H. Kashani, M. Shahpari, Hossein Ameri Mahabadi Jan 2008

Dual Band Dual Polarized Antenna With High Efficiency For Base Transceiver Stations, F. H. Kashani, M. Shahpari, Hossein Ameri Mahabadi

Hossein Ameri Mahabadi

In this paper new array element for use in dual band dual polarized antenna will be introduced that has high efficiency (more than 95%) and has high isolation in both 900MHz and 1800MHz bands. Also radiation pattern of this antenna is according to IEC recommendation.


A Novel Bandpass Waveguide Filter Structure On Siw Technology, Z. Sotoodeh, B. Biglarbegian, F. Hojat Kashani, Hossein Ameri Mahabadi Jan 2008

A Novel Bandpass Waveguide Filter Structure On Siw Technology, Z. Sotoodeh, B. Biglarbegian, F. Hojat Kashani, Hossein Ameri Mahabadi

Hossein Ameri Mahabadi

Taking the advantage of common waveguide filters and SIW technology, a new filter structure is proposed.This structure can be implemented for various microwave frequencies by choosing appropriate low loss substrates.An example of suggested structure in Ku band is presented in this paper.The filter is designed and simulated on a low loss RT/Duroid 5880 laminate.The resulted filter has a Quality factor around 150.The main advantage of the structure is low size and cost, simplicity in fabrication, and the ability of integration with other elements of the circuit


Gain Enhancement Of Dielectric Resonator Loaded Waveguide Antennas With Dielectric Overlays, M. Hakkak, Hossein Ameri Mahabadi Mar 1992

Gain Enhancement Of Dielectric Resonator Loaded Waveguide Antennas With Dielectric Overlays, M. Hakkak, Hossein Ameri Mahabadi

Hossein Ameri Mahabadi

The gain characteristics of a dielectric resonator loaded coaxial probe fed circular waveguide antenna (DRLWA) with overlaying parasitic discs have been investigated experimentally. Results indicate that, when properly spaced, the overlays can enhance the gain by more than 6 dB.