نتایج جستجو برای: active antenna

تعداد نتایج: 483364  

A novel printed octagonal fractal microstrip antenna with semi-elliptical ground plane is presented for ultra wide band applications. The proposed antenna has a compact size of 20×20×1 mm³. The measured result of the antenna exhibits the ultra wide band characteristics from 2/9 to 14/2 GHz. In this paper, reducing antenna’s size by 35%, the same results were achieved, while small dimension frac...

A. A. Lotfi Neyestanak, F. Hojjat Kashani, K. Barkeshli,

A modified circular patch antenna design has been proposed in this paper, the bandwidth of this antenna is optimized using the genetic algorithm (GA) based on fuzzy decision-making. This design is simulated with HP HFSS Program that based on finite element method. This method is employed for analysis at the frequency band of 1.4 GHz- 2.6 GHz. It gives good impedance bandwidth of the order o...

2008
Yoji Aramaki Hiromitsu Uchida Naofumi Yoneda Izuru Naito Hiroaki Yoshihiko Konishi

This paper shows injection molded millimeter-wave horn array antenna for the 1-dimensional APAA(Active Phase Array Antenna). The antenna is composed of horn antennas, grooved circular waveguide polarizers, E-plane T-junctions, and E-plane bends employing dielectric waveguides. This structure makes it possible to manufacture a feed circuit and radiating elements as an integrated unit by using in...

In this article, we present a new design of a coplanar waveguide fed (CPW-fed) ultra-wideband (UWB) antenna with dual band-notched characteristics. Two notched frequency bands are achieved by using two inverted U-shaped stepped impedance resonators. The proposed antenna can operate from 2.82 to 11 GHz (118%), defined by VSWR< 2, except two notched bands around 3.5 GHz (WiMAX) and 5.5 GHz (WLAN)...

2010
Robert Langwieser Christoph Angerer Markus Rupp

In this paper we show the dependence of the Signal to Self Interference Ratio (SSIR) and of the Signal to Noise Ratio (SNR) on the transmit power level of the reader and the transponder position. We describe the conducted measurements with our multi-antenna Radio Frequency Identification (RFID) research and development environment and compare passive transmitterreceiver isolation due to spatial...

2007
D F Santavicca A J Annunziata

We have designed and constructed a custom far-infrared Fourier transform spectrometer using an antenna-coupled bolometer as a detector. The active element of the detector is a superconducting niobium microbridge, and the far-infrared signal is coupled to the microbridge via a planar antenna mounted on a hyperhemispherical silicon lens. The spectrometer uses a broadband blackbody source with fre...

2017
Ke Han Zhongliang Deng

Abstract: In this paper, a silicon-based radio frequency micro-electromechanical systems (RF MEMS) pattern reconfigurable antenna for a Ka-band application was designed, analyzed, fabricated, and measured. The proposed antenna can steer the beam among three radiating patterns (with main lobe directions of −20◦, 0◦, and +20◦ approximately) at 35 GHz by switching RF MEMS operating modes. The ante...

1998
Vesna Radisic Yongxi Qian Tatsuo Itoh

This paper presents three novel architectures for high-efficiency amplifiers relying on new harmonic-tuning techniques. These methods yield high-efficiency power amplifiers and reduce unwanted harmonic radiation from the transmitter front end. The first method uses the active integrated-antenna approach to perform harmonic tuning. The second method uses a nontraditional periodic microstrip filt...

Journal: :the modares journal of electrical engineering 2015
hossein mehrpourbernety bijan zakeri reza gholami

in this paper, a novel directional super wide band micro strip antenna based on a simple and new geometry has been proposed. the antenna exhibits the widest bandwidth ever reported to the authors’ knowledge from 50 ghz to 200 ghz. its radiation pattern is approximately steady in the frequency ranges of 50 ghz to 200 ghz. the antenna consists of a club-like radiating patch, a combination of thre...

Journal: :Plant physiology 1979
B A Diner F A Wollman

Dark-grown etiolated cells of Cyanidium caldarium mutant III-C lacking >/=99% of their normal chlorophyll content and inactive for photosynthesis were greened in continuous light. Measurements of oxygen evolution and fluorescence kinetics indicate that during greening: (a) the photosystem II (PSII) antenna containing between 30 and 40 chlorophyll a per center undergoes little change in size fro...

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