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Electrical and Electronics

2011

Journal Paper

Articles 1 - 5 of 5

Full-Text Articles in Engineering

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.